Save Our Strathbogie Forest Inc v Secretary to the Department of Energy, Environment and Climate Action

Introduction 1 At some time during autumn this year, as part of the Victorian Government's bushfire risk management program, the Secretary to the Department of Energy, Environment and Climate Action (DEECA) intends to conduct planned fuel management burns in four defined areas within the Strathbogie State Forest, which is located approximately 120 kilometres north-east of Melbourne, Victoria. 2 The applicant contends that the planned burns involve a controlled action under the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (the EPBC Act) on the basis that they are likely to have a significant impact on the Southern Greater Glider, which is a listed threatened species included in the endangered category under the EPBC Act. Accordingly, the applicant contends that, in the absence of an applicable exemption, the action of the Secretary in carrying out the planned burns requires the approval of the Commonwealth Minister for the Environment (Commonwealth Minister) under Pt 9 of the EPBC Act. As no such approval has been given, the applicant seeks an injunction to prevent the Secretary from carrying out the planned burns without such an approval contrary to s 18(3) of the EPBC Act. 3 There is no dispute that the Strathbogie State Forest, and in particular the four planned burn areas, include habitat suitable for the Southern Greater Glider and that some gliders are likely to be present in the planned burn areas. 4 The ultimate question raised by this proceeding is whether the planned burns can proceed without being required to obtain the approval of the Commonwealth Minister under Pt 9 of the EPBC Act. That in turn raises three main issues. (a) whether it is likely that the planned burns will have a significant impact on the Southern Greater Glider as a listed threatened species included in the endangered category within the meaning of s 18(3) of the EPBC Act; (b) if so, whether s 43B of the EPBC Act operates to provide the Secretary with an exemption from the requirement to obtain an approval under Pt 9, on the basis that the planned burns amount to a lawful continuation of a use of land that was occurring immediately before the commencement of the EPBC Act on 16 July 2000; and (c) whether the application of s 18(3) of the EPBC Act to the functions and activities of the Secretary under s 62(2) of the Forests Act 1958 (Vic), or to the conduct of these four planned burns, offends the Constitutional principle recognised in the High Court's decision in Melbourne Corporation v The Commonwealth (1947) 74 CLR 31, and is to that extent invalid. 5 Each of the parties adduced a significant amount of evidence directed to the manner in which the fire might behave if and when the planned burns are carried out, and the possible effects of the fire on Southern Greater Gliders present in the burn area and their habitat. The Secretary also adduced evidence addressing the broader context of the State's bushfire risk management, including in particular the risk to lives and property, and the history of planned fuel reduction burns as one of the measures designed or intended to mitigate such risks. 6 There was a consensus between the parties that, in resolving the issues in dispute in this proceeding, this Court is not required to consider policy issues bearing upon whether or not the planned burns should be carried out, nor to attempt any balancing of the environmental values protected by the EPBC Act against the objectives of planned burning as a measure to address bushfire risk. The applicant submits that those issues are matters that are properly considered by the Commonwealth Minister in deciding whether or not to grant approval to the proposed action under the EPBC Act. The Secretary submits that no such approval is required. 7 In particular, neither the applicant nor the Secretary have invited the Court to consider or make any findings as to the effectiveness of planned burns as a bushfire risk management tool. There has been a long history of investigative commissions which have addressed many aspects of those matters, which lie well outside the scope of this proceeding: see e.g. 2009 Victorian Bushfires Royal Commission Final Report (2010), Fire Preparation, Response and Recovery: Land Management Vol II, Ch 7. The evidence and submissions in this proceeding focused on the impact of the planned burns on protected matters under the EPBC Act. The applicant's case is concerned with the direct and indirect effects of the proposed planned burns on gliders in the Strathbogie State Forest, but it is no part of that case that the planned burns might have an effect of increasing the risk or severity of bushfires in the future. Conversely, the Secretary does not contend that any risk to the Southern Greater Glider arising from the conduct of the planned burns can or should be offset against a reduction in the risk to gliders in the Strathbogie State Forest from future bushfires as the result of the planned burns. While the Attorney-General of Victoria (Attorney-General), who intervened under s 78A of the Judiciary Act 1903 (Cth) in relation to the Melbourne Corporation issue, places some reliance on the objectives of planned burns in the context of the performance by the Secretary of the statutory duty under s 62(2) of the Forests Act to carry out proper and sufficient work on certain public land for the prevention and suppression of fire, as well as the broader public function or duty of the State to protect lives and property in Victoria, that submission does not turn on any factual contentions concerning the efficacy of planned burns in that context, which for present purposes may largely be assumed. 8 At the request of the parties, the trial of this matter was listed on an expedited basis and was heard over two weeks commencing on 29 January 2024. 9 For the reasons set out below, I have concluded that s 18(3) of the EPBC Act validly applies to the Secretary in the conduct of works for the prevention of fire, including planned fuel reduction burns. However, on the evidence before the Court, I am not satisfied that the four planned burns that the Secretary proposes to carry out in the Strathbogie State Forest will have, or are likely to have, a significant impact on the population of Southern Greater Gliders in the Strathbogie State Forest or on the species as a whole within the meaning of s 18(3). 10 In summary, I have found that the planned burns will be conducted in accordance with the prescriptions and objectives set out in their Delivery Plans, and will generally result in low intensity fire with limited impacts on the canopy in most of the planned burn areas. While there is a real chance the planned burns may kill or injure some individual gliders that are present in areas where the fire burns with higher severity, so as to result in a high degree of canopy scorch, such areas (if any) will constitute a relatively minor proportion (less than 2.5%) of the planned burn areas, and an even smaller proportion of the Strathbogie State Forest as a whole. There is also a real chance that the collapse of hollow-bearing trees during or following the planned burns may kill or injure any individual gliders that are sheltering in such trees when they collapse, but the evidence does not establish that such losses are likely to be common or widespread. More generally, there is a real chance that the planned burns will cause some reduction in the abundance of hollow-bearing trees in the planned burn areas, but the evidence does not establish that this is likely to lead to any significant reduction in the abundance of gliders in the planned burn areas, nor in the Strathbogie State Forest. 11 In the circumstances, any impacts of the planned burns on individual gliders in the areas affected by fire are not likely to have a significant impact on the population of Southern Greater Gliders in the Strathbogie State Forest, or on the species, for the purposes of s 18(3) of the EPBC Act. 12 Otherwise, I have found that the four planned burns cannot be characterised as a lawful continuation of a use of land that was occurring immediately before the commencement of the EPBC Act, and accordingly the exception in s 43B of the EPBC Act is not attracted. Further, in relation to the Melbourne Corporation principle, I do not accept that the application of s 18(3) of the EPBC Act to the conduct by the Secretary of works for the planned prevention of fire in State forests, or to the conduct of these four planned burns, curtails or impairs either the capacity of the State to function as a government or the exercise by the State of its constitutional powers. As a consequence, the Secretary is generally required to comply with Pt 3 of the EPBC Act when conducting any planned burn that has or will have, or is likely to have, a significant impact on any matters of national environmental significance within the meaning of that Part. 13 It follows that the applicant's application for an injunction under s 475 of the EPBC Act in relation to the proposed conduct of the four planned burns must be dismissed.

The planned burns 14 Planned burning involves the deliberate introduction of fire into the landscape in order to manage fuel and bushfire hazard and damage potential: see generally s 4 of the Code of Practice for Bushfire Management on Public Land 2012 (amended 2022) (the Code). It has been defined as "the controlled application of fire under specified environmental conditions to a predetermined area and at the time, intensity, and rate of spread required to attain planned resource management objectives": Australian Fire Authorities Council, Bushfire Glossary (January 2012) (Australian Bushfire Glossary), p 24. The term "planned burning" is sometimes used interchangeably with terminology such as "prescribed burning" or "fuel reduction burning". It is different from "backburning", which refers to a fire suppression technique sometimes used when actively fighting bushfires. 15 As a part of the Victorian fuel management program to reduce bushfire risk in the Hume region, the Secretary proposes to conduct planned burns in four areas within the Strathbogie State Forest: (a) Lima East - Mt Albert (Lima East); (b) Barjarg / Harpers Road (Barjarg); (c) Strathbogie South / Ruoaks Road (Ruoaks Road); and (d) Tallangallook - Black Creek Track (Tallangallook). 16 I consider the evidence in relation to the planning and delivery of these four planned burns in more detail below. In order to give a general picture of the location of the planned burn areas in the context of the Strathbogie State Forest, the following map depicts the area of each of the planned burns (outlined in black) within the boundaries of the Forest, showing the distribution of ecological vegetation classes derived from the DEECA's spatial data (predominantly herb-rich foothill forest, with some damp forest, grassy dry forest, healthy dry forest, shrubby dry forest, valley grassy forest and riparian forest).

The Strathbogie Ranges and the Strathbogie State Forest 17 The Strathbogie Ranges are situated approximately 120 kilometres north-east of Melbourne. As summarised in a report by Dr Charles Meredith, an expert witness called by the applicant, drawing on a publication by the Victorian Environmental Assessment Council (Assessment of the values of the Strathbogie Ranges Immediate Protection Area (March 2022)): The Strathbogie Ranges cover an area of about 240,000 hectares north of the Great Dividing Range situated between the Goulburn River to the west, the Broken River to the east and the Hume Highway to the north (VEAC 2022). The Strathbogie Ranges are mostly within the Highlands - Northern Fall bioregion. The Ranges are effectively a promontory of granite extending northwest from the main part of the Great Dividing Range. Over much of the Ranges, the granite forms a relatively flat-topped 'tableland' between about 500 and 900 metres above sea level. This elevation draws rain from prevailing weather systems coming from the west and northeast, with less run off on the gentle topography of the tableland than on more dissected ranges in this part of Victoria (VEAC 2022). The Crown land within the Strathbogie Ranges falls into several land-use designations. The largest in area of these is State forest and the second largest is land leased for pine plantations. Small areas of other land-use designations include a reference area, several historic areas and an education area. By far the bulk of the native vegetation in the Ranges occurs in the State forest. 18 The Strathbogie State Forest comprises an area of approximately 23,000 hectares within the Strathbogie Ranges. State forests are Crown lands that are reserved or dedicated under the Forests Act and are managed by DEECA for a number of different uses, including timber production, recreation and the conservation of flora and fauna. State forests are distinct from parks and conservation reserves managed by Parks Victoria, committees of management or local government: see generally DEECA, Overview of Victoria's Forest Management System, December 2019, pp 7-8.

The Southern Greater Glider 19 The Greater Glider is a large gliding possum, which has a head and body length of 35-46 cm with a long, furry, non-prehensile tail measuring 45-60 cm, and an adult weight range from 900-1,700 grams. There are currently two recognised species: Petauroides minor (Greater Glider (northern)) found in north-eastern Queensland, and Petauroides volans (Greater Glider (southern and central)) found in south-eastern Australia. This proceeding is concerned with the latter species, which is generally referred to in Victoria as the Southern Greater Glider. I will adopt that terminology in these reasons for judgment, so as to distinguish the Southern Greater Glider from the Greater Glider (northern). I note in passing that the latter species is now separately listed under the EPBC Act and is the subject of a separate conservation advice. 20 The Southern Greater Glider is a listed threatened species included in the endangered category under the EPBC Act (with effect from 5 July 2022), and is included in the Threatened List with a category of threat of endangered under the Flora and Fauna Guarantee Act 1988 (Vic) (FFG Act). Under the applicable statutory definitions, this means that the species is one that is "facing a very high risk of extinction in the wild in the near future", but which is not critically endangered (i.e. facing an extremely high risk of extinction in the wild in the immediate future): see s 179(4) of the EPBC Act, s 3(1) of the FFG Act.

Conservation Advice under the EPBC Act 21 The EPBC Act requires an approved conservation advice to be prepared for each listed threatened species: s 266B(1). An approved conservation advice must contain a statement setting out the grounds on which the species is eligible to be included in the category in which it is listed and the main factors that are the cause of it being so eligible: s 266B(2)(a). It must also set out information about what could appropriately be done to stop the decline of, or support the recovery of, the species: s 266B(2)(b)(i). 22 Conservation advices under the EPBC Act are provided to the Commonwealth Minister by the Threatened Species Scientific Committee established under s 502 of the EPBC Act, whose expert members are appointed by the Commonwealth Minister. The functions of the Scientific Committee include advising the Minister on approved conservation advice and the amendment and updating of the lists established under Pt 13 of the EPBC Act (including the lists of threatened species for which ss 178 and 179 provide): s 503. A conservation advice must be approved in writing by the Commonwealth Minister, following consultation with the Scientific Committee, before its publication on the internet: s 266B(2)-(7). 23 In Friends of Leadbeater's Possum Inc v VicForests (No 4) [2020] FCA 704; 244 LGERA 92 at [25]-[26], Mortimer J (as her Honour then was) described such conservation advices as "the mandatory and foundational documents describing each threatened species, its characteristics and habitat, and the threats posed to it", and as containing "the formal recognition, for the purposes of the EPBC Act, of why the listed threatened species has been determined to need protection and what measures need to be taken to ensure its conservation and recovery". 24 In the present case, the applicant places considerable reliance on the approved conservation advice published under the EPBC Act for the Southern Greater Glider: Conservation Advice for Petauroides volans (greater glider (southern and central)) (as in effect from 5 July 2022) (the Conservation Advice). Although counsel for the Secretary accepted that the Conservation Advice is an "authoritative document", they submitted that it should not be "used as a proxy or surrogate for expert evidence in the case". While that may be so, the Conservation Advice is nevertheless itself in evidence and was referred to and relied on by several expert witnesses. 25 There does not appear to be any dispute about the correctness of the contents of the Conservation Advice in so far as it has any bearing on the issues for determination in this case (although counsel for the Secretary noted that the contents of the Conservation Advice had not been specifically pleaded). I note that Mortimer J, in her fact-finding in Friends of Leadbeater's Possum, considered that it was appropriate to place "significant weight" on the conservation advice for each of the species addressed in that case (which included an earlier iteration of the Conservation Advice for the Greater Glider, prior to the elevation of the Southern Greater Glider from the vulnerable category to the endangered category). As an instrument that has been approved by the Commonwealth Minister and published under the EPBC Act, the Conservation Advice is especially relevant to any assessment of whether an action will have or is likely to have a significant impact on a listed threatened species for the purposes of 18(3) of the EPBC Act. In the absence of any directly conflicting evidence or specific disagreement, I will proceed on the basis that the Conservation Advice is a reliable and accurate source of general information about the Southern Greater Glider, including its taxonomy, biology and ecology, distribution, and threats to its survival.

Conservation status 26 The Greater Glider was previously listed in the vulnerable category of the threatened species list under the EPBC Act effective from 5 May 2016. With effect from 5 July 2022, the Southern Greater Glider was recognised as a separate species and was listed in the endangered category following an assessment by the Scientific Committee against the applicable listing criteria, based on an observed, estimated, inferred, projected or suspected population reduction, the causes of which may not have ceased, may not be understood, or may not be reversible. The Conservation Advice states that "[t]he main factors that make the species eligible for listing in the Endangered category are an overall rate of population decline exceeding 50 percent over a 21-year (three generation) period, including population reduction and habitat destruction following the 2019-20 bushfires". The supporting evidence on which the Scientific Committee relied is set out in its listing assessment, which is included as an attachment to the Conservation Advice. It may be noted that the Scientific Committee assessed the species as ineligible for listing as vulnerable, endangered or critically endangered under other criteria dealing with geographic distribution, total population size and number of mature individuals. As population viability analysis had not been undertaken for the full species, there was insufficient data to determine the eligibility of the species for listing in any category under the criterion dealing with the probability of extinction in the wild.

Distribution 27 The Conservation Advice describes the Southern Greater Glider as the largest gliding possum in eastern Australia. It has a broad distribution "from around Proserpine in Qld, south through NSW and the ACT, to Wombat State Forest in central Vic". Its area of occupancy has decreased substantially since European settlement, mostly due to land clearing, and is continuing to decline due to further clearing, fragmentation impacts, edge effects, bushfire, climate change and some forestry activities. 28 In relation to important populations and sub-populations, the Conservation Advice states: Given its Endangered status, all populations of the greater glider (southern and central) are important for the conservation of the species across its range. Due to the species' low fecundity and limited dispersal capabilities, areas where the species has become locally extinct are not readily recolonised. Coastal populations may be important for maintaining genetic diversity, as they are geographically distinct from inland populations (DoEE 2016b). 29 The Strathbogie State Forest supports a high density of the Southern Greater Glider, with the total population across the Strathbogie Ranges having been estimated to be approximately 69,000: see generally J L Nelson et al, "Estimating the density of the Greater Glider in the Strathbogie Ranges, North East Victoria" (2018), Arthur Rylah Institute for Technical Environmental Research: Technical Report Series No. 293 (Nelson 2018). Referring to a comparison of survey data collected between 1983 and 2017, the Conservation Advice notes that the population of Southern Greater Gliders in the Strathbogie State Forest appears not to have declined over a 34-year period to the same extent as has been observed elsewhere in Victoria, and that surveys "found relatively high densities of gliders".

Habitat 30 The Southern Greater Glider is an arboreal nocturnal marsupial, predominantly solitary and largely restricted to eucalypt forests and woodlands of eastern Australia. It is typically found in highest abundance in taller, montane, moist eucalypt forests on fertile soils, with relatively old trees and abundant hollows. Gliders have an estimated longevity of 15 years, and females give birth to a single young from March to June. 31 During the day, the Southern Greater Glider shelters in tree hollows, with a particular preference for large hollows in large, old trees. While both live and standing dead trees are used for denning, the species prefers to use live hollow-bearing trees when adequate numbers are available. Most hollow-bearing trees used for denning by arboreal and scansorial mammals are at least 100 years of age. However, the size and age at which suitable hollows develop depends on tree species and climate. Multiple dens are used by each individual glider, typically within a relatively small home range (1 to 4 hectares). Densities of gliders vary significantly across the glider's range, and average densities have been found to range from 0.6 to 2.8 individuals per hectare in Victoria. 32 The availability of tree hollows is identified in the Conservation Advice as a key limiting resource and the probability of the occurrence of the species is positively correlated with the availability of tree hollows. The Conservation Advice notes that "[l]arge hollow-bearing trees are in rapid decline in some landscapes primarily due to timber production practices and bushfires that prevent trees growing to an age when they might produce hollows", and that this is a concern for recovery of the species. In addition, the abundance of hollow-bearing trees may be an overestimate of the actual number that are suitable for occupation by wildlife, as only one in every three to five hollow-bearing trees within montane ash forests is occupied by arboreal marsupials. The Conservation Advice states that "[a] decline or loss of hollow-bearing trees reduces the numbers of greater gliders in the landscape". 33 The Conservation Advice states that the Southern Greater Glider is sensitive to bushfire and is slow to recover following major fires. Thus, "[o]ver the longer term, repeated disturbance such as intense or too-frequent fires degrades greater glider habitat by changing the composition, structure and nutrient profile of forests", including the destruction of live and dead hollow-bearing trees, particularly in young forests. While unburnt areas provide critical refuges for gliders in regions heavily impacted by fires, Southern Greater Gliders have limited dispersal capabilities and are slow to recover and recolonise burnt sites following fire. 34 The Southern Greater Glider's diet mostly comprises eucalypt leaves supplemented by buds and flowers. It feeds from a restricted range of eucalypt species, including Narrow-Leaved Peppermint (Eucalyptus radiata) in Victoria. The tree species favoured by Southern Greater Gliders varies regionally. It favours forests with a diversity of eucalypt species, due to seasonal variation in growth and nutrient content of its preferred tree species. Approximately 85 percent of the Southern Greater Glider's water requirements are provided by consumed leaves. 35 The Conservation Advice describes habitat critical to the survival of the Southern Greater Glider as follows: Habitat critical to survival for the greater glider (southern and central) may be broadly defined as (noting that geographic areas containing habitat critical to survival needs to be defined by forest type on a regional basis): • large contiguous areas of eucalypt forest, which contain mature hollow-bearing trees and a diverse range of the species' preferred food species in a particular region; and • smaller or fragmented habitat patches connected to larger patches of habitat, that can facilitate dispersal of the species and/or that enable recolonization; and • cool microclimate forest/woodland areas (e.g. protected gullies, sheltered high elevation areas, coastal lowland areas, southern slopes); and • areas identified as refuges under future climate changes [sic] scenarios; and • short-term or long-term post-fire refuges (i.e. unburnt habitat within or adjacent to recently burnt landscapes) that allow the species to persist, recover and recolonise burnt areas. Habitat meeting any one of the criteria above is considered habitat critical to the survival of greater glider (southern and central), irrespective of the current abundance or density of greater gliders or the perceived quality of the site. Forest areas currently unoccupied by the greater glider (southern and central) may still represent habitat critical to survival, if the recruitment of hollow-bearing trees as the forest ages could allow the species to colonise these areas and ensure persistence of a subpopulation.

Threats 36 The Conservation Advice identifies the key threats to the Southern Greater Glider as frequent and intense bushfires, inappropriate prescribed burning, climate change, land clearing and timber harvesting - noting that "[t]here are synergies between these threats, and their combined impact needs to be considered in the recovery of the species". 37 The threat arising from "inappropriate fire regimes" is addressed as encompassing both extensive severe bushfires and high frequency fires. Dealing with the former, the Conservation Advice states: "Substantial population losses or declines have been documented in and after high severity bushfires … Losses can occur as a result of direct mortality due to lethal heating or suffocation from smoke, or indirect mortality due to the loss of key habitat features and resources". As to "high frequency fires", the Conservation Advice notes that "[f]requent fire can decrease the availability of hollow-bearing trees in the landscape, and change the floristic composition and nutritional profile of glider habitat". In that context, the Conservation Advice specifically addresses planned burning: Too intense or frequent planned burning may contribute to population losses or declines in the southern part of the greater glider's range. Bluff (2016) reported that hollow-bearing trees (HBTs) affected by fire during planned burns were 28 times more likely to collapse than HBTs that were not burnt. Parnaby et al. (2010) found that following low intensity prescription burns in the Pilliga forests (NSW), mean collapse rates for burnt HBTs were 14-26%. This was consistent with the collapse rate of 25.6% found by Bluff (2016). A survey following a planned burn at Tallarook Range in the Central Highlands (Vic) in 2021 found that a large number of potential greater glider habitat trees were burnt, with "many destroyed" (N. Stimson 2021, pers. Comm. 26 June). There is increased pressure from some parts of the community to undertake more hazard reduction burning, follow[ing] the severe bushfires of 2019-20. 38 It may be observed that the language used in the Conservation Advice here specifically refers to planned burning that is "[t]oo intense or frequent", rather than necessarily treating all planned burning as a threat to the Southern Greater Glider. 39 The Conservation Advice also refers to physical disturbances associated with firefighting operations, including the construction of roads and control lines, earthworks, tree removal and backburning. In relation to planned burning, the Conservation Advice relevantly notes: In Vic, loss of HBTs due to mechanical site preparation works associated with prescribed burning (which primarily occurs in foothill forests close to settled areas) may reduce suitable habitat for the greater glider (southern and central). Trees that are assessed as potentially hazardous (if they were to catch fire) are routinely removed from the perimeter of planned burns on public land in Vic. They are also removed from bushfire control lines during and after bushfire suppression activities (DELWP n.d). Although not all hazardous trees are hollow bearing, many are, or are likely to be trees that form hollows more quickly (J Nelson 2021. pers comm 16 April). 40 The conservation and recovery actions contemplated in the Conservation Advice relevantly include the following: • Re-assess and revise current prescriptions used for prescribed burning to ensure that the frequency and severity of fires in greater glider habitat are minimised, in order to mitigate the risk of further population declines and loss of hollow-bearing trees. Measures to reduce risk from future bushfires should be strategic, incorporate adaptive management, and include a risk assessment that considers trade-offs between fire control efficiency and environmental damage. • Implement and enforce measures to reduce direct mortality and loss of hollow-bearing trees during site preparation and execution of prescribed burns, including rake hoeing around the base of trees. • Ensure that eucalypt forests and the impacts of disturbance (including fire) are managed to prevent them transitioning to less nutritious, hotter, and/or more fire-prone plant communities, and to ensure that food tree species preferred by the greater glider (southern and central) continue to be the dominant canopy trees. • Protect and maintain sufficient areas of suitable habitat, including denning and foraging resources and habitat connectivity, to sustain viable subpopulations throughout the species' range. 41 The Conservation Advice also addresses survey and monitoring priorities both in relation to Southern Greater Gliders and hollow-bearing trees, as well as information and research priorities including "the development of guidelines for fire management by assessing the impacts of fire management and different fire regimes (including frequency and intensity) on habitat, subpopulation size and hollow availability".

Action Statement under the FFG Act 42 As mentioned above, the Southern Greater Glider is also classified as endangered under the FFG Act. Section 19 of the FFG Act relevantly requires the Secretary to prepare an action statement for any listed taxon of fauna as soon as possible after that taxon is listed, having regard to any management advice given by the Scientific Advisory Committee and any other relevant nature conservation, social and economic matters. The action statement must set out what has been done to conserve and manage that taxon and what is intended to be done, and may include information on what needs to be done: s 19(2). 43 An action statement for the Southern Greater Glider was published in 2019: Greater Glider (Petauroides volans subsp. volans): Action Statement No 267 - Flora and Fauna Guarantee Act 1988 (Action Statement). At the time the Action Statement was issued, the Southern Greater Glider was listed in the category of vulnerable (facing a high risk of extinction in the wild in the medium-term future) before its elevation in June 2023 to the category of endangered (facing a very high risk of extinction in the wild in the near future). 44 The contents of the Action Statement are consistent with the Conservation Advice. It states that Southern Greater Gliders are "forest dependent and prefer older tree age classes in moist forest types" and that they are "obligate users of hollow-bearing trees for shelter and nesting, with each family group using multiple den trees within its home range". The Action Statement continues: "Greater Glider density varies proportionally to the availability of hollow-bearing trees and do not persist in areas of forest where such trees are absent", and notes that "Lindenmayer et al. (1990) found the abundance of Greater Gliders in the Victorian Central Highlands was positively correlated with forest age and the density of hollow-bearing trees". 45 The Action Statement contains the following map showing the distribution of the Southern Greater Glider in Victoria: 46 Under the heading "Threats", the Action Statement states: The key threats to the Greater Glider can be summarised in terms of elevated mortality, habitat degradation and the risks associated with small, fragmented populations, including genetic decline. Factors contributing to elevated mortality and the loss of hollow-bearing trees include bushfire, planned burning, drought, timber harvesting and hyper-predation (SAC 2017). There is some evidence to indicate that climate change in the form of more extreme droughts and higher temperatures might result in a reduction in quality or availability of food. Increased morbidity or mortality might also be associated with heat stress. As populations decline and become more isolated, they are more prone to the effects of small population size and potentially genetic decline. This may result from habitat fragmentation due to land management practices or contraction of suitable habitat due to climate change. Fragmentation and isolation impact on the ability of Greater Gliders to recolonise suitable habitat and reduce genetic exchange between sub-populations. 47 In relation to "social and economic issues", under the sub-heading "Bushfire Risk", the Action Statement provides: Fuel management practices across Victoria's public and private lands aim to reduce the impact of bushfires to communities at risk and provide for the regeneration or preservation of forest assets including ecological and cultural values. This includes undertaking fuel management by planned burning, slashing and mulching. Forest Fire Management Victoria (FFMVic) further reduces risk on public land through early detection and rapid suppression of bushfires. Other works such as upgrading fire towers, building new bridges and improving roads make suppression more achievable and safer, helping to reduce the impact on community and the environment. These activities can require the removal of hazardous trees to ensure that staff can undertake bushfire management work safely. While these activities may have an impact on Greater Glider populations and their habitat, the protection of life and property is an overriding priority of the Victorian Government. Recognising that hazardous trees may also be important habitat for arboreal mammals, wherever possible FFMVic undertakes values checking before undertaking on-ground works to mitigate impacts to habitat. 48 Under the sub-heading "Animal Welfare", the Action Statement notes: The management of public land, including timber harvesting and bushfire prevention and suppression, has the potential to result in injury and death to many animals each year. As a large and readily observable mammal, the impact of these activities on the Greater Glider arouses concern. 49 The Action Statement addresses existing conservation measures, including in relation to "fire management". In that regard, the Action Statement provides: The primary objectives of DELWP's fuel management program is to minimise the impact of major bushfires on human life and other values - including the environment, as well as maintaining or improving the resilience of natural ecosystems. DELWP's fuel management processes are designed to consider forest values and how they can be protected through strategic planning and the way we operationally deliver any fuel management activities. Planning and delivery of this work is guided by expert knowledge and advice to ensure forests are managed for a diverse range of ecological, cultural and built values. The Greater Glider is recognised as a threatened species in DELWP's processes of strategic and operational bushfire management planning. In strategic bushfire management planning, DELWP will take account of Greater Glider habitat and colonies when designating different fire management zones in the landscape. Operational planning includes additional checks of values that may be impacted by fuel management activities. Nominated burns are tested against known data surveys which encompass a range of information, to determine if they overlap habitat areas and ranges of vulnerable species. If a potential impact is flagged, biodiversity experts within DELWP recommend options to minimise impact. Examples of mitigation measures include: • clearing fine fuels from around hollow-bearing habitat trees with rake hoes to ensure they do not burn; • burning at a lower intensity; • burning during particular seasons; • undertaking mechanical treatment rather than planned burning; and • avoiding using heavy machinery or chemicals in certain areas. 50 The Action Statement notes that research was being carried out by the Department of Environment, Land, Water and Planning (DELWP) (a predecessor of DEECA) to investigate "the impact of fuel management on Greater Glider as part of its monitoring, evaluation and reporting program for bushfire risk management while loss of hollow-bearing trees resulting from planned burning has been assessed for sites in East Gippsland (Bluff 2016)". The "intended management actions" listed in the Action Statement include: Determine the most appropriate fire management practices to ensure viable populations of Greater Glider and their habitat (including key features such as hollows in large old trees). This includes developing feasible, cost-effective measures to mitigate any significant impacts of planned burning on Greater Glider populations and their habitat. Incorporate these measures into strategic, tactical and operational fire management plans.

General comments 51 The Secretary led a great deal of evidence in relation to Victoria's approach to fire management, including the framework and context in which fire management activities are conducted. While much of this evidence was uncontroversial and unchallenged, it has limited direct relevance to most of the critical factual issues for determination in the proceeding. 52 As mentioned above, the case does not raise questions about the content of the broader fire management regime in Victoria or the efficacy of planned burning within that regime, nor any challenge to the public policy in relation to the mitigation of bushfire risks (whether to lives, property or environmental values). Those matters do not have a direct bearing on the question whether or not the conduct of the planned burns as proposed in the Strathbogie State Forest will have or is likely to have a significant impact on the Southern Greater Glider. Apart from that question, the defence under s 43B of the EPBC Act requires some consideration of the evidence in relation to the history of planned burns in the Strathbogie State Forest, including the planned burn areas, and the Melbourne Corporation issue requires some consideration of the purposes or objects of fuel reduction burns as works for the "prevention or suppression of fire". 53 The evidence about the framework of policies and procedures governing fire management in Victoria was given by Mr Chris Hardman, who is the Chief Fire Officer (CFO), Forest and Fire Operations Division, DEECA and Mr Shaun Lawlor, Regional Manager, Forest and Fire Operations for the Hume Region of Forest Fire Management Victoria (FFMVic). In the circumstances, it is necessary to refer to this evidence in order to provide background and context to the questions to be determined in the proceeding. 54 I will deal separately with the evidence of Mr Lawlor and Mr Hardman in relation to the actual conduct of planned burns, including the measures that are taken to keep fire under control and ensure that it does not behave in an unplanned manner, and their predictions or expectations based on their experience as to the likely fire behaviour in the proposed planned burns. In so far as the latter involved opinion evidence, its admissibility was not challenged, and it may be taken as having been accepted that their evidence in that regard was based on their specialised knowledge from training, study or experience: see Evidence Act 1995 (Cth), s 79. 55 As CFO, Mr Hardman leads DEECA's fire management operations under the Forests Act and is responsible for fire prevention, preparedness and response operations on behalf of the Secretary. As set out in further detail below, the Secretary is responsible under the Forests Act (and its predecessor legislation) for managing the risk of bushfire in State forests, national parks and other protected land in Victoria: see, currently, Forests Act, s 62(2). The CFO also represents DEECA in Victorian and national emergency management arrangements. 56 As the Regional Manager, Forest and Fire Operations for the Hume Region, Mr Lawlor is responsible for the tactical and operational planning and delivery of regional forest fire programs, including bushfire response, planned burning, and other forest management in the Hume Region.

Fire management in Victoria 57 Victoria has a particularly high bushfire risk when compared to other parts of the world and other parts of Australia due to its landscape, vegetation types and weather patterns. This risk is increasing as a result of climate change. Victoria has hot dry summers with very little rain. In summer, Victoria is generally subject to hot, dry northerly wind conditions, followed by south-westerly wind changes. When a bushfire ignites, it is common for a northerly wind to push a narrow bushfire from north to south and, when the wind changes to a south-westerly direction, the bushfire will move from west to east and have a broad and dangerous front. 58 Victoria has experienced an increase in scale of bushfires in the last 20 years, as evidenced by the increased number of megafires in the State. A megafire is a fire which burns over one million hectares. There have been three megafires in the last 20 years, being the 2003 Eastern Victorian alpine bushfires, the 2006-2007 Great Divide Complex bushfires in eastern Victoria, and the 2019-2020 bushfires in East Gippsland and other locations (known as the Black Summer bushfires). By comparison, in the 152 years leading up to 2003, Victoria experienced two recorded megafires (Black Thursday in 1851 and Black Friday in 1938-1939). 59 Victoria has a risk-based approach to bushfire management, which seeks to reduce impacts from bushfire including on people, property, the economy and the environment. This risk-based approach ultimately recognises that the protection of human life is the highest priority. 60 DEECA delivers programs to manage bushfire risk through FFMVic, which was established in 2013 and is responsible for all forest fire management activities in Victoria. FFMVic is led by DEECA, but also draws on capability from Parks Victoria, VicForests and Melbourne Water. FFMVic works with the Country Fire Authority (CFA) and Fire Rescue Victoria to deliver fire management services in Victoria. 61 Fuel management activities in Victoria are undertaken in accordance with the Code, which is a Code of Practice made by the Victorian Minister for Environment under Pt 5 of the Conservation Forests and Lands Act 1987 (Vic). The Code sets the objectives for bushfire management on public land across Victoria, and provides a risk analysis framework that assists DEECA to achieve those objectives. The Code does not prescribe the operational detail for the achievement of bushfire management outcomes and objectives. The operational detail is specified in bushfire management manuals and guidelines, which must be publicly available and consistent with the Code. 62 For administrative purposes in relation to the delivery of fire management services, Victoria is divided into six regions: Barwon South West, Grampians, Loddon Mallee, Gippsland, Hume and Port Phillip. The Strathbogie State Forest is located within the Hume region. There are four districts within the Hume region: Upper Murray, Ovens, Goulburn and Murrindindi. The Strathbogie State Forest is located within the Goulburn district. 63 Each of the six regions in Victoria has its own Bushfire Management Strategy, which describes the bushfire risk for that region, taking account of its unique environment and landscape. The Bushfire Management Strategies identify actions that can be taken to protect communities, infrastructure and the environment from the threat of bushfire, and provide the direction and options for fuel management across a region and for each district. 64 Fuel management is a key strategy for reducing the risk of bushfire in Victoria. While there are several layers to how the Bushfire Management Strategies are implemented on the ground, the objective is to reduce bushfire fuels and fuel hazard, particularly the leaves, bark, twigs and shrubs that cause the greatest risk of a bushfire spreading. Fuel management includes planned burning, mechanical treatment activities (such as mowing, slashing and mulching), and non-burn treatment activities such as spraying. 65 Victoria's fuel management program includes "residual risk targets" which are set by the CFO and implemented across the regions and districts. A residual risk target is the percentage of bushfire risk remaining after fuel in forests has been reduced, either through fuel management activities or as a result of bushfires, and before any fire suppression activities are undertaken. Bushfire risk is the risk of destruction of property from bushfire, which is also used in this context as a proxy for risk to human life. The State-wide residual risk target is 70%. The residual risk target for each region and district varies depending on factors including vegetation, topography, and the population and assets in the area. The target for the Hume region is 69%, and for the Goulburn district is 75%. 66 The specific activities that comprise a region's fuel management program are listed in a "Joint Fuel Management Program" for that region, which is created and implemented jointly between FFMVic and the CFA. A Joint Fuel Management Program sets out a rolling three-year program of planned fuel management activities, including planned burns. The Joint Fuel Management Program for the Hume Region refers to the regional residual risk target of 69% and notes that, without any fuel management, the projected residual risk will increase to 73%. Through the conduct of the activities programmed in the Joint Fuel Management Program, the region works towards managing local bushfire risk by identifying planned burns and other works that will meet regional and State-wide targets. 67 Fire Management Zones are "areas of public land where fire is used for specific asset, fuel and overall forest and park management objectives": see the Code at [122]. There are four different classes of Fire Management Zone: Asset Protection Zones, Bushfire Moderation Zones, Landscape Management Zones and Planned Burning Exclusion Zones. 68 As will be discussed further below, the four planned burns that are the subject of this proceeding are within an area that is zoned as a Bushfire Moderation Zone. According to the Code (at [128]), a Bushfire Moderation Zone "aims to reduce the speed and intensity of bushfires", and "complements the [Asset Protection Zone] in that the use of planned burning … is designed to protect nearby assets, particularly from ember spotting during a bushfire". The Code continues (at [129]): Where practicable, the [Bushfire Moderation Zone] will aim to achieve ecological outcomes by seeking to manage for ecologically desirable fire regimes, provided bushfire protection objectives can still be met. This may include using other fuel management methods. 69 This can be compared to the Landscape Management Zone, within which planned burning is used for three broad aims, namely: • bushfire protection outcomes by reducing the overall fuel and bushfire hazard in the landscape • ecological resilience through appropriate fire regimes • management of the land for particular values including forest regeneration and protection of water catchments at a landscape level. 70 The key principles of the fuel management strategy for the Hume Region, as set out in its Bushfire Management Strategy, include to "focus fuel management activities within Asset Protection Zone and Bushfire Moderation Zone, where fuel hazards are reduced to an acceptable level whilst protecting ecological assets where possible, and to select fuel management regimes that meet the target reduction in risk to life and property, reduce risk of large fires to other important values (such as water catchments) and minimise the negative impact on ecosystem resilience". Fuel management activities in the Landscape Management Zone are undertaken "where there is a clear bushfire risk reduction objective or ecological outcome", otherwise such activities are minimised within the Landscape Management Zone to reduce negative impacts on ecosystem resilience. Another key principle is to "avoid fuel management within high value ecological areas (HVEAs), particularly within [the Landscape Management Zone]". 71 The use of Fuel Management Zones is illustrated in the document published by DEECA titled "Hume Bushfire Management Strategy 2020: Bushfire Risk Engagement Areas" (2020) at p 43 using an example of zoning in areas around Jamieson. Among other things, this includes the placement of Landscape Management Zone "in areas further from communities, where fuel management can reduce overall fuel and bushfire hazard in the landscape", and where "[m]aintaining ecosystem resilience is equally important, and we apply fire regimes that protect ecosystem values (for example, old-growth vegetation that provides critical habitat for Greater Glider and Powerful Owl)".

Fuel management burning in Victoria 72 Section 4 of the Code addresses planned burning in the following terms: 111. Planned burning is the deliberate introduction of fire into the landscape to: • modify fuel hazard, bushfire hazard and damage potential • contribute to ecological objectives • contribute to regeneration following timber harvesting activities. 112. Planned burning is the most effective technique for managing fuel hazard over large areas. Other localised treatments include ploughing, mulching, herbicide application, chain rolling, grazing, mowing and slashing. 113. Planned burning assists bushfire suppression actions by reducing the intensity and severity of bushfires. 73 Consistently with the primary objectives for bushfire management on public land, the Code identifies the "outcomes" of fuel management including planned burning as "[r]educed impact of major bushfires on human life, communities, essential and community infrastructure, industries, the economy and the environment", and states that "[h]uman life will be afforded priority over all other considerations". 74 Prior to 2016, planned burning on public land in Victoria was administered to meet annual hectare-based bushfire fuel management targets, consistent with the recommendations of various Commissions of Inquiry and Royal Commissions. However, since 2016, Victoria has employed a risk reduction target (also referred to as a residual risk target), as noted above. The State-wide target of 70% "means that bushfire fuels have been reduced to the point where impacts to life and property are reduced by about a third of the maximum risk": DEECA, "Safer together: A new approach to reducing the risk of bushfire in Victoria" (2015). The regional residual risk targets and the delivery of the regional Bushfire Management Strategies are aggregated to assess the State-wide target of 70%. 75 In this context, the Secretary measures bushfire risk by using a model called Phoenix RapidFire to simulate a set of bushfires across the landscape using real time information about weather, topography, vegetation, fire characteristics (such as flame height, ember density, spotting distance, convection column strength and intensity), in order to show how the fire will spread and behave under specified conditions, and thereby predict bushfire behaviour both with fuel reduction and without fuel reduction. In broad terms, the Secretary models how fires would behave on a "worst case" scenario (assuming weather conditions such as those prevailing on Black Saturday and fuel at its maximum risk level), and then runs modified risk scenarios seeking to reduce the number of houses or "address points" that are lost down to the applicable residual risk target. In this way, the Secretary can determine the risk reduction value of a particular planned burn or burns. The results of this modelling are used to predict how different fuel management activities will affect bushfire risk across landscapes, so as to inform fuel management priorities and determine strategies for reducing bushfire risk.

EPBC Act 76 The EPBC Act commenced operation on 16 July 2000. The objects of the Act are set out in s 3(1) and relevantly include: (a) to provide for the protection of the environment, especially those aspects of the environment that are matters of national environmental significance; and … (c) to promote the conservation of biodiversity; and (ca) to provide for the protection and conservation of heritage; … ... 77 Section 3(2) of the EPBC Act provides that, in order to achieve those objects, the EPBC Act, inter alia: (a) recognises an appropriate role for the Commonwealth in relation to the environment by focussing Commonwealth involvement on matters of national environmental significance and on Commonwealth actions and Commonwealth areas; and ... (d) adopts an efficient and timely Commonwealth environmental assessment and approval process that will ensure activities that are likely to have significant impacts on the environment are properly assessed; and (e) enhances Australia's capacity to ensure the conservation of its biodiversity by including provisions to: (i) protect native species (and in particular prevent the extinction, and promote the recovery, of threatened species) and ensure the conservation of migratory species; … ... 78 The EPBC Act binds the Crown in each of its capacities: s 4. 79 Chapter 2 of the EPBC Act is headed: "Protecting the environment". The simplified outline of the Chapter set out in s 11 states that it "provides a basis for the [Commonwealth] Minister to decide whether an action that has, will have or is likely to have a significant impact on certain aspects of the environment should proceed", and that "[i]t does so by prohibiting a person from taking an action without the Minister having given approval or decided that approval is not needed". 80 Division 1 of Pt 3 of Ch 2 of the EPBC Act contains requirements for environmental approvals by imposing conditional prohibitions on the taking of actions that have or will have, or are likely to have, a significant impact on various "matters of national environmental significance": see the heading to Div 1; and the object set out in s 3(1)(a). While the term "matters of national environmental significance" is undefined, it is clear from the context and structure of the Division and from references elsewhere in the Act that it refers to the matters with which the Subdivisions contained in Div 1 are concerned, namely: World Heritage properties; National Heritage places; Ramsar wetlands; listed threatened species and ecological communities; listed migratory species; nuclear actions; actions in or affecting Commonwealth marine areas; actions in or affecting the Great Barrier Reef Marine Park; certain actions involving unconventional gas development or large coal mining development impacting on water resources; and actions prescribed by the regulations. Each Subdivision contains its own civil penalty provisions and offence provisions in respect of a contravention of the prohibitions, together with exceptions including where an approval has been given under Pt 9 of the EPBC Act in relation to the taking of the action. 81 Relevantly to the present case, Subdiv C of Div 1 deals with listed threatened species and ecological communities. Section 18 prohibits a person from taking an action that has or will have, or is likely to have, a significant impact on a listed threatened species that is included in the extinct in the wild, critically endangered, endangered or vulnerable categories, and imposes civil penalties for contravention by an individual or a body corporate. Section 18A creates corresponding criminal offences. 82 The central provision for the purposes of this case is s 18(3) of the EPBC Act, which provides: Endangered species (3) A person must not take an action that: (a) has or will have a significant impact on a listed threatened species included in the endangered category; or (b) is likely to have a significant impact on a listed threatened species included in the endangered category. Civil penalty: (a) for an individual - 5,000 penalty units; (b) for a body corporate - 50,000 penalty units 83 Section 18A(2) relevantly provides that a person commits an offence if the person takes an action that is "likely to have a significant impact" on a listed threatened species (other than one included in the extinct category or a conservation dependent species), which is punishable on conviction by imprisonment for a term not more than 7 years, a fine not more than 420 penalty units (or up to 5 times that amount for a body corporate), or both. For such purposes, the element whether the species is a listed threatened species is subject to strict liability: s 18A(2A). 84 Section 19 provides a range of exceptions or defences to the civil penalty and offence provisions, namely: if an approval is in operation under Pt 9; if Pt 4 lets the person take the action without such an approval; if there is in force a decision of the Minister under Div 2 of Pt 7 that the relevant subsection of ss 18 or 18A is not a "controlling provision" for the action; and if the action is one whose authorisation is subject to a special environmental assessment process as described in s 160(2). 85 The term "action" is relevantly defined to include "an activity or series of activities": s 523(1)(d). It may be noted that a decision by a government body, including a State or an agency of a State, to grant a governmental authorisation for another person to take an action is not itself an action: s 524(2). While a decision to grant a governmental authorisation is removed from the operation of the EPBC Act, the subsequent physical acts or activities pursuant to the authorisation or by way of implementation of the decision can be actions within the meaning of s 523: see Secretary, Department of Primary Industries, Parks, Water and Environment v Tasmanian Aboriginal Centre Inc (2016) 244 FCR 21 at [77]-[79] (Allsop CJ, Griffiths and Moshinsky JJ). The present case is concerned with the actions proposed to be taken by the State of Victoria or its agencies in conducting the planned burns, rather than the grant of any governmental authorisation. Neither the applicant nor the Secretary or the Attorney-General suggested that s 524(2) had any relevance to the present case. 86 The term "impact" is relevantly defined under s 527E as follows: 527E Meaning of impact (1) For the purposes of this Act, an event or circumstance is an impact of an action taken by a person if: (a) the event or circumstance is a direct consequence of the action; or (b) for an event or circumstance that is an indirect consequence of the action - subject to subsection (2), the action is a substantial cause of that event or circumstance. (2) For the purposes of paragraph (1)(b), if: (a) a person (the primary person) takes an action (the primary action); and (b) as a consequence of the primary action, another person (the secondary person) takes another action (the secondary action); and (c) the secondary action is not taken at the direction or request of the primary person; and (d) an event or circumstance is a consequence of the secondary action; then that event or circumstance is an impact of the primary action only if: (e) the primary action facilitates, to a major extent, the secondary action; and (f) the secondary action is: (i) within the contemplation of the primary person; or (ii) a reasonably foreseeable consequence of the primary action; and (g) the event or circumstance is: (i) within the contemplation of the primary person; or (ii) a reasonably foreseeable consequence of the secondary action. (Emphasis in original) 87 The term "listed threatened species" is defined in s 528 to mean a native species included in the list referred to in s 178, which requires the Minister by legislative instrument to establish a list of threatened species divided into the following categories: (a) extinct; (b) extinct in the wild; (c) critically endangered; (d) endangered; (e) vulnerable; (f) conservation dependent. 88 Section 179 of the EPBC Act addresses when a native species is eligible to be included in each of the categories listed in s 178(1). As noted above, the Southern Greater Glider has been included on the list of threatened species in the endangered category from 5 July 2023, having previously been included in the vulnerable category. Those categories are dealt with by s 179(4) and (5), which provide: (4) A native species is eligible to be included in the endangered category at a particular time if, at that time: (a) it is not critically endangered; and (b) it is facing a very high risk of extinction in the wild in the near future, as determined in accordance with the prescribed criteria. (5) A native species is eligible to be included in the vulnerable category at a particular time if, at that time: (a) it is not critically endangered or endangered; and (b) it is facing a high risk of extinction in the wild in the medium-term future, as determined in accordance with the prescribed criteria. (Emphasis in original) 89 Part 4 of the EPBC Act deals with cases in which environmental approvals are not needed, which generally provides an exception to the prohibitions contained in Div 1 of Pt 3. These include actions covered by Ministerial declarations in relation to the accreditation of management arrangements or authorisation processes either under State or Territory laws pursuant to bilateral agreements between the Commonwealth and the State or Territory, or under Commonwealth laws; Ministerial declarations in relation to bioregional plans; conservation agreements; forestry operations undertaken in accordance with a Regional Forest Agreement; actions in accordance with zoning plans in the Great Barrier Reef Marine Park; and actions with prior authorisation. The only provision contained in Pt 4 which has any potential relevance to the facts of the present case is s 43B (under Div 6 - Actions with prior authorisation), which deals with the lawful continuation of uses of land, sea or seabed that were occurring immediately before the commencement of the EPBC Act. The Secretary relies on s 43B as providing an exemption from the requirements of s 18(3) in relation to the conduct of planned burning in the Strathbogie State Forest. 90 Part 9 of the EPBC Act is contained in Ch 4, which sets out processes for environmental assessments and approvals by the Commonwealth Minister. These processes generally involve three stages: deciding whether approval is needed and identifying the applicable "controlling provisions" (Pt 7); assessing the relevant impacts of the action (Pt 8); and deciding whether or not to approve the action, and on what conditions (Pt 9). 91 The environmental assessment and approval process contained in Ch 4 of the EPBC Act is generally enlivened by a referral to the Commonwealth Minister by the proponent (generally the person proposing to take the action, or a party to a contract or agreement under which the action is proposed to be taken) or by a State or an agency of a State that is aware of the proposed action. The Commonwealth Minister also has a power to request a proponent to refer the proposal: s 70. A proposed action is a "controlled action" if the taking of the action by the person without approval under Pt 9 would be prohibited by a provision of Pt 3, which is referred to as a "controlling provision" for the action: see s 67. A proponent may refer the proposed action to the Commonwealth Minister for a decision whether or not the action is a controlled action even if the proponent does not think that the action is a controlled action: s 68(2). Thus, the referral mechanism can potentially be used as a way to obtain a decision by the Commonwealth Minister that the action is not a controlled action. 92 Once a proposed action is referred to the Commonwealth Minister, s 75(1) provides that the Minister must decide whether the action the subject of the referral is a controlled action and which provisions of Pt 3 (if any) are controlling provisions for the action. In so deciding, the Commonwealth Minister must consider all adverse impacts (if any) the action has or will have, or is likely to have, on the matter protected by each provision of Pt 3: s 75(2)(a). The Commonwealth Minister must not consider any beneficial impacts the action has or will have, or is likely to have, on the protected matters: s 75(2)(b). It is an offence for a proponent to take the action while a decision is pending on whether or not it is a controlled action: s 74AA. 93 The "relevant impacts" of a controlled action must be assessed in accordance with Pt 8 of Ch 4, which prescribes a range of different assessment approaches. The relevant impacts are the impacts that the action has or will have, or is likely to have, on the matter protected by each provision of Pt 3 that the Commonwealth Minister has decided is a controlling provision for the action. 94 After the controlled action has been assessed, the Commonwealth Minister must decide whether or not to approve the taking of the action for the purposes of each controlling provision: ss 130(1), 133. The Commonwealth Minister can attach conditions to the approval of the controlled action if he or she is satisfied that the conditions are necessary or convenient for protecting, or repairing or mitigating damage to, a matter protected by a relevant controlling provision: s 134. In deciding whether or not to approve the taking of an action, and what conditions to attach to an approval, the Commonwealth Minister must consider certain mandatory considerations set out in s 136(1) and (2), including matters relevant to the controlling provision or provisions, and "economic and social matters". The Commonwealth Minister may have regard to whether the proponent is a suitable person to be granted an approach, having regard to the person's environmental history: s 134(4). In relation to decisions about threatened species, the Commonwealth Minister must not act inconsistently with Australia's obligations under specified international conventions, or with a recovery plan or a threat abatement plan: s 139(1). If the Commonwealth Minister is considering whether to approve a proposed action for the purposes of a subsection of s 18 that has or will have, or is likely to have, a significant impact on a particular listed threatened species, the Commonwealth Minister must have regard to any approved conservation advice for the species or community: s 139(2). Otherwise, the Commonwealth Minister must not consider any matters that he or she is not required or permitted by Div 1 of Pt 9 to consider: s 134(5). 95 It must be emphasised that the present case does not directly concern any aspect of the assessment and approval processes set out in Ch 4 of the EPBC Act. Rather, the applicant's contention is that the Secretary is required to follow those processes by obtaining approval from the Commonwealth Minister under Pt 9 before carrying out the proposed planned burns, in order to avoid a contravention of s 18(3) of the EPBC Act. In the absence of any such approval, the applicant seeks injunctive relief under s 475 of the EPBC Act to restrain what it contends is a threatened contravention of the EPBC Act. Section 475 is in the following terms: 475 Injunctions for contravention of the Act Applications for injunctions (1) If a person has engaged, engages or proposes to engage in conduct consisting of an act or omission that constitutes an offence or other contravention of this Act or the regulations: (a) the Minister; or (b) an interested person (other than an unincorporated organisation); or (c) a person acting on behalf of an unincorporated organisation that is an interested person; may apply to the Federal Court for an injunction. Prohibitory injunctions (2) If a person has engaged, is engaging or is proposing to engage in conduct constituting an offence or other contravention of this Act or the regulations, the Court may grant an injunction restraining the person from engaging in the conduct. ... Meaning of interested person - organisations (7) For the purposes of an application for an injunction relating to conduct or proposed conduct, an organisation (whether incorporated or not) is an interested person if it is incorporated (or was otherwise established) in Australia or an external Territory and one or more of the following conditions are met: (a) the organisation's interests have been, are or would be affected by the conduct or proposed conduct; (b) if the application relates to conduct - at any time during the 2 years immediately before the conduct: (i) the organisation's objects or purposes included the protection or conservation of, or research into, the environment; and (ii) the organisation engaged in a series of activities related to the protection or conservation of, or research into, the environment; (c) if the application relates to proposed conduct - at any time during the 2 years immediately before the making of the application: (i) the organisation's objects or purposes included the protection or conservation of, or research into, the environment; and (ii) the organisation engaged in a series of activities related to the protection or conservation of, or research into, the environment. (Emphasis in original) 96 The jurisdiction of this Court to grant an injunction under s 475 of the EPBC Act is separate from the administrative processes established under Pts 7, 8 and 9 of the EPBC Act. As summarised above, the latter involves the referral of a proposed action to the Commonwealth Minister, who must then consider and determine whether the action is a controlled action and, if so, what the controlling provisions are. Such a determination will require the Commonwealth Minister to make factual findings as to whether the proposed action has or will have, or is likely to have, a significant impact on a protected matter, such as a listed threatened species within the meaning of s 18 of the EPBC Act. When determined administratively in that context, such findings will not involve matters of jurisdictional fact which constitute objective pre-conditions on the powers conferred on the Commonwealth Minister by the EPBC Act: see e.g. Anvil Hill Project Watch Association Inc v Minister for Environment and Water Resources (2008) 166 FCR 54 at 60 (Tamberlin, Finn and Mansfield JJ). Accordingly, while a decision made by the Commonwealth Minister that an action is (or is not) a controlled action is amenable to judicial review, the Court in any such judicial review proceedings would not be required itself to make findings of fact on the evidence as to whether or not the action is a controlled action under any of the provisions of Pt 3 of Ch 2 of the EPBC Act, that is, whether the action would be prohibited by the relevant provision in the absence of an approval under Pt 9. 97 In contrast, an application to this Court for an injunction under s 475 of the EPBC Act raises a justiciable issue whether a person "has engaged, is engaging or is proposing to engage in conduct constituting an offence or other contravention of this Act or the regulations". While the grant of any injunctive relief remains subject to discretionary considerations, it is clear that the Court is required to determine on the evidence before it whether the past, current or future conduct of the person contravenes a provision of the EPBC Act. Relevantly to the present case, this includes the question whether the action that the Secretary proposes to take in conducting the planned burns in the Strathbogie State Forest has or will have, or is likely to have, a significant impact on the Southern Greater Glider as a listed threatened species in the endangered category within the meaning of ss 18(3) and 18A of the EPBC Act. On an application for a prohibitory injunction under s 475(2), this is essentially a question of fact: see e.g. Friends of Leadbeater's Possum at [1292], [1342] ff; see also Booth v Bosworth (2001) 114 FCR 39 (Branson J); Minister for Environment and Heritage v Greentree (No 2) (2004) 138 FCR 198 at [192] (Sackville J); Australian Brumby Alliance Inc v Parks Victoria Inc (2020) 277 FCR 559. 98 For present purposes, it is unnecessary to explore fully the relationship between, on the one hand, the administrative processes of environmental assessment and approval by the Commonwealth Minister and, on the other hand, the enforcement provisions under the EPBC Act, including the jurisdiction to grant injunctions in respect of contraventions of the Act. At least in circumstances where a person threatens to engage in, or to continue to engage in, conduct that contravenes the EPBC Act, this Court may be required to determine the factual and legal questions as to whether that conduct constitutes an action that, in the absence of an approval under Pt 9 or some other statutory exception or defence, would contravene an applicable statutory prohibition under Pt 3 of the EPBC Act. The fact that the Commonwealth Minister may be able to determine similar questions in the context of a referral or an environmental assessment and approval under Ch 4 of the EPBC Act, including whether a proposed action is a controlled action in respect of one or more provisions in Pt 3 for which approval is required, does not detract from or qualify the Court's task in hearing and determining an application for an injunction under s 475 of the EPBC Act. Section 67A contains a prohibition on taking a controlled action without an approval under Pt 9, with a note indicating that a person can be restrained from contravening that section by an injunction under s 475. A "controlled action" is defined for such purposes by s 67 in terms that are not expressly confined to an action that the Commonwealth Minister has decided is a controlled action under s 75. In any event, even if s 67A were to be read as referring to actions that the Commonwealth Minister has decided are controlled actions, the jurisdiction conferred by s 475 is capable of being enlivened in appropriate circumstances by a threatened contravention of a prohibition in Pt 3, such as ss 18 or 18A of the EPBC Act. 99 It may be accepted that any injunction that might be granted by the Court under s 475 in such circumstances would ordinarily be conditional in nature, so as to be expressed to restrain the action unless and until an approval were granted under Pt 9 or some other statutory exception or defence were established: compare Booth at [120] (Branson J). On any referral of a proposal, it would be matter for the Commonwealth Minister to determine on the available material whether the proposed action is a controlled action and which provisions are controlling provisions for the action, as well as whether or not the taking of the action should be approved or conditionally approved in the light of the assessment of its relevant impacts. However, at least in circumstances where there has been no referral of the proposed action to the Commonwealth Minister under Pt 7 of the EPBC Act, and a person is threatening to "break the law" by taking such action without an approval under Pt 9, an application may be brought to this Court to restrain the threatened contravention of the EPBC Act. 100 I note for completeness that, in Tasmanian Aboriginal Centre at [93], the Full Court observed that the EPBC Act "reposes in the Minister the decision whether or not to approve, for the purposes of each controlling provision for a controlled action, the taking of the action, if there is a referral" and that "[t]he Act does not contemplate an ex ante decision in exercise of judicial power of what would be or would not be a contravention of the Act if action (as yet not fully identified) took place". The Full Court therefore considered that "questions of assessment of impact, such as dealt with in Pt 8, may best be seen as the task of the Commonwealth executive not judiciary, at least in the context of an ex ante analysis involving a party who does not threaten to break the law". The concluding qualification is important, in that it acknowledges the role of injunctive relief under s 475 of the EPBC Act to restrain an imminent contravention of the Act. The jurisdiction to grant such relief is borne out by past decisions of this Court. The Full Court in Tasmanian Aboriginal Centre acknowledged at [94] that the primary judge had granted an injunction in that case because the respondent "was threatening to go ahead with the project with significant dispatch". As the Full Court's decision illustrates, it might in some circumstances also be possible for the Court to grant declaratory relief in the light of which the respondent may consider whether a referral under s 68 of the EPBC Act is required. However, an "interested person" within the meaning of s 475 (such as the applicant in the present case) cannot unilaterally initiate a referral under Pt 7 of the EPBC Act. 101 By way of defence to the applicant's claim that the planned burns constitute an action or actions the taking of which without approval under Pt 9 would be prohibited by s 18(3), the Secretary relies on s 43B of the EPBC Act, which provides as follows: 43B Actions which are lawful continuations of use of land etc. (1) A person may take an action described in a provision of Part 3 without an approval under Part 9 for the purposes of the provision if the action is a lawful continuation of a use of land, sea or seabed that was occurring immediately before the commencement of this Act. (2) However, subsection (1) does not apply to an action if: (a) before the commencement of this Act, the action was authorised by a specific environmental authorisation; and (b) at the time the action is taken, the specific environmental authorisation continues to be in force. Note: In that case, section 43A applies instead. (3) For the purposes of this section, neither of the following is a continuation of a use of land, sea or seabed: (a) an enlargement, expansion or intensification of use; (b) either: (i) any change in the location of where the use of the land, sea or seabed is occurring; or (ii) any change in the nature of the activities comprising the use; that results in a substantial increase in the impact of the use on the land, sea or seabed. 102 In broad terms, the Secretary contends that s 43B provides an exemption from the requirement to obtain an approval under Pt 9 on the basis that the planned burns in the Strathbogie State Forest involve a lawful continuation of a use of land that was occurring immediately before the commencement of the EPBC Act on 16 July 2000. 103 Finally, s 158 of the EPBC Act sets out a further exemption to the application of the prohibitions under Pt 3. Under s 158, a person proposing to take a controlled action may apply in writing to the Commonwealth Minister for an exemption from a specified provision of Pt 3. This power is only indirectly relevant to the issues in this case, in so far as there was some evidence that the State of Victoria and its agencies have previously been granted exemptions under s 158 from the application of Pt 3 of the EPBC Act in relation to certain activities for the prevention and suppression of bushfires in 2009 and 2020.

Forests Act 104 The Forests Act confers on the Secretary the exclusive control and management of "all matters of forest policy": s 5(1)(a). The "land manager" (relevantly either Parks Victoria or the Secretary) shall protect State forests, which include reserved forests under s 42(1) and proclaimed protected forests, and shall have the control and management of State forests: s 18. 105 The Secretary has responsibility for all matters relating to fire in any State forest (s 18AA(a)). Section 61A provides that there must be a CFO of the Department of Environment and Primary Industries (now known as DEECA). The Secretary may authorise the CFO in writing to perform any of the Secretary's functions in respect of fire related activities in every State forest, national park or on protected public land (ss 29, 61B(a)). 106 Section 62(2) of the Forests Act imposes a statutory obligation on the Secretary to carry out work in State forests for the prevention and control of fire: (2) Despite anything to the contrary in any other Act or law, the Secretary must carry out proper and sufficient work in State forests, national parks and on protected public land - (a) for the immediate prevention and suppression of fire; and (b) for the planned prevention of fire. 107 In performing his or her functions and exercising his or her powers under s 62(2)(a), the Secretary is required to collaborate and consult with Emergency Management Victoria: s 61D. 108 Section s 62A(1) provides that the Secretary may apply and use fire in a State forest or national park or on protected public land for land and resource management: that is, as part of silvicultural activities; to control pest animals and pest plants; or to maintain, manage, protect or enhance the ecology of, or land or vegetation. In applying and using fire in a State forest or national park, or on protected public land, the Secretary must have regard to any relevant Code of Practice: s 62A(2).

Code of Practice for Bushfire Management on Public Land 109 As mentioned above, planned burning on public land in Victoria is undertaken in accordance with the Code, the purposes of which include setting "the objectives for bushfire management on public land, and strategies and actions across the prevention, preparedness, fuel management (including planned burning), response and recovery spectrum to achieve those objectives", and providing "a risk analysis framework that assists the Department to effectively and efficiently achieve bushfire management objectives". The primary objectives for bushfire management on public land in Victoria are: • To minimise the impact of major bushfires on human life, communities, essential and community infrastructure, industries, the economy and the environment. Human life will be afforded priority over all other considerations. • To maintain or improve the resilience of natural ecosystems and their ability to deliver services such as biodiversity, water, carbon storage and forest products. 110 Among other things, the Code identifies a number of "[p]rinciples for bushfire management on public land". The first two of those principles are as follows: Protection of human life as the highest priority The protection of human life (emergency services personnel and the community) will be given priority over all other obligations in bushfire management. Ecosystem resilience Fire will be used deliberately in the landscape to meet legislative obligations and land management objectives, which promote ecological resilience and facilitate ecosystem services at a landscape level. 111 The principles also acknowledge that "[b]ushfire risk cannot be eliminated" and that "[d]ecisions about bushfire management will be based on risk analysis and will be transparent". 112 Section 4 of the Code deals with fuel management including planned burning. The overview of this section of the Code states: Under the Forests Act 1958, the Secretary may use fire for land and resource management and is responsible for carrying out proper and sufficient work in State forests, national parks and on protected public land to prevent and suppress bushfires. Fuel management activities will contribute to meeting this objective. 113 The overview then addresses planned burning as set out in the extract set out earlier in these reasons at paragraph 72. 114 The strategies identified in s 4 of the Code relevantly include reducing the fuel hazard on public land, and using planned burning on public land for ecosystem resistance. The actions include undertaking strategic planning for fuel management including planned burning, and using Fire Management Zones to implement local bushfire management objectives.

The applicant's case 115 By its originating application dated 14 June 2023, the applicant relevantly sought the following substantive relief: 1. An injunction under s 475 of the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (the EPBC Act) to restrain the Respondent from conducting planned burns in the Strathbogie State Forest. 2. … 3. A declaration that planned burns in the Strathbogie State Forest are required to be referred under s 68 of the EPBC Act. 116 The applicant's amended statement of claim dated 26 October 2023 did not seek any declaratory relief, but rather sought an injunction under s 475(2) "restraining the respondent from undertaking or authorising the planned burning in the Strathbogie State Forest". The applicant did not press any claim for a declaration in either its opening or closing submissions. 117 In the amended statement of claim, the applicant relevantly alleged that the planned burns in the Strathbogie State Forest constitute an action that will have, or is likely to have, a significant impact on the Southern Greater Glider, in that fire leads to a long-term decrease in the size of an important population of Southern Greater Glider, reduces the area of occupancy of an important population of Southern Greater Glider, and adversely affects habitat critical to the survival of the Southern Greater Glider. The particulars of this allegation set out in the amended statement of claim were as follows: The decline of the Southern Greater Glider is accelerated by fire including because: (a) Some Southern Greater Gliders are killed directly by fire, being between 1-9 per cent of animals in the path of fire. (b) The Southern Greater Glider is dependent on hollow-bearing trees and low-severity planned burns cause hollow-bearing trees to decline by up to 26 percent. (c) Fire causes loss of food resources. 118 On 13 November 2023, pursuant to orders made by consent on 19 October 2023, the applicant filed further and better particulars of the allegation set out above, in the following terms: (d) Using the FRaME model described in the report of Adj. A/Prof. Philip Zylstra dated 13 November 2023, the burns proposed at Barjarg, Lima East, Strathbogie South, and Tallangallook can be expected to have the following severity: (e) The burns proposed at Barjarg, Lima East, Strathbogie South, and Tallangallook can be expected to cause a reduction in the number of hollow-bearing trees by between 9% and 47%. The fire mitigation measures lack the prescription of raking around hollow-bearing trees except in the small area that is in proximity to the control lines and burn boundaries, indicating that the overall risk of decline of hollow-bearing trees is at the higher end of this range. (f) Applying the 90th percentile severity of the table set out in paragraph (d), the burns proposed at Barjarg, Lima East, Strathbogie South, and Tallangallook can be expected to cause the following effects on Southern Greater Gliders: (g) These effects will kill some Southern Greater Gliders through partial thickness burns via asphyxiation following burns to their respiratory tracts. (h) High severity fires have been reported to cause a decline in Southern Greater Glider numbers by half in affected areas. A significant proportion of each of the fires proposed at Barjarg, Lima East, Strathbogie South, and Tallangallook will likely burn with high severity. This consequence is independent of the "intensity" of the fire itself. (i) The effects set out above constitute a significant impact on the Southern Greater Glider because this is an important impact on the species in that: a. The Risk Matrix in Table 2 of the Conservation Advice for the Southern Greater Glider identifies "inappropriate fire regimes" as having a "catastrophic" impact on the species as a whole. b. The nature of inappropriate fire regimes is described in Table 1 of the Conservation Advice for the Southern Greater Glider, where the following is stated under the heading "high frequency fires": Too intense or frequent planned burning may contribute to population losses or declines in the southern part of the greater glider's range. Bluff (2016) reported that hollow-bearing trees (HBTs) affected by fire during planned burns were 28 times more likely to collapse than HBTs that were not burnt. Parnaby et al. (2010) found that following low intensity prescription burns in the Pilliga forests (NSW), mean collapse rates for burnt HBTs were 14-26%. This was consistent with the collapse rate of 25.6% found by Bluff (2016). A survey following a planned burn at Tallarook Range in the Central Highlands (Vic) in 2021 found that a large number of potential greater glider habitat trees were burnt, with "many destroyed" (N. Stimson 2021, Pers. comm. 26 June). There is increased pressure from some parts of the community to undertake more hazard reduction burning, follow the severe bushfires of 2019-20. c. Whilst the four proposed burns might not reach the level of "catastrophic" impact themselves according to the Risk Matrix in the Conservation Advice, by reasonable inference from the evidence as to the likely severity of the fires, the impact on the Southern Greater Glider reaches the level of "significant impact" in the sense of an important impact for the listed matter. 119 As will become apparent, these further particulars drew heavily on the report of the applicant's expert witness Dr Philip Zylstra. 120 In opening submissions, counsel for the applicant submitted that the four proposed burns amounted to one "action" that is likely to have a significant impact on the Southern Greater Glider. The applicant relied on the Conservation Advice, including in relation to the taxonomy and distribution of the Southern Greater Glider, the significance of hollow-bearing trees as habitat, and the identification of key threats to the Southern Greater Glider including in particular "frequent and intense bushfires, inappropriate prescribed burning, climate change, land clearing and timber harvesting". The applicant emphasised that the Conservation Advice recognises that "too intense or frequent planned burning may contribute to population losses or declines in the southern part of the greater glider's range". The applicant also relied on the Action Statement in relation to the Greater Glider issued under the FFG Act, including its acknowledgment that planned burns are among the factors that contribute to elevated mortality and the loss of hollow-bearing trees. 121 The applicant contends that the Strathbogie State Forest contains a large population of approximately 69,000 Southern Greater Gliders which is important to the conservation of the species. In the applicant's submission, the area of the planned burns would comprise approximately 8% of the Strathbogie State Forest, potentially affecting approximately 5,600 gliders. The conduct of the planned burns would be likely to kill individual gliders in the affected areas, although the precise number of likely deaths is unknown. Further, it would cause the collapse of a substantial number of hollow-bearing trees in the areas reached by fire, and potentially cause structural damage to other hollow-bearing trees rendering them more vulnerable to future collapse. The applicant submitted that this amounted to a significant impact on the species. 122 As mentioned above, the applicant stressed in its opening submissions that "[t]he efficacy of planned fuel reduction burns as a tool in managing bushfire risks is not an issue in this case". Rather, the applicant's case focused on the impact of the four planned burns on the Southern Greater Glider. Among other things, the applicant contended that fire severity is relevant to: (i) the extent of injury to and mortality of gliders caused by heat, and that this could be approximated by the extent of "canopy scorch" caused by the fire; and (ii) the extent of collapse of hollow-bearing trees during or following the fire. 123 In relation to canopy scorch, the applicant relied in opening submissions on the model developed by its expert Dr Zylstra to predict flame height and canopy scorching, and contended that there would be some degree of canopy scorching to more than 50% of the areas in which the planned burns occurred, in contrast to the assumption on which the Secretary's experts had proceeded of between 1% and 2% of the planned burn areas that would experience (high) canopy scorch. In this regard, the applicant took issue with the notion that it was possible to distinguish between degrees of canopy scorch (i.e. in terms of low, medium or high canopy scorch). The applicant submitted that Dr Zylstra's predictions were consistent with past fire severity mapping of planned burns undertaken previously by the State, and that "[c]anopy scorching of the extent predicted by [Dr] Zylstra will cause injury and death to many [Southern Greater Glider] individuals due to direct heat exposure". This was because canopy scorch was the best available "proxy" for heat and for flame height and length sufficient to give rise to a risk to gliders. 124 It will be necessary to return to these submissions below in the light of the oral evidence at the hearing and the applicant's closing submissions which placed far less weight on Dr Zylstra's modelling and greater emphasis on concessions that were said to have arisen from the evidence given by the Secretary's witnesses. 125 In relation to the loss of hollow-bearing trees, the applicant submitted that there would be a substantial collapse of such trees that are reached by fire in the course of the planned burns, leading to the loss of dens used by the Southern Greater Glider. 126 In addressing the risks of both canopy scorch and the loss of hollow-bearing trees, counsel for the applicant placed some reliance in opening submissions on the timing of the planned burns during a period in which female gliders may be pregnant or nursing their young, and therefore more vulnerable and at risk of "hyper-predation". The Secretary's counsel objected to any reliance on such a contention, on the basis that it went beyond the scope of the case that had been pleaded and particularised by the applicant. In any event, this matter received little if any attention in the evidence, and there are therefore limits to the extent to which any weight can be placed on it. 127 In relation to the defence raised by the Secretary under s 43B of the EPBC Act, the applicant submitted that the conduct of planned burning on the relevant land comprising the burn areas does not fall within the exemption under s 43B, because planned burning is intermittent, irregular and infrequent, rather than a "continuation" of a use of land that was occurring immediately before the commencement of the EPBC Act. Further, the applicant submitted that most of the planned burn areas had never been the subject of fuel reduction burns, and that the current planned burns would involve an enlargement or expansion of fuel reduction burning in the Strathbogie State Forest, or a change in the location of where the use of the land is occurring that results in a substantial increase in the impact of the use of the land within the meaning of s 43B(3). 128 In relation to the Secretary's reliance on the Melbourne Corporation principle to argue that s 18(3) is invalid in its application to s 62(2) of the Forests Act, or alternatively to the four planned burns, the applicant submitted that s 18(3) of the EPBC Act imposes a minimal burden on the State, in so far as it involves a procedural requirement to obtain approval rather than an absolute prohibition on planned burning, and that such a requirement has no bearing on the continued functioning of the State as a polity. The applicant further contended that s 18(3) of the EPBC Act cannot realistically be triggered by actions undertaken for the immediate prevention and suppression of fire under s 62(2)(a), and that planned burns under s 62(2)(b) of the Forests Act are not "immediate" works and involve sufficient time during the development of plans and before the conduct of the burn for the action to be referred for approval under Pt 9 of the EPBC Act.

The Secretary's case 129 The Secretary filed an amended defence dated 27 October 2023. The Secretary relevantly pleaded that: (a) it is the "land manager" of the Strathbogie State Forest as defined in s 3(1) of the Forests Act; (b) it shall protect and, subject to the Forests Act, has the control and management of the Strathbogie State Forest pursuant to s 18 of the Forests Act; and (c) it must under s 62(2) of the Forests Act carry out proper and sufficient work in State forests for the immediate prevention and suppression of fire and for the planned prevention of fire. 130 The Secretary pleaded that it presently plans to carry out the planned burns in the four areas of the Strathbogie State Forest on a day or days in the period between 1 March 2024 and 31 May 2024, with the particular details of the conduct of those planned burns likely to change as further information is obtained and the plans are refined (including to adjust for environmental conditions on the day of a burn). The total size of the nominal burn areas is approximately 2,000 hectares, within which a smaller area will in fact be subject to burning as determined by specific operational planning and the identification of treatable fuels within each area. The Secretary pleaded that the object of the current planned burns is the reduction of fuel (comprising leaf and bark litter, twigs and like matter) in order to reduce the speed and intensity of bushfires, as part of a State-wide program for the planned prevention of fire, and that whether and when the planned burns go ahead will depend on conditions in autumn 2024. 131 The Secretary's opening submissions make it clear that it is not part of the respondent's case in this proceeding that "any immediate impacts on [Southern Greater Gliders] are to be netted off against the positive effects of the planned burns for the [Southern Greater Gliders]", although the Secretary maintains that the purpose of the planned burns is to mitigate the risk of future bushfires (including for the benefit of the species). 132 The Secretary denies that the planned burns constitute an action that will have, or is likely to have, a significant impact on the Southern Greater Glider within the meaning of s 18(3). On the contrary, the Secretary submits that the impact of the planned burns on Southern Greater Gliders within each burn area is likely to be minimal, and that the evidence does not establish that any impact on individual gliders or their habitat is likely to have an impact (let alone a significant impact) on the listed species. 133 In this regard, in its opening submissions the Secretary submitted that the planned burns are not likely to produce the effects for which the applicant contends, which are said to rely on predictions and characterisations of the fire likely to be caused by the planned burns as "high severity", and on eliding the fundamental differences between planned burns and high severity bushfires. The Secretary disputed the prediction made by Dr Zylstra and his "FRaME" model (as defined in paragraph 148 below) that the planned burns will produce "high severity" fire in a significant proportion of each planned burn area, having regard to the limits on the use of computer models to predict fire behaviour during planned burns, the various factors that can be manipulated by a knowledgeable operator of a prescribed burn in order to reduce the risk of undesirable fire behaviour, and the experience of senior officers in relation to the conduct and delivery of planned burns on past occasions. The Secretary submits that the planned burns are sophisticated operations conducted by personnel experienced in the use of ignition methods and other measures to control the intensity and spread of the fires. 134 The Secretary referred to the specific mitigation measures directed to the protection of gliders in the Delivery Plans for each planned burn. The Secretary contends that the available evidence suggests that arboreal animals such as the Southern Greater Glider regularly survive fires that do not significantly affect the canopy, and that the number of individual gliders that might be killed or injured through heat exposure is likely to be minor given the small area of canopy scorch that is predicted. The Secretary contends that a short-term reduction in the abundance of hollow-bearing trees in the burn areas would be unlikely to threaten the persistence of the population of Southern Greater Gliders, and that the areas that remain unburnt (such as south facing slopes and moist areas associated with drainage lines or creeks) will include the highest-quality habitat for gliders. 135 In its opening submissions, the Secretary submitted that there was a large population of Southern Greater Gliders in the Strathbogie State Forest which had continued without significant decline notwithstanding the influence of planned burning in the past. The Secretary therefore submitted that the evidence does not support a finding that the planned burns, separately or cumulatively, are likely to have any impact, or any significant impact, on the Southern Greater Glider as a species. 136 Further or alternatively, the Secretary pleads the following defences. (a) First, the Secretary says that the planned burns are a lawful continuation of a use of land that was occurring immediately before the commencement of the EPBC Act, and pursuant to s 43B of the EPBC Act are permitted to be carried out without an approval under Pt 9 of that Act. In this regard, the Secretary relies on the history of planned burning by State agencies and DEECA and its predecessors in the protection against bushfire, including the history of planned burns in the Strathbogie State Forest. (b) Secondly, the Secretary says that, to the extent that s 18(3) of the EPBC Act purports to prohibit the planned burns in the Strathbogie State Forest without an approval under Pt 9, it imposes a special disability or burden on the exercise of powers and fulfilment of functions of the State of Victoria which curtails its capacity to function as a government, and accordingly is invalid either in its application to the work pursuant to s 62(2) of the Forests Act or in its application to the four planned burns in the Strathbogie State Forest. By way of particulars of this defence, the Secretary says that it is an essential constitutional function of the government of the State of Victoria to protect its people and land from bushfire, including by managing and controlling the immediate prevention and suppression of fire and the planned prevention of fire. 137 As to the first of these two defences, the Secretary submits that it (and its predecessors) have long had statutory authority to engage in planned burning, which may amount to a relevant use of land for the purposes of s 43B of the EPBC Act. The Secretary submits that an action or activity need not be "continuous" or constant in order to amount to a lawful continuation of an existing use of the land, and that s 43B of the EPBC Act is capable of covering actions that are only carried out from time to time or that are inherently intermittent. It is submitted that the "land" that is the subject of the continuing use is a broader concept than the specific location on which each instance of the particular use is carried out, and is not limited to the precise areas which are the subject of a planned burn. In the present context, the Secretary submits that the "land" that was being used for planned burns immediately before the commencement of the EPBC Act is properly identified as the land comprising the Strathbogie State Forest, and to that end relied on evidence as to the history of planned burns in the Strathbogie State Forest since the 1960s, including the specific history of the current planned burn areas. 138 As to the second of the two defences, which relies on the principle recognised in Melbourne Corporation, the Secretary relied on and adopted the submissions of the Attorney-General. It may be noted that, as ultimately developed in written and oral submissions, the Attorney-General did not rely on the imposition of a special disability or burden on the State, in the sense of any targeted or discriminatory operation of s 18(3) of the EPBC Act. Rather, the focus of the submissions was on the practical operation of s 18(3) in its application to the Secretary so as to curtail or interfere with an essential constitutional function of the State.

The Attorney-General for the State of Victoria 139 The Attorney-General intervened in the proceeding pursuant to s 78A of the Judiciary Act in relation to the issue raised by the Secretary's defence referred to in paragraph 136, namely whether s 18(3) of the EPBC Act infringes the Melbourne Corporation principle in its application to fire prevention and suppression works conducted by the Secretary under s 62(2) of the Forests Act or, alternatively, in its application to the four planned burns that are the subject of this proceeding.

Standing 140 The Secretary does not dispute that the applicant satisfies the definition of an "interested person" under s 475 of the EPBC Act and has standing to seek an injunction in relation to the proposed conduct of the planned burns. 141 In that regard, the applicant relied on evidence relating to its incorporation on 15 November 2019 under the Associations Incorporation Reform Act 2012 (Vic), its purpose under its Rules of "seeking to protect the Strathbogie Forest from inappropriate management, including native forest logging", and its activities in relation to the protection of the Southern Greater Glider population in the Strathbogie State Forest. In relation to the latter, the applicant's recent activities from about January 2023 include corresponding and meeting with officers from DEECA and FFMVic in relation to its concerns about the planned burns and their impact on Southern Greater Gliders (particularly as a result of the collapse of hollow-bearing trees), corresponding with State Ministers and members of Parliament in relation to the planned burns, conducting citizen surveys and making reports on the presence of individual gliders in parts of the Strathbogie State Forest, making freedom of information requests in relation to fuel load assessments carried out by DEECA in the planned burn areas, issuing media releases in relation to the planned burns and their impact on Southern Greater Gliders, holding public meetings, and maintaining a website and Facebook page containing publicly accessible information about its activities. 142 Having regard to its purpose and the applicant's activities undertaken in respect of the Strathbogie State Forest, I find that the applicant is an "interested person" within the meaning of s 475(7) of the EPBC Act, on the basis that its interests are or would be affected by the proposed conduct, its objects or purposes include the protection or conservation of the environment, and it has engaged in activities related to the protection or conservation of the environment.

The applicant's evidence 143 The applicant relied on the following evidence: (a) an affidavit affirmed 14 June 2023 by its Chairperson, Mr Lobert (Lobert affidavit); (b) an expert report by Adjunct Associate Professor Philip Zylstra dated 13 November 2023 (Zylstra report), together with an expert report in reply dated 8 January 2024 (Zylstra reply report); (c) an expert report of Associate Professor Grant Wardell-Johnson dated 20 November 2023 (Wardell-Johnson report), together with an export report in reply dated 8 January 2024 (Wardell-Johnson reply report); and (d) an expert report of Dr Charles Meredith dated 19 November 2023 (Meredith report). 144 Each of the applicant's expert witnesses gave oral evidence and was cross-examined.

Bertram Otto Lobert 145 Paragraphs 3 to 8 of the Lobert affidavit (and associated exhibits to that affidavit marked BL -2 to BL-9) were directed to establishing the applicant's standing to seek the injunctive and declaratory relief sought in the originating application, including as an "interested person" who may apply for an injunction under s 475 of the EPBC Act, and I made an order under s 136 of the Evidence Act limiting their use to that question. 146 The Lobert affidavit also addressed the listing of the Southern Greater Glider as an endangered species under the EPBC Act and as threatened under the FFG Act, exhibiting copies of the Conservation Advice and Action Statement, and information from documents produced by DEECA and FFMVic about the planned burns in the Strathbogie State Forest more generally.

Adjunct Associate Professor Philip Zylstra 147 Dr Zylstra is an Adjunct Associate Professor at Curtin University in Perth, Western Australia. In 2011, he developed a forest fire behaviour model for the purposes of his Ph.D. at the Australian Defence Force Academy and the University of New South Wales. In addition to his research into fire behaviour, he has performed work for various public bodies in New South Wales in relation to fire management, including the planning and conduct of prescribed burns. 148 After developing the initial model for his Ph.D. thesis, Dr Zylstra worked on a project to "validate" the model, leading to the publication of a peer-reviewed journal article that he co-authored in 2016: P Zylstra et al, "Biophysical mechanistic modelling quantifies the effects of plant traits on fire severity: species, not surface fuel loads determine flame dimensions in eucalypt forests" (2016) PLoS One 11 e0160715. The model was subsequently further developed into the "Fire Research and Modelling Environment", or "FRaME", with the goal of producing "the first ever mechanistic fire effects model, capable of demonstrating direct or first-order fire impacts on fauna" (with the term "first-order" impacts referring to "immediate injury or death of individual animals caused by flames and/or smoke"). The Zylstra report refers to several ensuing reports and articles published by Dr Zylstra in which the FRaME model was used to predict fire behaviour and to assess the impacts on particular classes of fauna. 149 Among other things, Dr Zylstra considers that the FRaME model is better at predicting the height of flames than other models which are based primarily on surface fuel load. Dr Zylstra claims that FRaME is "a scientific tool developed with transparent methodology and peer-reviewed", in contrast to the "McArthur-based industry-standard modelling" (which is explained in further detail below). Dr Zylstra considers that there is no relationship between fuel loads and the rate of spread of a fire. Instead, FRaME "models fire behaviour by calculating the flammability of leaves, and scaling this up to plants, plant strata and entire plant communities using the physics of convective heat transfer". As Dr Zylstra accepts, this "requires descriptors of forest structure and composition that are not included in the Fuel Hazard Scoring system, so precise predictions of fire behaviour for these sites are not possible without additional field surveys". 150 One of Dr Zylstra's recent publications (P Zylstra, "Quantifying the direct fire threat to a critically endangered arboreal marsupial using biophysical, mechanistic modelling" (2023) Austral Ecol 48, 266-288) is said to have examined a prescribed burn conducted in Western Australia in which 77% of a population of critically endangered Western Ringtail possum (Pseudocheirus occidentalis) had been killed, and used FraME to model the causes and mitigating factors of mortality, so as to provide validation for the model by "correctly" predicting heavy mortality from burns and asphyxiation. It may be noted in passing that the particular study population considered in this article comprised 22 individual possums in an urban reserve south of Perth. 151 Dr Zylstra was instructed to describe the nature and intensity of the fire that is likely to occur in the Strathbogie State Forest pursuant to the proposed planned burns, in the highest degree of detail and with the greatest degree of particularity that he was able. The conclusions reached in the Zylstra report were summarised as follows: a. A significant proportion of each block will burn with high severity. b. High severity fire will likely kill a small to medium proportion of gliders through partial-thickness burns and via asphyxiation following burns to their respiratory tracts. c. Prescribed burns cause the collapse of a proportion of hollow-bearing trees that have previously been scarred by fire. d. Measures to mitigate the collapse of hollow-bearing trees focus only on trees immediately adjacent to control lines such as roads, protecting only the very small part of the area that is visible. e. Prescribed burns will cause scarring to the base of many hollow-bearing trees, making them vulnerable to collapse from future planned or unplanned fires. 152 Dr Zylstra considered that the scale or exact proportions of these impacts in terms of direct mortality and damage to habitat are unknown, but that they "may be quantified with detailed vegetation survey and data on animal hollow sites and behaviours".

Predicted fire behaviour 153 In his report, Dr Zylstra took into account the prescriptions contained in the Delivery Plans and Operations Maps for each of the four planned burns, and made predictions of the likely fire behaviour using both his FraME model and the "industry-standard approach", the latter of which is based on a model developed by Arthur Grant McArthur (see A G McArthur, "Fire behaviour in Eucalypt forests" (1967) (McArthur 1967)) (which is used for what is known as the McArthur meter) and is contained in a fire modelling tool called "Amicus" that was developed by the CSIRO. Dr Zylstra notes that the McArthur meter's equations for flame height and rate of spread are also used in Phoenix Rapidfire modelling; these models are further discussed later in these reasons. The results of Dr Zylstra's fire modelling using the "industry-standard approach" was that "fire intensity was predicted to be low to moderate", and the predicted scorch height "was not sufficient to scorch the tree canopies". This was contrasted with the modelled fire behaviour using FRaME. 154 To predict fire behaviour using FRaME, in the absence of actual data concerning the forest structure and composition in the planned burn areas, Dr Zylstra was required to construct "a series of model forests based on the dominant Ecological Vegetation Class" in each of the planned burn areas, namely herb-rich foothill forest, which he supplemented with site-specific details of fuel hazard values drawn from the burn Delivery Plans. This involved postulating a notional or hypothetical "stand" of vegetation that was populated with representative species for each of the applicable strata (canopy, midstorey, understorey and near-surface), in respect of which values were attributed for "cover" and height. The various "leaf traits and crown shape parameters" required for modelling in FRaME were taken from ratios for the relevant species in previous publications by Dr Zylstra. The manner in which this notional "stand" of vegetation was constructed, including in particular the selection by Dr Zylstra of representative species of canopy and midstorey trees, was the subject of some attention in his cross-examination. 155 Dr Zylstra then applied a "script" in FRaME in order to model fire behaviour by calculating 1,000 "predictions" for each burn block, with randomly varied values within defined ranges for plant species composition, canopy dimensions, slope and weather conditions. The code comprising this "script", which was set out in an annexure to the Zylstra report, included parameters for slope, temperature, fuel moisture content and wind speed. Without reproducing here the detailed tables setting out the mean and maximum results or the figures showing the modelled flame heights and rates of spread against wind speed, the FRaME modelling predicted higher flames with a greater rate of spread in each of the planned burn areas than the values that were predicted by Dr Zylstra using the industry-standard tools. 156 Further, as depicted in Table 6 of the Zylstra report (set out immediately below), FRaME predicted higher fire severity, with crown scorch predicted for between 32% and 77% of each planned burn area (32%, 68%, 73% and 77% respectively) and crown fire of 1% in three of the four planned burn areas. 157 Addressing the interpretation of these differing fire behaviour predictions as between the industry-standard approach and the FRaME model, Dr Zylstra states in his report that "it is not possible to say with certainty which predictions are the most reliable, but there are several reasons to have greater confidence in those derived using FRaME". These include the fact that FRaME has been peer-reviewed, whereas the claims made by McArthur (1967) regarding the influence of fuel load on fire behaviour and flame height are regarded as contrary to a range of peer-reviewed evidence. Dr Zylstra states that, in order to develop FRaME, he "developed models for leaf flammability and up-scaled this to plants and entire forests using simplified physics of heat transfer", and "then tested this against a database of wildfire flame heights in diverse forests, finding that vegetation structure and composition accounted for most of the variability in flame heights". The predictions differed "because the industry-standard expectations are derived from a measure that is unrelated to fire severity" (which, according to Dr Zylstra, refers to the effect of fire on vegetation). 158 Dr Zylstra accepted in his report that there was some uncertainty in the predictions of fire behaviour using the FRaME model. For example, he stated: As already detailed, predictions using FRaME required estimates of structural and species traits, and these introduce uncertainty. For example, I estimated the heights of midstorey plants from a single photograph. If those plants were shorter in a physical burn block, then they would more often ignite, and if they were taller then they would ignite less often. There is reason, however, to expect that large flames causing crown scorch are possible. Past severity mapping shows some degree of crown scorch across much of the area as per Table 6. I also note that the elevated fuel hazard scores are very high (Table 2) for a forest described as having a typically open understorey. (Citations omitted.) 159 Accordingly, Dr Zylstra expressed the view that burning under low or moderate fire danger conditions will not guarantee low severity fire and that, "[a]lthough industry standard modelling predicts that crown scorch will not occur, this is dependent upon an already disproved relationship to fuel load, which has no bearing on fire severity".

First-order impacts - external and respiratory burns 160 In the light of Dr Zylstra's predictions regarding fire behaviour in the four planned burn areas, Dr Zylstra then addressed the impact of the planned burns on the Southern Greater Glider. As set out above, the ultimate conclusion expressed by Dr Zylstra in his report was that "[h]igh severity fire will likely kill a small to medium proportion of gliders through partial-thickness burns and via asphyxiation following burns to their respiratory tracts". However, Dr Zylstra's opinions on questions concerning the likely impact on individual gliders, the population of gliders in the Strathbogie State Forest and the Southern Greater Glider as a species were subject to an initial caveat: To address these three questions adequately, I would require quantitative descriptions of the distribution of gliders in the proposed burn blocks, with details on the likelihood of their location and sheltering behaviour. Given this and the lack of precise detail on forest structure to enable better fire behaviour predictions, I am limited to more general answers. 161 In relation to the "risk environment" for the Southern Greater Glider, Dr Zylstra noted that there was a high risk posed by inappropriate fire regimes and habitat clearing. A risk assessment for the Southern Greater Glider carried out for DELWP (the predecessor to DEECA) in 2022 had assessed the risk posed by "increased fire frequency/intensity" as significant to high. Prescribed burning was listed as one of the mitigation controls, but its efficacy "was ranked as poor due to the ineffectiveness of prescribed burns under catastrophic conditions, and their impacts on hollow-bearing trees" (emphasis in original). Dealing with "first-order impacts", the Zylstra report stated: A NSW study found that first-order fire effects from even a single fire in ten years more than halved Southern Greater Glider numbers in their study area, arguing that such impacts only arose if high severity fire (crown scorch) occurred. The authors concluded that prescribed burns in glider habitat should only be conducted under "low/moderate fire weather conditions where canopy scorch does not occur." In contrast, surveys of glider populations before and after burns in the Strathbogie Ranges have reported either minimal losses or slight increases, and the population appears to have remained stable. (Citations omitted). 162 Before coming to his predictions concerning the first-order impacts on gliders, Dr Zylstra acknowledged a number of "knowledge gaps". These include that "[i]t has not been shown that crown scorch is synonymous with first-order impacts on Greater Gliders", and that the recommendation to that effect "was taken from a personal comment that characterised fire behaviour across a large area with a single metric, and the assumption that this metric is adequate to explain the direct impact of fire on gliders", referring to a 2018 paper by C M McLean et al, "The threatened status of the hollow dependent arboreal marsupial, the Greater Glider (Petauroides volans), can be explained by impacts from wildfire and selective logging" (2018) 415-416 Forest Ecology and Management 19-25 (McLean (2018)). Further, while crown scorch "may approximate the heat flux that will cause fatal injury to gliders", Dr Zylstra noted that "gliders sheltering in hollows, coated in insulating fur, or climbing to tree tops may be at lower risk" and that "the threshold for injury to respiratory tracts may be lower than it is for foliage". Conversely, however, Dr Zylstra considered that the data was "not yet sufficient to show that first-order effects of burning can be dismissed", observing that "[a]lthough existing studies showing continued population growth of gliders at burn sites are promising, most of the survey transects were outside of the area mapped as burnt". 163 In order to address these knowledge gaps, Dr Zylstra relied on FRaME to calculate first-order effects on gliders "accounting for animal morphology and behaviour". Dr Zylstra used a script to model the likelihood of mortality due to burns of the body and respiratory tracts, based on assumptions that gliders would climb to a height of 23 meters (being 2 meters from the top of the mean tree height) and would shelter in hollows at mid-canopy height of 18.7 meters. The effects on gliders were modelled for the 90th percentile of modelled flame heights - that is, as I understand it from Dr Zylstra's evidence in his cross-examination, taking the 900th highest flame from the results modelled for each burn area in the earlier section of the Zylstra report. The modelled first-order effects on gliders were set out in a series of graphs showing predictions generated by FRaME of the temperature over time in tree tops and hollows respectively in respect of air temperature and the temperature of the epidermis, papillary dermis and reticular dermis of an animal in the tree tops or sheltering in a tree hollow. The conclusions drawn from this analysis were set out as follows: At the 90th percentile, exposed gliders in tree tops were expected to suffer partial-thickness burns and burns to the respiratory tract in all burn blocks, and full-thickness burns in the Lima East - Mt Albert block (Table 7, Fig. 6). Gliders sheltering in hollows were modelled to receive burns to respiratory tracts in all blocks. These results suggest that all gliders would be killed at the 90th percentile of modelled behaviour.

Second-order impacts - hollow-bearing trees 164 Dr Zylstra addressed the "risk environment" for second-order impacts by referring to previous estimates of collapse rates for hollow-bearing trees in Victorian prescribed burns. While the proposed mitigation for this impact was to rake fuels away from the base of trees, Dr Zylstra noted that such measures are "specifically focused close to control lines" and offered no protection to the main area of each burn. 165 Dr Zylstra opined that FRaME can be used "to calculate the likelihood of stem 'girdling' by fire, where heat penetrates to kill the cambium around the full stem", and that he had added a function to FRaME to model fire scarring from flame contact with the tree bole after the fire front has passed. Dr Zylstra used published data in relation to wood density for the species Mountain Gum (Eucalyptus dalrympleana), together with information about bark thickness and assumptions about stem diameter. He then used FRaME to model the capacity for fire scar formation based on the 50th percentile of modelled flame heights (that is, taking the median or 500th highest flame from the results modelled for each burn area). The results were set out in a series of graphs showing the predicted temperature over time of the bark and at different increments to the cambium of the tree, with fire scarring occurring when the cambium is heated above 60 degrees Celsius. The Zylstra report concluded that "FRaME modelling predicted the capacity for fire scar formation in each block at the 50th percentile of modelled flame heights". 166 Based on earlier research that found that hollow-bearing trees were more vulnerable to collapse if they had existing fire scars, Dr Zylstra expressed the conclusions set out above in paragraph 151 in relation to the risk of collapse of hollow-bearing trees in future planned or unplanned fires.

Zylstra reply report 167 In his reply report, Dr Zylstra addressed and responded to criticisms of his fire behaviour modelling, particularly by one of the respondent's experts, Dr Trent Penman. In summary, Dr Zylstra stated that objections to his modelling "were predominantly grounded in hypothetical conjecture and unsupported claims of authority for older models", and maintained that the FRaME predictions of canopy scorch and crown fire were consistent with mapping for previous prescribed burns. 168 Dr Zylstra considered that fire behaviour that is likely to impact Southern Greater Gliders mainly occurs away from control lines, where habitat trees do not receive protection, and that ground crews and photographers predominantly see only "the better-controlled fire close to control lines". He stated that favourable post-burn monitoring of Southern Greater Gliders had almost entirely monitored areas that were not subject to crown scorch in which gliders had sought refuge. He therefore expressed his expectation that "impacts of prescribed burns on southern greater gliders are significantly higher than they are currently perceived to be". 169 In defending the FRaME predictions as realistic, Dr Zylstra stressed that he had aggregated differing scorch categories (low, moderate and high) into the single category of "crown scorch", based on the guidance contained in McLean (2018) that the use of prescribed fire as a tool to limit the spread and intensity of unplanned fires in habitats known to contain high densities of greater gliders "should only occur under low/moderate fire weather conditions where canopy scorch does not occur". Dr Zylstra regarded this recommendation as referring only to a single aggregated category of "canopy scorch", and he therefore adopted that approach (while keeping crown fire or "canopy burnt" separate). Accordingly, the FRaME predictions of crown scorch in 32% to 77% of the planned burn areas included "low canopy scorch". Dr Zylstra noted that the category of low canopy scorch was not the lowest category of fire severity in burnt areas, as it was possible for fire to burn only leaf litter and low plants without scorching the tree canopy at all (which would be mapped from satellite photography as an unburnt area). I note here that the respondent's witness Mr Lawlor maintained in his evidence that such areas would usually be classified as low canopy scorch, which included burnt areas in which there was 0% scorch, rather than as "unburnt". 170 Dr Zylstra concurred with an observation made by Mr Lawlor that the maximum predicted flame heights using FRaME were extreme, but queried whether such possibilities were unlikely, referring to the Annual Review of the Hume Region Fuel Management Program 2022-2023 (2023 Hume Region Annual Review) in which 0.9% of planned burns areas in the Hume region were categorised as crown fire, aligning with the FRaME predictions. Dr Zylstra explained that his predictions of crown fires were "when a sufficient 'ladder' of understorey and midstorey plants was present to convey fire into the tree canopy", and that this "occurred at low rates of spread in what is frequently referred to as 'torching', or 'passive crown fire' events" which "do not precipitate major runs of fire, because they involve the ignition of a single tree that then extinguishes" (in contrast to major fire runs resulting from active crown fires which "typically involve strong winds or steep terrain"). 171 The Zylstra reply report dealt with the range of options that are available to fire crews to control fire behaviour, and responded to Dr Penman's claim that such techniques are sufficient to mitigate fire severity across each of the planned burn areas. Dr Zylstra queried the practicalities involved in many of those techniques, such as the manipulation of weather conditions, lighting patterns and topography. He provided a detailed discussion of such techniques in order to illustrate his general claim that the theoretical control of a prescribed burn diminishes significantly as fire spreads beyond ignition lines. He stated that "[t]he notion that light-up patterns and other skills of burn practitioners can be used to ensure low severity across burn blocks is not borne out by mapping". 172 Dr Zylstra accepted in his reply report that it was "difficult to predict the fire behaviour of the proposed burns with accuracy". However, he reiterated that his "purpose in providing predictions was not to state what the fire behaviour would definitely be, but to demonstrate the range of possibilities that could occur within the prescriptions for each burn", in a context where "predictions made using the industry standard approach predict a very limited range of results that do not reflect the occurrence of canopy scorch and crown burn mapped for prescribed burns in the area". Accordingly, he stressed that the purpose of his predictions "was therefore to determine whether first-order impacts on gliders are possible within the prescription envelope" (emphasis in original). 173 In relation to the inputs used for the FRaME modelling, Dr Zylstra notes that his approach provides a "significantly improved representation of each site" than the single value for fuel load or Forest Fire Danger Index (FFDI) on which the prescriptions for the planned burns are based. It is useful to interpose here a brief explanation of FFDI and Fire Danger Indexes more generally. The FFDI is a type of Fire Danger Index (FDI). The Australian Bushfire Glossary defines the term "Fire Danger Index" as "a relative number denoting the potential rates of spread, or suppression difficulty for specific combinations of temperature, relative humidity, drought effects and wind speed". The FFDI is a summary statistic adopted by McArthur (1967) which forms part of the McArthur meter. In his oral evidence, Dr Zylstra described the FFDI as "a way of combining all the parameters together" (e.g. air temperature, wind speed, humidity and a drought factor) so as "to give some measure of how much fire risk there is in a certain day so that the hotter, drier, windier days come up as having a higher risk". 174 In response to the criticism that FRaME is highly sensitive to small changes in the input variables, Dr Zylstra accepted that input errors could be made, the significance of which was not always apparent to users, but claimed that "these errors become less likely as the experience of the user increases". In particular, Dr Zylstra claimed that his experience in developing and using such inputs over the last 20 years meant that he had "become adept at finding inputs that may be highly sensitive under some circumstances (e.g., preventing or facilitating crown fire)", whereas "until FRaME is developed as a more user-friendly product, others do not have this option". As will become apparent below, this self-confidence was perhaps belied by the discovery in the course of Dr Zylstra's oral evidence of a significant error in the input of one of the variables (in relation to the range limits for dead fuel moisture content) that had been used to model the fire behaviour in the planned burn areas for the purposes of his expert report. 175 Dr Zylstra stated that "the validation of FRaME demonstrated its accuracy in predicting broad variation in fire behaviour from a low severity surface fire on one extreme, through to an extreme severity crown fire on the other extreme", which had value for the purpose for which FRaME was used in his expert report, namely "to detect whether large flames that were damaging to the greater gliders were possible". While he accepted that FRaME did not always provide "precise predictions for minor changes in [fire] behaviour" and that "important questions remain around the correct prediction of small flames", Dr Zylstra considered that this was a distraction from the purpose for which FraME had been used in his expert report. 176 More generally, the Zylstra reply report addressed other issues that had been raised in relation to the FRaME model, including the status of critical comments made by other scientists following Dr Zylstra's initial journal publication in relation to FRaME and his response to that critique, and the low rate of adoption of the FRaME model by others.

Oral evidence 177 Dr Zylstra was cross-examined on the development and design of the FRaME model in relation to the parameters used for different "stands" of vegetation. He indicated that a number of input values in relation to different classes of vegetation were based on estimates or approximations, which introduced some "noise" in the data (that is, "error in either direction", whether exaggeration or underestimate) that could render the modelling "slightly less precise". The purpose of the model was to test the relevance of different leaf traits and other vegetation characteristics on flammability and fire severity, using the physics of convective heat transfer. 178 Dr Zylstra said that he had proceeded on the basis that the predominant class of vegetation in the planned burn areas was herb-rich foothill forest. In constructing a forest stand for the purposes of the FRaME modelling, Dr Zystra chose Mountain Gum (Eucalyptus dalrympleana) as the representative species for canopy trees, notwithstanding that it was not on the list of species contained in the Ecological Vegetation Class benchmark issued by the Department of Sustainability and Environment (a predecessor of DEECA) in 2009 for the Highlands-Northern Falls Bioregion in respect of Herb-rich Foothill Forest (EVC 23) (EVC Benchmark). Dr Zylstra said that the EVC Benchmark does not contain an exhaustive list of representative species, but rather only gives "benchmark" species. Dr Zylstra had instead relied on a different source (Nelson (2018)) in making his selection of Mountain Gum, on the basis that it is a species favoured by the Southern Greater Glider and he was "particularly interested in looking at those parts of the forest where the gliders are most likely to be". In responding to a suggestion that Nelson (2018) had identified Narrow-leaf Peppermint (Eucalyptus radiata) as a dominant species which was considered to be preferred by the Southern Greater Glider, Dr Zylstra said that Nelson (2018) had not found evidence to confirm that belief and had noted a strong positive relationship between the abundance of Southern Greater Gliders and the basal area of both Mountain Gum (Eucalyptus dalrympleana) and Blue Gum (Eucalyptus globulus). Ultimately, his choice was influenced by the fact that he already had data on the Mountain Gum: thus, he said that "it's a matter of which species do I have the best information on hand for myself to put that in", and that he "chose a species that the paper said has a strong relationship with gliders and for which I have good inputs for without driving down to Strathbogie and measuring them myself". 179 In this context, Dr Zylstra explained: I'm not trying to create an authoritative model on that forest because I don't have that data and I've made that quite clear in the report. All I'm trying to do is seeing if we can improve on the modelling that guides the prescription and that modelling is based on the FFDI and the fuel load. … So I suppose that's the premise we're starting from that the reason these burns have been designed in this way is because there is already a simplistic form of modelling that has said, "These conditions are safe. We know that it's safe to burn under this wind, this temperature range, etcetera, because we've measured this fuel load, we've put it into this model and we've now got an FFDI that tells us it's safe within that range." And my question was: can I improve on that? 180 Dr Zylstra was further interrogated in some detail on the composition of the forest "stand" that he used in his modelling, and the data that was used for each species that was selected. The tenor of Dr Zylstra's evidence was that, in populating his "stand", he was "trying to approximate something that I can't see … and trying to improve on a single number of fuel load", and that he had generally selected common species on which he already had some data from his previous work. Dr Zylstra acknowledged that he had not visited the Strathbogie State Forest. He did not accept that the forest stand that he had constructed for modelling purposes was "hypothetical", because he regarded it as being underpinned by evidence rather than pure hypotheses. Nevertheless, he described his forest stand as "theoretical", in that it was "an approximation ... based on raw data". 181 Dr Zylstra explained that he had used the FRaME model to test what would occur if his theoretical forest stand was ignited, by running random variations within defined parameters for different vegetation structures and plant traits under varying weather conditions. The code for each of those variables generally contained a specified value together with a given range and standard deviation. The datasets in respect of vegetation in the planned burn areas were chosen by Dr Zylstra based on available data and his own experience, and involved some degree of subjectivity. He derived the variables for conditions such as temperature, wind and fuel moisture content from the prescribed ranges contained in the Delivery Plans for the planned burns. Dr Zylstra did not use actual data in relation to the topography of the planned burn areas, because he considered that the prescriptions for the planned burns were designed to limit the influence of slopes - for example, "your intention is … to try to not have fire governed by the terrain of the site but that you take some degree of control of that with your lighting pattern". Accordingly, his model excluded steep slopes and instead used a narrow range of slope in order to "keep things close to level ground". 182 Dr Zylstra confirmed that, when running the random variations to simulate fire behaviour, the FRaME model did not correlate or link any of the different variables, such as temperature and fuel moisture content. Dr Zylstra considered that there was insufficient information to support such an approach - "for example, you can have a hot day with still a higher dead fuel moisture content because it rained the day before" - and that he was "trying to use the raw numbers that are given in the prescription" without introducing too many additional assumptions. He agreed that the prescription set the range or outer limits, rather than stating what the conditions were likely to be on the day that the burns were conducted. 183 It is convenient here to set out an extract from the code that was used by Dr Zylstra in FRaME to model fire behaviour in each of the planned burn areas: #BUILD PARAMETER FILES if (a == 1) { temp <- 21.5 tempRange <- 7 } else { temp <- 22.5 tempRange <- 9 } base.params <- buildParams(Structure = ST, Flora = FL, default.species.params = TR, a = a) #MODEL PROBABILISTIC FIRE BEHAVIOUR probFire_Frame(base.params, Structure = ST, Flora = FL, a = a, db.p"th = "out"mc.db", slope = 0, slopeSD = 5, slopeRange = 10, temp = temp, tempSD = 5, tempRange = tempRange, DFMC = 0.125, DFMCSD = 0.05, DFMCRange = 7, wind = 10, windSD = 10, windRange = 20, jitters = 1000, l = 0.1, Ms = 0.01, Pm = 1, Mr = 1.001, updateProgress = NULL, testN = 10, threshold = 1) 184 While this is only a small extract from a lengthy and complicated computer script, it was addressed in oral evidence as the part of the code that primarily deals with the variables that were derived from the Delivery Plans for the planned burns. Thus, if the Delivery Plan prescribes a temperature range between 18 to 27 degrees Celsius, this indicates a range of 9 degrees Celsius around a mid-point of 22.5 degrees Celsius. The standard deviation was chosen by Dr Zylstra, and could potentially be greater than the range parameters (which would have the effect of "flattening" the bell curve of the results). 185 The number of "jitters" indicates the number of times the simulation was run, namely 1,000. Although it was not entirely clear from Dr Zylstra's oral evidence, this seems to have been treated as representative of the possible fire behaviour at 1,000 possible points or locations within each of the planned burn areas, each with different variations of weather conditions and plant conditions, rather than the possible fire behaviour throughout the relevant burn area under different conditions on 1,000 possible occasions. Thus, the percentages for the area in which there was canopy scorch set out in Table 6 represented the percentage of randomly generated runs of the model that resulted in canopy scorch in the theoretical constructed stand of forest vegetation. On the other hand, Dr Zylstra accepted that it was difficult to express the scenarios in terms of a percentage of the area, as opposed to a percentage of modelled cases. 186 There might be no material difference between these two approaches for the purposes of the conclusions sought to be drawn by Dr Zylstra. However, it seems to indicate some potential limitations on the practical use of the results of such modelling. For example, while there might be some variation in the conditions present in different parts of each burn area on any particular day, those conditions are unlikely to be entirely unconnected or random. Similarly, the ignition of a single theoretical forest stand on 1,000 different occasions is not necessarily indicative of the way in which fire is likely to behave across each entire planned burn area on any given occasion. 187 Another issue affecting Dr Zylstra's modelling arose in the course of his cross-examination, when it became apparent that he had made an input error in the line of code relating to the parameters for dead fuel moisture content or "DFMC". The relevant Delivery Plans prescribed a range for DFMC between 9% and 16%. As set out above, this was entered by Dr Zylstra into the code as "DFMC = 0.125, DFMCSD = 0.05, DFMCRange = 7". Converting decimals into percentages, this represented a value for DFMC of 12.5% with a standard deviation of 5%. However, instead of entering a value of 0.07 for the DFMCRange (which would translate to a range of 7%, that is, between 9% and 16% in accordance with the applicable prescription), Dr Zylstra inadvertently entered a value of 7 (which would translate to a percentage of 700%). The effect of this error was to remove any range limits in the variations for DFMC. As a result, while there was still a standard deviation of 5%, approximately one-third of the 1,000 variations run by Dr Zylstra using FRaME would have been outside that standard deviation and would have used a value for DFMC that was outside the prescription in the Delivery Plans. Further, because the standard deviation for DFMC was greater than the prescribed range, some of the DFMC values within the standard deviation would still have been outside the range for the planned burns. 188 Dr Zylstra clarified that, on an examination of his data, he estimated that approximately 26% of the scenarios modelled by FRaME for the purposes of his report had used a DFMC below the prescribed minimum of 9%. While there were also some modelled scenarios that used a DFMC above 16%, Dr Zylstra assumed that this would have resulted in lower flammability (and therefore less severe fire). Dr Zylstra maintained that an underestimate in the DFMC would not have significantly affected the results or his conclusions and "was inconsequential", on the basis that he considered that the overall results demonstrated that DFMC was not a significant driver of flame heights. 189 The error in the DFMC range came to light in relation to a "case study" that was included in the Zylstra report to illustrate a scenario of possible crown fire in the Lima East planned burn area. This case study was identified by Dr Zylstra from the 1,000 variations that were modelled by FRaME for that area. Dr Zylstra acknowledged that this particular scenario was at the more extreme end, representing the 1% of modelled variations that involved crown fire (that is, where flames ignite the canopy). The conditions applicable to the selected case study included a DFMC of 8% (that is, below the prescribed range of 9-16%), and a temperature of 26 degrees Celsius (that is, towards the upper end of the prescribed range of 18-27 degrees Celsius). Dr Zylstra said that, while an unrealistically low DFMC could produce a result with "too big a surface flame", the FRaME model included "hard" limits on the length of surface flames based on what experiments had shown was possible. The predicted surface flame length in the case study was 0.7 meters, which he regarded as "quite a modest surface flame", indicating that the low value for DFMC did not have a significant impact on the fire behaviour prediction. The total height that was reached by flames in this case study was 30.1 meters. Dr Zylstra explained that this was not referring to the length of a continuous flame from the ground, but rather that the flame climbed up the vegetation to that height so as to produce fire burning in the top of the tree. When asked why he had included this particular case study in his report, Dr Zylstra said that it was to show that it was possible that a large flame could occur in 1% of cases, albeit that this was "not typical of the fire behaviour through the block". 190 Dr Zylstra was taken in cross-examination to some of his correspondence with the applicant's solicitors in connection with his instructions to prepare an expert report. In an email dated 25 October 2023, Dr Zylstra referred to the "limitations" that were "going to be an issue", in that "[t]he letter of instruction is asking for specifics of fire behaviour and its effects on gliders … and these are the things I said that I wouldn't be able to provide without a detailed survey". He advised that in order to provide answers "to a level of accuracy that is better than [FFMVic] already have", he would "need to conduct surveys across diverse terrain and forests, then process and model them". Dr Zylstra said that, if he had information on the forest structure, he could "use FRaME to model hypothetical scenarios that show fire behaviour and damage that their approach will miss" (emphasis in original), which "won't give probabilities that they will kill gliders, but it will show that they can't claim they won't [kill gliders]". In cross-examination, Dr Zylstra said that he had subsequently formed the view that he was "copping out a bit too easily" in the position taken in his email. While he had originally been "hesitant to make predictions", he ultimately decided that a detailed survey was not necessary in order for him to improve on FFMVic's predictions which were based entirely on fuel load. This was primarily because he became aware that he could use information on the fuel hazard scores in the planned burn areas, together with the general descriptions of the forest structure taken from available publications such as the EVC Benchmark. 191 In relation to his assessment of the impacts of the predicted fire on the Southern Greater Glider, Dr Zylstra accepted that his training and expertise was not "glider-focused" and that he had sourced relevant facts about Southern Greater Gliders from elsewhere. He had modelled the likelihood of mortality by reference to the 90th percentile of flame height in order to represent a scenario at the "worse end" in which there was a "genuine possibility of negative outcomes for the gliders". Dr Zylstra said: I could have taken the - the median possibility, but the question was not, are gliders likely to suffer damage, you know, over half the block. The question was, is there a real genuine risk to the gliders? And the genuine risk … is likely to happen in those worse ends of fire behaviour. So I didn't want to take the most extreme example, but I went … back to the 90th percentile. So you've got about - roughly, you can estimate a one in 10 chance of … this occurring. So it's not an insignificant chance, but it's a real chance that gliders in these situations may suffer these outcomes. 192 The flame heights at the 90th percentile in each planned burn area would be below crown height, because there would not be fire in the canopy. However, the Zylstra report did not set out the data in relation to the precise flame height at the 90th percentile, nor the input variables or detailed predictions produced by FRaME for that particular scenario. Dr Zylstra considered that the most important "drivers" of flame height were wind speed and vegetation structure, and that temperature and DFMC had much smaller effects. In modelling effects on Southern Greater Gliders from the effects of heat, Dr Zylstra used the single scenario at the 90th percentile of flame height as "a point that is towards the bad end but not completely unlikely". Dr Zylstra accepted that it might be better to have been able to model the effect on Southern Greater Gliders for a wide range of fire scenarios and then take a percentile of effects on the Southern Greater Gliders, but that this would not be logistically feasible because it took a long time to run each of the models. 193 Dr Zylstra's conclusions in relation to the effects of fire on Southern Greater Gliders assumed that a glider was in a tree or a hollow that was reached by fire. His opinion that a "small to medium proportion" of gliders would be killed by fire appears to have been based on his selection of the 90th percentile (at which Dr Zylstra's modelling indicated that gliders would be killed), in that "10 per cent is a small proportion" and he couldn't rule out that Southern Greater Gliders would also be killed at slightly lower percentiles with less severe fire behaviour. In re-examination, Dr Zylstra said that the level of heat at the 90th percentile was well above the threshold that would cause mortality to gliders, and that it would need a significant reduction in flame height not to reach that threshold. Accordingly, although he did not quantify the number of gliders that would be killed by fire, he gave an estimate of a "small to medium" proportion. This seems to proceed on an implicit assumption that the various scenarios modelled by FRaME can be spread across the burn area so that, for example, 10% of the area would have flame heights at or above the 90th percentile with corresponding effects on the gliders that happen to be in those locations. It also implicitly assumes an even distribution of gliders across the planned burn areas. There did not appear to be any direct evidence to support either of those assumptions. 194 Dr Zylstra did not specifically perform any modelling in relation to the collapse rates of hollow-bearing trees, but relied on estimates derived from other sources. In modelling the risk of scarring to Mountain Gums, he had selected the 50th percentile or median flame height on the basis that the height of flames was less important when looking at scarring to the base of hollow-bearing trees. 195 Dr Zylstra was also cross-examined at some length on his experience and qualifications, and some challenges were made to his independence from the applicant. Those matters were not ultimately relied upon as going to the admissibility of Dr Zylstra's evidence. In so far as they have a potential bearing on the weight to be given to Dr Zylstra's opinion, I will return to these matters below.

Adjunct Associate Professor Grant Wardell-Johnson 196 Dr Wardell-Johnson is an Adjunct Associate Professor in the School of Molecular and Life Sciences in the Faculty of Science and Engineering at Curtin University. He has qualifications in the fields of forest ecology and botany, including specialised knowledge in relation to fire in native forests. His previous experience includes providing expert opinion evidence in relation to the impact of timber harvesting operations in East Gippsland on the Southern Greater Glider and the Yellow-bellied Glider. 197 Dr Wardell-Johnson was asked to provide an opinion on the characteristics and distribution of the Southern Greater Glider, and the likely impact of planned burning on individual gliders, the population of Southern Greater Glider in the Strathbogie State Forest and the Southern Greater Glider as a species. 198 Dr Wardell-Johnson had not previously prepared any reports on the Southern Greater Glider in the Strathbogie State Forest, but for the purposes of his report he visited the Forest including the proposed burn areas in order to conduct "field reconnaissance". Among the points which are said by Dr Wardell-Johnson to have emerged from this field visit are: (a) "the vegetation is (in general) in very good condition, with many old-growth characteristics", and "[i]t is therefore unsurprising that there is a healthy population of [Southern Greater Gliders] (as found by Nelson et al 2018) in Strathbogie Forest"; (b) "Strathbogie Forest includes an array of vegetation types (including Damp Forest and Herb-rich Foothill Forest) with abundant mature trees and old-growth characteristics that provide excellent habitat for [Southern Greater Gliders]"; and (c) "[t]he initial prescribed burns would certainly kill some [Southern Greater Gliders] (though the numbers would be difficult to predict without detailed knowledge of their whereabouts or prior knowledge of the outcomes of the fires)". 199 After describing the species of Southern Greater Glider and its distribution, Dr Wardell-Johnson notes in his report that "[c]learing, fire, logging and fragmentation have long been recognised as the major threats to the [Southern Greater Glider]". Dr Wardell-Johnson describes the Southern Greater Glider's habitat and reproductive cycles, as well as where in Victoria the Southern Greater Glider is found. Dr Wardell-Johnson states: Within Victoria, the [Southern Greater Glider] is distributed throughout the forested parts of the east, including inland and southern falls of the Great Dividing Range, as well as the Strzelecki and Strathbogie Ranges. In eastern Victoria, the [Southern Greater Glider] is absent from high altitude alpine and sub-alpine habitats, Wilson's Promontory and cleared areas. In western Victoria, [Southern Greater Gliders] are found in forested areas, west to Daylesford, but are absent elsewhere in western Victoria, including large areas of potentially suitable habitat such as the Otway Ranges and Grampians. 200 Dr Wardell-Johnson states in his report that "[t]he forests and woodlands of the Strathbogie Ranges have been subject to a long history of disturbance and modification", and that "[f]ire has also influenced the Strathbogie landscape, predominantly through fuel reduction burning but also with some smaller scale bushfire events". However, a large proportion of the Strathbogie State Forest has not been impacted by a large-scale bushfire for a significant time period, so that "it is likely that there are large proportions of older growth state vegetation which have not been fire affected since the 19th century, with some areas exhibiting centuries-old trees". 201 Dr Wardell-Johnson states that the Southern Greater Glider "is found on a variety of forested areas of the Strathbogie Ranges on highly fertile soils such as areas of Damp Forest (usually south-facing slopes at higher elevations) and Herb-rich Foothill Forest (approximately 60% of the public land estate of Strathbogie forest - easterly and southerly aspects of moderate to high rainfall and well-drained soils - often on the lower slopes or gullies)". He refers to Nelson (2018), which estimated the population of gliders in the Strathbogie Ranges to be about 69,000, with mean densities of 2 to 4 individuals per hectare across the study area. Dr Wardell-Johnson considers that the Nelson (2018) study "supported the contention that a large and regionally important population of the Greater Glider occurs in the Strathbogie Ranges", and "suggested that the Strathbogie Ranges population has not declined to the extent that has been observed elsewhere in Victoria". Dr Wardell-Johnson described the Strathbogie State Forest as "an extremely important conservation area for [Southern Greater Gliders]", and "effectively an island of high-quality habitat (for Southern Greater Gliders) on the western margins of the distribution of this species". 202 While Dr Wardell-Johnson was not able to provide a map showing the locations of individual Southern Greater Gliders within the Strathbogie State Forest, which would require a targeted survey, he stated that it is known that there are Southern Greater Gliders within each of the planned burn areas. According to Dr Wardell-Johnson, each of the planned burn areas have substantial proportions of habitat suitable for Southern Greater Gliders. Dr Wardell-Johnson considered that the mitigation measures contained in the Delivery Plans to reduce the impact on gliders, at least in their application to protected areas along boundary tracks, "would be inconsequential in terms of safeguarding habitat trees or of individuals, populations, or the species from the planned prescribed burn operations". Rather, he described these as "basic operational fire control measures that are usually implemented to prevent escape of prescribed burning operations and to ensure they are implemented as scheduled", which "would have negligible bearing on the safety of [Southern Greater Gliders] in relation to these proposed operations". 203 In response to questions about the likely impact of the planned burns on the Southern Greater Glider, Dr Wardell-Johnson referred in his report to a risk assessment that had been carried out by Dr Jenny Nelson in 2022 for Victoria's Regional Forest Agreement areas, which had nominated three risks to the Southern Greater Glider associated with fire, namely: bushfire, increased fire frequency/intensity; and inappropriate fire regimes - prescribed burning (J Nelson, Victoria's Regional Forest Agreements: Risk Assessment for the Southern Greater Glider (2022). Dr Wardell-Johnson largely summarised aspects of Dr Nelson's assessment, before concluding: Some [Southern Greater Gliders] will die as a direct result of the proposed prescribed burns (i.e., burnt, injured, or suffocated) though it remains uncertain how many. This will only be known by having an accurate census prior to the fires and at various times after the fires. Further, some [Southern Greater Gliders] will die soon after the fire from predation, starvation, or exposure (see Wardell-Johnson and Robinson 2022, Tyndale-Briscoe and Smith 1969). Again, it would be uncertain as to how many, and actual number would again rely on an accurate census having been taken prior to and at various times after the fire. … The processes associated with the deaths of [Southern Greater Gliders] following the proposed burns would only be known by conducting detailed habitat measures prior to and following the fires (with appropriate controls and replication to ensure validity and reliability of the findings - see earlier background information, Green 1979). Considerable focus is directed by land management agencies towards examining the impacts of prescribed burning on [Southern Greater Gliders] and their habitat (see Macak et al. 2021). However, the reliability and validity of research to inform understanding of the effects of fuel management on threatened species can be fraught (see Wardell-Johnson et al. 2004). Research design requires considerable thought if the results of research endeavour are to be both valid and reliable. 204 In his reply report, Dr Wardell-Johnson stated that, although many precautions are taken to implement planned burns according to their prescriptions and safeguards, the natural world is changeable. Thus, weather and other conditions can change during the implementation of the fire, and "despite the best intentions, much can go wrong after the fire (e.g., if not fully blacked out along edges, or if very strong winds carry sparks beyond boundaries following implementation of the burn etc)", adding to uncertainty and the risk of impact on Southern Greater Gliders.

Oral evidence 205 Dr Wardell-Johnson confirmed that his expertise in forestry management and disturbance ecology included publications on fire as a disturbing agent. He has been involved in providing expert evidence in previous court proceedings in relation to the impacts of timber harvesting on the Southern Greater Gilder. He did not accept that his previous work and experience in relation to the impact of fires was confined to wildfires or intense fire, as opposed to low intensity planned burns. 206 Dr Wardell-Johnson described that the purpose of the field visit he undertook in the Strathbogie State Forest was to familiarize himself with the ecology and vegetation of the area, as he had not previously visited the Forest. 207 Dr Wardell-Johnson accepted that the primary causes of the decline in Southern Greater Gliders in New South Wales and Victoria had been significant logging of areas of habitat containing hollow-bearing trees and the effects of the "Black Summer" bushfires in 2019-2020. He did not suggest that this decline was caused by planned burning. Nevertheless, he considered that the planned burns would be a form of disturbance that will be detrimental to Southern Greater Gliders. He considered that it was important to ensure that areas of suitable habitat were protected from "any management activity … that might tip the balance or not make the environment as suitable for the species". 208 In relation to the risk or threat to the Southern Greater Glider from inappropriate fire regimes, Dr Wardell-Johnson accepted that there were a range of fire intensities or severities. His opinion that some gliders would die as a result of the planned burns was based on an assumption that the fire is "on the higher level of severity" or "on the higher end of the spectrum", which "would probably be because of flames going up the trunks of trees or … being carried through the vegetation". Nevertheless, he considered that this would "undoubtedly" happen because planned burns vary in their intensity and severity, so that there would be some patches or "intense pockets" that burn with higher levels of severity. While Dr Wardell-Johnson had some experience with prescribed burns in Western Australia, he had no operational experience of conducting planned burns in Victoria in autumn. 209 Dr Wardell-Johnson considered that most of the gliders that he predicts might die "won't be from the immediate effects of the flames", but rather as a result of "microclimate changes" and an increased risk of predation in the months following the fire which might put the gliders "on a downward spiral". Dr Wardell-Johnson accepted that there was considerable uncertainty as to the number of Southern Greater Gliders likely to be affected by the planned burns, and he considered that surveys should be conducted involving the tagging of individual gliders to determine the extent and causes of mortality. He maintained that there would be an impact on Southern Greater Gliders, but it was difficult to quantify that impact without further surveys.

Dr Charles Meredith 210 Dr Meredith is a scientist who specialises in forest and fire ecology, with particular experience in the management of endangered species. He has been involved as a consultant in multiple ecological and impact assessments of forest sites in Victoria, New South Wales and Tasmania, including many within the range of the Southern Greater Glider. Dr Meredith was asked to provide his expert opinion on questions relating to the characteristics and distribution of the Southern Greater Glider, including its presence in the Strathbogie State Forest, and the likely impact of planned burning on the Southern Greater Glider. 211 Dr Meredith referred to the Action Statement for the Greater Glider as providing "an excellent summary of the species' ecology". Among other things, he stated that the Southern Greater Glider "shelters and breeds in tree hollows, generally in tall older or dead eucalypt trees", showing "a preference for larger tree hollows and for living trees with large hollows", and that they "will have more than one den tree within their home range, typically five to six", which provide both shelter from predators and a thermally stable environment on hot summer days. Dr Meredith noted that the Southern Greater Glider is "very sensitive to overheating", and that it has a low reproductive rate. 212 Dr Meredith stated in his report that the Southern Greater Glider occurs in suitable habitat throughout the Strathbogie State Forest, which supports some of the highest recorded densities of the Southern Greater Glider in Victoria, and where the population appears not to have declined significantly in the last 20 years (in contrast to other parts of Victoria). Again, this appears to be consistent with, if not drawn from, sources such as the Conservation Advice and the Action Statement. 213 Dr Meredith observed that the Southern Greater Glider is highly sensitive to high intensity fire and that, while the planned burns are not intended to be of high or even moderate intensity, "the reality on the ground is that fire intensity within a planned burn can be highly variable and will often include localised (and sometimes quite large) areas that burn at higher intensities". In support of that statement, Dr Meredith cited the Zylstra report, as well as his own personal observations. Although Dr Meredith accepts that he is not an expert in modelling fire behaviour, he relied on his own observations of the outcomes of planned burns "over nearly 50 years" to state that "[w]hile some planned burns do go largely to plan, many don't". In particular, a burn may be more intense than planned - "[m]ost frequently, these higher intensities are localised at sites where the vegetation is more flammable than average, conditions were not as predicted or where dead timber or tree bases have ignited and burnt at high temperatures for a considerable period". 214 In his report, Dr Meredith opined that "[f]ire intensities that are too high can directly kill [Southern Greater Gliders] through burning them, fatally damaging their respiratory tracts through heat or smoke inhalation, or through physical injury caused when they are in a falling tree that has collapsed after being weakened by the burning through of its trunk". In his oral evidence, however, Dr Meredith accepted that the number of gliders that would be directly killed as a result of a planned burn is likely to be low. 215 Dr Meredith continued: Fire can kill [Southern Greater Gliders] indirectly through the enhanced rates of loss of habitat trees caused by trees collapsing after being damaged by fire. Even quite mild fires can lead to tree loss if they ignite the base of a tree which then slowly burns until the tree is significantly weakened. Denning trees for the [Southern Greater Glider] are critical components of their habitat. Den trees must have suitable hollows and, while some may be dead stag trees, the best den trees are thought to be tall, old trees in good condition that would normally be expected to stand for many decades. Such trees are a scarce resource (much depleted in Victoria through timber harvesting, land clearance and extreme fires) and cannot be replaced in the short to medium term as young regrowth trees do not have large hollows. 216 Accordingly, Dr Meredith considered that, if the planned burns proceed, "there is an appreciable risk of a highly significant impact on the [Southern Greater Glider] population within the Strathbogie State [F]orest". In his oral evidence, Dr Meredith qualified this by removing the word "highly". Dr Meredith concluded that "[g]iven the apparent importance of this population (high density, stable), this would constitute a significant risk of impact at the State level and potentially at the national level".

Oral evidence 217 During his cross-examination, Dr Meredith addressed the significance of the population of Southern Greater Gliders in the Strathbogie State Forest and its importance to the species: What was in my mind is very much that this [the Strathbogie population] is a particularly important population. We know that it has been at a higher density than other areas for decades, and we know that it still is a higher density than other areas when other areas are largely declining. So that makes this a particularly important sub-population. We don't know why any of those factors are occurring or what factors lie behind it, which increases the risk, if you like, of doing the wrong things. We don't know what's going on. But that's what was in my mind about it being a significant - potentially significant impact at the state and possibly national level. So it's the basis that the Strathbogie population seems to have some special characteristics that will make it long-term very important for the conservation of the species in Victoria. 218 Dr Meredith accepted that there were significant differences between planned fuel reduction burns and large, severe wildfires, particularly in relation to intensity. He agreed with the view expressed by the respondent's expert Dr Swan that a low-intensity fire that mostly affects understorey vegetation will have little direct impact on Southern Greater Gliders through exposure to heat. This was consistent with Dr Meredith's opinion in an earlier discussion paper that, while there was limited available data, arboreal mammals "are probably little affected by low-intensity fires if the trees are not burnt". Dr Meredith also agreed with Dr Swan's opinion that individual gliders in areas affected by low severity fire generally survive the initial fire event, although he considered that there may be subsequent impacts from changes to vegetation. He agreed that the food resources of the Southern Greater Glider were unlikely to be affected by planned burns that do not significantly affect the tree canopy, and that any reduction in foraging resources in areas of localised canopy scorch is likely to be transient, in terms of weeks or months. 219 Dr Meredith clarified that, in giving his opinion as to the impact on the Southern Greater Glider population in the Strathbogie State Forest, he had assumed the consequences set out in the Zylstra report, including that a significant proportion of each planned burn area would likely burn with high severity resulting in significant areas of crown scorch. Dr Meredith interpreted "significant" as meaning "more than minor", and considered that "anything more than 20 per cent is significant" and "roughly greater than 50 per cent is severe" (in each case looking down at the crown using aerial photography or remote sensing). He emphasised that "the high severity factors are very much in terms of the impact on killing individuals, which I think is the much lesser of the potential impacts compared to long-term habitat change from loss of hollow-bearing trees". Nevertheless, Dr Meredith considered that "any degree of crown scorch will have some risk of killing - or impacting directly on individual Southern Greater Gliders", and that the risk would be higher as one moves from mild to severe crown scorch. 220 Dr Meredith accepted that his view that Southern Greater Gliders could be directly killed by fire intensities that are too high was directed to localised areas where there was fire at a higher intensity than planned and a glider in close proximity. He considered that it was relatively unlikely that a glider would glide out of a tree to escape a fire, particularly taking into account the limited distance over which they were able to glide. Nevertheless, Dr Meredith ultimately did not suggest that a significant number of gliders would be killed directly by fire if the planned burns were carried out. In this regard, when he was asked whether his conclusion about the appreciable risk of a significant impact on the Southern Greater Glider population was directed to direct mortality or the loss of habitat trees or both, Dr Meredith said: I believe the direct mortality is a relatively minor impact and would be hard to - even if it occurred, it would be hard to distinguish from background, unless there were extreme failure in fire control, which is unlikely. So my concern is very much based around the loss of hollow-bearing habitat trees. 221 Dr Meredith accepted that the history of planned burns was relevant to an understanding of the impact on Southern Greater Gliders. However, he noted that it would be necessary to take into account the timing, extent and frequency of any past burning, and whether there were any surveys conducted in relation to the abundance of gliders after the burns were carried out. Without doing more detailed surveys, Dr Meredith stated that it was possible that there may have been an impact on local abundance, but that it was "very difficult to say anything" based on the available information. 222 In relation to hollow-bearing trees, Dr Meredith did not agree that it was difficult to predict the rate of collapse as a result of fire, noting that it was clear from existing research that there will be an increase in the rate of collapse of both dead and live trees, but probably more in relation to dead trees. Dr Meredith expressed the view that a collapse rate of 25% was "probably unusually high", but surmised that there would be a collapse rate of between 15% and 20% from a particular planned burn. Dr Meredith accepted that he was not in a position to make a quantitative assessment of the impact on the Southern Greater Glider, in circumstances where he did not have information about the amount of suitable habitat (including the abundance of hollow-bearing trees) or the effects of past planned burning in the Strathbogie State Forest. Although hollow-bearing trees are a scarce resource that cannot be quickly replaced, Dr Meredith agreed that a single fire would not on its own have a significant impact if there were a surplus of habitat trees relative to need. However, multiple fires including planned burns could give rise to cumulative losses that would become important. The rate of loss of hollows would be far higher than the creation of new hollows that are habitable for Southern Greater Gliders. 223 Dr Meredith considered that a "conservative approach" would be not to burn areas that had not been previously burned, on the basis that "[l]ong-unburned areas are now very rare in the Victorian environment". However, Dr Meredith gave evidence that most Australian forests "can cope with one fire within its normal fire regime", which in the case of the Strathbogie State Forest was in the order of 20 to 60 years on average (although Dr Meredith considered this was "overly optimistic" and should be a longer period), and the concern was with cumulative impacts from more frequent fires. 224 Dr Meredith agreed with Dr Swan's evidence that there would be no change in the abundance of hollow-bearing trees in areas that remained unburnt, where there would remain a "background" annual collapse rate of 1-4%. He accepted that, at least in a "coarse" way, the unburnt areas would include south-facing slopes and moist areas associated with drainage lines and creeks, where Southern Greater Gliders were likely to be found, but said that it was difficult to generalise in relation to the Strathbogie Ranges which was "at the dampest end of dry forest", and that Southern Greater Gliders were more widespread throughout the Strathbogie State Forest. 225 While Dr Meredith had not been directly involved in the conduct of a planned burn, he had conducted studies involving the mapping of fire histories to measure the effects of planned burns and the extent of crown scorch. He had also observed the effects of planned burns in the course of conducting field work as an ecologist. Dr Meredith considered that it was uncommon for fire to go beyond the boundaries of a planned burn, but that the intensity of the fire could vary within the planned burn area. There were past outcomes of planned fuel reduction burns in which there had been some evidence of crown scorch, notwithstanding that this was not the intention of the planned burn. Dr Meredith said: [T]here's a degree of things that can vary from the planned burn. … as I've said, they can be milder than they want and they're not very effective for fire protection. They can be just as planned, perfect, or they can be more intense. And that can be patchy, as can the mild - being more mild, it can be patchy. Typically, the variation is patchy. They're complex environments. Things such as wind, it might be a calm night but you will get a gust of wind that comes from nowhere halfway through the night and that area burns much more intensively until that wind has gone. There are all those sort of factors. And, particularly, the one that I'm very conscious of is that where you've got particularly - if you've got large old trees, they tend to have a - a high bark accumulation both around the base of the trunk and on the ground and you will get a much hotter fire. If it burns into that, then that's a much higher fuel load and you will get a much hotter fire. Now, that might only be an area of a few metres. It might be a few tens of metres. It might be half a hectare or a hectare. You know, it's very variable. But it's typically patchy. At the same time, you know, the department's own figures say that two per cent of planned burns - that's the planned burns that they do, not ones conducted by farmers on private land or whatever - turn into wildfires. So that's, you know, what, one in 50. So you can have a - you know, things can go really badly wrong. 226 Dr Meredith gave evidence that he had taken the figure of "two per cent" for planned burns resulting in bushfires from figures published by DEECA or by FFMVic, although the source of that information was unable to be located. Counsel for the applicant sought to take Dr Meredith to information published on the FFMVic website to the effect that planned burn escapes amount to about 2% of all bushfires on public land (which I note is very different to Dr Meredith's proposition that 2% of planned burns turn into wildfires). At the end of the day, the evidentiary support for such propositions remained unresolved and unidentified.

The respondent's evidence 227 The respondent relied on the following lay evidence: (a) an affidavit affirmed 19 December 2023 by Christopher Stephen Hardman, Chief Fire Officer, Forest and Fire Operations Division, Department of Energy, Environment and Climate Action (Hardman affidavit); and (b) an affidavit affirmed 19 December 2023 by Shaun Patrick Lawlor, Regional Manager, Forest and Fire Operations for the Hume Region, Forest Fire Management Victoria (Lawlor affidavit). 228 The respondent also relied on the following expert evidence (a) an expert report of Dr Matthew Swan dated 12 December 2023 (Swan report), together with a supplementary report dated 18 January 2024 (Supplementary Swan report); and (b) an expert report of Professor Trent Penman dated 18 December 2023 (Penman report). 229 Each of the respondent's witnesses gave oral evidence and was cross-examined.

Mr Chris Hardman 230 To a significant extent, Mr Hardman's affidavit addressed uncontroversial matters in relation to the context and history of bushfire risk management in Victoria, the salient features of which are set out above. Mr Hardman's evidence in relation to the history of planned burning in the Strathbogie State Forest, including the four planned burn areas, is dealt with further below in relation to the defence raised by the Secretary under s 43B of the EPBC Act. 231 In his affidavit, Mr Hardman gave evidence about the method of planned burning based on his direct experience of having attended many planned burns both as a crew member and in senior leadership roles. Mr Hardman stated that "the delivery of a planned burn has always involved applying fire to the landscape in a controlled fashion in order to achieve a certain objective". This involves first burning off the perimeter of the area by hand, in order to control the boundary of the burn, and then burning the interior of the area either by hand or by aerial incendiary devices (such as by "ping-pong balls" of potassium permanganate injected with ethyl glycol from an aircraft). 232 In response to the suggestions that the flames in the four planned burns could reach a maximum height of between 26 and 33 meters and that between 32% and 77% of the planned burn areas would experience high severity fire in the nature of crown scorch, Mr Hardman states that he has "never seen a planned burn produce flames of that height" and "[t]hat outcome is completely inconsistent with my experience attending and observing planned burns". 233 Mr Hardman's experience is that "planned burns are conducted in a way that actively mitigates against the risk of those sort of effects". He states that, as the CFO, he is "confident that the techniques and methods employed by the Department in conducting planned burns are appropriate to achieve the fuel reduction objective without causing flames or high severity fire of the kind described above". 234 Mr Hardman also gave evidence about the range of fire suppression activities carried out by the Secretary in conjunction with other State bodies or agencies in performance of the statutory obligation under s 62(2) of the Forests Act.

Oral evidence 235 In relation to immediate suppression activities, in examination-in-chief by counsel for the Attorney-General, Mr Hardman distinguished backburning from planned burning, in that the former is conducted as a suppression activity when a bushfire is in progress in order to remove surface fuel in front of the fire to slow or stop its spread. Mechanical plant such as bulldozers or tractors are also regularly used along with mowing and slashing to support suppression or prevention activities, by reducing vegetation density or creating fire control lines and strategic breaks to enable firefighters to carry out suppression activities in a safe manner. Mr Hardman confirmed that all of these activities are carried out in State forests, national parks and protected public lands. 236 In terms of s 62(2) of the Forests Act, Mr Hardman said that the Secretary distinguishes between activities "for the immediate prevention and suppression of fire" within s 62(2)(a) and activities "for the planned prevention of fire" within s 62(2)(b). The former relate to the time at which a fire is occurring, and that latter relates to work that is done before a fire in order to mitigate the risk of fire. 237 Mr Hardman explained that the technology in relation to the respondent's fire history mapping of has progressively developed and improved, so that the maps in relation to burns conducted in more recent decades (i.e. 2000-2009, 2010-2019 and beyond) are more likely to reflect the area within a planned burn that is actually burnt. This improvement was not completely linear, so that any particular planned burn carried out in that period may or may not have been mapped using the newer technology. Such mapping is carried out following a planned burn to ascertain the impact on vegetation in terms of fire severity and to evaluate whether the burn had gone to plan and met its objectives. Mr Hardman said that avoiding or reducing crown scorch was usually part of the objectives of a planned burn, and that "the burn officer in charge and the lighting teams would be burning in a way to reduce the likelihood of crown scorching". Mr Hardman believed that the post-burn assessment would include an evaluation of crown scorch and impact on vegetation, but was not certain whether this was mapped or specifically measured. He stated that the data was collected and entered into a system so that it could be used in regional and State reporting frameworks. 238 Mr Hardman stated that, in his experience, only about 0.5% to 1.0% of planned burns "escape" beyond control lines outside the planned burn area. An escape is not necessarily the result of an error in the conduct of the planned burn, but could be caused by a gust of wind or some other natural phenomenon. Mr Hardman noted that, while a burn escape could be a serious adverse event with potentially devastating impacts, "quite often an escaped planned burn can be caught very, very quickly and it can have little or no impact as well". In his time as CFO (since 2018), out of around 1,800 planned burns, five had breached control lines and been declared bushfires, increasing the area burnt by approximately 800 hectares over about 500,000 hectares of planned burning. Mr Hardman considered that the respondent was "very effective at keeping burns within control lines" and that "of the hundreds of burns we do every year, it's a very small minority of those burns" that escape. The respondent has defined triggers as to when a fire that goes significantly beyond the boundary of a planned burn will be declared to be a bushfire, and minor breaches that are readily controlled or contained would not be declared as a bushfire. 239 It was put to Mr Hardman that the prescriptions or objectives contained in the Delivery Plans concerning the percentages of the planned burn area that would be burnt were not reliable estimates, and that it was possible that a greater area would in fact burn. Mr Hardman said that this had not occurred in his experience and that often the burnt area was smaller than desired, and that "[i]t would depend on the environmental conditions of the day and the vegetation and fuel arrangements and a whole range of variables that the burn planners would take into consideration". 240 Mr Hardman was questioned about the prescriptions contained in the Delivery Plan for the Lima East burn, which is to be conducted over three ignition days and three patrol days. He accepted that there may still be some vegetation burning within the planned burn area on the patrol days (days four, five and six). It was put to Mr Hardman that the Delivery Plan did not include prescriptions for temperature on days beyond day one. Mr Hardman noted that he was not a "burn practitioner" and had highly skilled people within his organisation who would look at the detail of the burn plans. He stated: So there's a range - what I can tell you from my own experience, not necessarily reporting on this plan, but everything from the fuel moisture, the relative humidity in the atmosphere, the temperature, the wind. We then look at fuel arrangement, and slope, and bark hazard, and all of those things. And what happens is all of those issues are evaluated. The weather forecast is critical. And that will look at a seven-day window where burning could occur. On the day, or before the day if the forecast changes, a burn [officer in charge] will - has - is full accountability not to proceed with a burn if it is outside of prescription significantly and any variation cannot be managed. So we don't - there's no pressure on people to burn. If it can't be done safely and to plan, we empower everybody making those decisions not - to be able to not ignite a planned burn. 241 In relation to the temperature and wind speed forecasts, Mr Hardman noted that the weather forecast is over a large area, whereas the planned burn is "done in a very narrow geographic area". Accordingly, Mr Hardman explained that temperature and wind speed readings are taken on the days leading up to the day of the planned burn, and "it really is about the conditions on the day whether or not it is suitable to conduct the planned burn or to not conduct the planned burn". 242 Mr Hardman said that it was difficult not to complete or continue a planned burn after fire had been introduced into the area, due to the amount of unburned fuel. Rather, the burn team would need to "adjust and finish to manage the risk", and that "even if it is out of prescription, it would be a lot smarter to continue to burn to reduce that fuel and not to allow it to burn far more intensely and do far more damage on its own". 243 Mr Hardman accepted that it was possible that the FDI could increase after day two of a planned burn, depending on the weather conditions, and could even conceivably reach an FDI of 25 on those days. In such circumstances, those in charge of the operation of the particular burn would have to "adjust our strategies and approach to continue to mitigate those risks". In re-examination, Mr Hardman stated that the FDI is based on a range of variables, and that the respondent looks at a "seven-day window" when undertaking a planned burn. Planned burn officers will choose whether or not to ignite based on what that window looks like, so that if it appears that the FDI is going to increase during that seven-day period, they may choose not to burn. The Secretary ultimately relies on experienced burn officers in charge to make such decisions. If the conditions change during the conduct of a planned burn, the officers could adjust lighting patterns to reduce the speed and intensity of the fire. Mr Hardman said: speaking to our staff, they will vary and change things because prescriptions are never exactly right. … you may need to vary things and we empower people to make those decisions. And, as I said, we also empower people not to proceed if they believe that the risk is significant to achieving the outcome of the burn. And the good thing is that, you know, people don't feel pressured to do this work. They know that they've got that full individual authority to make those decisions. 244 Mr Hardman explained that the Phoenix Rapidfire model was used "across a broad range of fire suppression and planning systems and processes", including to measure fire spread and risk values. However, while is used to assist in evaluating risk for planned burns, it is not used to model how a planned burn will or might behave. The inputs into the Phoenix Rapidfire model included fuel, temperature, relative humidity, and topography. The input for fuel was measured in tonnes per hectare, through estimates of the bark and fine fuels on the ground in a range between low and extreme. 245 Mr Hardman stated that, during the conduct of a planned burn, officers might be able to enter into the planned burn area, depending on the burn plan, the lighting pattern and the intensity of the fire. For example, he said that officers often walk ridge lines and excluded areas while igniting, and that "quite often, staff would walk up drainage lines and riparian strips within the burn unit to assess how it's going within the burn unit as long as it can be done safely". 246 Mr Hardman maintained that he had never seen flames occurring at a height of between 26 and 33 meters during a planned burn, although he could not say that it does not happen. While he considered that it was "not … such a terrible thing" for this to happen in relation to a single tree or a couple of trees within a planned burn area, he would be concerned if this occurred across the whole planned burn area. He considered that, if there were flame heights of that nature, "we shouldn't be burning". 247 Mr Hardman was shown a map depicting the "post burnt extent and severity" of an area known as "Strathbogie Tames Rd", which classified areas into low, medium and high canopy scorch, as well as unburnt and canopy burnt. Mr Hardman agreed that it appeared from this map that about half of the planned burn area experienced medium canopy scorch or higher, but noted that he was unable to say whether that was a good or a poor result without having seen the burn plan and objectives. 248 Finally, Mr Hardman was questioned about the timing of the planning process for planned burning. He accepted that the planning process usually involves at least six-months commencing during winter, with preparation in spring and summer, and then ignition taking place in autumn subject to weather conditions. The planning process involves consideration of environmental values, including any values under the EPBC Act and the FFG Act. In this regard, the Secretary has a biodiversity division and a chief conservation scientist, and a natural environment programs area which evaluates the relevant burn plan in order to provide comments and identify risk mitigations. Mr Hardman was not aware of any planned burn in respect which approval was sought under the EPBC Act, but was aware of past exemptions from the EPBC Act having been obtained for bushfire response activities.

Mr Shaun Lawlor 249 The evidence of Mr Lawlor in relation to the broader context of Victorian bushfire risk management has been dealt with above in these reasons in the section dealing with background factual matters. It is necessary here to address Mr Lawlor's evidence in so far as it bears upon the conduct of the planned burns the subject of this proceeding. 250 The four planned fuel reduction burns cover a total area of just over 2,000 hectares, and are relevantly described in the Hume Region Joint Fuel Management Plan (see Schedule 1 of Appendix 1), which contains a list of FFMVic-led fuel management activities, in the following terms: Burn No. Burn Name Land Management Objective Planned burn size (ha) HR-GBN-BEN-0080 Lima East - Mt Albert To develop fuel reduced areas of sufficient width and continuity to reduce the speed and intensity of bushfires 669.65 HR-GBN-BEN-0075 Barjarg - Harpers Road To develop fuel reduced areas of sufficient width and continuity to reduce the speed and intensity of bushfires 540.20 HR-GBN-BEN-0052 Strathbogie South - Ruoaks Road To develop fuel reduced areas of sufficient width and continuity to reduce the speed and intensity of bushfires 491.35 HR-GBN-BEN-0076 Tallangallook - Black Creek Track To build on protection works in adjacent Asset Protection Zone. 299.25

251 The Fire Management Zone for each of the planned burn areas is predominantly Bushfire Management Zone. Although the stated land management objective for the Tallangallook burn is expressed in different terms, Mr Lawlor stated that, in practice, the objective for that planned burn is the same as the other three planned burns. 252 While the planned burns are among those listed for the Goulburn District for the 2022/2023 year, the Hume Region Joint Fuel Management Plan notes in Appendix 1 that "the planned burn year and season identified for each planned burn is indicative only and may be changed due to weather conditions and operational requirements". Mr Lawlor states that the four planned burns are currently scheduled to occur in autumn 2024, when conditions permit. 253 Mr Lawlor states that the area specified as the planned burn size for each of the planned burns is significantly larger than the proportion of the area that will actually be treated with fire during the delivery of the planned burns. This is because each of the Delivery Plans for each burn specifies a "fuel treatment objective" - for example, achieving an overall fuel hazard of moderate or low over a given proportion of the planned burn area. 254 Mr Lawlor described that the four fuel reduction burns the subject of the present proceedings were been planned using the risk modelling program Phoenix RapidFire. As explained in the affidavit of Mr Hardman, this model is used to measure bushfire risk based on simulating a set of bushfires across the landscape to show how the fire will behave under specified conditions, allowing for predictions of bushfire behaviour without and with (or before and after) fuel reduction. Models of different scenarios are run with the aim of reducing the number of houses or "address points" that are lost in the fire so as to reach the applicable residual risk target. The results are used to inform fuel management priorities. The effect of this evidence is that Phoenix Rapidfire is not used to model the behaviour of a planned burn itself, but rather is used to model bushfire risk as a relevant consideration in the planning process. Phoenix Rapidfire is also used to support bushfire response by informing the preparation and positioning of firefighters, aircraft and equipment on days of high fire danger. 255 By using Phoenix Rapidfire modelling, the Secretary produced a "risk rationale" for the four planned burns, which showed show a reduced fire size and reduced modelled property impacts across a 50,000 hectare area around the Strathbogie State Forest. The risk rationale for the four planned burns concludes as follows: Modelling of fires in the vicinity of the planned burns with and without treatment demonstrates a reduction in fire intensity and fire size, and consequently reduced property impacts - which underpins the achievement of Residual Risk targets. The difference in average fire intensities across the reporting grid, points to the impacts burns have on reducing area of impact, and zones of reduced impact conferred under the anticipated fire weather. 256 Mr Lawlor addressed the planning process for planned burns under the Code. Pursuant to the Code, each planned burn is undertaken in accordance with an approved burn plan, which includes land management and burn objectives with regard to percentage cover, residual fuel hazard and ecological outcomes. Where appropriate, the burn plan also includes specific prescriptions to reduce impacts on particular values. DEECA's Bushfire Management Manual includes standard operating procedures for the planning and delivery of planned burns. The planning process can take up to two years to complete. 257 Each of the four planned burns has a Delivery Plan and Operations Map, which are "live" documents that can change up to the time of burn delivery depending on operational factors (such as resourcing, e.g. the number of personnel or equipment required), weather conditions, or adjustments with respect to values present within the burn area. Taking the Delivery Plan for the Barjarg burn as an example: (a) The "Program Priority" is "amber". The program priority is based on the risk reduction value of the planned burn, and ranges from red (highest priority), amber (medium priority) and green (lowest priority). (b) The "Resource Priority" is "high". The resource priority refers to the allocation of resources within the planned burning program, which informs decisions as to how resources get allocated when there are insufficient resources available to conduct all of the burns under the particular Joint Fuel Management Program. (c) There is a map depicting the planned burn area, surrounded by a "contingency area" in which the burn planners have assessed that there may be minor routine spot-overs (where light burning material is carried by the wind over a control line). The map also indicates burn exclusion zones in which fire will not be applied and where fire will be actively prevented from entering by the ground crew. (d) A more detailed accompanying Operations Map of the planned burn area contains a legend which sets out the proposed fuel treatments, control lines, lighting patterns and burn exclusion zones. Aerial ignition is mapped to occur on ridgelines and spurs, so as to reduce fire speed and intensity and to maintain control of the fire, because fire moves more slowly downhill. Ignition is not planned to take place on mapped waterways and drainage lines, both because they are less susceptible to burning and because they are higher quality habitat for the Southern Greater Glider. (e) The "Fuel Treatment Objective" is "[t]o achieve an Overall Fuel Hazard of Moderate or Low over 50% to 70% of the planned area". Mr Lawlor explained in his affidavit that this means that the intention is to apply controlled low intensity fire to 50% to 70% of the planned burn area, which is judged to be sufficient to achieve the risk reduction sought to be achieved by this particular burn. This proportion of coverage is typical for planned burns conducted in Bushfire Management Zones. (f) Under the heading "Fuels and Prescriptions", the vegetation type and ecological vegetation class is specified, along with the applicable prescriptions in relation to Fire Danger Index or "FDI", temperature, relative humidity, Keech-Byram drought index or "KBDI", wind speed at both 10 meters and 1.5 meters, and fine fuel moisture context or "FFMC". For the Barjarg burn, the prescriptions are: (i) FDI: ≤ 8 (ii) Temperature: ≤ 25 degrees Celsius (iii) Relative humidity: 35-70% (iv) KBDI: ≤ 50 (v) Wind speed (at 10 m): ≤ 20 km/h (vi) Wind speed (at 1.5 m): ≤ 12.5 km/h (vii) FFMC: 9-16% (g) The "Overall Fuel Hazard" is "extreme". This comprises fuel hazard scores in respect of bark (very high), elevated (very high), near-surface (extreme), and surface (very high). Mr Lawlor refers to the Overall Fuel Hazard Assessment Guide: 4th Edition July 2010 (Fuel Hazard Assessment Guide) published by the predecessor to DEECA to explain that fuel hazard is assessed visually by reference to detailed descriptions of various different kinds of fuels set out in the Fuel Hazard Assessment Guide. (h) The "Fire History" is set out in a table in the Delivery Plan, indicating the size of areas affected by past bushfire and previous planned burns. (i) The "Values" identified in relation to the planned burn area include Aboriginal cultural heritage and biodiversity values. In relation to the latter, the Delivery Plan addresses "Significant Values" in relation to the Southern Greater Glider and Powerful Owl, and relevantly states (updated as at March 2023): To best protect high-quality Southern Greater Glider (SGG) and Powerful Owl (PO) habitat during planned burning operations, NEP Hume recommend the following: The key environmental risks to these hollow-dependent species will be the collapse of hollow-bearing trees and fire impacting critical foraging habitat (tree canopy). NEP has identified areas of highest value Southern Greater Glider and Powerful Owl habitat (at a burn scale); predominantly along gullies and major drainage lines. Mitigation measures to reduce the impact of planned burning are provided below. 1. Ensure PBOOs and Crew leaders are briefed on high value habitat and high density of Southern Greater Glider records and are encouraged to restrict fire in these areas. 2. Identify critical hollow-bearing trees (HBTs) in proximity to control lines and ensure active patrol immediately post-ignition to supress fire entering HBTs on the burn boundary, where safe and practical to do so. 3. Minimise crown scorch and fire severity to reduce HBT collapse and impact on nest sites and foraging habitat. 4. Limit burn severity and cover to the minimum required to achieve burn cover target. (j) A previous update in September 2022 states: This burn unit was part of recent monitoring project which detected high densities of Southern Greater Glider. It is likely this species occurs throughout Foothill Forest within the broader burn footprint - especially along gully and drainage lines where larger hollow-supporting trees are numerous. Mitigation measures to reduce impacts on this important area for Greater Glider are: - An overall focus on reducing the amount of trees that are lost along the boundaries of the burn during pre and post-burn operations. Recommended measures would include: - A focus on protection of trees during burn preparation along boundary. Limit the extent of bulldozer activity outside of the road footprint\containment line and ensure all practical efforts are made to retain larger trees along these boundaries. Any trees deemed hazardous should be properly assessed and consideration given to limb\branch removal before clear-felling. - During post-burn blacking-out activities - limit the use of Bulldozers and other heavy machinery in manipulating trees\vegetation other than when clear and present hazardous trees need to be treated due to being within range of the road. - Ensure that fuel moisture differentials are sufficient that they moderate against higher intensity burn coverage and exclude fire from damper drainage lines and gully systems (k) The "Burn Complexity" is stated as "Complex (Level 2)". The Delivery Plan sets out a "questionnaire" covering matters such as fuels (bark hazard, variability, coverage, external), topography, values, ignition, and control lines. The Delivery Plan notes that there is a very high or extreme bark hazard "with very high risk of spotting outside of burn boundary under planned conditions into fuels which are very likely to sustain fire", that there are "[m]ultiple fuel types with varying flammability across the [burn] unit", and that burn coverage is expected to be greater than 60%. The external fuel hazard is very high and "likely to carry fire under prescribed conditions". There is "significant variability in topography and slope" and "[s]ignificant cultural or environmental values within or adjacent to the burn unit that require management on burn day". There is also "[h]igh stakeholder, political or community interest likely requiring significant on ground engagement prior to and during the burn". (l) The indicative ignition plan states that the operation has been planned for three ignition days and three patrol days. The areas to be treated on each ignition day are 200 hectares (day one), 200 hectares (day two) and 140.2 hectares (day three) respectively. It may be noted that these figures address the total area of the planned burn, as opposed to the area that will actually be treated by fire. The preferred wind conditions for ignition are northerly winds, and unacceptable wind conditions for ignition are southerly winds. The plan notes that the ignition plan "is indicative only" and that "detailed ignition instructions will be provided by the Planned Burn Operations Officer on the day of delivery and will be adjusted as required to meet weather and fuel conditions". (m) Finally, the plan sets out an estimate of resources required in terms of personnel, plant and equipment over the duration of the operation. 258 The Delivery Plan in respect of each of the Lima East, Ruoaks Road and Tallangallook planned burns is in a similar format, with slightly differing prescriptions and operational details. The parties did not attach any significance to the differences between the respective Delivery Plans for the purposes of the issues raised by this proceeding. 259 The district fuel management team is responsible for monitoring the conditions to determine when it is possible to conduct a planned burn, taking regular measures of fuel moisture content in preceding days and using localised spot weather forecasts from the Bureau of Meteorology. Wind speed, relative humidity and temperature are regularly measured by FFMVic staff on the day of the planned burn. A burn will not be conducted if the FDI or wind speeds are outside the prescription. If other conditions are slightly outside the prescribed ranges, the decision whether or not to conduct the burn will depend on the totality of the circumstances, and will be referred to the Deputy CFO or Regional Manager Forest and Fire Operations or, in some cases, the CFO. 260 The person in charge of a planned burn on the day of delivery is the Planned Burns Operations Officer (PBOO), who is referred to in the applicable standard operating procedure as the Burn Officer in Charge. The delivery of a planned burn is a large logistical exercise that usually requires the coordination of dozens of crew members across large areas of the forest. After site safety checks and briefings have been conducted, the PBOO makes a final assessment (including having regard to indicators such as weather conditions and fuel moisture content) before deciding whether to ignite the burn. The PBOO ensures that a lighting pattern is implemented that is proportionate to the prevailing weather, fuel and topographic conditions. 261 The approved methods of igniting a burn are handheld drip-torches, matches and vehicle-mounted drip-torches (by ground crews), and self-propelled incendiary devices (by aerial crews). The most common ignition patterns are referred to as Backing Fire, Spot Fire Ignition (Grid) and Chevron Fire Ignition (Flanking), each of which is described in further detail in the Work Instruction contained in the applicable standard operating procedure published by FFMVic and DEECA. 262 Typically, the first step involves ground crews lighting around the boundary of the planned burn area using slow, controlled hand lighting techniques. For safety and efficacy reasons, ground crews typically do not travel far into the internal area of the planned burn area, at least where the planned burn area is larger than around 300 hectares. Aerial ignition generally commences once the boundaries have been lit by the ground crews, by dropping incendiary capsules from a helicopter flying approximately 10 meters above the tree canopy, usually along ridgelines and spurs in order to control the fire speed and intensity. 263 As an illustration of the use of controlled hand ignition by ground crews, Mr Lawlor referred to various photographs of fuel reduction burns that were reproduced in the 2023 Hume Region Annual Review, at pp 20 and 23. Mr Lawlor states that, in his experience, the height of the flames in those photographs is typical of a fuel reduction burn, in relation to fire created both by hand ignition and by aerial ignition. 264 Because the areas around gullies and waterways will not usually sustain fire, ignition crews generally do not light those areas. Similarly, it is difficult to get southern and (to a lesser extent) eastern aspects to burn, as they are less exposed to sunlight and there is therefore less drying of fine fuels. Conversely, northern and western aspects typically burn more readily. 265 During the ignition of a planned burn, the PBOO is in radio communication with both the ground crews and the aerial crews, who assist in making strategic decisions. In this regard, the aerial crews perform an important role in monitoring fire behaviour across the landscape which is not visible to those on the ground. 266 At the end of a day of ignition, which can take anywhere between one hour and eight hours, patrol crews will continue to perform blacking out activities to extinguish hot-spots near the edge of the burn. The fire will self-extinguish in most places where the fuel has burnt away, or when available fuel has gained moisture from the air and transitions to not sustaining ignition, which often occurs during the evening and night. Blacking out and patrol activities are repeated each day over the course of a multi-day planned burn, and further blacking out and site rehabilitation activities take place when the ignition days are concluded. 267 The contingency area around the planned burn area is checked and patrolled in order to detect and extinguish any fire that may occur outside the planned burn area. Mr Lawlor explains that minor spot fires are a routine and anticipated part of many planned burns. In some cases, such minor spot fires may be treated as planned burn "breaches". Mr Lawlor refers to Victoria's Inspector-General for Emergency Management being tasked in 2015 with investigating all planned burn breaches. Mr Lawlor states that he has never been involved with a fuel reduction planned burn that breached the perimeter of the planned burn area in any other manner than as a minor spot fire. In particular, he has not been involved in any burns that were declared bushfires. 268 Mr Lawlor states that fuel reduction burns are often referred to as "low intensity burns". They may be contrasted with high intensity regeneration burns, and ecological burns which may be either high or low intensity depending on the burn objective. The applicable Work Instruction issued by FFMVic and DEECA provides that the usual aim of low intensity planned burning is "to remove some portion of surface litter and lower shrub and bark fuels with minimum damage to overstory vegetation", and that such burns are characterised by low flame height (less than three metres), slow rates of spread (less than 100 metres/hour), and fire intensities of less than 500 kW/m. Mr Lawlor considered that this was a fair description of what occurs during a fuel reduction burn noting that in his experience flame heights are typically well below three metres. 269 Mr Lawlor referred to the results of the Hume Monitoring Evaluation and Reporting program set out in the 2023 Hume Region Annual Review. This included fire severity mapping in relation to fuel reduction burns conducted in the 2022-23 financial year. During that period, there were nine completed fuel reduction burns with a total treated area of approximately 6,000 hectares, which were classified as follows: 270 The area of 144 hectares (or 2.4%) that was classified as either high canopy scorch or canopy burnt was said in the 2023 Hume Region Annual Review to be "largely attributable to a single burn". 271 The classification categories set out in the 2023 Hume Region Annual Review were explained by Mr Lawlor in the following terms, using definitions taken from the Fire History Data Standard and Schema dated 14 August 2020: (a) "Unburnt", which includes only unburnt or un-scorched forest or non-forest vegetation; (b) "Low canopy scorch", which means up to 20% canopy scorch (by area), resulting in a predominantly green (unaffected by fire) canopy with some scorched crowns, where no canopy is burnt; (c) "Medium canopy scorch", which means between 20% to 80% canopy scorch (by area), where some canopy crowns may also be burnt; (d) "High canopy scorch", which means that greater than 80% of the canopy is scorched (by area), where some canopy crowns may also be burnt; (e) "Canopy burnt", in which the majority of forest canopy is burnt; and (f) "Burnt non-forest", which means burnt or scorched non-forest vegetation (essentially, grassy areas with no canopy). Mr Lawlor clarified that areas classified as "low canopy scorch" could include burnt areas in which there was no canopy scorch (that is, 0% canopy scorch). 272 Mr Lawlor states that all planned burns in the Strathbogie State Forest involve the implementation of mitigations for the Southern Greater Glider. This includes taking steps to protect hollow-bearing trees in proximity to the control lines, usually by one or more of rake-hoeing around the base of the tree, spraying the base and lower trunk with firefighting foam, or (where operationally feasible), excluding higher tree densities from the burn area. Patrol crews routinely patrol the fire edge and will intervene if they detect that fire is about to impact a hollow-bearing tree. 273 Mr Lawlor acknowledged that it would not be possible to protect every hollow-bearing tree across a burn area. This is because, for safety reasons, ground crews should not traverse the entire planned burn area. In addition, there are insufficient resources and time to cover and treat all hollow-bearing trees within hundreds of hectares of forest. Accordingly, Mr Lawlor states that "it is physically impossible to treat all the hollow-bearing trees in a burn". 274 In response to the Zylstra report, Mr Lawlor states that, across his career, he has never seen a fuel reduction burn produce flames as high or as severe as those predicted by Dr Zylstra (namely, maximum flame heights between 26 and 33 meters, and between 32% and 77% of the planned burn area experiencing high severity fire in the nature of crown scorch). Mr Lawlor considers that such flame heights would be "in the order of a major bushfire" that would be impossible to control within burn boundaries, and would render the planned burn a "complete disaster". 275 Mr Lawlor states that he has lived and worked in the Hume Region for virtually all of the past 33 years, and that planned burns have been part of forest and fire management for his entire career. He states that the policy, practices and essential methods or techniques of planned burning have not changed over that period. More recently, however, there is a heightened (and still growing) awareness and understanding of forest values, including cultural heritage and biodiversity, which has resulted in mitigations to planned burning practices and a more deliberate and systematic approach to identifying and protecting such values.

Oral evidence 276 In cross-examination, Mr Lawlor confirmed that he had visited the Strathbogie State Forest many times, including some of the planned burn areas, and was familiar with parts of the forest, particularly at the northern end. In relation to the trees and vegetation that were specified by Dr Zylstra as representative species in his report, Mr Lawlor accepted that those species were present in the forest, and that the heights given in the Zylstra report were "in the order of being correct". Mr Lawlor admitted that it was possible that the representation of the forest stand used in the Zylstra report existed somewhere in the Strathbogie State Forest, although he added that it is a "very diverse forest" and said that the particular representation in the Zylstra report was "not representative of something that I have observed" in terms of the species. For example, he said that Mountain Gum (Eucalyptus dalrympleana) "was not a great deal of the whole forest" as opposed to Narrow-leaf Peppermint (Eucalyptus radiata) which was "highly representative" through large parts of the forest. Mr Lawlor referred to other species including Blue Gum (Eucalyptus globulus), Manna Gum (Eucalyptus viminalis), Red Stringybark (Eucalyptus macrorhyncha) and Messmate (Eucalyptus obliqua) and said: So there's a whole range of species that exist across the Strathbogies. Sometimes they're in pure stands, sometimes they're intermixed. But, in terms of [Eucalyptus] dalrympleana, yes, it's there, yes. But it's not characteristically what you would see a lot of as you travelled through the forest. 277 Mr Lawlor said that there were typically between 70 and 90 planned burns conducted each year in the Hume region, although not that many had been carried out in the last three years. In general, the outcomes of all planned burns were monitored and reported upon, including by measuring the extent of the burnt area and the degree of fire severity using aerial or satellite imagery, together with verification from ground crews. 278 Mr Lawlor stated that the Secretary used the Phoenix Rapidfire modelling to test how useful or effective the four planned burns would be in fighting a future bushfire. However, the Secretary did not use Phoenix Rapidfire or any other fire behaviour model in developing the prescriptions for the planned burns. While Mr Lawlor was aware of a project called Vesta, which had developed models to predict fire behaviour, Vesta was not used by the Secretary to model how planned burns might behave. 279 Mr Lawlor said that there is a range of information about expected fire behaviour, including the McArthur meter which is used to predict flame heights, spotting distances and rates of spread under a range of parameters including the amount of fuel (in tonnes per hectare) and the FFDI calculated from wind speed, temperature, relative humidity and how dry the landscape is. Mr Lawlor explained that the McArthur meter had gone from being a manual calculation to a computer-generated output. While it was an important tool used in developing a planned burn, Mr Lawlor stated that officers would also bring in other information including "training manuals with all sorts of rules of thumb for things … over and above the McArthur meter" and a "whole range of … different methodologies and information that people use to bring together an overall picture of what might happen". For example, the figures given by the McArthur meter for flame height, spotting potential and rate of spread are based on flat ground, and would change when topography is taken into account. Officers would also take into account the composition of the forest structure and fuel layers when conducing overall fuel hazard assessments. In relation to the use of the McArthur meter, Mr Lawlor stated that "[t]he officers allocated those burns would be starting to think very much about the factors involved in delivering that burn, of which [the McArthur meter] would be one of a multitude of things they would be thinking about", in that "the burn prescription is designed to set up the parameters on which we frame conducting the operation to elicit an outcome that we're aiming for". 280 Mr Lawlor agreed that, once ignition of a planned burn had commenced, the safest course of action is usually to complete the burn over the remaining days in accordance with the burn plan. However, in some planned burns, there might be opportunities to "section off" the burn and not complete the whole operation. If there were an unexpected "spike" in the FFDI after the first day of a planned burn, the burn officers would carry out a "rigorous planning exercise, including fire behaviour analysis, to look at what the options were and the risk and consequences that would be attributed to each of those options", and would have to "work hard to … keep things under our control and … to meet our objectives as best we can". Mr Lawlor said that, while there was a possibility that the FFDI might increase from 10 or 12 on the first day of ignition to 25 on a subsequent ignition day or patrol day, that had not occurred in his experience. 281 In re-examination, Mr Lawlor stated that, while the Delivery Plans contained prescriptions for the FFDI on day one or day two of the planned burns, the decision whether to ignite was influenced by the whole weather forecast period (five to seven days) and "[i]f there was anything in the forecast even at the backend of it that wasn't favourable, we would almost certainly not conduct an operation". 282 Mr Lawlor was asked questions about whether and how a planned burn was conducted to exclude burning in particular areas, and whether there was monitoring of the fuel moisture content in gullies and drainage lines in the days leading up to a planned burn. Mr Lawlor stated that there was monitoring of fuel moisture in some but not all of the drainage lines, and that ultimately the burn officer was accountable for achieving the outcomes articulated in the burn plan. 283 As noted above, fuel hazard assessments are carried out in accordance with the Fuel Hazard Assessment Guide, under which each fuel layer is assessed "simply and visually" and given a hazard rating. Those ratings are then combined to produce an Overall Fuel Hazard Rating that ranges from low to extreme. The arrangement of the fuel in each layer can have an effect on fire behaviour. Mr Lawlor said that the intention of the four planned burns was to reduce as much as possible of the surface and near surface fuels (i.e. the principal accumulation of fine fuels), with less of a focus on elevated fuel. In relation to the consumption of bark fuel (such as stringybark), Mr Lawlor did not agree that a higher bark fuel score would be a significant factor in producing canopy scorch, because it was "more of a smouldering fire" as opposed to "flames leaping off … the trunk". Mr Lawlor agreed that elevated fuel can be burnt, and that a fire with a flame height above 0.5 metres might not pass beneath the elevated fuel layer without consuming any of it. If the elevated fuel layer ignites, Mr Lawlor said that the risk of canopy scorch would depend on a range of factors, including how much elevated fuel was present. 284 Mr Lawlor agreed that stringybark is flammable when dry and that such fires will readily climb the trees, at least in the context of a bushfire. However, under planned burning where the conditions are far more mild and moderate, the fire generally does not burn the branches but rather will climb to about two-thirds the height of the trunk before running out of energy and fuel, at which point it "peters out". In addition, there would be a reduction in the FFDI towards each evening. In relation to ribbon or candle bark trees, the outcome was subject to the arrangement of the bark that had fallen off the tree. 285 Mr Lawlor agreed with a table set out in the Fuel Hazard Assessment Guide (Table 3.1) that indicated that fire would climb some or most stringybark trees at FFDI 25 if the bark fuel hazard rating is high or very high, as was the case in each of the planned burn areas. (It may be noted in this regard that the specific weather conditions used in the Fuel Hazard Assessment Guide to achieve FFDI 25 comprise a temperature of 33 degrees Celsius, relative humidity of 25%, wind speed of 20 km/h, drought factor of 10 and slope of zero degrees, which would be outside the prescriptions for the four planned burns). Mr Lawlor accepted that, at least for stringybark, fire would also climb the trees at a lower FFDI. Nevertheless, the FFDI was important in understanding what will occur once the bark catches fire, in that at a lower FFDI the fire "will be much more moderate in terms of its intensity and how much of [the bark] will actually burn and the behaviour that you get as a result". 286 Mr Lawlor was asked to address a table contained in the Fuel Hazard Assessment Guide (Table 9.2) to estimate indicative fuel loads in tonnes per hectare based on the fuel hazard rating for each fuel layer, which could then be used in applying the McArthur meter to predict flame height, spotting distance and rate of spread for the applicable FFDI. Using the fuel hazard ratings from the Delivery Plan for the Lima East burn, it was put to Mr Lawlor that the cumulative fuel load for all layers (surface, near surface, elevated and bark) would be between 27 and 34 tonnes per hectare. Using a table reproduced in a copy of a manual McArthur meter, counsel for the applicant suggested to Mr Lawlor that this would result in a predicted flame height at FFDI 10 of at least 7 metres above the ground, and (inferentially) an even higher flame at FFDI 12. Mr Lawlor confirmed that this was a correct interpretation of the table set out in the physical copy of the McArthur meter. He agreed that, depending on the composition and flammability of the understorey, surface flames could at some point develop into a crown fire. He also stated that he "wouldn't disagree strongly" with the proposition that canopy scorching might occur at up to seven times the flame height.

Professor Trent Penman 287 Dr Penman is a Professor of Bushfire Science in the School of Agriculture, Food and Ecosystem Sciences at the University of Melbourne. He has undertaken research since 2003 on the environmental and human impacts of fire, prediction of wildfire behaviour and fire risk modelling. 288 Dr Penman was asked to prepare an expert report addressing questions relating to the manner in which fire is likely to behave in the conduct of the four planned burns. For such purposes, Dr Penman was briefed with information regarding the planned burns, including the Code, the Hume Region Bushfire Management Strategy and Joint Fuel Management Program, extracts from FFMVic's standard operating procedures in relation to the conduct of fuel management burns, and the Delivery Plans and Operations Maps for the planned burns. 289 In his report, Dr Penman described fire severity as "a retrospective estimate of the amount of biomass consumed during a fire", as opposed to fire intensity which is a reference to the energy output of a fire (rarely measured outside experimental fires due to the lack of accurate data on the inputs such as rate of spread and fuel consumed). Usually, severity is estimated from remotely sensed changes in "productivity indices", which can be thought of in simple terms as the "greenness" of the vegetation, before and after the fire. Four or five categories are usually used in estimating fire severity ranging from unburnt to complete canopy consumption. 290 In Dr Penman's opinion, it is difficult to predict the fire behaviour in the four planned burns with any degree of accuracy without further information because fire behaviour in planned burning is dependent on a number of factors which can be manipulated during the day to achieve the desired outcome. These factors included the method of ignition, topography, weather conditions, and fuel moisture content. (a) Ignition methods can be used to slow fire spread, particularly through the use of spot ignitions when fuels are ignited at a single point and the fire spreads slowly until it reaches a "quasi-steady state", meaning an equilibrium in the rate of spread of a fire in the absence of any dynamic or extreme fire behaviours. Spacing of the ignitions to ensure most of the fire spread occurs in the period before the quasi-steady state can reduce the rate of spread, and the potential for crown scorch. (b) While topography is fixed throughout the landscape, it is also a tool of an effective prescribed burn operator. As fires will spread slower downhill compared to uphill, the selection of ignitions along ridge tops (as is proposed in the Delivery Plans) will result in slower spread and lower flame heights. (c) Weather can be manipulated within an area by a good prescribed burn manager. For example, if there is a constant wind from the west, fires can be ignited to spread towards the wind, resulting in the fire backing into the wind where the fire spread is significantly more benign than fire running with the wind. Unlike wildfires, planned burns can be undertaken under ideal conditions, and burn managers can select the day and the time of day where fire behaviour will fit the objectives of the planned burn. (d) Values in fuel moisture vary throughout the day and across the landscape. These fuel moisture gradients can be used by prescribed burn crews to limit or slow the spread of fire, and to minimise the occurrence of crown scorch. Utilising fuel moisture gradients simply means choosing the time of day that is most likely to support mild fire behaviour, usually late in the day as the effect of solar radiation from the sun is reduced. Further, fine scale features (such as logs, rocks and bare patches of ground) also play a significant role in planned burns and can prevent the spread of surface fires. 291 Accordingly, Dr Penman considered that "a knowledgeable prescribed burn operator is able to manipulate fire behaviour to reduce the risk of undesirable fire behaviour (in this case crown scorch or consumption)", by selecting the appropriate weather window and ignition pattern so that the burns could be conducted with low occurrence of canopy consumption or scorch. Dr Penman did not believe that the application of any model was likely to provide a true representation of actual fire behaviour within the four planned burn areas, without detailed information on how the burn operators plan to use the above factors to achieve the burn objectives. 292 Dr Penman described Dr Zylstra's FRaME model as a hypothesis that "remains contested on many levels", and referred to a debate between Dr Zylstra and two CSIRO scientists who had provided critical comments on Dr Zylstra's 2016 paper. Dr Penman considered that "[s]uch a debate highlights the issues surrounding the model and the diverse opinions of the strengths and weaknesses of the model". Among other things, Dr Penman considers that species inputs to the model are "challenging and time consuming to collect" and the use by Dr Zylstra of photographs, generic descriptions and fuel hazard guide rankings "cannot be defensible as an adequate representation of these sites [the planned burn areas] for use in the model". Further, FRaME "is highly sensitive to small changes in the input variables", and "[a]ny assumptions made about inputs that are incorrect or even inaccurate are likely to introduce significant doubt as to the validity of the outputs". Dr Penman therefore considered that: Given the breadth of inputs required for FRAME, I do not believe the analysis of [Dr] Zylstra has produced meaningful outputs for the prediction of potential fire behaviour for the purposes of this court case. 293 More generally, Dr Penman noted that fire behaviour models "are most commonly used to forecast the spread of wildfires operationally or strategically", and that most such models "are not developed for primary use in the prediction of prescribed fire behaviour". In contrast to an empirical model which is developed from measured relationships between predictors (such as fuel load, fuel moisture, temperature, humidity, etc.) and response variables in terms of fire behaviour (such as flame height, intensity or rate of spread), FRaME is a "mechanistic" model based on understandings of underlying processes which are then sought to be validated against data. While FRaME has been tested against wildfire data, empirical models such as the McArthur meter and Vesta rely heavily on prescribed burning data in building the empirical relationships between fuel, weather, topography and fire. Dr Penman took issue with the claims made by Dr Zylstra that he had validated FRaME against a prescribed fire in relation to possum mortality. 294 For these reasons, Dr Penman disagreed with the results of the fire behaviour modelling undertaken by Dr Zylstra in his report, which he considered "fails to use appropriate site-based data and does not account for the role of the operator in controlling the burn".

Oral evidence 295 Dr Penman was cross-examined relatively briefly on matters going to his independence, including his communications with Dr Swan and the source of funding for his research, which I address below. 296 Otherwise, Dr Penman agreed that he was familiar with the Delivery Plans and Operations Maps for each of the four planned burns. He agreed that, in order to give a reliable prediction of fire behaviour in a planned burn, it was necessary to know details of the steps available to burn operators relating to ignition method, topography, weather conditions, and fuel moisture values. 297 Dr Penman stated that, in his opinion, the proposition that canopy scorch could occur at up to seven times the flame height was a "generalisation" that was "imprecise", and there are more detailed empirical equations that are able to predict scorch height as a function of fire intensity. Within any given forest structure, there is a positive correlation between flame length and intensity.

Dr Matthew Swan 298 Dr Swan is a Senior Research Fellow at the School of Agriculture, Food and Ecosystem Sciences at the University of Melbourne, whose field of research is the effects of fire on animals, plants and forest structure. He was instructed to provide his expert opinion on questions relation to the impact of the planned burns on Southern Greater Gliders, including direct mortality or indirect effects on habitat and food resources. 299 In giving his opinions, Dr Swan was asked to make a number of factual assumptions - in particular, that each of the planned burns would be a "low-intensity" burn which aimed "to remove a portion of surface litter and lower shrub and bark fuels, with minimum damage to overstory vegetation", and with a low flame height (up to three metres), a slow rate of spread (up to 100 metres/hour) and intensities of less than 500 kW/metre. He was also asked to assume that "[o]ne to two per cent of the planned burn area [for each of the four planned burns] may experience some 'canopy scorch'", and that "[t]he planned burn intensity will not change, even if some deviations from the indicative Delivery Plans and Burns Operations Maps are necessary on the day of the activity". 300 Dr Swan identified the two main potential direct impacts of the planned burns on individual Southern Greater Gliders as "heat related injury/death and injury/death from trees collapsing during and shortly after the planned fire operations". 301 In relation to the former, Dr Swan considered that a low intensity fire that mostly affects understorey vegetation will have minimal direct impact on individual Southern Greater Gliders through exposure to heat from flames. Dr Swan relevantly stated in his report: Where fire severity is low (the canopy is largely unaffected) there is unlikely to be major heat related risk to individuals occupying the tops of tree canopies in these forests. Direct fire effects are difficult to study but the available evidence suggests that arboreal animals regularly survive fires that don't significantly affect the canopy. … In forests affected by recent bushfires in SE Australia, areas of low-severity fire generally have substantially higher abundance of arboreal mammals (including SGGs) than areas affected by high severity fire (Lindenmayer et al. 2013; Chia et al. 2015; McLean et al. 2018). This suggests that individuals occupying areas affected by low severity fire, survive the initial fire event and changes to the vegetation in the short term. While the overall risk of heat related injury/death is likely to be low under low fire intensities some individual SGGs may be at risk of injury or death from heat exposure in areas of the burns that are subject to canopy scorch. Given the assumed facts, this would be a small minority of individuals occupying the burned areas. Where significant canopy scorch occurs, this suggests high temperatures which can lead to mortality in arboreal mammals especially those that are exposed outside of hollows (Zylstra 2023). Tree hollows will likely provide insulation from these effects as they can buffer external temperature (O'Brien et al. 2006; O'Connell and Keppel 2016) but this is difficult to estimate accurately, at temperatures experienced in different canopy scorch scenarios as very few studies of heat penetration into tree hollows of different tree species exist. 302 Dr Swan therefore accepted that "[i]t is possible that an individual [Southern Greater Glider] occupying areas that are affected by high canopy scorch could be killed or injured through heat exposure", but stated that "this is likely to be minor in extent under the assumed conditions given the small area of canopy scorch predicted". 303 Dr Swan considered that "tree collapse during and in the days and weeks after the burn operation has the potential to kill or injure arboreal animals", where the collapse occurs during the day when animals are sheltering in tree hollows. Accordingly, Dr Swan stated that "it is likely that at least one individual [Southern Greater Glider] will be killed or injured through tree fall either during or in the days and weeks after the planned burns", although the extent of possible mortality from treefall is difficult to predict. Among other things, dead hollow-bearing trees were at a much higher risk of collapse, and Southern Greater Gliders prefer live hollow-bearing trees depending on availability. 304 In relation to the impact on habitat, Dr Swan stated that Southern Greater Gliders are reliant on hollow-bearing trees for shelter and breeding, with individual gliders using multiple hollows within their relatively small home range (1 to 4 hectares). He stated that the planned burns are likely to accelerate the collapse of hollow-bearing trees in areas that are directly affected by fire within the four burns. Dr Swan referred to two studies of collapse rates of hollow-bearing trees following planned burns in Eucalypt forests: one study (L Bluff, "Reducing the effect of planned burns on hollow-bearing trees" (2016) Fire and Adaptive Management Report No 95 DEECA (Bluff 2016)) found that approximately 26% of hollow-bearing trees reached by fire collapsed, being 20% of hollow-bearing trees in the planned burn area; another smaller study (P Cowie, "The Alpine North East Risk Landscape Hollow Bearing Tree Interim Report 2016/2017" (2016) (Cowie 2016)) estimated a collapse rate of 15% (and 10% of live hollow-bearing trees). Dr Swan continued: The exact collapse rates that are likely to be experienced in the four planned burns are difficult to predict. It will depend on the tree species, fire intensity, amount of fuel at the base of the trees and the status of the trees present (likelihood of collapse is significantly higher in dead [hollow-bearing trees] and trees with the presence of basal scars than for healthy live trees). 305 In areas that remain unburnt (comprising 30% to 50% of the planned burn area), which would typically include south-facing slopes and moist areas associated with drainage lines or creeks, Dr Swan considered there would not be any change to the rate of tree collapse nor any impact on Southern Greater Glider habitat. 306 Dr Swan noted that the planned burns had the potential to accelerate development of hollows by causing damage that weakens the trees' defences to insect and fungal excavation. However, there was little evidence about how fire effects hollow development in the forest types present in the Strathbogie State Forest, and the process was likely to take years. 307 Dr Swan considered that the food resources of the Southern Greater Glider, which has a specialised diet of eucalypt leaves, are unlikely to be affected by planned burns that do not significantly affect the canopy. While localised canopy scorch could reduce the available foraging resources of a small number of individuals within their home ranges, this effect was likely to be transient (weeks or months), as the Eucalypt species that occur in the Strathbogie State Forest resprout after fire. 308 Dr Swan did not consider that the planned burns were likely to change the Southern Greater Glider's area of occupancy, which was reportedly extensive in the Strathbogie State Forest. He considered it unlikely that there would be local extinction within the planned burn areas, noting that there is good evidence that populations of Southern Greater Gliders persist in areas subject to low intensity fire. While there is likely to be a short-term reduction in the abundance of available hollow-bearing trees in each of the planned burn areas, Dr Swan considered that any potential effect on the local abundance of Southern Greater Gliders is unlikely to result in an overall change in its area of occupancy or to threaten the persistence of the population in the short term. Dr Swan noted unburnt areas, especially south facing slopes and gullies, would provide refuge from the effects of fire. 309 Dr Swan considered the mitigations that are contained in the Delivery Plans to reduce the impact on Southern Greater Gliders and hollow-bearing trees. Where those mitigation measures include actively excluding fires from riparian areas and damp forest, this was likely to be protective of important habitat areas. Other measures to protect hollow-bearing trees by raking or wetting down around their base were likely to be effective at reducing the collapse of a small number of hollow-bearing trees, but as this was limited to areas around control lines and boundary tracks it was unlikely to significantly change the outcomes across the planned burn areas. 310 Dr Swan drew a contrast with the likely impacts on Southern Greater Gliders of a bushfire in the Strathbogie State Forest, in which larger proportions of the area would be likely to burn at high severity and a smaller proportion would burn at low to moderate severity or would be unburnt. In Dr Swan's view, this would substantially increase the extent of mortality of gliders from direct fire effects and treefall "in areas that are subject to high intensity bushfire that affects the canopy through full scorch or consumption", leading to a significant reduction in the abundance of Southern Greater Gliders. There would be more widespread collapse of hollow-bearing trees that are reached by fire, and it would be possible that resource depletion could have detrimental effects on the glider population if significant areas of the canopy were affected. 311 In so far as those views were directed to the impacts of bushfires, they have limited relevance to the questions raised in this proceeding, particularly in the light of the consensus between the parties that the effect of the planned burns on bushfire risk is not an issue for determination. Nevertheless, Dr Swan's opinions on this topic are consistent with the view that individual gliders are likely to be killed in areas affected by high severity fire involving a high degree of canopy scorch or canopy consumption, and that there might be an adverse impact on the population if significant areas were so affected. Dr Swan also acknowledged that Southern Greater Gliders "are a slow breeding species that occupy relatively small home ranges and show limited dispersal", and are "slow to reoccupy areas where populations have been significantly reduced or lost". Accordingly, if a substantial proportion of the planned burn areas were to burn at high severity, "it is possible that the area of occupancy would be reduced and it could take many years for the population to recover". 312 In response to the Zylstra report, Dr Swan considered that Dr Zylstra's estimates of the proportions of the planned burn areas affected by high canopy scorch were "theoretically possible but would be very rare in planned burns", based on available evidence from previous fires in similar vegetation types and Dr Swan's own observations after planned burns in Victorian forest ecosystems. In Dr Swan's view, "[t]he estimates of proportion of area burnt at high severity are similar to what would be expected from high intensity bushfires not most planned fire". Dr Swan agreed with the view that planned burning is likely to cause an acceleration in the collapse of hollow-bearing trees, noting that there was potential for overall abundance of hollow-bearing trees to be reduced under frequent fires. He noted that the degree of scarring was likely to be related to fire intensity and fuel loads and composition at the base of the trees, and queried whether the modelling in relation to Mountain Gum (Eucalyptus dalrympleana) was applicable to other dominant tree species in the areas which have much thicker bark. 313 In response to the Meredith report, Dr Swan maintained that his "recent experience over the past 14 years of studying the ecological effects of numerous planned burns has been that planned burns in similar forest types to the [Strathbogie State Forest], very rarely burn at high severity and significantly scorch the canopy over extensive areas", especially for "larger planned burns that often achieve low burn coverage well under the burn objectives". 314 In response to the Wardell-Johnson report, Dr Swan disagreed with the view that any fire that burns the habitat is likely to be damaging to individuals, populations or the species of Southern Greater Gliders, reaffirming that "[p]opulations of this species can persist in areas affected by low intensity fires including areas of bushfires that have burned less intensely than surrounding areas". Dr Swan considered that there was no evidence provided by Dr Wardell-Johnson as to the mechanism by which fires would increase risk to Southern Greater Gliders through changes to the microclimate. 315 In the Supplementary Swan report, Dr Swan was asked to answer an additional question whether any of his opinions would be affected by an assumption that the four planned burns would experience the specified gradations of canopy scorch as set out in the table extracted above at paragraph 269 (being the outcomes of the planned burns carried out in the Hume region in 2022-2023). The supplementary letter of instructions to Dr Swan clarified that the assumption given in Dr Swan's previous instructions (that 1-2% of the planned burn area may experience "some canopy scorch") was intended to mean that 1-2% of the planned burn area may experience "high canopy scorch or canopy burnt", consistent with the table which indicated that 1.4% of areas were categorised as "high canopy scorch" and 0.9% of areas were categorised as "canopy burnt". 316 In essence, Dr Swan stated in the Supplementary Swan report that, because he had already interpreted the assumption of 1-2% experiencing some canopy scorch as a reference to high canopy scorch, the additional information in the supplementary instructions did not substantially affect his responses to the questions in his earlier report. While areas of "canopy burnt" would pose a higher risk of injury or death to individual Southern Greater Gliders than areas of "high canopy scorch", Dr Swan's overall conclusions regarding the effect of the planned burns on individual gliders were unchanged.

Oral evidence 317 Dr Swan clarified that he had interpreted his initial instructions as referring to high canopy scorch or high severity fire, because that was the "most conservative way of looking at it". Accordingly, in his initial report, Dr Swan had not taken into account any areas that may have some canopy scorch other than high canopy scorch (such as moderate or low canopy scorch). In his supplementary report, having been provided with further details as to the different gradations of canopy scorch, Dr Swan considered that the figure of 2.3% categorised as either canopy burnt or high canopy scorch aligned with the assumption in his initial report (namely, 1-2% of the area may experience high canopy scorch or high severity fire). In relation to whether he had turned his mind to the potential impact on gliders of low canopy scorch or medium canopy scorch, Dr Swan stated: I considered it in my supplementary report. I didn't comment on. So the low canopy scorch, in my experience, areas that have low canopy scorch are mostly understorey burnt only. Medium canopy scorch can be some localised canopy effects, but it's hard to know what medium canopy scorch from satellite means on the ground, so I didn't change my answer in terms of those two things. So I guess - I guess I glossed over it in this report and didn't mention it. … I focused on the higher end. 318 Accordingly, in stating that his overall conclusions regarding the effects of the planned burns on individual gliders were unchanged from those expressed in his original report, Dr Swan said that he had also taken into account the areas that would be subject to low canopy scorch and medium canopy scorch but "didn't comment on it" and "focused on the higher end". It may be observed that this was not made clear in the Supplementary Swan report, which is presumably what Dr Swan meant when stating that he had "glossed over" or not mentioned that aspect in his supplementary report. 319 Dr Swan did not accept that he may have missed gradients or degrees of canopy scorch that were below the most severe levels but were still significant for the questions that he was asked. Dr Swan said that there was "a lot of variability" in areas that were mapped as moderate canopy scorch (between 20% and 80%), so that it was difficult to say with confidence what the effects would be. He accepted that there is a "continuum" of risk of mortality from direct heat impacts, and that "as more canopy gets scorched, then the risk would increase". Thus, moderate canopy scorch "at the upper end of [the] range" might be a risk factor. 320 Dr Swan was asked whether there might be some risk to Southern Greater Gliders in areas surrounding those categorised as high canopy scorch or canopy burnt. Dr Swan's response was inconclusive - he said that it would depend on exactly "where the gliders were in relation to the heat" but that "heat related risk [in such areas] would be higher than low severity areas, for example". He did not agree that he had excluded this from the assessment in his expert report, but stated that it was "difficult to say much about what's going to happen" without knowing where and how the patches of high severity fire were aggregated. Dr Swan stated that he "couldn't rule it out that at a lower level of canopy scorch there wouldn't be mortality", but thought that "the risk is substantially greater where there's high canopy scorch". When asked whether he agreed that there is a real chance of mortality at a lower level of canopy scorch, he answered, "[h]onestly I don't know", adding that there is "not much direct evidence of what happens inside tree hollows when … the canopy is scorched". He stated that, based on the available evidence, he had assumed that "where there's high severity fire that that's where mortality risk is the greatest". 321 Dr Swan was asked about the abundance of hollow-bearing Mountain Gums in the Strathbogie State Forest. He considered that it was possible that there would be around 20 such trees per hectare, but that 50 trees per hectare would be "pretty high" and he could rule out 100 trees per hectare. Dr Swan noted that Mountain Gums were not the only hollow-bearing habitat tree, and that all of the Eucalypts in the area would form hollows that would be habitable. Dr Swan considered that it was reasonable to assume that there was a correlation between the number of hollow-bearing trees and the number of gliders in an area. He stated that a loss of hollow-bearing trees would not necessarily lead to a reduction in the density of Southern Greater Gliders, as it would depend on how dense the population was and the magnitude of the loss of hollow-bearing trees. However, he accepted that there was a real chance of a reduction in glider density. 322 Dr Swan was cross-examined on the basis for his opinion that arboreal animals regularly survive fires that don't significantly affect the canopy. He accepted that there were variances between the different species that had been the subject of previous studies, many of which he was not familiar with. He accepted that there was no direct evidence of the effect of planned burns on the Southern Greater Glider. He was not aware of the particular strategies adopted by the Southern Greater Glider to cope with the direct effect of fire. 323 Dr Swan was also cross-examined on the basis for his opinion that areas of low severity fire generally have substantially higher abundance of arboreal mammals (including Southern Greater Gliders) than areas affected by high severity fire - citing DB Lindenmeyer et al, "Fire severity and landscape context effects on arboreal marsupials" (2013) Biological Conservation 137-148 (Lindenmeyer 2013); EK Chia et al, "Fire severity and fire-induced landscape heterogeneity affect arboreal mammals in fire-prone forests" (2015) Ecosphere 6 (Chia 2015); and McLean (2018). Dr Swan accepted that post-fire abundance studies might potentially be missing direct mortality of some individual animals from low severity fires. Lindenmeyer (2013) established that severe fire had a negative effect or a decline in abundance of gliders, and moderate fire (without canopy scorch) had a smaller negative effect or decline, but with no change in occupancy (the number of sites at which the species occur). Dr Swan stated that this indicated a "statistical significance" or a "real effect" or in relation to the abundance of gliders in areas of low severity fire as compared to more severe fire, albeit without demonstrating the size or the cause of that effect. Chia (2015) indicated that mortality is high in severely burnt sites, but that there was not much evidence of mortality in areas affected by low severity fires. Dr Swan considered that this supported a conclusion about the survival of animals in areas affected by low-severity fires; while leaving open the question whether individual animals might be dying, the study did not show that there was high mortality in those areas. Dr Swan relied on McLean (2018) in his report to support a general proposition that areas of low severity fire generally have substantially higher abundance of arboreal mammals including Southern Greater Gliders than areas affected by high severity fire. 324 In re-examination, Dr Swan explained that he had relied on the abundance studies following bushfires as providing a good indication of how fire had affected vegetation and what had happened to abundance in relation to the effect on habitat. 325 In relation to the proposition that tree hollows are likely to provide insulation from heat effects on arboreal mammals, Dr Swan accepted that one of the studies on which he had relied had dealt with a species of Cuban parrot, but he nevertheless considered that the paper supported "a very general proposition that tree hollows will insulate against heat". Another study cited by Dr Swan related to insulation from ambient temperatures during hot days, as opposed to the potential insulating effects of tree hollows under fire conditions. Dr Swan stated that he cited this paper to show that tree hollows and wood in general can insulate. He said that he had not been specific about how much insulation would be provided because it is "not well known … how heat penetrates into tree hollows". Dr Swan accepted that gliders shelter in tree hollows during the daytime, but stated that "there's not much information on what gliders do during fire". He accepted that, if a glider were to leap from one tree in order to glide to another tree, it would have to descend in height although he could not give an estimate of how much they descend when gliding nor the angle of the glide. 326 Dr Swan considered that, where a species was experiencing a decline, "every population" of that species was important. He accepted that, if a particular population was "bucking that trend" and was not in decline, it provides scientists with an opportunity to assess the differences compared to those areas that are in decline, with a view to reversing declines elsewhere. 327 Dr Swan stated that individual gliders use multiple tree hollows as dens, with some possible den sharing. Where there are more hollow-bearing trees, it is more likely that an arboreal species that uses tree hollows will occur. Dr Swan considered that there would be a minimum number of tree hollows to sustain a population. He stated that, at lower densities, there may be a relationship between the number of tree hollows and the density of gliders, but he was not sure of the nature of that relationship, including whether it was linear relationship. He was "not sure" whether the abundance or density of gliders would reduce in line with a reduction in available hollows, but accepted that there "could potentially" be such a reduction in glider abundance or density. Dr Swan stated: I think there's a chance, but I'm not sure that there's much evidence on - there's not much evidence directing - not much evidence showing a decline in hollow availability and, you know, a small decline in hollow availability and arboreal species, so it probably depends on how dense the population is and how - how limiting the hollows are for the species, and that is just unclear. 328 Dr Swan was cross-examined on the studies of collapse rates of hollow-bearing trees following exposure to fire, including in relation to fire scars and structural damage and the relevance of burn history and frequency of fire events to the risk of future collapse. 329 Dr Swan was taken to a draft of his initial report in which he had referred to a "worst case scenario" of a reduction in abundance of Southern Greater Gliders due to a reduction in hollow-bearing trees, although stating that this was "far from certain". This sentence was changed in Dr Swan's final report as filed, which relevantly stated that "[a] decrease in hollow availability could potentially affect local abundance of SSGs within the planned burns, but this would be unlikely to threaten the persistence of the population in the short term". Dr Swan confirmed that the reference in the draft report to a "worst case scenario" was not addressing an extreme or implausible outcome such as an uncontrolled bushfire, and he accepted that there is a real chance of a reduction in the abundance of gliders in the planned burn areas as a result of the planned burns. In re-examination, Dr Swan could not recall why he removed the reference to "worst case scenario" from his final report. However, he noted that he had accepted in his final report that a decrease in hollow availability could potentially affect local abundance of gliders, which was what he regarded as the worst case scenario, but he compared that to a loss in the area of occupancy which he considered was "very" unlikely. 330 Finally, having regard to the assumptions that he had been asked to make about the nature of the planned burns, including that they would be low intensity burns involving a maximum flame height of 3 metres, Dr Swan was asked whether he would change his evidence if he were asked to assume a flame height that might exceed 7 metres. Dr Swan stated that he had "very little experience" in translating flame heights to an ecological impact, and that the question of severity and canopy scorch (i.e. that 1-2% of the area would experience high canopy scorch) was more relevant to his opinion.

Issue 1: Will the planned burns have, or are the planned burns likely to have, a significant impact on the Southern Greater Glider within the meaning of s 18(3) of the EPBC Act?

General principles 331 Section 18(3) of the EPBC Act relevantly prohibits the taking of an action that has or will have, or is likely to have, a significant impact on a listed threatened species included in the endangered category. 332 Subject to one qualification in relation to the meaning of the word "likely", the principles relating to the construction and application of s 18(3) were largely common ground between the parties. Those principles have been articulated and developed in a number of previous decisions of this Court. 333 The term "action" is relevantly defined under the EPBC Act to include "an activity or series of activities": s 523(1)(d). There is no dispute that the four planned burns proposed by the Secretary in the present case constitute an "action" for the purposes of s 18(3) of the EPBC Act. 334 The impacts to which a provision such as s 18(3) are directed can be described as negative or adverse impacts. This is reflected in s 75(2)(b), contained in the provisions of Pt 7 of Ch 4 dealing with Ministerial decisions about whether an action is a controlled action, which provides that the Commonwealth Minister must not consider any beneficial impacts the action has or will have, or is likely to have, on the matter protected by each provision of Pt 3. 335 The EPBC Act does not define the term "significant impact". In the present case, the parties accepted that a significant impact is one that is "important, notable or of consequence having regard to its context or intensity": Booth at [99]-[100] (Branson J); VicForests v Friends of Leadbeater's Possum Inc (2021) 285 FCR 70 at [62] (Jagot, Griffiths and SC Derrington JJ) (Friends of Leadbeater's Possum FC). In a related context under s 139(2)(b) of the EPBC Act, the term "significant" has been taken to operate as a limitation to "exclude impacts which are minor or negligible on a listed threatened species": Northern Inland Council for the Environment Inc v Minister for the Environment (2013) 218 FCR 491 at [92] (Cowdroy J). As Dowsett J observed in Krajniw v Brisbane City Council (No 2) [2011] FCA 563 at [10], the purpose of the EPBC Act "would not be achieved if any possibly adverse effect upon a species, however minor and however unlikely, was sufficient to engage either of ss 18 and 18A". 336 Whether a proposed action is likely to have a significant impact under s 18 of the EPBC Act is a question of fact: Greentree at [192] (Sackville J); Australian Brumby Alliance at [230] (O'Bryan J). Importantly, assessing whether an impact is significant "is not a mathematical exercise, but rather a matter of considering the evidence as a whole": Friends of Leadbeater's Possum at [1308] cited with approval by the Full Court in Friends of Leadbeater's Possum FC at [267]. 337 The text of s 18(3) refers to a significant impact on a "listed threatened species". It has been accepted that this requires demonstration of a significant adverse impact on the relevant species as a whole: Krajniw at [10]. However, this does not necessarily preclude assessment of impacts on individuals of a listed threatened species of fauna, or on localised populations of that species: see Friends of Leadbeater's Possum at [1304]; Friends of Leadbeater's Possum FC at [267]. Although the term is not itself used in s 18, a "population" of a species is defined in s 528 of the EPBC Act to mean an occurrence of the species or community in a particular area. While the statutory question remains one of impact on the species, evidence of impacts or effects on individuals or local populations "is capable of being probative of impact on the species as a whole": Friends of Leadbeater's Possum at [1308]. This can encompass consideration of the long-term survival of the species "at sufficient and sustainable levels of abundance, with sufficient and sustainable genetic diversity and across the species' natural range": Friends of Leadbeater's Possum at [1304]. 338 The term "likely" is also not defined in the EPBC Act. The weight of first-instance decisions in this Court supports a conclusion that "likely" in s 18(3) refers to "a real or not remote chance or possibility", in the sense of "prone" or "with a propensity" or "liable", as distinct from a test of "more probable than not": Polaris Coomera Pty Ltd v Minister for the Environment [2021] FCA 254 at [226] (Rangiah J); Friends of Leadbeater's Possum at [1298]; Northern Inland Council at [91]-[92]; Booth at [97]-[98]; see also Environment Council of Central Queensland Inc v Minister for the Environment and Water (No 2) [2023] FCA 1208; 413 ALR 318 at [58]-[59] regarding s 78(1)(a) (McElwaine J). 339 Among other things, such a construction of "is likely to have" has been regarded as consistent with the immediate context in which that phrase is used in juxtaposition to the phrase "will have". In so far as the future impacts that an action "will have" under s 18(3)(a) are to be proved on the balance of probabilities, it is seen as unlikely that the reference in the alternative to the impacts that an action "is likely to have" under s 18(3)(b) would have been intended to refer to future impacts that are more probable than not, as such impacts would already be covered by the preceding paragraph: see Polaris at [224]-[225]. This construction has also been seen as one that advances the statutory objects set out in s 3(1) and the principles set out in s 3A of the EPBC Act: Booth at [97]-[98]; Northern Inland Council at [92]; Polaris at [227]. 340 The alternative construction would essentially treat s 18(3)(a) as referring to a proven certainty of future impacts, and s 18(3)(b) as referring to a proven probability of future impacts. While it might be possible in some contexts to distinguish the standard of proof (on the balance of probabilities) from a particular chance or likelihood that is the subject of such proof, it does not necessarily follow that "likely" in s 18(3)(b) should be construed as meaning a greater than 50% chance. The terms of other provisions such as s 97(3) and (3A), s 102(3) and (3A), s 132A(3) or s 146(1A) which refer to the "certain and likely impacts" of an action might lend some indirect support to that argument, although each of those provisions appears in a different context to the provisions in Pt 3 such as s 18(3). I note that the genesis of the construction of "likely" adopted in Polaris was the comparable approach adopted in Tillmanns Butcheries Pty Ltd v Australasian Meat Industry Employees' Union (1979) 42 FLR 331 at 339 (Bowen CJ) and 346 (Deane J) in relation to broadly analogous language contained in a provision of the Fair Trade Act 1974 (Cth), which has been more recently confirmed by a Full Court of this Court (albeit with some reservations) in relation to s 50 of the Competition and Consumer Act 2010 (Cth): Australian Competition and Consumer Commission v Pacific National Pty Limited (2020) 277 FCR 49 at [243]-[244] (Middleton and O'Bryan JJ). 341 In its opening written submissions, the Secretary noted that the meaning of "is likely to have" in s 18(3) has not been authoritatively settled (at least prior to the decision in Polaris), and submitted that "likely" should be construed to mean "more probable than not". This submission was not developed in the Secretary's opening submissions, and was not revisited in its written or oral closing submissions. The Secretary contended that, even on the broader construction of "likely", the evidence did not establish that there was a real or not remote chance or possibility of a significant impact on the Southern Greater Glider from the conduct of the planned burns. 342 Accordingly, no submission was directly made by the Secretary that the Court should decline to follow the approach to the term "likely" that has been adopted in previous decisions such as Booth, Northern Inland Council, Friends of Leadbeater's Possum and Polaris. Although the proper construction of "likely" was not contested in the first three of those cases, there was a live controversy determined by Rangiah J in Polaris at [203]-[228] in relation to s 18(4), the terms of which are materially indistinguishable from s 18(3). No attempt was made by the Secretary to argue that the conclusion reached by Rangiah J in Polaris was plainly wrong. 343 In these circumstances, I propose to adopt a construction of s 18(3)(b) of the EPBC Act that is consistent with the conclusion reached by Rangiah J in Polaris at [226], namely that the phrase "is likely to have" refers to "a real or not remote chance or possibility". Although this formulation is expressed in disjunctive terms, I do not consider that there is any material distinction in this context between a "real" chance or possibility and a "not remote" chance or possibility, nor that there is any material distinction between a "chance" and a "possibility". In other words, the phrase in s 18(3)(b) is directed to a real (in the sense of not remote) possibility of an impact of the relevant kind. 344 Nevertheless, the applicant bears the onus of establishing on the balance of probabilities that the proposed action will have or is likely to have a significant impact on the Southern Greater Glider as a species. In other words, the applicant must establish on the evidence as a whole that there is a real (in the sense of not remote) possibility that the planned burns will have an impact on the species that is important, notable or of consequence having regard to its context or intensity. 345 For such purposes, in deciding whether or not the applicant has proved its case on the balance of probabilities, s 140 of the Evidence Act requires the Court to take into account the nature of the cause of action, the nature of the subject matter of the proceeding, and the gravity of the matters alleged: see generally Booth at [69] ff. Section 140 reflects the common law as explained by Dixon J in Briginshaw v Briginshaw (1938) 60 CLR 336: see e.g. Employment Advocate v Williamson (2001) 111 FCR 20 at [65]-[67] (Branson J); Communications, Electrical, Electronic, Energy, Information, Postal, Plumbing & Allied Services Union of Australia v Australian Competition and Consumer Commission (2007) 162 FCR 466 at [31]-[32] (Weinberg, Bennett and Rares JJ). Accordingly, "the strength of the evidence necessary to establish a fact or facts on the balance of probabilities in a case of this kind [that is, involving an alleged contravention of a statutory prohibition] might, depending on the nature of the particular fact or facts, be greater than would be required to establish a fact in issue on the balance of probabilities in a proceeding of a different kind": Booth at [70]. 346 In the present case, the applicant seeks injunctive relief pursuant to s 475(2) of the EPBC Act to restrain the Secretary from carrying out the planned burns, alleging that the planned burns would constitute an action that is prohibited by s 18(3) of the EPBC Act. Such an allegation is serious - in addition to injunctive relief, conduct in contravention of s 18(3) attracts a civil penalty and can constitute a criminal offence under s 18A of the EPBC Act. On the other hand, the proceeding seeks to restrain future conduct and does not allege that the Secretary has engaged in any past conduct in contravention of the EPBC Act. The granting of an injunction may nevertheless have significant consequences for the Secretary, and its ability to carry out planned burns as part of its fuel reduction program in the Hume region. If the matter were required to be referred to the Commonwealth Minister for assessment and approval, there is likely to be consequential impacts on the timing of the planned burns, although the applicant submitted that such processes are capable of being accommodated in the Secretary's planning processes and suggested that it was likely that the Commonwealth Minister would ultimately grant approval on appropriate conditions. 347 In relation to the nature of the subject matter of the proceeding, I take into account that the objects under s 3(1) of the EPBC Act include the protection of the environment, especially matters of national environmental significance, and the conservation of biodiversity by including provisions to protect native species and to prevent the extinction, and promote the recovery, of threatened species. To that end, the EPBC Act requires the assessment and approval of actions that have, will have, or are likely to have a significant impact on listed threatened species, and confers standing on a wide class of interested persons to apply for injunctions to restrain actions in contravention of those requirements. This proceeding involves an assessment of the impact of the planned burns on the Southern Greater Glider as a listed threatened species in the endangered category under the EPBC Act. As will be discussed further below, I accept that the Strathbogie State Forest, including the planned burn areas, contain suitable habitat for a population of Southern Greater Gliders that is important to the conservation of the species. 348 On the construction of s 18(3) that I have adopted above, the proceeding is directed to whether there is a real (in the sense of non-remote) chance or possibility that the planned burns will have a significant impact (i.e. an impact that is important, notable or of consequence) on the Southern Greater Glider as a species. I consider that this should ultimately be regarded as one question involving a single evaluative judgment: compare Australian Competition and Consumer Commission v Pacific National Pty Limited (No 2) [2019] FCA 669 at [1276]-[1279] (Beach J); Australian Competition and Consumer Commission v Pacific National Pty Limited (2020) 277 FCR 49 at [161], [245]-[246] (Middleton and O'Bryan JJ); see also Australian Competition and Consumer Commission v Metcash Trading Ltd (2011) 198 FCR 297 at [227]-[228] (Yates J); Vodafone Hutchison Australia Pty Limited v Australian Competition and Consumer Commission [2020] FCA 117 at [65] (Middleton J). While that question might entail or turn on a number of different factual issues, the assessment of whether there is a real (in the sense of not remote) possibility of a significant impact on the Southern Greater Glider should not be diluted by separately addressing whether there is some possibility of each of the multiple factual elements which might together give rise to such an impact. Rather, it is necessary to consider the interrelationship of all of the facts, matters and circumstances and to ask whether there is a real (in the sense of not remote) possibility of a significant impact on the Southern Greater Glider. 349 In so far as there is uncertainty on the evidence regarding the impacts of the proposed action, in order to warrant the grant of injunctive relief under s 475 of the EPBC Act, the onus remains on the applicant to establish on the balance of probabilities that there is likely to be (i.e. that there is a real and not remote chance of) a significant impact on the listed threatened species. This onus is not removed or addressed by the precautionary principle - that is, the principle that lack of full scientific certainty should not be used as a reason for postponing a measure to prevent degradation of the environment where there are threats of serious or irreversible environmental damage (see s 391(2) of the EPBC Act). It was accepted by the parties that the precautionary principle does not itself have any direct application in the present proceeding. In this regard, the position of the Court in determining an application for injunctive relief can be distinguished from the position of the Commonwealth Minister in making decisions under the EPBC Act, including on whether or not an action is a controlled action or whether to grant approval for an action. The Commonwealth Minister is required to take account of the precautionary principle in making such decisions, to the extent he or she can do so consistently with the provisions of the EPBC Act: s 391. It is also necessary to distinguish cases in which issues have arisen about the conduct of forestry operations in accordance with the Victorian Code of Practice for Timber Production 2014, which expressly incorporates and implements the precautionary principle: see e.g. Friends of Leadbeater's Possum at [137], [800]-[806]. 350 The Court was referred to a document published by the Commonwealth Department of Environment in 2013 entitled "Matters of National Environmental Significance: Significant impact guidelines 1.1" (Significant Impact Guidelines). This document states that the purpose of the guidelines is to assist the proponents of an action to decide whether or not the action should be referred for assessment and approval by the Commonwealth Minister pursuant to the EPBC Act. For that purpose, the Significant Impact Guidelines set out criteria for determining whether an action is likely to have a significant impact on a listed threatened species. In relation to critically endangered and endangered species, the Significant Impact Guidelines relevantly state: Significant impact criteria An action is likely to have a significant impact on a critically endangered or endangered species if there is a real chance or possibility that it will: • lead to a long-term decrease in the size of a population • reduce the area of occupancy of the species • fragment an existing population into two or more populations • adversely affect habitat critical to the survival of a species • disrupt the breeding cycle of a population • modify, destroy, remove, isolate or decrease the availability or quality of habitat to the extent that the species is likely to decline • result in invasive species that are harmful to a critically endangered or endangered species becoming established in the endangered or critically endangered species' habitat • introduce disease that may cause the species to decline, or • interfere with the recovery of the species. What is a population of a species? A 'population of a species' is defined under the EPBC Act as an occurrence of the species in a particular area. In relation to critically endangered, endangered or vulnerable threatened species, occurrences include but are not limited to: • a geographically distinct regional population, or collection of local populations, or • a population, or collection of local populations, that occurs within a particular bioregion. 351 The Significant Impact Guidelines also address the questions "What is a significant impact?" and "When is a significant impact likely?" in a manner consistent with the authorities that have been discussed above. 352 As has been pointed out in previous cases, the Significant Impact Guidelines are not given statutory force and do not themselves have any legal authority: Friends of Leadbeater's Possum at [1311]; Australian Brumby Alliance at [123], [225]. The document sets out administrative policy which represents the prevailing interpretation that has been adopted by the Commonwealth Department in relation to the "significant impact" question (noting, however, that the position adopted by the Secretary in the present case on the construction of the phrase "is likely to have" in s 18(3) departs from the approach set out in the Significant Impact Guidelines). In Friends of Leadbeater's Possum at [1315], Mortimer J (as her Honour then was) observed that "much of what is set out in the [Significant Impact] Guidelines reflects the agreed and established construction of the statutory phrase" and that "the examples … which are given… about the kinds of effects which are capable of constituting a significant impact are plainly examples which fall within that agreed and established construction". While accepting that the Significant Impact Guidelines should not be used as statutory criteria, Mortimer J regarded the examples as "capable of assisting consideration and assessment of the application of what is otherwise a broad statutory concept": Friends of Leadbeater's Possum at [1321]. 353 In the present case, in circumstances where the Strathbogie State Forest contains a population of Southern Greater Gliders that is important to the conservation of the species, it may be accepted that there would be a significant impact on the Southern Greater Glider if it were established that the planned burns were likely to result in a long-term and significant decrease in the size of the population of Southern Greater Gliders in the Strathbogie State Forest, or to cause a significant reduction in the area of occupancy of Southern Greater Gliders in the Strathbogie State Forest, or to have a significant adverse effect on habitat critical to the survival of the Southern Greater Glider in the Strathbogie State Forest.

Challenges to experts' independence or experience 354 In the course of hearing and in closing submissions, each of the parties raised challenges to the independence of the expert witnesses called by the opposing party. Ultimately, it was accepted that such matters were relevant to the weight, rather than the admissibility, of the expert evidence. This is consistent with the approach generally adopted in this Court in relation to the objectivity and independence of expert witnesses: see e.g. Ananda Marga Pracaraka Samagha Ltd v Tomar (No 4) (2012) 202 FCR 564 at [35] (Dodds-Streeton J); Rush v Nationwide News Pty Limited (No 5) [2018] FCA 1622 at [36] (Wigney J); FGT Custodians Pty Ltd (formerly Feingold Partners Pty Ltd) v Fagenblat [2003] VSCA 33 at [22], [24] (Ormiston JA, Chernov and Eames JJA agreeing); Australian Broadcasting Corporation v Kane (No 2) [2020] FCA 133; 377 ALR 711 at [238] (Abraham J). Accordingly, I have taken such matters into account in assessing the weight of the evidence given by each of the experts. 355 There was also cross-examination and submissions directed to the nature and quality of the experience of each of the expert witnesses. Where relevant, I have had regard to the witnesses' background and field of expertise when considering their opinions.

Dr Zylstra 356 The Secretary submitted that Dr Zylstra is an opponent of prescribed burns and approached his role as one involving "making a case for the applicant". This was said to have been revealed through emails between Dr Zylstra and the applicant's solicitors in connection with his retainer. Further, it was submitted that Dr Zylstra had sought to promote fundraising by the applicant in relation to these proceedings. 357 During his cross-examination, Dr Zylstra was taken to a series of posts from his personal account on "X" (formerly Twitter). These included a "reposting" by him of a post which encouraged readers to "provide support" to the applicant for the present proceedings and contained a link to a public fundraising website though which donations could be made. Dr Zylstra agreed that he had promoted the raising of funds for the applicant, but stated that he did so because he would like to see "the case represented properly" and "a fair coverage of both sides of the issue so that the science is properly considered". 358 Dr Zylstra was also taken to an email he sent to the applicant's solicitor prior to his engagement as an expert where he had stated that "we have our argument for significant impact", which was said to suggest that he was not acting impartially or independently but rather was workshopping potential arguments for the applicant's case. Notwithstanding that he had subsequently expressed reservations about the limitations on his ability to answer questions about the specifics of fire behaviour and its effect on gliders in the absence of detailed surveys, he nevertheless proceeded to offer to "make the case that their [i.e. the Secretary's] science is inadequate to guarantee a safe prescription". 359 An expert who has been or is about to be engaged by a party to litigation as an independent expert witness should be discouraged from making social media posts of the kind made by Dr Zylstra indicating implicit support for the case that the party seeks to prosecute. Nevertheless, I do not consider that this social media post, or the communications between Dr Zylstra and the applicant or its solicitors more generally, significantly affect the weight that Dr Zylstra's evidence should otherwise be afforded. As addressed below, Dr Zylstra's evidence did not ultimately form the backbone of the applicant's closing submissions, and I have not generally relied on his evidence in making findings as to the likely impact of the planned burns. 360 The Secretary also made submissions in respect of the limits of Dr Zylstra's experience and expertise, and the lack of transparency as to the underlying basis for his opinions. In particular, the Secretary submitted that Dr Zylstra is not an expert in mathematics or statistics, and the Court should have regard to the fact that he is only an "Adjunct Associate Professor" and not presently in paid employment by Curtin University. I do not consider that these matters have any bearing on the weight of Dr Zylstra's evidence. Dr Zylstra's expertise clearly extends to the development of the FRaME model for the prediction of fire behaviour, and his evidence is ultimately directed to his opinion on the application of that model to the circumstances of the planned burns. It is not in dispute that Dr Zylstra has no particular expertise in relation to the Southern Greater Glider, in relation to which he has relied on assumptions drawn from other sources.

Dr Wardell-Johnson 361 The Secretary challenged the scope of Dr Wardell-Johnson's experience in relation to the Southern Greater Glider, submitting that he had published one paper that was concerned with logging and disturbances from "intense wildfire" as opposed to planned burning, and that his past involvement in litigation as an expert witness was concerned with the environmental impacts of logging. 362 In my view, Dr Wardell-Johnson was able to give evidence of his opinions as to the effects of disturbances caused by fire on forest ecology. However, some aspects of his evidence were not central to the applicant's case, which did not ultimately rely on changes to the microclimate that might be brought about by planned burning. 363 It was also put to Dr Wardell-Johnson during cross-examination that he had obtained information from a range of websites, including the applicant's website, prior to receiving his instructions in this proceeding, and that this had not been disclosed in his report and "the risk of contamination cannot be excluded". Nevertheless, nothing specific was identified that would give rise to any significant concern that Dr Wardell-Johnson's opinions had been inappropriately influenced by any undisclosed information. I accept that Dr Wardell-Johnson was endeavouring to acquaint himself in general terms with the subject-matter on which he was to be asked to give his opinion.

Dr Meredith 364 The Secretary submitted that Dr Meredith had no specific expertise in relation to the Southern Greater Glider, apart from some surveys that he had conducted near the Strathbogie State Forest in 1973. The Secretary also submitted that, while Dr Meredith has some experience in reviewing the outcomes of planned burns from maps and other documents, he had never himself attended the delivery of a planned burn. Accordingly, it was put that his experience in assessing planned burn outcomes was "macro" in nature, in so far as it involved the assessment of mapped fire extent and severity over large areas of land, rather than direct experience of the conduct of planned burns. 365 I have taken these matters into account in considering the opinions expressed by Dr Meredith. By and large, Dr Meredith demonstrated substantial familiarity with the effects of fire on forest ecosystems, and some knowledge about the characteristics and behaviour of the Southern Greater Glider. He concurred on several points with the opinions expressed by Dr Swan in his expert report. While he ventured some opinions about the behaviour of fire in a planned burn, the primary significance of his evidence relates to the effects of fire on the forest vegetation and fauna including the Southern Greater Glider.

Dr Penman 366 The applicant challenged Dr Penman's independence on the basis that he had been paid by the Secretary for his role as an advisory board member for the Victorian Office of Bushfire Risk Management, which is part of DEECA, and that the research team that he directs at the University of Melbourne (which he agreed during cross-examination reflects "very well on him professionally") is largely funded by DEECA. 367 Dr Penman sought to explain that government funding is fairly commonplace for research in his field. He accepted that it may have been an error not to disclose the government funding in his report, however, he maintained that this would have been apparent from the research set out in his curriculum vitae. The applicant submitted that "even if one considers that government funding is common in relation to bushfire and planned fire research", the Secretary should have engaged a fire expert from interstate in order to avoid any potential lack of independence. 368 In the circumstances, I am not persuaded that these matters warrant any substantial discounting of the weight of Dr Penman's evidence. I note that Dr Penman was not cross-examined at any length on the substance of the opinions expressed in his report, other than to extract a concession that Dr Penman was familiar with the Delivery Plans and the Operations Maps for the planned burns, on which the applicant ultimately relied to advance a submission that Dr Penman had ready access to the information which he said he needed in order to give a reliable prediction of fire behaviour in a planned burn (including details as ignition method, topography, weather conditions, and fuel moisture values).

Dr Swan 369 The applicant also challenged Dr Swan's independence on the basis that the source of funding for his research is the respondent's Department. Dr Swan is currently the chief investigator on a major research and monitoring project in relation to the influence of bushfires and planned burning on ecosystem resilience, which is funded from a grant by Natural Hazards Research Australia. During his cross-examination, Dr Swan accepted that the funding for this grant "comes from DEECA". Dr Swan also gave evidence during his cross-examination that some of his other previous research projects and scholarships have been directly or indirectly funded by DEECA. 370 Although Dr Swan had flagged with the respondent's solicitors "a potential conflict of interest in that the funding for my work and my position comes from DEECA", he went on to explain that "most fire ecologists in Victoria will be in the same position". In my opinion, the details of Dr Swan's previous research were adequately disclosed in his report.

The applicant's closing submissions 371 The applicant's closing submissions took on a different shape from the case that was originally pleaded and particularised. In closing submissions, the applicant contended that that there was "something wrong with the prescriptions" for each of the planned burns, on the basis that there was a real chance that, under the conditions prescribed in each Delivery Plan, flame heights would exceed those associated with a "low intensity" burn and would lead to high severity fire and extensive crown scorching across the planned burn areas. The tacit suggestion advanced by the applicant was that the planned burns might safely be conducted under different prescriptions that do not carry such risks (for example, by lowering the maximum FDI), and even that a conditional approval to that effect might be the outcome of any referral of the action to the Commonwealth Minister under the EPBC Act. 372 For the purposes of the present proceeding, however, the question for determination is whether s 18(3) of the EPBC Act prohibits the conduct of the planned burns without an environmental assessment and approval under Ch 4 of the EPBC Act, and it is neither possible nor relevant to speculate as to the outcome of any such administrative process. 373 The applicant largely abandoned its primary reliance on Dr Zylstra's evidence of the predicted fire behaviour using the FRaME model, and instead sought to rely on evidence given by Mr Lawlor under cross-examination about predicted flame heights in the planned burn areas using the McArthur meter in conjunction with the fuel hazard scores and other prescriptions contained in the Delivery Plans. Dr Zylstra's report was said to have utility in so far as it provided "a worked example of how canopy fires and severe canopy scorching can occur even under low intensity conditions through the phenomenon of laddering", and that Dr Zylstra's modelling could be given probative weight "in exposing the mechanism by which low surface flames may lead to crown fire depending on the vertical arrangement of vegetation (that is, 'laddering')". However, the applicant's written closing submissions conceded that limitations in Dr Zylstra's report had been exposed in his cross-examination and, in oral closing submissions, counsel for the applicant went so far as to accept that the case pleaded and particularised in reliance on Dr Zylstra's opinions had "failed". 374 The applicant nevertheless submitted that the flame heights for each of the planned burn areas were likely to be greater than 3 metres, and in some cases well over 7 metres. It was submitted that flame heights at such levels would reach elevated fuels, giving rise to a substantial risk of crown scorch and laddering. The applicant submitted that this gave risk to a real chance of substantial direct mortality of Southern Greater Gliders, and substantial collapse of hollow-bearing trees resulting in a reduced abundance of Southern Greater Gliders in the planned burn areas. Accordingly, the applicant submitted that the conduct of the planned burns as proposed by the Secretary is likely to have a significant impact on the Southern Greater Glider within the meaning of s 18(3) of the EPBC Act.

The Secretary's closing submissions 375 The Secretary submitted that, in so far as the applicant's case depended on the opinions expressed by Dr Zylstra, none of those conclusions could be sustained on the evidence. The Secretary made a number of criticisms of Dr Zylstra's reasoning and conclusions, which I will address further below, and submitted that his overarching conclusion of "significant negative impacts" of the planned burns on the resident Southern Greater Glider populations was "manifestly deficient as a matter of substance". 376 The Secretary submitted that Dr Wardell-Johnson had made assumptions about fire severity that were "disconnected from how the case was framed" by the applicant, and that he could not reliably predict any first order impacts on Southern Greater Gliders in the planned burn areas, nor quantify any effect on the species as a whole. Further, Dr Meredith had, in the Secretary's submission, assumed the correctness of Dr Zylstra's conclusions, and in any event had substantially agreed with the conclusions of Dr Swan that low-intensity fire where the canopy is largely unaffected will have minimum direct effects on Southern Greater Gliders and its food resources. 377 The Secretary relied on the evidence of Mr Hardman and Mr Lawlor in relation to the manner in which the planned burns would be conducted, including their experience of having never seen flame heights of the magnitude predicted by Dr Zylstra, and the factors and different activities employed by those conducting the burns to control the spread and severity of fire during a planned burn. The Secretary also relied on the evidence of Dr Penman regarding the limitations on the use of the FRaME model to predict potential fire behaviour, and the evidence of Dr Swan in relation to the impacts of the planned burns on Southern Greater Gliders and their habitat. 378 In broad terms, the Secretary submitted that the risk of direct mortality to Southern Greater Gliders was from "high severity" fire involving a significant amount and degree of canopy scorch or canopy burn. The Secretary submitted that none of the planned burns will significantly affect the canopy, and that the planned burns can be conducted in a way that actively mitigates against such consequences, as evidenced by fire severity mapping of past planned burns in the Hume region including the Strathbogie State Forest. While there might be some very small areas that are affected by high canopy scorch or canopy burn in the conduct of the planned burns, and it was possible that an individual Southern Greater Glider present in such an area would be killed through heat exposure, the Secretary submitted that any such direct mortality would be minimal. Similarly, while it was possible that an individual Southern Greater Glider present in a hollow-bearing tree might be killed directly as a result of the collapse of that tree, the Secretary submitted that it was not possible on the evidence for the Court to make findings as to how many individual gliders would be present in trees that fall as a result of the fire. 379 The Secretary accepted that Southern Greater Gliders depend on hollow-bearing trees, and that planned burns can result in the collapse of some proportion of such trees. However, the Secretary submitted that, without an understanding of the local abundance of Southern Greater Gliders relative to the local abundance of hollow-bearing trees, it was not possible to make any prediction about the effect of any reduction of hollow-bearing trees on individual Southern Greater Gliders, let alone the local population or the species as a whole. 380 Accordingly, while accepting that there is a broad consensus that the Strathbogie State Forest contains an important population of Southern Greater Gliders, the Secretary submitted that the planned burns were not likely to have a significant impact on the Southern Greater Glider at the species level. Rather, the Secretary submitted that the Southern Greater Glider population in the Strathbogie State Forest is stable and resilient, in a context in which there is a history of planned burning being conducted across the Strathbogie State Forest over past decades. 381 The Secretary submitted that, in so far as the applicant's case in closing submissions went beyond or departed from the evidence given by Dr Zylstra, the applicant should not be permitted to advance a new case of which notice had not been given in its pleadings and particulars, nor in its opening submissions. Nevertheless, the Secretary handed up a table setting out a written response to each of the "steps" in the applicant's "new case", and addressed that table in its oral closing submissions. The Secretary submitted that none of those steps were supported by the evidence, and many were in fact contradicted by the evidence. 382 In particular, the Secretary disputed that there was any evidence (including expert evidence) to establish that the McArthur meter was or should be used to predict how fire will behave during the four proposed planned burns. Further, the Secretary submitted that the evidence did not support the propositions that there could be crown scorch at heights up to seven times the flame height, or that there would be significant crown scorch across extensive parts of the planned burn areas. The Secretary contested the applicant's contentions regarding the numbers and densities of Southern Greater Gliders in the planned burn areas, along with the applicant's mathematical calculations of the impacts of the fire on individual Southern Greater Gliders in the planned burn areas.

Direct impacts of planned burns on the Southern Greater Gliders 383 The first question raised for determination is whether and to what extent the planned burns are likely to result in the death or injury of Southern Greater Gliders from the direct effects of the fires. This in turn raises the following central issues: (1) how is the fire likely to behave during the planned burns; (2) is it likely that Southern Greater Gliders will be killed or injured from exposure to heat and smoke from the planned burns; and (3) is it likely that Southern Greater Gliders will be killed or injured from the collapse of hollow-bearing trees caused by the planned burns?

Fire behaviour 384 Each of the above issues requires findings of fact to be made on the balance of probabilities, although such findings can potentially relate to the existence of a likelihood in the sense of a real or non-remote chance. However, as explained above, the ultimate single question is whether or not it is likely (that is, whether there is real and non-remote possibility) that the conduct of the planned burns will have a significant impact on the Southern Greater Glider as a species within the meaning of s 18(3) of the EPBC Act. A compounding series of non-remote possibilities of various events or consequences might not give rise to a real chance of a significant impact based on the combination of all of those events or consequences - in other words, the possibility that all of those events or consequences will occur together may be too remote. Conversely, the fact that the possibility of one or more events or consequences is less than 50% does not preclude a finding that there is a real and non-remote possibility of a significant impact based on the possible occurrence of all of those events or consequences. 385 I do not accept Dr Zylstra's evidence that a significant proportion of each of the planned burn areas will burn with high severity. As mentioned above, the applicant did not ultimately rely on the Zylstra report in support of such a conclusion. Nevertheless, for the following reasons, the modelling carried out by Dr Zylstra using FRaME cannot be relied upon to give a reliable prediction of the likely fire behaviour in conducting the planned burns. (a) The use of the FRaME model in the present context does not purport to be predictive of actual fire behaviour in the planned burn areas. At best, it serves as an illustration of the range of possible ways in which fire might behave in a theoretical stand of vegetation under various randomly selected conditions within parameters defined by reference to the prescriptions contained in the Delivery Plans for the planned burns. (b) The manner in which the stand was constructed by Dr Zylstra for such purposes does not necessarily reflect the actual vegetation or forest structure in any particular part of the planned burn areas, let alone throughout each of the planned burn areas. While the species that were chosen by Dr Zylstra do occur in the planned burn areas, they are not necessarily representative or exhaustive of the composition of the forest within the planned burn areas. Dr Zylstra had not himself visited the Strathbogie State Forest or any of the planned burn areas, and his selections were based on secondary sources or photographs and were influenced by the availability of information about particular species from his previous research. (c) It was not clear from Dr Zylstra's evidence how the results of the 1,000 different runs of the model could or should be translated into conclusions about fire behaviour across the planned burn areas. As the Secretary submitted, there was an "aspatial" quality to the modelling results. The random variable inputs applicable to each of the 1,000 model runs did not necessarily reflect different geographic locations within the planned burn areas on any given day on which the planned burns might be conducted, and therefore cannot be treated as leading to any conclusion about the proportion of the planned burn areas that might experience particular fire behaviour (for example, crown scorching). Further, it is unrealistic to use randomly generated variables (even within defined parameters) that do not take into account the potential relationship between each of those variables in any given location and even between different locations on the days on which the planned burn is conducted. (d) The outcomes of the FRaME modelling do not adequately take into account the range of measures that are available to burn operators in order to control the spread and intensity of the fire under planned burn conditions, including ignition methods, topography, weather conditions, and fuel moisture. Nor do they directly account for the fact that the decision whether or not to proceed with ignition will be made by an experienced burn officer having regard to all of the circumstances and available information, including weather forecasts, and contemporaneous wind speed and fuel moisture measurements. After ignition, the burn officers will continue to monitor the conditions in order to control the fire in the landscape. (e) The FRaME model is highly sensitive to small changes in the input variables which, in addition to affecting its reliability as a predictive tool, renders the model vulnerable to input errors. This was demonstrated by the error introduced by Dr Zylstra in relation to the range for fuel moisture content (or "DFMC"), which effectively meant that more than one-quarter of the modelled runs were based on a DFMC that was below the prescription in the Delivery Plans (in other words, an incorrect assumption that the fuel would be drier than is permitted by the prescription). This included the particular "case study" that was included in the Zylstra report to illustrate the possibility of crown fire. While Dr Zylstra sought to play down the effects of this error, by explaining that it did not significantly or materially change the conclusions to be drawn from the modelling, no attempt was made to correct the error nor to demonstrate the outcomes of running the model with the correct values. (f) While the inadvertent mistake in relation to the DFMC range does not of itself mean that the opinions expressed by Dr Zylstra are wholly unreliable, it is a cogent illustration of one of the criticisms levelled at the use of such mathematical or mechanistic models to make predictions of fire behaviour in the conduct of a planned burn. (g) Dr Zylstra's conclusion was based on a premise that any degree of crown scorch should be treated as a "high severity" fire, without attempting to distinguish between gradients or degrees of crown scorching. This was not consistent with other evidence about the manner in which fire severity is usually categorised. Even putting to one side medium or moderate crown scorch (between 20% and 80%), the evidence does not support a conclusion that low crown scorch (from 0% to 20%) indicates a fire that can be described as "high severity". Accordingly, in addition to the difficulty arising from the "aspatial" nature of the modelling, the conclusion expressed by Dr Zylstra that up to 77% of the planned burn area (in the case of the Barjarg burn, for example) will experience some degree of crown scorch does not establish that there will be high severity fire or high crown scorch in such an area. (h) Dr Zylstra's predictions of maximum flame heights of 26 to33 metres are inconsistent with the evidence of both Mr Hardman and Mr Lawlor as to their observations of flame heights in previous planned burns with which they have been involved. 386 I accept the evidence of Mr Hardman and Mr Lawlor in relation to the manner in which the planned burns will be conducted. Taking into account the experience of the officers involved in designing the Delivery Plans and the burn officers involved in carrying out the planned burns, I find that the burns are likely to be conducted in accordance with their objectives and prescriptions. It can be accepted that the objectives of fuel reduction burns in the Bushfire Moderation Zone are directed primarily to the reduction of bushfire risk to lives and property, with the highest priority being accorded to the protection of human life. Nevertheless, the applicable principles in planning fuel reduction burns in such areas accommodates the protection of ecological and environmental values. In the present case, the Delivery Plans address the significant values in relation to the Southern Greater Glider, and include some mitigation measures to reduce the impact of planned burning on high value habitat. In this regard, however, I note that there is general agreement that mitigation measures to protect hollow-bearing habitat trees will be limited to areas in relatively close proximity to control lines. 387 Nevertheless, while the aim of each planned burn is to use low-intensity fire to reduce surface, near-surface and elevated fuel without significantly impacting on the overstorey or canopy, I find that there is a real chance that some areas or patches within the planned burn areas might burn with higher intensity than planned, and may experience high-severity fire leading to high canopy scorch. The evidence suggests that the areas in which there is high scorch or fire in the canopy are likely to be in the vicinity of 1 to 2%, or perhaps as high as 2.5%, of the planned burn areas. On the evidence before me, I find that the balance of each planned burn area will experience either low or medium canopy scorch, or will not be reached by fire and will be unburnt. In this regard, the areas on or around south-facing slopes, gullies or drainage lines are more likely to be unburnt or to experience low canopy scorch. 388 I also find that there is no real chance that the planned burns will "escape" the boundaries of the planned burn areas, other than minor spotting that is capable of being controlled and extinguished by burn officers. Mr Lawlor gave evidence that minor spotting routinely occurs and is an anticipated part of many planned burns, and officers specifically patrol to detect and suppress these kinds of minor spot fires during and after a planned burn. Mr Hardman gave evidence that, although a small proportion of past planned burns have escaped beyond control lines, many such escapes have had little or no impact and very few are declared to be bushfires. Dr Meredith also considered that it was uncommon for planned burns to go beyond their boundaries. The suggestion that 2% of planned burns escape or become bushfires was not directly supported by any evidence (although the applicant sought to tender a statement on the FFMVic's website to the effect that planned burn escapes amount to about 2% of all bushfires on public land). Having regard to all of the evidence, including the measures taken by burn officers to conduct and control a planned burn, I find that any possibility that these four planned burns might escape beyond control lines is no more than a remote chance. 389 These findings are generally supported by the evidence of Mr Hardman, Mr Lawlor and Dr Penman as set out above. Further, they are consistent with the outcomes of past planned burns conducted in the Hume region (see the 2023 Hume Region Annual Review discussed at paragraph 269 above) including the Strathbogie State Forest. In relation to the latter, the Secretary relied on maps showing the extent of planned burns in the Strathbogie State Forest in each decade since 1960. In more recent decades, the maps sometimes showed the areas that were actually burnt. In addition, the Secretary produced fire severity mapping in relation to a number of more recent planned burns conducted in the Strathbogie State Forest - these included planned burns at Warrenbayne - Jones Hill - Moonee Range in 2021, Tallangalook Road in 2022 and Mt Strathbogie in 2022. In each case, the majority of the planned burn area was classified as unburnt or low canopy scorch, with a small proportion of medium canopy scorch and (in one case) a very small area of high canopy scorch. In another fire severity map in relation to a planned burn at Barjang - Nillahcootie Track in 2020, around 50% of the area was unburnt and the balance was shaded as "burnt unclassified". While the fire severity map in relation to the Tames Road planned burn, on which the applicant relied, showed a higher proportion of the area that was classified as "high canopy scorch", there were still large areas that were unburnt, particularly around apparent drainage lines, or classified as low/medium canopy scorch. 390 For the following reasons, I do not accept the case that was advanced by the applicant in closing submissions based on the predicted fire behaviour using the McArthur meter. 391 The applicant submitted that the best evidence of how the planned burns might behave was derived from the application of the McArthur meter to the fuel hazard ratings and prescriptions in the Delivery Plans. The applicant sought to put such propositions to Mr Lawlor during cross-examination, in order to establish that there is a likelihood under the burn prescriptions of flame heights that are inconsistent with a low-intensity fire, which would lead to crown scorch or even crown fire. 392 In this regard, the applicant relied on the following table that forms part of the physical copy of the McArthur meter tendered by the applicant: 393 It should be noted that the copy of the McArthur meter also includes the following statements about "fire behaviour relationships": ... The meter is designed for general fire danger forecasting purposes and is based on the expected behaviour of fires burning for an extended period in high eucalypt forest carrying a fuel quantity of 12.5 tonnes per hectare and travelling over level to undulating topography. The behaviour of individual fires can be predicted with reasonable accuracy providing the effect of fuel quantity and slope is taken into account. The variation of some fire behaviour characteristics with fuel quantity is shown below. ... Fires travel upslope with the prevailing wind faster than on level ground. A five degree slope increases spread by 33 per cent; a ten degree slope by a factor of two and a twenty degree slope by a factor of four. Corresponding reductions occur on downslopes. ... The meter can be used to determine broad control burning conditions although a high degree of precision should not be expected. Buning at an index greater than twelve (12) would be very risky except in very light fuel types. ... Atmospheric instability is not indicated as a factor affecting fire behaviour. However, the rates of spread indicated are for generally unstable conditions and may be less under conditions of stability. 394 Taking the Delivery Plan for the Lima East burn, for example, the applicant made the following submissions. (a) There is a real chance that up to 70% of the area (or approximately 470 hectares) will be burnt. (b) The recorded fuel hazard scores for the various fuel layers represent an estimated fuel quantity of 27 to 34 tonnes per hectare (based on Table 9.2 in the Fuel Hazard Assessment Guide). (c) The prescribed maximum FDI is 10 on day one, and 12 on day two. There is no prescribed maximum FDI for the third ignition day, nor for any of the three patrol days. Similarly, there is no prescribed maximum for temperature or wind speed other than on day one, nor for drought index or fuel moisture. The applicant contended that there is a real chance that the FDI might be higher than 12 on those days for which there is no prescribed maximum, and there might be "spike" days on which there is a large and unexpected increase in the FDI. (d) The applicant relied on the table contained in the physical version of the McArthur meter to predict that the flame height on day one of the Lima East burn will be "well over 7 metres", based on a FDI of 10 and a fuel quantity of more than 25 tonnes per hectare. The table in the McArthur meter relevantly states that, at a fuel quantity of 25 tonnes per hectare and FDI of 10, the predicted flame height is 7.0 metres (with a rate of spread of 0.3 km/h and spotting distance of 800 metres). The applicant contended that it can be expected that flame heights will be even higher on day two, when the prescribed maximum FDI is 12. (e) The applicant submitted that, if the fuel quantity is at the top of the estimated range and the FDI moves above 12 on days three to six of the planned burn, there is a realistic possibility of crown fire. 395 The applicant engaged in a similar analysis in relation to each of the other planned burn areas, so as to predict flame heights of 3 to 7 metres for Barjarg, 3.5 to 5 metres for Ruoaks Road and 5 to 7 metres or more for Tallangallook. 396 Based on this analysis, the applicant contended that there is something wrong (or seriously wrong) with the prescription for each of the planned burns, and that the maximum FDI should be substantially reduced. The applicant submits that the fuel hazard scores in each of the planned burn areas "call for exceptional caution in the conduct of these burns", and that the FDI should be kept to 5 or lower in order to keep flame heights at the desired level associated with a low intensity burn. The applicant sought to distinguish the evidence of Mr Lawlor and Mr Hardman regarding their own observations of flame heights in past fuel reduction burns on the basis that there was no evidence about the conditions of those burns, including in particular the fuel loads. 397 In my view, the evidence does not support the use of the McArthur meter in this fashion to support such findings. Mr Lawlor gave evidence about the McArthur meter as underpinning the FDI, and its use as one of the tools used in the development of the prescriptions for the planned burns. However, there is no evidence that the McArthur meter is used, or designed for use, to predict fire behaviour in a planned burn. While it was put to Mr Lawlor that the McArthur meter predicted flame heights of more than 7 metres in Lima East under the prescribed conditions, he was not directly challenged on his evidence that flame heights in planned burns are typically well below 3 metres. I do not consider that it is open to rely on Mr Lawlor's evidence to support a positive proposition that the McArthur meter can be used to predict flame heights in excess of 3 metres. 398 More generally, there was little (if any) evidence as to whether or to what extent fire behaviour models are or can be used to predict the behaviour of a planned burn. To the extent that the evidence touched on the use of models (including McArthur, Phoenix Rapidfire and Vesta), they appear to be used primarily to predict fire behaviour of uncontrolled fires under different conditions. It is not clear that such models are designed to take into account the specific decisions made or measures adopted by burn operators in order to control a planned burn. While there was some evidence that the Secretary performs modelling of bushfire behaviour in its assessment and implementation of fuel management strategies and plans, there is no direct evidence that it models the predicted behaviour of the planned burns themselves. For example, Dr Penman described Dr Zylstra's "attacks" on the Phoenix Rapidfire model as "futile as Phoenix is not used by any agency for prediction of fire behaviour within prescribed burns", noting that "Phoenix was never designed to do this". 399 Differing views were expressed by Dr Penman and Dr Zylstra respectively as to the use of the McArthur and Vesta models, including the question of which model should be regarded as the "industry standard". However, on the state of the evidence and having regard to the issues raised in the present proceeding, this Court is not in a position to make any findings about the relative advantages and disadvantages of competing fire behaviour models, nor to attempt to wade into any area of potential debate in that regard. 400 Accordingly, in so far as applicant submitted that the Court should draw an adverse inference from the Secretary's failure to produce modelling of the predicted behaviour of the planned burns using Vesta, there is an insufficient basis (including what any such modelling is directed to and what it might be capable of demonstrating) to be able to draw any such adverse inference. 401 In addition, the applicant's reliance in closing submissions on a version of the McArthur meter does not sit comfortably with the evidence given by Dr Zylstra, who also performed modelling of expected fire behaviour "using the standard industry approach based on McArthur (1967) and contained in the CSIRO fire modelling tool 'Amicus'" (citations omitted). (Dr Zylstra clarified in his reply report that he had subsequently realised that Amicus used an earlier 1962 McArthur model.) The results of that modelling predicted low to moderate fire intensities, with maximum flame heights between 0.3 metres and 1.5 metres, or 0.5 metres to 2.3 metres if the weight of near-surface fuels was included. Such flame heights are consistent with the evidence of Mr Lawlor. The predicted height of crown scorch using Amicus was between 2.1 metres and 10.5 metres (or 3.5 metres to 16.1 metres including the weight of near-surface fuels). Dr Zylstra's conclusion was that, under modelling based on McArthur's equations, scorch height "was not sufficient to scorch the tree canopies, which had a mean base height of 12.4 metres". More generally, Dr Zylstra was adamant that surface fuel load is not itself a good predictor of fire intensity or severity. 402 While the applicant sought to distinguish these conclusions on the basis that they did not take into account bark and elevated fuels, I nevertheless consider that Dr Zylstra's modelling casts significant doubt on the applicant's submission based on flame heights using the McArthur meter. I also note that surface and near-surface fuels are by far the highest contribution to the indicative fuel loads calculated under the Fuel Assessment Guide. At the end of the day, there was simply no expert evidence to support a use of the table contained in the physical version of the McArthur meter directly to calculate predicted flame heights. The simple application of that table does not take into account variations in topography, nor the differing fire behaviour in areas such as south-facing slopes, gullies and drainage lines. Nor does it take into account the role of burn operators in conducting a planned burn to achieve its objectives, both in deciding whether and when to ignite the planned burn and in adopting measures to control the burn after its ignition, including in the event of any unanticipated change in weather conditions.

Direct effects of fire on Southern Greater Gliders. 403 To the extent that it remains relevant, I do not accept Dr Zylstra's conclusion that "high severity fire" (in the sense in which he uses that term) is likely to kill a "small to medium proportion" of Southern Greater Gliders through burns or asphyxiation. As discussed below, there is other evidence to support a finding that there is a real possibility that high severity fire resulting in high crown scorch might kill some individual gliders that are present in the affected areas. However, the approach adopted in the Zylstra report seeks to extrapolate a general conclusion about the direct effects of the fires on Southern Greater Gliders by modelling the temperatures at a single percentile of flame height, which constitutes only one of the 1,000 different "runs" of the FRaME model. In addition to my observations set out above concerning the limitations of the FRaME modelling in the present context, Dr Zylstra did not specify either in his reports or in his oral evidence what the flame height was at that particular percentile, nor what other variables had been applied in that run of the model. He chose the 90th percentile of flame height on the basis that it showed what was likely to happen at the "worse ends of fire behaviour" but not the "most extreme example", which was said to represent a "one in ten" or 10% chance. Apart from stating that he considered that similar outcomes would also occur at lower flame heights under the 90th percentile, there was no modelling performed in order to demonstrate the effects on Southern Greater Gliders at differing flame heights, or what percentile of flame height might be regarded as a threshold above which mortality was likely to occur. More generally, Dr Zylstra did not have any particular expertise on Southern Greater Gliders. 404 The applicant did not ultimately rely in its closing submissions on Dr Zylstra's evidence about the effects of fire on Southern Greater Gliders in the planned burn areas. Instead, the applicant sought to estimate the number of individual gliders that may be directly killed by the planned burns by calculating how many gliders might be present in areas where there is "substantial canopy scorch", and adding the number of gliders that might be present in hollow-bearing trees that collapse as a result of the planned burns. (a) The applicant submitted that, if there is substantial canopy scorch across the planned burn areas, many or even most Southern Greater Gliders present in the areas that are burnt will die. Based on an estimated density of 0.96 gliders per hectare (taken from Cripps et al, Double-observer distance sampling improves the accuracy of density estimates for a threatened arboreal mammal (2021) 48(8) Wildlife Research 756), and a total burnt area of up to 1,290 hectares across all four planned burn areas (taken from the burn objectives in the Delivery Plans), the applicant submitted that there is a real chance that 1,238 individual gliders will die as a result of the planned burns. (b) Alternatively, under what was described as a "low severity assumption", the applicant submitted that there is nevertheless a real chance of crown fire or high canopy scorch in 2.3% of the planned burn areas (based on the 2023 Hume Region Annual Review). Based on the estimated density of gliders in the burn areas, this would directly kill up to 28 or 29 individual gliders that are present in those areas affected by high canopy scorch or canopy burn, having regard to the fact that gliders shelter in hollows during the day and have no known effective strategy to escape fire. (c) In addition, the applicant submitted that there is a real chance that the collapse of hollow-bearing trees as a result of the planned burns will kill up to 322 individual gliders that are present in such trees when they collapse. This is based on assumptions that 26% of the hollow-bearing trees reached by fire will collapse (relying on Bluff (2016)), that there is a density of 0.96 gliders per hectare, and that a glider will always die if it is sheltering in a hollow-bearing tree at the time of its collapse. On those assumptions, the figure of 322 gliders is produced by multiplying the area reached by fire (1,290 hectares) by the glider density (0.96 per hectare) by the tree collapse rate (26%). 405 For the reasons set out above, the evidence does not support a finding that there will be substantial canopy scorch of such a degree as to kill or injure Southern Greater Gliders across the entire area reached by fire in the planned burn areas. Further, I note that Dr Zylstra identified as one of the "knowledge gaps" that "[i]t has not been shown that crown scorch is synonymous with first-order impacts on Greater Gliders". There is no evidence that establishes a direct link between canopy scorch of any particular degree and mortality to gliders. There is evidence to suggest that gliders are not generally harmed by low intensity fire with surface flames that do not reach the canopy and do not cause significant canopy scorch. Accordingly, I do not accept that there is a real chance that every Southern Greater Glider that is present in areas reached by fire during the planned burns will be killed from the direct effects of heat or smoke. 406 However, based on the evidence of Dr Swan and Dr Meredith, it is possible that individual Southern Greater Gliders will be killed or injured by fire that results in high canopy scorch or crown fire. I therefore find that there is a real chance that Southern Greater Gliders will be killed if they are present in areas that are affected by high severity fire resulting in high canopy scorch or crown fire. On the evidence, this is likely to be no more than between 1% to 2.5% of the planned burn areas. 407 The evidence does not establish a real chance that Southern Greater Gliders will be directly killed by the effects of fire in areas that are affected by low intensity fire with no crown scorch, low crown scorch, or medium crown scorch. I have some reservations about Dr Swan's evidence about the possible effects of low or moderate canopy scorch on Southern Greater Gliders. His supplementary report was directed primarily to reaffirming his conclusions in relation to the areas that were affected by high severity fire, in the light of the outcomes in the 2023 Hume Region Annual Review which indicated that 2.3% of planned burns areas in the Hume region were categorised as either "high canopy scorch" or "canopy burnt". While Dr Swan stated in his oral evidence that he had also taken into account the proportion of the areas that experienced a lower degree of canopy scorch, he was unable to say what would happen in those areas other than to state that the risk of mortality is greater where there is high severity fire. It was implicit in his answers that he accepted that there might be some risk at the upper end of the category of medium scorch, which presumably means that he did not consider that "low" canopy scorch would be a risk factor. Notwithstanding the limitations of Dr Swan's evidence, however, there is no other evidence indicating that low or medium canopy scorch poses a direct risk to Southern Greater Gliders. 408 It is common ground that there is a large population of Southern Greater Gliders across the Strathbogie State Forest. No survey or other evidence was put before the Court in relation to the distribution of this population either generally or within the planned burn areas. Without any direct evidence as to the quantity or distribution of gliders in the planned burn areas, it is difficult to estimate with any precision the number of individuals gliders that are likely to be killed in those patches or areas within the planned burn area that might be affected by high severity fire. Dr Swan accepted that an individual glider in an area affected by high canopy scorch might be killed or injured through heat exposure, but considered that this is likely to be minor in extent given the limited area of high canopy scorch. Dr Meredith generally agreed with Dr Swan's main conclusions, and considered that, putting to one side the unlikely scenario of an extreme failure in fire control, direct mortality of gliders from fire would be "a relatively minor impact" which, "even if it occurred", would be difficult to distinguish from background levels of mortality (for example, through predation by Powerful Owls). 409 In the circumstances, I accept that there is a real and not remote possibility that one or more individual Southern Greater Gliders in any areas affected by high canopy scorch or crown fire may be directly killed from the effects of heat or smoke. 410 In relation to the direct effects of the possible collapse of hollow-bearing trees, the abundance of hollow-bearing trees in the planned burn areas is not known. In the absence of that information about abundance, the calculation put forward in the applicant's closing submissions is based on a premise that is either incorrect or at least unsupported by the evidence, namely that the number of hollow-bearing trees is equal to the number of gliders (i.e. that the mortality from tree collapse can be estimated by applying the collapse rate to the total number of gliders in the planned burn area). On the contrary, there is evidence that each glider may use multiple den trees within its home range and that, while there might be some den sharing, it is likely that the abundance of hollow-bearing trees is greater than the abundance of gliders. It also cannot be assumed that a glider will be present in every hollow-bearing tree at the time of its collapse, which might possibly be days or weeks after the planned burn, and taking into account that dead trees are more prone to collapse and that Southern Greater Gliders have a preference for live hollow-bearing trees. 411 It is not in dispute that hollow-bearing trees in the planned burn areas may collapse during or after the fire, and that the collapse rate may be higher than would generally apply in the absence of the planned burns. In other words, I accept that the planned burns may bring about the collapse of some hollow-bearing trees or render them more vulnerable to collapse, and that there is therefore a real chance that there will be some reduction in the abundance of hollow-bearing trees in the planned burn areas at least in the medium term. It is difficult to estimate the precise rate of collapse of hollow-bearing trees following a planned burn. There is one study (Bluff 2016) which found a collapse rate of up to 26%, while another study (Cowie 2016) estimated a collapse rate of around 15%. Dr Meredith considered that a collapse rate of 25% would be "unusually high", and instead suggested a collapse rate of between 15% and 20%. It appears to be accepted that the collapse rate is higher in relation to hollow-bearing trees that are dead. 412 In estimating mortality from the direct effects of both fire and tree collapse, there are obvious dangers in attempting to adopt a mathematical approach based on an assumed density of gliders and the size of the affected areas. The evidence supports an inference that gliders are more likely to be found in the most suitable habitat which is found in wetter areas such as south-facing slopes, gullies and drainage lines, and such areas may be less likely to experience high severity fire. There is also evidence that Southern Greater Gliders have a preference for live hollow-bearing trees where available, and such trees have a lower risk of collapse following a fire. I cannot adopt the applicant's submission that the planned burns may kill up to 28 or 29 gliders from the direct effects of fire, and about 322 gliders from the direct effects of tree collapse. Particularly in relation to the latter, the extent of any mortality is likely to be far lower. 413 I accept that the Strathbogie State Forest contains a large population of Southern Greater Gliders and that this population is important to the conservation of the species, which is listed as endangered and is facing a very high risk of extinction in the wild in the near future. Accordingly, I find that an action that has a significant impact on the population of Southern Greater Gliders in the Strathbogie State Forest may be regarded as having a significant impact on the species for the purposes of s 18(3) of the EPBC Act. 414 For the reasons set out above, I find that there is a real chance that a relatively small number of Southern Greater Gliders may be killed by the direct effect of the planned burns, whether by the effects of high severity fire or by the resulting collapse of hollow-bearing trees. However, in all of the circumstances, I am not satisfied that the mortality of Southern Greater Gliders will reach a level that amounts to an adverse impact on the species that is important, notable or of consequence. In particular, I find that any mortality of Southern Greater Gliders as a direct result of the planned burns is not likely to lead to a long-term decrease in the size of the population in the Strathbogie State Forest, nor to reduce the area of occupancy of the species, nor to fragment the existing population into two or more populations, nor to disrupt the breeding cycle of the population. I will consider separately below whether there are likely to be any adverse effects on habitat critical to the survival of the species. 415 Accordingly, the direct effects of the planned burns are not likely to have a significant impact on the Southern Greater Glider population in the Strathbogie State Forest, nor on the species as a whole, within the meaning of s 18(3) of the EPBC Act. 416 For completeness, I note that the applicant placed some reliance on the conclusions reached by Mortimer J in Friends of Leadbeater's Possum at [1433] ff in relation to the significant impact of VicForests' forestry operations on the Greater Glider. Since that decision, the Southern Greater Glider has been elevated from the vulnerable category to the endangered category on list of threatened species under the EPBC Act. Justice Mortimer noted the high rate of decline in the population of Greater Gliders in the Central Highlands, and that its prime habitat largely coincided with areas suitable for logging. In that case, there was survey evidence and modelling as to the numbers of gliders in the logged coupes. Justice Mortimer accepted estimates of up to around 600 gliders affected by the forestry operations in those coupes, and inferred that "a not insignificant proportion of them may have been killed", especially given that the gliders are nocturnal and therefore more likely to be in their dens during the day when forestry operations took place. Justice Mortimer at [1442] considered that such numbers were "beyond negligible" and were a notable effect. The numbers of gliders that may be killed were material - … not so much as individual members of the species, but because losses of that number of individuals is capable of affecting genetic diversity, the density levels of the Greater Glider in particular areas of forest and what might then occur as they come together from their otherwise rather isolated existence to breed. Effects on this number of individual animals is capable of further weakening the Central Highlands population as a whole. Further, the fact of such considerable numbers illustrates the actual - not potential - value of the habitat in the impugned coupes to the Greater Glider. These matters support a conclusion of significant impact. 417 Justice Mortimer also had regard to the value of the habitat in the relevant coupes "in a qualitative sense", finding that it included high quality habitat with abundant large old hollow-bearing trees. Her Honour found that such habitat could justifiably be described as "critical" habitat, the destruction of which was a contributing factor to the conclusion of significant impact. In this regard, Mortimer J found on the evidence in that case that the forestry operations would remove the habitat in the relevant coupes, and that the quality of the habitat to support the Greater Glider was unlikely to be regained. Her Honour rejected the contentions advanced by VicForests that the impact was not significant because of the amount of habitat available for the Greater Glider within the Comprehensive, Adequate and Representative reserve system. Justice Mortimer found that the forestry operations were "geographically and numerically extensive", and were likely to have a significant impact on the Greater Glider. For such purposes, the statutory concept of significant impact was not limited to avoiding, or attempting to mitigate the likelihood of, extreme situations such as extinction in the wild, nor was it restricted to ensuring that a listed threatened species does not move from one threatened category to a worse one. 418 As the Secretary submitted, the findings made by Mortimer J were made in a different factual context and were based on different evidence, and do not dictate the proper conclusion on the facts of the present case. The proceedings in Friends of Leadbeater's Possum involved the complete removal of habitat by logging, or at least rendering such habitat unsuitable for the Greater Glider in the medium to long term. There was also direct evidence in that case about the numbers of gliders present in the relevant areas that would be affected by the proposed action, based in part on extensive field work directed to "what is actually in the coupes, not what is mapped or modelled, or extrapolated, or what is hypothetical": Friends of Leadbeater's Possum at [245]. 419 Accordingly, I do not consider that there is anything raised in Friends of Leadbeater's Possum that is inconsistent with the findings that I have made in the present case.

Effects of planned burns on hollow-bearing trees and habitat 420 The next question is whether the planned burns are likely to have a negative effect on habitat in the planned burn areas that amounts to a significant impact on the Southern Greater Glider. 421 The applicant submitted that the Court should accept that there is a real chance that 26% of hollow bearing trees reached by fire will collapse after the four planned burns are conducted. The applicant relies on a study conducted by Bluff (2016) who found that, following a planned burn in Eucalypt forest, approximately 26% of hollow bearing trees reached by fire collapsed (being 20% of hollow bearing trees in the planned burn area). The applicant submits that the expert evidence in the present case essentially did not improve on this study of the effects of planned burns "presumably under low intensity conditions". The applicant submits that such a rate of collapse is substantial, resulting in the loss of more than a quarter of the habitat trees in the area of 1,290 hectares that will be reached by fire under the planned burns. The applicant further submits that these areas represent "perhaps 10% of the best quality habitat" for the Southern Greater Glider in the Strathbogie State Forest, and that suggested mitigation measures in relation to the protection of hollow-bearing trees from fire are not sufficient to bring the impact beneath the threshold of "significant impact". 422 The applicant submitted that Dr Swan had accepted there was a real chance that the planned burns might result in a reduction in the abundance of the Southern Greater Glider in the planned burn areas. The applicant submitted that such a reduction in abundance is a significant impact on the Southern Greater Glider in the Strathbogie State Forest and on the species as a whole, given that it is facing a very high risk of extinction in the wild in the near future based on an overall decline in its population. 423 The Secretary submitted that the applicant had failed to lead sufficient evidence to enable the Court to be satisfied that the collapse of hollow-bearing trees during or after the planned burns is likely to have a significant impact on Southern Greater Gliders, particularly in the absence of evidence in relation to the local abundance of Southern Greater Gliders relative to the local abundance of hollow bearing trees. The Secretary submitted that any hypothesised collapse rate of hollow-bearing trees was "a poor predictor" of the impact on Southern Greater Gliders in the circumstances of the present case, noting that: (a) Southern Greater Gliders prefer to use live hollow-bearing trees, which have a far lower collapse rate than dead hollow-bearing trees; (b) the preferred habitat of Southern Greater Gliders is around south-facing slopes and moist areas associated with drainage lines or creeks, and these areas are more likely to remain unburnt; and (c) the severity of fire is important to the collapse of hollow-bearing trees, and there was evidence the effect that some portions of the planned burn areas are long unburnt and less flammable. 424 In respect of Dr Swan's acceptance that there might be a reduction in the abundance of Southern Greater Gliders as a result of the collapse of hollow-bearing trees, the Secretary submitted that any such possible reduction in abundance was no more than an abstract proposition that was not tied to any predicted effect on the population or its area of occupancy, let alone an extrapolation to the population in the Strathbogie State Forest or the species as a whole. 425 Taking into account all of the evidence, I find that there is a real chance that a proportion of hollow-bearing trees in the planned burn areas will collapse during or after the planned burns. While I understand that there is a pre-existing "background" rate of collapse of hollow-bearing trees in eucalypt forests, the collapse rate is increased following fire events, including planned burning. As there are only a few published studies, it is difficult to estimate the collapse rate with any precision, but the evidence suggests that it is likely to be somewhere between 15% and 25% of the hollow-bearing trees in areas that are reached by fire, with dead hollow-bearing trees having a higher risk of collapse. As a consequence, the conduct of the planned burns is likely to lead to an overall decrease in the abundance of hollow-bearing trees in the planned burn areas. 426 In this regard, while the Delivery Plans for each of the planned burns include some mitigation measures directed to the protection of hollow-bearing trees, including raking around or wetting the base of such trees, those measures will largely be limited to hollow-bearing trees that are along the perimeter of the planned burn areas or adjacent to control lines or patrol lines. Those measures will not protect the majority of hollow-bearing trees that will be reached by fire within the planned burn area. 427 However, the evidence does not establish on the balance of probabilities that there is a real chance that such a reduction in abundance of hollow-bearing trees will have a significant impact on the Southern Greater Glider population in the Strathbogie State Forest, or on the species as a whole. 428 There is no evidence as to the number of hollow-bearing trees (whether live or dead) present in any of the planned burn areas, nor as to the distribution of hollow-bearing trees within those areas. Nor is there any evidence as to the number of hollow-bearing trees that might be in use by individual gliders in the planned burn areas at any particular time. In the absence of such evidence, it is a matter of speculation as to whether the reduction in the abundance of hollow-bearing trees will have any impact, let alone a significant impact, on the abundance of gliders present in the planned burn areas. Even if it is accepted that there might be some reduction in the abundance of gliders in the planned burn areas (which was accepted by Dr Swan but is not otherwise definitively established by the evidence), it is not clear that any such reduction would be substantial. The planned burns are less likely to reach areas that are not intended to be burnt, or that are unlikely to be burnt because they have a higher fuel moisture content, including areas around south-facing slopes, gullies or drainage lines, which would remain suitable and perhaps preferred habitat for Southern Greater Gliders. 429 Further, and in any event, it cannot be concluded that any reduction in the abundance of gliders in the planned burn areas from the reduction in available hollow-bearing trees might be such as would constitute a significant impact on the population of gliders in the Strathbogie State Forest, and thereby a significant impact on the species. This is consistent with the evidence that, notwithstanding the conduct of several planned burns over past decades in different areas within the Strathbogie State Forest, there has continued to be a robust population of Southern Greater Gliders that appears so far to have resisted the declines that have been observed in other regions. On the other hand, I am careful not to place too much weight on the past conduct of planned burns, in circumstances where large parts of the areas in question in the present case have remained relatively unburnt by either planned or unplanned fires. 430 Nevertheless, having regard to the burn history in the Strathbogie State Forest and in the burn areas, together with my findings about the likely behaviour and effects of the planned burns, none of the four planned burns is likely to involve fire that is either "too intense" or "too frequent", in the terms referred to in the Conservation Advice when addressing the threats to the Southern Greater Glider. 431 Finally, while there was some evidence directed to the risk that hollow-bearing trees in the planned burn areas might be scarred by fire, causing structural damage that rendered those trees more vulnerable to future collapse in the event of a subsequent planned or unplanned fire, this was never pleaded or particularised by the applicant as a significant impact for the purposes of s 18(3) of the EPBC Act, and was not independently relied on in closing submissions.

Issue 2: Do the planned burns fall within the exemption in s 43B of the EPBC Act?

Overview of submissions 432 The Secretary submitted that, irrespective of whether the planned burns are likely to have a significant impact on the Southern Greater Glider for the purposes of s 18(3) of the EPBC Act, they involve the lawful continuation of a use of land that was occurring immediately before the commencement of the EPBC Act on 16 July 2000 within the meaning of s 43B of the EPBC Act. For such purposes, the Secretary contends that planned burning has long been a major and important part of the State's work to protect Victoria from bushfires, and that that planned burning has been carried out in the Strathbogie State Forest (including the planned burn areas) since the 1960s. 433 The Secretary submitted that ss 43A and 43B, contained in Div 6 of Pt 4 of the EPBC Act, show a broad intention to "grandfather" actions that have already been approved or recognised as lawful land management practices. Section 43A deals with actions that were specifically approved prior to the commencement of the EPBC Act by an authorisation under a Commonwealth, State or Territory environmental law which remains in force (or, in some circumstances, a renewal or extension of such an authorisation). Section 43B deals with actions that, while not authorised by a specific environmental authorisation that continues to be in force, involve a lawful continuation of a pre-existing use of land, sea or seabed. 434 In the Secretary's submission, planned burning is a relevant use of land for the purposes of s 43B, which is "lawful" in that the Secretary has authority to engage in planned burning under s 62(2)(b) of the Forests Act. The Secretary submits that, although planned burning may be intermittent, s 43B does not require actions involved in a use of land to be "continuous" and does not exclude actions that are only carried out from time to time. In this regard, the Secretary seeks to draw an analogy with s 359A of the EPBC Act, which deals in a different context with the continued traditional use of an area in a Commonwealth reserve for hunting or food gathering or for ceremonial and religious purposes, being uses which may be periodic or sporadic in nature. The Secretary also refers to the possibility of continuing uses of land that involve recurrent seasonal activities, such as some farming activities. 435 The Secretary submitted that, for the purposes of s 43B, the concept of "land" on which a continuing use is identified is broader than the specific location on which an instance of that use is proposed. This is said to be supported by the terms of s 43B(3)(i), which expressly contemplate changes in the location of where the use of the land is occurring. Accordingly, the Secretary submitted that the "land" in question in the present case is not limited to the planned burn areas, but is more naturally identified as the land comprising the Strathbogie State Forest. This is said to accord with a "sensible, practical application" of the EPBC Act as opposed to one that is overly complex or technical: see Friends of Leadbeater's Possum at [1292] (Mortimer J). The Secretary also noted that "guidance" published by the Commonwealth Department of Climate Change, Energy, the Environment and Water (DCCEEW) refers to "activities done cyclically over long periods of time such as works to reduce the fire risk", including "routine controlled burns of the type that have occurred in the past", as examples of actions that may be within s 43B of the EPBC Act: see Commonwealth DCCEEW, "Bushfire management and national environment law" (https://www.dcceew.gov.au/environment/epbc/publications/factsheet-bushfire-management-and-national-environment-law) (as at 10 August 2022). 436 The Secretary relies on the evidence about the history of planned burns in Victoria and, more specifically, the evidence on the history of planned burns in the Strathbogie State Forest since the 1960s, as recorded in a Fire History Database held by the State Government and depicted in a series of maps exhibited to the affidavit of Mr Hardman which show the location and extent of planned burning in each decade. The Secretary therefore contends that planned burning was an established land management practice in the Strathbogie State Forest immediately before the commencement of the EPBC Act, with a planned burn having been conducted as recently as April 2000. Further, the Secretary contends that the practice of planned burning has continued in the Strathbogie State Forest since 16 July 2000. (a) In the decades leading up to 2000, the total area subject to planned burns in the Strathbogie State Forest was approximately: (i) 2,334 hectares in the 1970s; (ii) 3,039 hectares in the 1980s; and (iii) 4,122 hectares in the 1990s. (b) In the period since 16 July 2000, the total area subject to planned burns in the Strathbogie State Forest was approximately: (i) 3,466 hectares from July 2000 to 2009; (ii) 3,715 hectares from 2010 to 2019; and (iii) 682 hectares from 2020 to present. 437 The Secretary also relies on the planned burning that has previously been carried out on parts of the four proposed burn areas, which is detailed in the Delivery Plan of each burn. 438 In so far as the applicant submits that the four planned burns would constitute an enlargement or expansion of any pre-existing use, or a change in location that will result in a substantial increase in the impact of that use on the land within the meaning of s 43B(3), the Secretary argues that the applicant either has not properly pleaded such an allegation or has not discharged its onus to prove the additional or special facts necessary to attract the "proviso" in s 43B(3). In any event, the Secretary contends that s 43B(3) is not engaged because: the size of the proposed planned burns is in line with historical figures, and does not involve any expansion or enlargement of such use; there has not been any change in the essential nature of the activities comprising the use since the commencement of the EPBC Act; and any changes in the location of planned burns within the Strathbogie State Forest from time to time is an inherent and inevitable feature of planned burning practice which does not have a substantial negative impact on the land. 439 The applicant contends that s 43B(1) and (3) should be treated as a single exception in respect of which the Secretary bears the onus of proof, at least in the context of a claim for injunctive relief under s 475 of the EPBC Act. In order for the Secretary to establish that the defence in subs (1) applies, the applicant submits that it is necessary for the Secretary to establish that the case is within the limits to that defence in subs (3). 440 While the applicant accepts that fuel reduction burning may be regarded as a use of land, it submits that there was no use of the land in question for planned burning immediately before the commencement of the EPBC Act on 16 July 2000. In this context, the applicant submits that it is inappropriate to treat the relevant "land" as the Strathbogie State Forest as a whole, having regard to the fact that it comprises multiple individual parcels of land in accordance with declarations that may change over time. Rather, the applicant submits that the better view is that the "land" for the purposes of s 43B is identified by reference to the specific boundaries of the four proposed planned burn areas. 441 Further, the applicant submits that a use of land that is necessarily discontinuous and intermittent or that occurs irregularly and infrequently cannot, in the applicant's submission, meet the statutory requirement of a "continuation" of a use of land. 442 In relation to the planned burn history in the Strathbogie State Forest prior to 16 July 2000, the applicant submits that there is minimal overlap with the current planned burn areas. Accordingly, the applicant contends that the four planned burns are an enlargement or expansion of fuel reduction burning for the purposes of s 43B(3)(a), or involve a change in location of the use that will have a substantial increase in the impact of the use on the land for the purposes of s 43B(3)(b). In this context, the applicant notes that a substantial increase in the impact of the use of the land within the meaning of s 43B(3)(b) is not to be equated with a significant impact on a listed threatened species within the meaning of s 18(3) of the EPBC Act.

Consideration 443 Section 43B of the EPBC Act is reproduced above. It provides an exemption to the requirement to obtain an approval under Pt 9 of the EPBC Act in respect of an action that is "a lawful continuation of a use of land, sea or seabed that was occurring immediately before the commencement of this Act" (which occurred on 16 July 2000). For such purposes, s 43B(2) provides that the exception does not apply (that is, the requirement for approval under Pt 3 continues to apply) in respect of: (a) an enlargement, expansion or intensification of use; or (b) any change in the location of where the use of the land, sea or seabed is occurring, or in the nature of the activities comprising the use, that results in a substantial increase in the impact of the use on the land, sea or seabed. 444 The first step involved in the application of s 43B requires the identification of a use of land, sea or seabed that was occurring immediately before 16 July 2000, and the question whether (putting to one side the qualifications in subs (2)) the relevant "action" can be characterised as a lawful continuation of that use. Where there was a pre-existing use of land, sea or seabed immediately before 16 July 2000 that is continued after that date, the next question is whether that use is enlarged, expanded or intensified, or whether there is a substantial increase in the impact of the use on the land as the result of a change in the location of the use or the nature of the activities comprising the use. 445 Section 43B has not received extensive judicial consideration. In Huon Aquaculture Group Ltd v Minister for the Environment [2018] FCA 1011; 160 ALD 292, Kerr J dismissed an application for judicial review of a decision made by the Commonwealth Minister that a proposed expansion of fish farming operations conducted under pre-existing marine leases was not a "controlled action" if implemented in a particular manner. It was not disputed that the lessees were entitled to continue marine farming after the commencement of the EPBC Act, and that their individual entitlements were "grandfathered" by s 43B of the EPBC Act: see at [22]. However, this was subject to the qualification that there not be any enlargement, expansion or intensification of that use of the land, sea or seabed within s 43B(3): at [23]. The context in which this issue arose in Huon Aquaculture was somewhat complicated, in that it involved a question whether a subsequent "repudiation" of an enlargement, expansion or intensification of use within s 43B(3) could "revive" the person's entitlement to continue the original (i.e. pre-commencement) use without approval: at [183]. In that context, Kerr J concluded that the protection of s 43B was unavailable if the subsequent expansion had broken the continuity of the original use. Kerr J stated at [185]-[188]: In the Court's opinion, a plain reading of the text of s 43B supplies the answer: the section does not apply to an action which is not a continuation of a use. If, by reason of s 43B(3)(a), an action does not have that character because there has been an enlargement, expansion or intensification, a later repudiation of an enlargement, expansion or intensification does not restore the original position. Once continuity of use for an action has been broken, for that reason, the protection is lost. The text of s 43B operates on the fact that there has been a lawful continuation of a pre-existing use that the person taking that action has not enlarged, expanded or intensified. An enlargement, expansion or intensification of the action takes the action as a whole outside of the definition of an action which does not require an approval. For the purposes of s 43B there is not both a protected use action and a distinct second action of enlargement, expansion or intensification such that the second stands outside the first. There is only one action which, if it is enlarged, expanded or intensified, no longer is an action for which approval is not required. Such a literal construction is not inconsistent with the provision read in its context as part of the Act as a whole. The objects of the EPBC Act as stated in s 3 commence with the statement that the objects of the EPBC Act are "to provide for the protection of the environment, especially those aspects of the environment that are matters of national environmental significance". The EPBC Act provides a comprehensive regime for that purpose, binding not only private persons but the Crown in all its capacities. In that statutory context, and having regard to the objects of the EPBC Act, it would be consistent with the overarching objects to construe a provision protecting pre-existing user rights from the requirement to seek approval for an action as having ceased to have any application once the action has been enlarged, expanded or intensified. 446 The observations made by Kerr J in Huon Aquaculture have only limited relevance to the present case, where the Secretary denies that the planned burns will involve any enlargement, expansion or intensification of the pre-existing use of the land in question. The issues raised in the present case are primarily concerned with: (a) the identification of the use that is said to be lawfully continued, and the land to which that use relates; and (b) whether, (i) there is an expansion or enlargement of that use; or (ii) there is a change in location of where that use is occurring, which results in a substantial increase in the impact of the use on the land. 447 Apart from a passing reference to the predecessor provisions in Booth v Bosworth [2000] FCA 1878 at [8]-[9] (Spender J), Huon Aquaculture appears to have been the only occasion on which s 43B has directly arisen for judicial consideration. In Greentree, Sackville J considered the separate exception in s 43A (in an earlier form prior to its amendment in 2006). Justice Sackville concluded that the requirements of s 43A were not satisfied in relation to clearing and other farming activities on land within a declared Ramsar wetland because, although some of those actions were specifically authorised under a law of the State prior to the commencement of the EPBC Act, further environmental authorisation was necessary at that time to allow the actions to be taken lawfully: see at [138]-[187]. The decision in Greentree was concerned with the concept of "actions" that were "specifically authorised" within the meaning of s 43A (see e.g. at [149]), and did not deal with or shed light on s 43B and the concept of "use" of land. 448 Neither the legislative history nor the extrinsic materials provide much assistance on the application of s 43B in the present context. On its commencement, the former s 523(2) of the EPBC Act contained an exclusion from the definition of "action" in similar terms to current s 43B, namely "a lawful continuation of a use of land, sea or seabed that was occurring immediately before the commencement of this Act", where for such purposes "an enlargement, expansion or intensification of use" was not a continuation of a use. The Explanatory Memorandum for the Environment Protection and Biodiversity Conservation Bill 1998 did not shed any light on the operation of this provision, stating (at paragraph 686): The continuation of an existing use of land (existing at the time the Act commences) is not an action. An enlargement, expansion or intensification of a use is not a continuation of an existing use. 449 Former s 523(2) was replaced by s 43B with effect from 11 July 2001: see Environment Protection and Biodiversity Conservation Amendment (Wildlife Protection) Act 2001 (Cth). The Explanatory Memorandum for those amendments explained that the provision was relocated to Pt 4 of Ch 2 of the EPBC Act in order to ensure that the exemption applied to the environmental assessment and approval requirements, rather than exempting the actions from all parts of the Act. The amended provision also clarified that the exemption for actions with prior authorisation (formerly s 522B, which became s 43A) was limited to environmental authorisations. 450 Section 43B was further amended by the Environment and Heritage Legislation Amendment Act (No 1) 2006 (Cth), which introduced s 43B(3) in its current form. The Explanatory Memorandum for these amendments did little more than restate the effect of the subsection, namely "to make it clear that the continuing use exemption under section 43B does not apply to an action comprising a use of land, sea or seabed, if there is a change in the location of, or a change in the nature of the activities comprising, the use, that results in a substantial increase in the impact of the use on the land, sea or seabed". 451 Some potential guidance on the application of s 43B might be derived from case law in relation to existing lawful uses of land in other legislative contexts, including town planning: see e.g. C McGrath, "Key concepts of the Environment Protection and Biodiversity Conservation Act 1999 (Cth)" (2005) 22 Environmental and Planning Law Journal 20 at 28-31. Nevertheless, it must be recognised that the statutory context and objects of s 43B of the EPBC Act are different from the context and purpose of existing use provisions in town planning legislation, where any ambiguity is often resolved in favour of the protection of existing use rights. In contrast, while s 43B of the EPBC Act recognises and "grandfathers" pre-existing lawful uses of land as at the commencement of the EPBC Act, that recognition must be balanced against the objects of the EPBC Act and the express statutory limitations by reference to the manner in which the use was being conducted as at the time of the commencement of the EPBC Act. 452 At a general level, it may be accepted for present purposes that a "use" of land for the purposes of s 43B might include a "passive" use of land in some circumstances, or an intermittent or variable use at different times or over different parts of the land. However, it remains necessary for the relevant use to be one that is "occurring immediately before the commencement of this Act". Accordingly, whether the use in question is active, passive or intermittent, it must be a current use of the relevant land, sea or seabed as at 16 July 2000. What this requires in any particular case is likely to turn on the nature of the use and the circumstances of the particular land, sea or seabed. However, to establish a current use that was occurring immediately before the commencement of the EPBC Act, it will not necessarily be essential to show that physical activities were taking place on the land, or on all parts of the land, on 15 July 2000: compare e.g. Rosenblum v Brisbane City Council (1957) 98 CLR 35 at 45-46. 453 In determining how s 43B of the EPBC applies to the proposed planned burns, no assistance can be gained from the online fact sheet published by DCCEEW entitled "Bushfire management and national environment law" (referred to in paragraph 435 above). Apart from the fact that it post-dates the enactment of s 43B, the advice set out in that fact sheet represents no more than a view or approach espoused by certain officers of the Executive as to the operation of the statutory provisions. 454 In the present case, a threshold issue involves the identification of the relevant "land" which is said to have been used for the purposes of planned fuel reduction burning immediately before the commencement of the EPBC Act. On what land was such a use "occurring" at that time? 455 At their broadest, the Secretary's closing submissions appeared to suggest that s 43B of the EPBC Act is capable of operating on an established use of land, sea or seabed which existed immediately prior to the commencement of the EPBC Act, divorced from any particular area of land, sea or seabed that was the subject of such use. In other words, because planned burning was an established land management practice at the time of the commencement of the EPBC Act, the Secretary can continue to use any public land for such a purpose without an approval under the EPBC Act. Any changes in the "location" of that use of land would then be dealt with by s 43B(3)(b)(i). In so far as such a submission was made, I do not accept it. In my view, it is necessary to identify a particular area of land, sea or seabed that was the subject of a given use occurring immediately before the commencement of the EPBC Act. Section 43B exempts the lawful continuation of that use from the environmental assessment and approval processes under the EPBC Act, provided that there is no material change in the use and its impact on the relevant land, sea or seabed within the meaning of s 43B(3). I note that a requirement to identify a particular area of land, sea or seabed that is the subject of a pre-existing use is consistent with language of s 43B(3)(b), which refers to a change in the location of where the use of the land, sea or seabed is occurring, and to a substantial increase in the impact of the use on the land, sea or seabed, each of which must to taken to refer back to the land, sea or seabed referred to in subs (1). 456 In the present case, I consider that the land in question is that comprised in the four planned burn areas. On balance, I do not consider that it is appropriate to treat the whole of the Strathbogie State Forest as land that was being used for planned burning immediately before the commencement of the EPBC Act. Among other things, the land that comprises the Strathbogie State Forest is too large and ill-defined for the requirements of s 43B to be capable of any sensible application in relation to the whole of that area, at least in relation to activities such as planned burning (cf. less intensive activities carried out as part of the ordinary day-to-day management of a State forest). Accordingly, the history of planned burning in the Strathbogie State Forest is not directly relevant to the application of s 43B, except perhaps in so far as it demonstrates that the nature of the activities involved in planned burning has not changed since the commencement of the EPBC Act. 457 It remains relevant to consider the burn history in relation to each of the planned burn areas, in determining whether the proposed planned burns can be regarded as a lawful continuation of the use of that land for the purposes of planned burning. 458 The Secretary adduced evidence of planned burning in the Strathbogie State Forest, as well as the extent to which fuel management burns have previously been carried out in the particular areas of the four proposed planned burns. That evidence was derived from records maintained by DEECA of the size and location of previous planned burns in spatial datasets which are contained in a Fire History Database. Accurate records for the Strathbogie State Forest exist from 1961 onwards. 459 In relation to each of the proposed planned burns, the Delivery Plan contains a "Fire History" setting out the area and proportion of the planned burn area that has been affected by previous fuel reduction burns. (a) Lima East: The area was subject to previous burns conducted in 1977 (67.61 hectares or 10.1%), 1993 (75.64 hectares or 11.3%), 2001 (206.85 hectares or 30.9%), 2010 (0.12 hectares or 0.0%), and 2017 (11.75 hectares or 1.8%). (b) Barjarg: The area was subject to previous burns conducted in 1978 (62.19 hectares or 11.5%), 1981 (68.60 hectares or 12.7%), 2001 (125.01 hectares or 23.1%), 2008 (149.51 hectares or 27.7%), and 2015 (0.98 hectares or 0.2%). (c) Ruoaks Road: The area was subject to previous burns conducted in 1975 (3.72 hectares or 0.8%), 1977 (2.75 hectares or 0.6%), 1996 (149.79 hectares or 30.5%), 1999 (0.77 hectares or 0.2%), 2002 (335.06 hectares or 68.2%) and 2009 (488.51 hectares or 99.4%). Two further burns are listed to have occurred in 2017 and 2015 but are said to have burnt zero hectares. (d) Tallangallook: The area was subject to previous burns conducted in 1982 (1.49 hectares or 0.5%), and 2008 (200.84 hectares or 67.1%). 460 For the purposes of s 43B, the fire history of each planned burn area is relevant only in so far as it establishes a use of land that was occurring immediately before 16 July 2000. Accordingly, the extent of planned burns conducted after July 2000 must be largely, if not entirely, put to one side in applying s 43B. 461 The above evidence establishes that, at various times in the decades prior to July 2000, planned burns had been carried out in some parts of each of the planned burn areas. However, the frequency and extent of such burns was relatively limited. In Lima East, there were fuel reduction burns conducted in 1977 and 1993 respectively covering 10.1% and 11.3% of the area (it is not clear whether and to what extent these figures are cumulative). In Barjarg, burns had been carried out in 1978 and 1981 respectively covering 11.5% and 12.75% of the area. In Ruoaks Road, in addition to small areas that were subject to burns carried out in 1975 (0.8%), 1977 (0.6%) and 1999 (0.2%), a burn was conducted in 1996 covering 30.5% of the area. Tallangallook was almost unburnt as at the commencement of the EPBC Act, with one burn in 1981 covering 0.5% of the area. Although there have been further planned burns carried out in each of the planned burn areas since 2000, those burns cannot themselves be relied on to establish a use occurring immediately prior to 16 July 2000. It may be observed that, with some minor exceptions, the planned burn areas have not been subject to any fuel reduction burns since 2009. 462 As discussed above, I accept that s 43B is capable of encompassing an intermittent, irregular or variable use of land. Nevertheless, in the particular circumstances of the present case, I am not satisfied that the fire history set out above, whether alone or taken together with the broader context of fuel reduction burns in the Strathbogie State Forest, establishes that the planned burn areas were used for planned burning immediately before the commencement of the EPBC Act, or that the four proposed planned burns are properly characterised as a lawful continuation of any such use. 463 In any event, even if the planned burn areas or the Strathbogie State Forest more generally could be regarded as being used for the purposes of planned burning immediately prior to 16 July 2000 (or perhaps being used as State forest including any proper and sufficient work for the prevention of fire), the conduct of the proposed planned burns will involve a change in the location of where that use is occurring within the meaning of s 43B(3)(b)(i), and that change will result in a substantial increase in the impact of the use on that land. Alternatively, the conduct of the proposed planned burns could be regarded as an enlargement or expansion of use, in so far as the planned burn areas are concerned. I make these findings based on the evidence adduced by the applicant and the Secretary, without needing to resolve any question as to where the onus of proof lies in relation to the requirements of s 43B(3). In circumstances where large parts of the planned burn areas had not been subject to fuel reduction burns prior to 16 July 2000, the subsequent introduction of fire to those areas has physical impacts on that land. It makes no difference that planned burning of a similar nature and scale may have been previously conducted in other parts of the Strathbogie State Forest. 464 Accordingly, s 43B of the EPBC Act does not exempt the Secretary from the requirements of Pt 3 of the EPBC Act in conducting the proposed planned burns.

Issue 3: Is s 18(3) of the EPBC Act invalid in its application to the respondent's conduct?

Overview of submissions 465 The Attorney-General submitted that s 18(3) of the EPBC Act is invalid in its application to fire prevention and suppression works conducted by the Secretary under s 62(2) of the Forests Act, or alternatively in its application to the four planned burns that are the subject of this proceeding. In so far as s 18(3) prohibits the Secretary from taking actions considered to be necessary for the purpose of protecting people and property in Victoria from bushfires, the Attorney-General submitted that the provision curtails the exercise of an essential function of the State government, and thereby infringes the implied limitation on Commonwealth legislative power recognised in Melbourne Corporation. 466 The Attorney-General relied on the unchallenged evidence considered above in relation to the risk of bushfires in Victoria, against the background of which the State government has long had statutory obligations to carry out proper and sufficient work in State forests for the prevention of control of fire. That statutory obligation is currently contained in s 62(2) of the Forests Act, the terms of which have been set out earlier in these reasons. The overriding obligation or duty imposed by s 62(2) applies in relation to State forests, national parks and protected public land, and contains two limbs - first, carrying out proper and sufficient work "for the immediate prevention and suppression of fire"; and second, carrying out proper and sufficient work "for the planned prevention of fire". 467 The Attorney-General noted that the obligation under s 62(2) of the Forests Act sits within a broader framework of statutory powers and duties of public authorities in relation to the protection of people and property throughout Victoria from fires: see e.g. Country Fire Authority Act 1958 (Vic), ss 20, 43, 50B; Fire Rescue Victoria Act 1958 (Vic), ss 32AA(1) 32B; Forests Act, s 62AA(1). 468 In performance of the obligation under s 62(2) of the Forests Act, the Secretary carries out a range of activities which include fuel management in State forests. Fuel management activities include planned burning and other mechanical or non-burn methods such as mowing, slashing, mulching or spraying. While many fuel management activities are planned works, they may also be performed as part of the immediate response to a fire (e.g. backburning). 469 The Attorney-General submitted that planned burning carried out by the Secretary in the discharge of the duty under s 62(2) of the Forests Act is an important aspect of the manner in which the State protects against loss or life and property caused by bushfires, referring to the following evidence given by Mr Hardman: The case studies demonstrate how planned burning has assisted with suppression. Suppression is a very important tool to protect against the loss of property, life and damage to the environment. Planned burning is a key tool in achieving early suppression, can slow the spread of fire, and, in turn, supports efforts to keep fire size smaller and less intense, to reduce the potential impacts. 470 The Attorney-General submitted that the Secretary is required to make choices about the work that is "proper and sufficient" to be carried out in State forests, national parks and on protected public lands in order to protect people and property from bushfires, and then to carry out that work. This includes choices about where, when and how planned burning should be conducted in order best to reduce risks to lives and property from bushfires. 471 Section 18(3) of the EPBC Act imposes a prohibition on a person from taking an action that has or will have, or is likely to have, a significant impact on a listed threatened species in the endangered category, unless one of a number of exceptions applies. The usual exception is if the taking of the action has been approved by the Commonwealth Minister under Pt 9 of the Act, or if the Commonwealth Minister has decided that s 18(3) is not a controlling provision for the action. Other circumstances under Pt 4 of the EPBC Act in which an environmental approval is not needed turn on an agreement with or decision by the Commonwealth or Commonwealth Minister, apart from ss 43A and 43B which are addressed at actions with prior authorisation and actions that are a continuation of pre-existing use of land. The Commonwealth Minister also has a broad discretionary power under s 158 of the EPBC Act to exempt a specified person from the application of a specified provision of Pt 3 of Ch 2 in relation to a specified action, provided that the Commonwealth Minister is satisfied that it is in the national interest that the provision not apply in relation to the person or the action. 472 The Attorney-General submitted that s 18(3) of the EPBC Act cannot be characterised as a mere "procedural requirement", and that the various exceptions to the prohibition in s 18(3) highlight the degree of control that is given to the Commonwealth over actions taken by the State. The Attorney-General sought to distinguish the manner in which s 18(3) of the EPBC Act restricts the liberty of action of the State from the provisions that were considered in cases such as Western Australia v The Commonwealth (the Native Title Act Case) (1995) 183 CLR 373; Fortescue Metals Group Ltd v Commonwealth (2013) 250 CLR 548; or Albrecht v Federal Commissioner of Taxation (2014) 228 FCR 177. 473 In these circumstances, the Attorney-General submitted that the restrictions purportedly imposed by s 18(3) of the EPBC Act on actions taken by the Secretary pursuant to the statutory duty under s 62(2) of the Forests Act curtail the exercise of "perhaps one of the most fundamental and essential functions of a State government - namely, protecting the people and property in the State", and that, given the importance of that function, even a more limited constraint on the State's liberty of action could be regarded as significant or substantial in the relevant sense. The Attorney-General submitted that it is critical to the performance of the State's fundamental constitutional function of protecting life and property that the Secretary not be prevented from taking actions considered necessary to discharge the duty under s 62(2) of the Forests Act. 474 In this regard, the Attorney-General submitted that the fundamental purpose of a body politic is to maintain peace and order and to protect its people from harm: see e.g. Albrecht at [13] (Perram, Robertson and Griffiths JJ); Thomas v Mowbray (2007) 233 CLR 307 at [142] (Gummow and Crennan JJ), [440]-[441] (Hayne J), [611] (Heydon J). The Attorney-General accepted that, in a federal system, governmental responsibilities for the protection of the people are divided between the States and the Commonwealth, as is reflected in s 119 of the Constitution. However, the Attorney-General submitted that the government of each State has primary responsibility for the protection of its people from harm arising from bushfires and other natural disasters, having regard to the powers of the State in respect of matters such as land management, fire and emergency services, and police services. 475 The Secretary adopted the submissions of the Attorney-General in relation to the Melbourne Corporation principle. 476 The applicant submitted that s 18(3) of the EPBC Act was not an absolute prohibition on planned fuel reduction burning, and that it was only the requirement for approval (or exemption) which engaged the Melbourne Corporation principle. Accordingly, the applicant submitted that a "procedural requirement" to obtain approval from the Commonwealth for fuel reduction burns does not affect the continued functioning of the State as a polity, particularly in circumstances where the relevant works are for the planned prevention of fire under s 62(2)(b) of the Forests Act and there is ample time for the Secretary to seek an assessment and approval under Pt 9 of the EPBC Act before the burns are conducted. The applicant submitted that this is a "minimal burden" that falls short of the Melbourne Corporation principle.

Consideration 477 It has been recognised since the decision in Melbourne Corporation that there is an implied constitutional limitation on the legislative powers of the Commonwealth Parliament derived from the federal structure established by the Constitution, including the fundamental premise that there will continue to be State governments that are separately organised: see e.g. Austin v Commonwealth (2003) 215 CLR 185 at [24], [26] (Gleeson CJ), [115] (Gaudron, Gummow and Hayne JJ), [219]-[223] (McHugh J), [281] (Kirby J); Clarke v Federal Commissioner of Taxation (2009) 240 CLR 272 at [15], [32] (French CJ), [95] (Hayne J); Spence v Queensland (2019) 268 CLR 355 at [100] (Kiefel CJ, Bell, Gageler and Keane JJ). 478 As the Full Court stated in Albrecht at [11] (Perram, Roberston and Griffiths JJ): As a matter of general theory, the States are not immune from Commonwealth regulation. The federal nature of the Commonwealth has as its corollary, however, State immunity from Commonwealth legislation which significantly interferes with a State's capacity to function as a government: Bayside City Council v Telstra Corporation Ltd (2004) 216 CLR 595 at [31]. The precise metes and bounds of the immunity have proved elusive but its central element strikes down Commonwealth legislation which restricts or burdens one or more of the States in the exercise of their constitutional powers: Fortescue Metals Group Ltd v Commonwealth (2013) 250 CLR 548 (Fortescue) at [134]-[137]. 479 In Austin at [115], Gaudron, Gummow and Hayne JJ observed that "it is difficult, if not impossible, to articulate [the limitation on power] except in negative terms which are cast at a high level of abstraction". One of the central concepts in many expressions of the principle is that the legislative powers of the Commonwealth "cannot be exercised to destroy or curtail the existence of the States or their continuing to function as such": see Re Australian Education Union; ex parte Victoria (1995) 184 CLR 188 at 227 (Mason CJ, Brennan, Deane, Toohey, Gaudron and McHugh JJ), referring to Melbourne Corporation at 56, 60 (Latham CJ), 66 (Rich J), 74 (Starke J) and 82 (Dixon J). While it now appears to be generally accepted that there is a single limitation (see Austin at [124] (Gaudron, Gummow and Hayne JJ); cf. Queensland Electricity Commission v The Commonwealth (1985) 159 CLR 192 at 216 (Mason J), it is also accepted that there are two kinds of laws that can potentially infringe that limitation: first, discriminatory laws that impose a special burden or disability on the State or the execution of its constitutional powers; and second, general laws that operate to curtail or interfere in a substantial manner with the performance or exercise of State governmental functions or powers. 480 There is no suggestion in the present case that the EPBC Act is targeted at the States or operates in a discriminatory manner to single out a State or States or to impose a special burden of disability on them. Accordingly, the present case is concerned with the second aspect of the implied limitation, concerning the impairment of or interference with State governmental functions. 481 In Austin at [146]-[152], Gaudron, Gummow and Hayne JJ considered the guidance provided by earlier High Court decisions "as to the content of the limited State immunity". Among other things, their Honours referred to the The Commonwealth v Tasmania (the Tasmanian Dam Case) (1983) 158 CLR 1 at 140 and 223, where Mason and Brennan JJ had "pointed out that the concern was with the capacity of a State to function as a government rather than interference with or impairment of any function which a State government may happen to undertake". Justices Gaudron, Gummow and Hayne also referred to the joint judgment in the Native Title Act Case at 480, where "the relevant question for the application of the Melbourne Corporation doctrine was not whether Commonwealth law effectively restricted State powers or made their exercise more complex or subjected them to delaying procedures", but rather "whether the Commonwealth law affects what Dixon J called the 'existence and nature' of the State body politic", a conception that "relates to the machinery of government and to the capacity of its respective organs to exercise such powers as are conferred upon them by the general law which includes the Constitution and the laws of the Commonwealth". 482 The starting point is that, unless the Commonwealth law in question offends the Melbourne Corporation limitation, the States must comply with applicable Commonwealth laws of general application when performing governmental functions or exercising governmental powers. This has been firmly established since the decision in Amalgamated Society of Engineers v Adelaide Steamship Co Ltd (1920) 28 CLR 129 (Engineers' Case). In Melbourne Corporation (at 78), Dixon J articulated the effect of the Engineers' Case, "stripped of embellishment and reduced to the form of a legal proposition", in the following terms: "[t]he prima-facie rule is that a power to legislate with respect to a given subject matter enables the [Commonwealth] Parliament to make laws which, upon that subject, affect the operations of the States and their agencies", subject to certain reservations or qualifications including the limitation with which the decision in Melbourne Corporation was concerned. 483 The scope of that limitation is often identified by reference to the following passage from the judgment of Starke J in Melbourne Corporation (at 75): It is a practical question, whether legislation or executive action thereunder on the part of a Commonwealth or of a State destroys, curtails or interferes with the operations of the other, depending upon the character and operation of the legislation and executive action thereunder. No doubt the nature and extent of the activity affected must be considered and also whether the interference is or is not discriminatory but in the end the question must be whether the legislation or the executive action curtails or interferes in a substantial manner with the exercise of constitutional power by the other. The management and control by the States and by local governing authorities of their revenues and funds is a constitutional power of vital importance to them. Their operations depend upon the control of those revenues and funds. And to curtail or interfere with the management of them interferes with their constitutional power. (Emphasis added). 484 There may be some ambiguity as to what is meant by "the exercise of constitutional power" for such purposes, in addition to what might be required to give rise to an interference with such power "in a substantial manner". Apart from the facts of Melbourne Corporation itself, which involved a statutory provision curtailing the State government's freedom to conduct banking business (that was regarded as essential to the discharge by the States of their constitutional functions), those concepts are elucidated by reference to subsequent decisions in which the implied limitation has been considered. 485 In any particular case, the question whether or not a Commonwealth law offends the implied limitation will require an assessment of the impact of the law and will turn on matters of evaluation and degree, based on relevant "constitutional facts": Austin at [124] (Gaudron, Gummow and Hayne JJ), [283] (Kirby J); see also Spence at [314]-[315] (Edelman J). This does not mean that the size or magnitude of the burden placed on the State will be determinative. There can be a "disabling effect on State authority", an "impairment of constitutional status", or an "interference with capacity to function as a government", even if the financial or other burden that is imposed on the State is not of itself significant: see e.g. Austin at [24] (Gleeson CJ); Clarke at [33] (French CJ), [63] (Gummow, Heydon, Kiefel and Bell JJ). Nevertheless, the cases in which an infringement of the implied limitation has been found have often involved Commonwealth laws which had an adverse effect on the organs or institutions of government through which the State performs its (essential) constitutional functions, whether legislative, executive or judicial - for example, the terms and conditions on which State judicial officers are appointed and remunerated, or the engagement of executive officers at the "higher levels of government". 486 In Clarke, French CJ formulated the limitation as follows (at [1]): Under the authority conferred upon it by the Constitution the Parliament of the Commonwealth can make laws affecting the States and their agencies. It cannot, however, make laws which destroy or significantly burden, curtail or weaken either the capacity of the States to carry out their proper legislative, executive and judicial functions or their exercise of those functions. 487 In so far as the principle is directed to the capacity of the States to carry out the functions of government, it is more likely to be concerned with the impact of a Commonwealth law on the organs or institutions of a State government and their ability to perform governmental functions. This reflects the underlying premise on which the implied limitation is based, namely the continued existence of the States as separately organised bodies politic and constituent entities within the federation, so as prevent an exercise of Commonwealth legislative power "to destroy or curtail the existence of the States or their continuing to function as such": Re Australian Education Union at 227 (Mason CJ, Brennan, Deane, Dawson, Toohey, Gaudron and McHugh JJ). 488 The expression of the principle as extending to laws which interfere in a significant or substantial manner with the exercise by the States of their governmental functions may ostensibly have a broader reach. Nevertheless, as is demonstrated by the Engineers' Case, this cannot be treated as carving out an area of immunity from the operation of Commonwealth laws which on their proper construction apply to activities engaged in by the State and its agencies, merely because those laws are said to involve a restriction or "curtailment" on the exercise by the State of its statutory or non-statutory powers. In this regard, propositions drawn from past judgments should not "take on, by further judicial exegesis, a life of their own which is removed from the constitutional fundamentals which must sustain them": Austin at [145] (Gaudron, Gummow and Hayne JJ); see also Fortescue Metals Group at [134] (Hayne, Bell and Keane JJ). Thus, the limitation "recognises that there may be some species of Commonwealth laws which would represent such an intrusion upon the functions or powers of the States as to be inconsistent with the constitutional assumption about their status as independent entities": Clarke at [32] (French CJ). 489 The focus of the implied limitation is on Commonwealth laws that destroy or weaken the capacity or functions of State governments, and not simply Commonwealth laws that affect the exercise of powers or the performance of functions by a State government, without significantly impairing or curtailing the exercise of its constitutional powers. This might entail a "multifactorial assessment" of the kind referred to by French CJ in Clarke at [34], which relevantly takes into account the effect of the law upon the capacity of the States to exercise their constitutional powers or upon the exercise by the States of their functions, together with the nature of the capacity or functions affected. 490 The present case concerns the impact of s 18(3) of the EPBC Act on the Secretary in carrying out planned burns in State forests as "proper and sufficient" work for the planned prevention of fire pursuant to s 62(2)(b) of the Forests Act. 491 No question is raised on the facts of the present case concerning the Secretary's duty to carry out works "for the immediate prevention and suppression of fire" under s 62(2)(a) of the Forests Act, or more generally the State's performance of functions in responding to emergency situations arising immediately from active bushfires. 492 In this regard, it does not appear that the EPBC Act contains any general exception or exemption dealing with actions taken in circumstances of urgency, such as in the face of a bushfire, which might have significant impacts on matters of national environmental significance. The Commonwealth Minister has a power to grant exemptions under s 158 of the EPBC Act where he or she is satisfied that it is in the "national interest" that a provision or provisions of Pt 3 not apply in relation to a specified person or a specified action. As noted in paragraph 103 above, this power has been exercised in the context of actions taken in response to severe bushfires in Victora in 2009 and 2019-2020. The exemption granted on 11 February 2009 included (but was not limited to) "clearance of vegetation, building of fire breaks and back-burning". The exemption granted on 14 January 2020 was expressed to cover "[t]he taking of firefighting activities, fire prevention activities and fire recovery activities", each of which was defined in terms that referred to "emergency" or "urgent" actions. As pointed out by counsel for the Attorney-General, these exemptions had a prospective operation and took effect on the date of the relevant notice, and therefore did not cover the immediate responses to the bushfires that had already been taken by State agencies. 493 Ultimately, it is unnecessary for present purposes to determine whether or to what extent provisions such as s 18(3) of the EPBC Act might apply to actions taken by the Secretary (or other State agencies) in the context of the immediate prevention or suppression of fire. That is a question best left to be determined if and when it arises in the particular factual context of a future case: compare, e.g. Clubb v Edwards (2019) 267 CLR 171 at [34] (Kiefel CJ, Bell and Keane JJ), [135] (Gageler J); see also Mineralogy Pty Ltd v Western Australia (2021) 274 CLR 219 at [57]-[60] (Kiefel CJ, Gageler, Keane, Gordon, Steward and Gleeson JJ); Farm Transparency International Ltd v New South Wales [2022] HCA 23; 96 ALJR 655 at [19]-[21] (Kiefel CJ and Keane J), [209] (Edelman J). 494 In my view, it is doubtful that the conduct by the Secretary of works for the planned prevention of fire, including planned burning, in State forests, national parks and on protected public land can properly be characterised as a "core constitutional function" of the State (cf. Albrecht at [16]) for the purposes of the Melbourne Corporation principle. 495 The particular duty or function under s 62(2)(b) of the Forests Act relates to particular categories of land for the management of which the State is responsible. I accept that, as the Attorney-General submitted, the duty under s 62(2)(b) arises in a more general context of functions and duties of the State and its agencies to protect people and property throughout Victoria from the impacts of fires. Nevertheless, the immediate context of the function and duty imposed by s 62(2)(b) is in relation to the responsibility of the State for public land from which there might arise a risk of fire impacting on lives and property, for example, in adjoining lands. This is reflected in provisions such as s 62AA, which requires the Secretary to issue warnings and provide information in relation to fires in State forests, national parks and on protected public lands if the Secretary considers it necessary for the purposes of protecting life and property. 496 The Attorney-General sought to characterise the statutory duty of the Secretary under s 62(2) of the Forests Act as an aspect of a "fundamental and essential" function of the government of the State, namely, the protection of people and property in the State. Accepting that one of the central roles of a body politic is to maintain peace and order and to protect its people from harm, it must be recognised that this is not an exclusive function of the State government. As the Attorney-General recognised, the people of Victoria are also among the people of the Commonwealth, and the responsibility for the protection of those people is divided in accordance with the federal division of powers. Section 119 of the Constitution, which provides that "[t]he Commonwealth shall protect every State against invasion and, on the application of the Executive Government of the State, against domestic violence", is consistent with the Commonwealth's responsibility for defence and the prohibition on the States from raising or maintaining any naval or military force without the consent of the Commonwealth Parliament (see Constitution ss 51(vi), 68 and 114). In so far as s 119 of the Constitution contemplates that a State may apply to the Commonwealth for protection against "domestic violence", this does not imply that the States have an area of exclusive or reserved power in relation to the protection of the people of the State from internal threats. 497 The Attorney-General submitted that the constitutional function of protecting lives and property from bushfires and other natural disasters fell within the "primary responsibility" of the State under the federal division of powers, being concerned with matters such as land management, fire and emergency services and police services. Some support for that proposition was sought from the Court's acceptance in Albrecht at [13], in the context of the impact of Commonwealth laws on a State police force, that "the maintenance of peace and order by the State is a central constitutional aspect of a State". Ultimately, however, this submission in the present context is redolent of the "reserved powers" doctrine that was rejected in the Engineers' Case. Each of the Commonwealth and the States may have a role within their respective areas of constitutional competence in discharging the governmental function of maintaining peace and order and protecting lives and property. The critical question is not one of who is responsible for the protection of lives and property in Victoria, but rather whether the Commonwealth laws in question have an operation or effect that significantly interferes with or curtails the constitutional functions or powers of the State. 498 In my view, the operation of s 18(3) of the EPBC Act in its application to the Secretary when carrying out work considered to be proper and sufficient for the planned prevention of fire does not significantly curtail or interfere with the capacity of the State to function as a government or with the exercise by the State of its governmental functions. 499 For such purposes, I accept that it is not an answer to say that a provision in the form of s 18(3) of the EPBC Act is no more than a "procedural" requirement to obtain the approval of the Commonwealth Minister before taking actions within the scope of the provision. The conditional prohibition imposed by s 18(3) subjects those actions to control and approval by the Commonwealth Minister, who has a discretion to refuse to grant approval or to impose conditions on the approval. While those discretions are not at large, and are limited by the statutory scheme of the EPBC Act, they nevertheless involve a substantial measure of Commonwealth control over whether and how the actions take place. Such control is generally directed to subject-matters which fall within the Commonwealth's responsibilities, including ensuring compliance with international treaty obligations. Nevertheless, the imposition of a requirement of Commonwealth consent or approval is capable of giving rise to a substantial interference with the constitutional powers and functions of the States, as is illustrated by the provision that was held to be invalid in Melbourne Corporation, which prohibited banks from conducting banking business for a State or a State authority "[e]xcept with the consent in writing of the Treasurer". 500 In the present case, if there is a real chance that the four planned burns will have a significant impact on a listed threatened species such as the Southern Greater Glider, the application of s 18(3) of the EPBC Act would (in the absence of any applicable exception or exemption) require the Secretary to refer the four planned burns to the Commonwealth Minister for a decision on whether or not they are controlled actions and, if so, the conduct of an environmental assessment and a decision whether or not to approve the action with or without conditions. It cannot be said that such requirements involve an interference with the capacity of the State to perform its constitutional or governmental functions. In so far as there is any restriction on the exercise by the State of its power or authority to carry out planned burns in State forests or other work for the prevention of fire, such a restriction does not amount to a significant or substantial impairment of the exercise of the State's constitutional powers. Accordingly, such an operation or application of s 18(3) of the EPBC Act to the Secretary in relation to the carrying out of the planned burns does not infringe the implied limitation derived from Melbourne Corporation. 501 The present case is more comparable to the Native Title Act Case at 476-482, where the application of the "future act" provisions of the Native Title Act 1993 (Cth) in relation to acts by the States was held not to infringe the Melbourne Corporation limitation. The plurality (Mason CJ, Brennan, Deane, Toohey, Gaudron and McHugh JJ) stated (at 477): If the power prima facie available to support a Commonwealth law is such that the law may govern a particular act, matter or thing, the fact that a State exercises or has been accustomed to exercise legislative or executive power to govern the same act, matter or thing does not establish either discrimination against the State or an impermissible interference with the State's performance of its constitutional functions. 502 The plurality referred to Re Lee; ex parte Harper (1986) 160 CLR 430 at 453, where Brennan and Deane JJ observed that the implied limitation does not "protect the States from an erosion in their status occasioned by the increasing regulation of community affairs by the Commonwealth in accordance with its powers". The plurality also did not accept that the application of the Native Title Act to Western Australia, in the light of its particular history and geography having created a greater area of land which might be subject to native title, deprived the government of that State of the capacity to function as a government or burdened and impeded its function as a government. 503 Of most relevance to the present case, the plurality addressed a submission that the capacity and power of the State to grant, regulate and otherwise deal with land and other resources in Western Australia constituted a "fundamental sovereign function" that was essential to the continued existence of the State and its capacity to function as a government. For the purposes of determining constitutional validity, the plurality accepted (at 480) that the Native Title Act would "complicate government administration in Western Australia and delay the making of administrative decisions". However, on the question whether such effects constituted an impermissible interference with the capacity of the State government to function as such, their Honours said: These effects touch upon the scope of State power and the difficulty of its exercise, not upon the machinery of the government of the State. … For constitutional purposes. the relevant question is not whether State powers are effectively restricted or their exercise made more complex or subjected to delaying procedures by the Commonwealth law. The relevant question is whether the Commonwealth law affects what Dixon J called the 'existence and nature' of the State body politic. As the Melboume Corporation Case illustrates, this conception relates to the machinery of government and to the capacity of its respective organs to exercise such powers as are conferred upon them by the general law which includes the Constitution and the laws of the Commonwealth [Constitution, Covering Clause V]. A Commonwealth law cannot deprive the State of the personnel, property, goods and services which the State requires to exercise its powers and cannot impede or burden the State in the acquisition of what it so requires. 504 The plurality continued (at 481): The Act does not purport to affect the machinery of the government of the State. The constitution of the three branches of government is unimpaired; the capacity of the State to engage the servants it needs is unaffected; the acquisition of goods and services is not impeded: nor is any impediment placed in the way of acquiring the land needed for the discharge of the essential functions of the State save in one respect, namely, the payment of compensation. The Act does not impair what Dawson J described as 'the capacity to exercise' constitutional functions though it may affect the ease with which those functions are exercised. 505 While the Attorney-General sought to distinguish the decision in the Native Title Act Case on the basis that the Commonwealth legislation in that case did not prohibit State government action but simply imposed procedural requirements or compensation entitlements on the taking of such action, I consider that the decision is consistent with a more general proposition that compliance with applicable Commonwealth legislative requirements does not itself offend the Melbourne Corporation limitation if it does not substantially impair the machinery of government through which the State discharges its essential functions and exercises its constitutional powers. The implied limitation is not infringed simply because the State's liberty to make choices about how to perform its functions or exercise its powers is constrained by the requirement to comply with applicable Commonwealth laws: see also Fortescue Metals Group at [131]-[137] (Hayne, Bell and Keane JJ). Unless the Commonwealth laws operate to weaken or impair the discharge by the States of their constitutional functions, they form part of "the general milieu in which the States must operate": see Austin at [129] (Gaudron, Gummow and Hayne JJ). 506 In summary, I conclude that s 18(3) of the EPBC Act is valid in its application to the Secretary in carrying out the planned burns pursuant to s 62(2)(b) of the Forests Act, and that the provision does not operate to curtail or interfere in a substantial manner with the capacity of the State to function as a government nor with the exercise of its constitutional powers.

Conclusion 507 On the evidence before the Court, although s 18(3) of the EPBC Act validly applies to the Secretary and the exception under s 43B of the EPBC Act is not applicable, the four planned burns proposed to be conducted by the Secretary in the Strathbogie State Forest will not have, and are not likely to have, a significant impact on the Southern Greater Glider as a species within the meaning of s 18(3) of the EPBC Act. 508 Accordingly, I conclude that the applicant has not established that the Secretary is engaging in or proposes to engage in an act or omission that constitutes an offence or other contravention of the EPBC Act, and that there is therefore no basis for the grant of a prohibitory injunction under s 475 of the EPBC Act. 509 The application is therefore dismissed. The parties are invited to make submissions on costs within 14 days after the delivery of these reasons for judgment. I certify that the preceding five hundred and nine (509) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Horan.