The plants are part of endangered ecological communities
116The final element is whether the plants that were picked were part of one or both of the Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest, endangered ecological communities. Evidence establishing the presence of endangered ecological communities on Lot 1, and that the plants picked were part of those communities, was given by Dr Keith, an ecologist, and Dr Hazelton, a soil scientist.
Dr Keith's evidence on the ecological communities
Dr Keith's expertise in ecological communities
117The principal evidence on this issue was that of Dr David Keith, a highly qualified and knowledgeable ecologist whose current position is a Senior Principal Research Scientist in the Biodiversity Conservation Science Section of the Office of Environment and Heritage. Dr Keith has served for 6 years on the NSW Scientific Committee, the statutory body established under the Threatened Species Conservation Act, with responsibility for listing threatened species, populations, ecological communities and threatening processes under that Act.
118Dr Keith has 25 years experience in vegetation survey, including diagnosis, description and analysis of ecological communities and their associated soils. He has particular research interest in ecological communities and floodplain vegetation. He has authored over 60 peer reviewed scientific articles in leading national and international journals and books, a compilation map of native vegetation for NSW for the NSW Biodiversity Strategy and the award winning monograph on native vegetation in NSW, Ocean Shores to Desert Dunes: The native vegetation of NSW and the ACT , Department of Environment and Conservation, Sydney, 2004.
119Dr Keith's research work and papers on coastal floodplain vegetation provided much of the scientific basis for the Scientific Committee's Final Determinations under the Threatened Species Conservation Act to list the two endangered communities of Swamp Oak Floodplain Forest and River-Flat Eucalypt Forest, amongst others. The Scientific Committee's Final Determinations to list each of these ecological communities cites Dr Keith's research papers, including Keith D A and Scott J "Native vegetation of coastal floodplains - a diagnosis of the major plant communities in New South Wales" (2005) 11 Pacific Conservation Biology 81-104.
Dr Keith's evidence
120Dr Keith's evidence comprised an affidavit of 10 November 2009 and annexed expert report as well as oral evidence at the hearing. His expert testimony was based on a site inspection on 30 June 2009, aerial and site photographs at various times, and various reports, papers, books, maps and websites that he consulted in preparing his evidence.
121Dr Keith identified two portions of the Disturbed Area on Lot 1: the low-lying flat on the lake-side and an elevated area on the land-side of the Disturbed Area. Dr Keith concluded that Swamp Oak Floodplain Forest was and still is present on the low-lying flat and River-Flat Eucalypt Forest was and still is present on the elevated area.
Dr Keith's conclusion and reasons that Swamp Oak Floodplain Forest exists on Lot 1
122Dr Keith concludes that Swamp Oak Floodplain Forest is present on the subject site and was present within the Disturbed Area prior to the Relevant Conduct [of clearing and filling]. "This ecological community currently occurs as remnant patches on the low-lying flat within and adjacent to the Disturbed Area and formerly occurred on areas of the low-lying flat that had been disturbed by the Relevant Conduct." (Keith expert report, p 3).
123Dr Keith's conclusions were based on application of the description in the Final Determination for Swamp Oak Floodplain Forest to the facts concerning the assemblage of species, the location in the particular area in which the assemblage of species occurs, the edaphic and physiographic conditions and the structure of the vegetation community on Lot 1.
Assemblage of species
124Paragraph 1 of the Final Determination lists the characteristic species of the Swamp Oak Floodplain Forest endangered ecological community.
125Dr Keith recorded 31 species of native plants in remnant vegetation on the low-lying flat within and adjacent to the Disturbed Area. Of the 31 recorded species, 16 are included in the 45 native plant species listed in paragraph 1 of the Final Determination of Swamp Oak Floodplain Forest (Keith expert report, p 4).
126Paragraph 4 of the Final Determination contains a text description of the dominant tree species and a selection of frequent or prominent species found in the understorey of Swamp Oak Floodplain Forest. Dr Keith analysed the consistency of the vegetation in and around the Disturbed Area with the description of dominant and subordinate species in paras 4 and 5 of the Final Determination. Dr Keith states:
"During my inspection of the study site, I recorded nine of the 22 species mentioned in paragraph 4 of the Final Determination ... Paragraph 4 notes that Swamp Oak Floodplain Forest 'has a dense to sparse tree layer in which Casuarina glauca (swamp oak) is the dominant species northwards from Bermagui'. Paragraph 5 of the Final Determination further identifies dominance by Casuarina glauca as one of the 'features that distinguish Swamp Oak Floodplain Forest from other Endangered Ecological Communities on the coastal floodplains.' During my inspection, I observed that Casuarina glauca was 'common' on the subject site ... and I identified this species as the dominant tree of the local vegetation on the low-lying flat. I also identified Casuarina glauca as occurring within the Disturbed Area based on my examination of aerial photography and site photographs that were taken prior to the Relevant Conduct. Paragraph 4 also states that 'other trees including Acmena smithii (lilly pilly), Glochidion s pp (cheese trees) and Melaleuca spp (paperbarks) may be present as subordinate species, and are found most frequently in stands of the community northwards from Gosford.' I recorded two of these subordinate species ( Glochidion ferdinandi and Melaleuca quinquenervia ) on the subject site". (Keith expert report, pp 4-5).
127Dr Keith said the vegetation in and around the Disturbed Area was consistent with the characteristic species and the dominant and subordinate trees identified in the Final Determination. Dr Keith states:
"The Final Determination contains a general description of the community that is intended to be applicable to its entire distribution along more than 1,000 km of NSW coastline. The Disturbed Area and its surrounds represent a very small fraction of this total distribution. In view of this relativity, the 16 Identified Indigenous Species that I recorded on the subject site that are listed in the Final Determination as characteristic of Swamp Oak Floodplain Forest, in my opinion, indicate the existence of this Endangered Ecological Community within and near the Disturbed Area. The presence of species identified in the Final Determination of dominant and subordinate trees of Swamp Oak Floodplain Forest further supports the conclusion that this community is present within and near the Disturbed Area. Based on photographic evidence, a larger area of Swamp Oak Floodplain Forest than currently exists was present within the Disturbed Area prior to Relevant Conduct (see below)" (Keith expert report, p 5).
128Dr Keith considers the issue of variability of the species composition of Swamp Oak Floodplain Forest. Dr Keith states:
"A number of species listed as characteristic of the community in Paragraph 1 of the Final Determination were not recorded within or near the Disturbed Area. In my opinion, this is expected because Swamp Oak Floodplain Forest exhibits natural variability in species composition and because the subject site represents a very small fraction of the total distribution of the community. Recognising natural variability in the community, Paragraph 1 of the Final Determination states, 'the composition of Swamp Oak Floodplain Forest is primarily determined by the frequency and duration of waterlogging and the level of salinity in the groundwater. Composition also varies with latititude.' Paragraph 2 of the Final Determination further states that 'The species composition of a site will be influenced by the size of the site, recent rainfall or drought conditions and by its disturbance (including fire, grazing, flooding and land clearing) history. The number and relative abundance of species will change with time since fire, flooding or significant rainfall, and may also change in response to changes in grazing regimes. At any one time, above-ground individuals of some species may be absent, but the species may be represented below ground in the soil seed banks or as dormant structures such as bulbs, corms, rhizomes, rootstocks or lignotubers.' My field experience in Swamp Oak Floodplain Forest at other locations indicates that small areas of the community typically support low numbers of vascular plant species ... In my opinion, the number of species found in remnant vegetation (less than 1 ha in extent) within or near the Disturbed Area is consistent with expectations based on the above estimates, taking into account the natural variability within the community" (Keith expert report, pp 5-6).
129Finally, Dr Keith considers the presence of other native plant species that are found in Swamp Oak Floodplain Forest as corrobative of his conclusion that that community occurs on Lot 1:
"A number of Identified Indigenous Species recorded during my inspection of the Disturbed Area are not listed in Paragraph 1 of the Final Determination. Paragraph 2 of the Final Determination states 'the total species list of the community is considerably larger than given above [in Paragraph 1], with many species present at only one or two sites or in low abundance.' Based on my field experience in Swamp Oak Floodplain Forest, the additional species that I recorded on the subject site are part of this larger list referred to in paragraph 2 of the Final Determination. For example, two species recorded on the subject site, Apium prostratum and Leptinella longipes , were listed in descriptions of map units 106 and 107 (see Tindall et al. 2004), both of which are defined as part of Swamp Oak Floodplain Forest in Paragraph 8 of the Final Determination. In my opinion, this indicates that these Identified Indigenous Species are part of Swamp Oak Floodplain Forest, even though they are not listed as characteristic species of the community in Paragraph 1 of the Final Determination" (Keith expert report, pp 6-7).
The location in particular area
130The Final Determination describes the location in which the Swamp Oak Floodplain Forest endangered ecological community occurs in terms of biogeographical region and local government area. Dr Keith concludes that Lot 1 accords with this locational description:
"Paragraphs 1 and 3 of the Final Determination of Swamp Oak Floodplain Forest state that the community occurs within the NSW North Coast, Sydney Basin and Southeast Corner bioregions, as defined by Thackway & Cresswell (1995). Paragraph 3 states that the community is known from parts of a number of Local Government Areas within these bioregions including Wyong Local Government Area. The Disturbed Area occurs within the Sydney Basin bioregion as defined by Thackway & Cresswell (1995) and within the Wyong Local Government Area. The location of the Disturbed Area therefore matches the Final Determination's description of the particular area in which Swamp Oak Floodplain Forest occurs" (Keith expert report, p 7).
Edaphic and physiographic conditions
131The Final Determination describes the edaphic and physiographic conditions in which the Swamp Oak Floodplain Forest endangered ecological community occurs. Edaphic conditions may include the physical, chemical and biological properties of soils and the parent rock from which the soils are derived. Physiographic conditions include topographical elements such as aspect, slope, drainage, microclimates and elevation.
132Paragraphs 1 and 6 of the Final Determination of Swamp Oak Floodplain Forest described the edaphic and physiographic conditions of Swamp Oak Floodplain Forest. Dr Keith concludes that land within and surrounding the Disturbed Area matches these edaphic and physiographic conditions:
"Paragraph 1 of the Final Determination states that Swamp Oak Floodplain Forest is 'associated with grey-black clay-loams and sandy loams, where the groundwater is saline or sub-saline, on waterlogged or periodically inundated flats, drainage lines, lake margins and estuarine fringes associated with coastal floodplains.' Paragraph 5 [now 6] further states that the community 'generally occupies low-lying parts of floodplains, alluvial flats, drainage lines, lake margins and fringes of estuaries; habitats where flooding is periodic and soils show some influence of saline ground water. This latter habitat feature sets it apart from other floodplain communities.' I inspected surface soils on the subject land at several locations within and immediately surrounding the Disturbed Area. The soils on the low-lying flat adjacent to Lake Munmorah differed from those on the elevated area to the west of the Disturbed Area. On the flat, these soils were of dark grey colouration and included quartz sand particles within a matrix of fine loamy organic material. They therefore fit the description of 'grey-black' and 'sandy loam' in the Final Determination. On elevated area to the west of the Disturbed Area, the soils had a paler grey colouration and sandier texture.
The subject site is located on the shores of Lake Munmorah, which forms part of a chain of connected coastal lakes, opening to the sea at The Entrance, and hence subject to title influence. Available data on the salinity of waters in Lake Munmorah indicate that salinity varied within the range 18.6-29.8 parts per thousand (equivalent to 1.86-2.98%) during sampling periods between 1963 and 1991 (King & Hodgson 1985, p 24), with variations related to the proximity to freshwater inflow or ocean influence. This range of values is well above levels regarded typical of freshwater (less than 0.1%), less than average salinity of ocean water (approximately 3.5%) (UCAR 2001) and therefore fits the description of saline or sub-saline water. The soils inspected were on a flat within 3-15 metres of the lake's edge and approximately one metre elevation or less above the lake surface. Given the close lateral and vertical proximity of saline or sub-saline lake waters to the subject site, it is very likely that saline salts diffuse laterally into the water table beneath the subject site. This is corroborated by the local abundance on the site of Identified Indigenous Species such as Casuarina glauca , Baumea juncea and Juncus kraussii subsp australiensis , as these are known to be associated with sub-saline soils. In view of the above, I consider it very likely that the groundwater on the subject site is 'saline or sub-saline', as described in the Final Determination.
On the day of my inspection, the soils contained copious moisture at surface level and standing water was visible within local depressions on the site (as depicted in Photograph P6300021, Attachment C). This indicates that soils on the site are 'waterlogged or periodically inundated', consistent with the description in the Final Determination. The location of the site on the 'lake margins' of Lake Munmorah is also consistent with the description in the Final Determination. King & Hodgson (1985) state that the hydrodynamics of the lake system are controlled largely by catchment runoff and that Colongra Creek is the only major stream flowing into Lake Munmorah. Inundation and waterlogging of land on the lake margins (including the subject site) is therefore likely to be influenced by catchment runoff and flooding of Colongra Creek, which enters the lake approximately one kilometre to the north of the subject site. These hydrological processes define a means by which the ecological community within and near the Disturbed Area is associated with a floodplain landform (i.e. the floodplain of Colongra Creek).
The association between a floodplain and the ecological community within and near the Disturbed Area is further corroborated by mapping of soil landscapes on the Lake Macquarie 1:100 000 map sheets (Murphy 1993) ... This map shows an area of the Wyong Soil Landscape extending along Colongra Creek and around the margin of Lake Munmorah, including the subject site, on the northern and north-eastern perimeters of Colongra Lake [sic, Swamp] Nature Reserve. The Wyong Soil Landscape is described by Murphy (1993) as 'broad, poorly drained deltaic floodplains and alluvial flats of Quaternary sediments on the Central Coast Lowlands. Slope gradients 200cm Yellow Podsolic Soils (Dy 5.11, Dy 5.51), Brown Podzolic Soils (Db 2.11), Soloths (Dy 5.81, Dy 5.41) with some Humus Podzols (Uc 2.22) around lake edges.' The notes further comment that the Wyong Soil Landscape is subject to 'flooding, seasonal waterlogging, foundation hazard, permanent waterlogging (localised), streambank erosion (localised), acid sulphate potential (localised), strongly acid, poorly drained, impermeable soils of very low fertility with saline subsoils.' These features are consistent with those described in the Final Determination of Swamp Oak Floodplain Forest.
Paragraph 1 of the Final Determination states that 'Swamp Oak Floodplain Forest generally occurs below 20 m (rarely above 10 m) elevation.' Examination of the Catherine Hill 1:25,000 scale topographic map sheet (NSW Land Information Centre Map Number 9231-4S), shows the entire Disturbed Area and its surrounds as lying below the 10 m contour line ... A Spot Height marked on this map in the south-western area of Colongra Swamp Nature Reserve suggests that the maximum elevation within the Reserve is 11 metres. My observation during field inspection confirmed that the surface level of the tidally-influenced Lake Munmorah lies only a few metres below the Disturbed Area in vertical dimension. From this information, I conclude that the elevation of the Disturbed Area and its surrounds is below 10 m, consistent with the elevational range of Swamp Oak Floodplain Forest described in the Final Determination.
In my opinion, the nature of soils, hydrology, landscape and elevation of the Disturbed Area and its immediate surrounds conform with the description of these features in the Final Determination of Swamp Oak Floodplain Forest. As supplementary descriptors, these features corroborate the existence of Swamp Oak Floodplain Forest within and near the Disturbed Area. My opinion is based on direct observations of the site, as well as information obtained from literature and maps relating to the Disturbed Area. In my opinion, the close correspondence of soils, hydrology, landscape and elevation observed and mapped within and near the Disturbed Area with those described in the Final Determination also indicate that the habitat of Swamp Oak Floodplain Forest is present within and near the Disturbed Area" (Keith expert report, pp 8-11).
Structure of the vegetation community
133The Final Determination of Swamp Oak Floodplain Forest also contains a description of the structure of the community. Dr Keith concludes that the vegetation in and around the Disturbed Area is consistent with the structure of Swamp Oak Floodplain Forest described in the Final Determination:
"Paragraph 1 of the Final Determination states that 'The structure of the community may vary from open forests to low woodlands, scrubs or reedlands with scattered trees. Typically these forests, woodlands, scrubs and reedlands form mosaics with other floodplain forest communities and treeless wetlands, and often they fringe treeless floodplain lagoons or wetlands with semi-permanent standing water (e.g. Pressey 1989a).' The trees observed immediately adjacent to the Disturbed Area are indicative of forest or woodland structure. An abundance of reedland species, Juncus kraussii subsp australiensis and Baumea juncea , was observed to be present beneath and amongst the trees. Inspection of an aerial photograph taken on 16 December 2006 ... before the Relevant Conduct, indicates that trees were present in the Disturbed Area and open areas visible amongst the trees indicate that the site supported a mosaic of forest, woodland and reedland, consistent with the description of vegetation structure in the Final Determination." (Keith expert report, p 11).
Adoption of Dr Keith's conclusion and reasons on Swamp Oak Floodplain Forest
134I accept and adopt Dr Keith's evidence, including his conclusion and reasons, that Swamp Oak Floodplain Forest did occur and still occurs on the low-lying flat in and near the Disturbed Area of Lot 1. Dr Keith was cross examined but only on a few particular matters. The cross-examination did not challenge or cause Dr Keith to withdraw his conclusion or his reasons for reaching his conclusion that Swamp Oak Floodplain Forest was and still is present on the low-lying flat in and near the Disturbed Area of Lot 1.
Dr Keith's conclusion and reasons that River-Flat Eucalypt Forest exists on Lot 1
135Dr Keith concludes:
"[I]t appears more likely than not that River Flat Eucalypt Forest on coastal floodplains is present within and near the Disturbed Area." (Keith expert report, pp 20-21, see also p 3).
136Dr Keith's conclusion was based on application of the description in the Final Determination for River-Flat Eucalypt Forest to the facts concerning the assemblage of species, the location in the particular area, and the edaphic and physiographic conditions of Lot 1.
Assemblage of species
137Dr Keith observed that the elevated area contains a different ecological community to that present on the low-lying flat. Its distinguishing features include dominance by Eucalyptus tereticornis and Angophora floribunda with an understorey that includes prominent small trees and shrubs. In particular, Dr Keith found:
" · seventeen of 29 species recorded on the elevated area are listed in the Final Determination as characteristic of River-Flat Eucalypt Forest on Coastal Floodplains ...
· the dominant tree species on the site ( Eucalyptus tereticornis and Angophora floribunda ) are identified in the Final Determination as amongst the most widespread and abundant dominant species of the community". (Keith expert report, p 20).
The location in the particular area
138Dr Keith noted that "the location of the site is within a bioregion (Sydney Basin) and Local Government Area (Wyong) identified in the Final Determination as part of the particular area within which the community occurs". (Keith expert report, p 20).
Edaphic and physiographic conditions
139Dr Keith found that "some abiotic components of the Habitat, such as soil texture (sandy loam) and elevational range (below 50 m above sea level) are consistent with the Final Determination". (Keith expert report, p 20).
Adoption of Dr Keith's conclusion and reasons on River-Flat Eucalypt Forest
140I accept and adopt Dr Keith's evidence, including his conclusion and reasons, that River-Flat Eucalypt Forest did occur and still occurs on the elevated area within and near the Disturbed Area of Lot 1. Dr Keith's evidence concerning River-Flat Eucalypt Forest was not challenged in cross-examination.
Dr Hazelton's evidence on the soils and landforms of the ecological communities
141Dr Hazelton gave evidence, in the form of an affidavit of 30 March 2011 and enclosed expert report, on the soils and geomorphology of Lot 1 and whether they matched those described in the Scientific Committee's Final Determination for the Swamp Oak Floodplain Forest and River-Flat Eucalypt Forest endangered ecological communities.
142Dr Hazelton noted that Lot 1 was in the Wyong Soil Landscape described in Murphy C L (1993), Soil Landscapes of Gosford - Lake Macquarie 1:100 000 Sheet, Department of Conservation and Land Management NSW as:
" · topography generally poorly drained deltaic floodplains and alluvial flats,
· limitations including flooding and both seasonal and permanent waterlogging,
· surface soil material ranging from loam to silty clay loam." (Hazelton expert report, p 4).
143Dr Hazelton inspected Lot 1 on 28 April 2010 and excavated 9 soil pits. Soil pits 1, 4 and 9 had fill to a depth of 90cm - 100cms, then sandy clay loam, clay loam or sandy loam beneath. Other soil pits had less or no fill on top but still had soils from sandy loams to clay loams. Dr Hazelton concludes that:
"All of the soil materials described and examined at Lot 1 at sites 1-9 have the same soil texture (black clay loams and sandy loams with some evidence of silt) as the soils described in the Final Determinations for the listed endangered ecological communities Swamp Oak Floodplain Forest EEC and River-Flat Eucalypt Forest EEC. Although no samples were taken to test for salinity, according to Murphy (1993) the subsoils in the Wyong Soil Landscape are moderately saline.
The soil materials, clay loams and sandy loams at Lot 1 have been deposited by streams to form an alluvial landscape and this is apparent because a distinctive profile characteristic has not developed." (Hazelton expert report, p 23).
144Dr Hazelton also concluded that the landform characteristics match those in the Final Determinations for the two endangered ecological communities:
"Lot 1 is located within the Wyong Soil Landscape, described by Murphy (1993) as a broad, poorly drained floodplain. According to Speight (1990) a floodplain is an alluvial plain 'characterised by frequently active erosion and aggradation by channelled or overbank stream flow'.
From the Soil Landscapes of the Gosford-Lake Macquarie 1:100 000 map sheet [Murphy and Tille (1993)] it can be seen that a creek line which would have flowed into Lot 1 has been captured by a drain. Numerous streams are evident in the area of Lot 1 ... There is also a distinctive 'stone line' at Site 6 which could be attributed to stream disposition.
The topography at Lot 1 is a poorly drained flat close to a lake margin and similar to that described by Murphy (1993) and quoted on page 2 of this report. There was evidence of poor drainage and waterponding between Site 3, Site 4 and Site 5 because of the presence of peaty topsoil. At Site 3 the soil was wet at 40 cm evidence of the water table. These characteristics fit the descriptions in the Final Determinations for the listed endangered ecological communities Swamp Oak Floodplain Forest EEC and River-Flat Eucalypt Forest EEC.
At Sites 7, 8, 9 there is also a slightly elevated terrace (see photo 8) for the River-Flat Eucalypt Forest EEC." (Hazelton expert report, pp 23-24 and see also p 25).
145Dr Hazelton's evidence was not challenged by Mr Venn and she was not required for cross-examination. I accept and adopt Dr Hazelton's evidence, including her conclusions and reasons.
Mr Venn's denial of presence of endangered ecological communities
146Mr Venn denied that the vegetation on Lot 1 was part of the endangered ecological community of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest for three reasons. First, Mr Venn said that two prior reports on Colongra Swamp generally described the vegetation differently and not as part of either Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest. Secondly, Mr Venn said that his use of Lot 1 since around 1975-1976 has so damaged the vegetation that it no longer meets the description of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest. Thirdly, Mr Venn said that the subsidence of Lot 1 and surrounding lands in 1992 and 1998, and the concomitant inundation by saline lake water, changed the environment and vegetation so that it does not meet the description of Swamp Oak Floodplain Forest and River-Flat Eucalypt Forest. I do not accept these arguments.
Prior vegetation surveys of Colongra Swamp
147Mr Venn did not call any experts to give evidence, including in relation to the vegetation, soils or landforms, to establish that neither the Swamp Oak Floodplain Forest nor the River-Flat Eucalypt Forest endangered ecological communities existed on Lot 1.
148Instead, Mr Venn sought to rely on two prior reports on the vegetation of Colongra Swamp, which he submitted established that the vegetation was not part of either Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest.
149Mr Venn also sought to rely on his own observations of the vegetation and topography and the effects of subsidence and inundation.
150Mr Venn annexed to his first affidavit of 16 February 2011, a report prepared by Sainty & Associates in November 1998 on Colongra Wetland Subsidence Impacts Assessment ("the Sainty Report"). Mr Venn did not call any witness from Sainty & Associates to give evidence. The Sainty Report was prepared for a different purpose and, for the most part, for different land to Lot 1.
151The Sainty Report noted that the Endeavour Colliery (now owned by Powercoal Pty Ltd) had mined a large area, including beneath the Colongra Wetland, from 1963 and that mining of the wetland ceased in about 1988. Subsidence as a result of mining had caused a loss in elevation of the wetland and surrounding buffer zone, which included an area of foreshore to the north of the wetland on the margins of Lake Munmorah. The Sainty Report noted that Sainty & Associates were commissioned by Powercoal Pty Limited to "undertake an investigation of the current and potential impacts, due to subsidence, and to determine feasible rehabilitation and management strategies for the impacted areas of Colongra Wetland." (Sainty Report, p (i) Executive Summary).
152Colongra Wetland is a perched freshwater wetland next to, but separated by a natural land barrier or weir from, the saltwater Lake Munmorah. Part of the southern, open water zone of the wetland extends on to Lot 1. It is, however, outside and to the west of the part of Lot 1 disturbed by clearing and filling, the subject of these proceedings.
153Mr Venn relied on the Sainty Report for its description of the vegetation at that time of the site survey to found his submission that the vegetation was not part of either Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest. Mr Venn, first, relies on the Sainty Report identifying and labelling distinct vegetation communities as "Swamp Forest", "Rush/Sedge community", "Foreshore Forest" and "Wetland margin including 'Weir'" and not "Swamp Oak Floodplain Forest" or "River-Flat Eucalypt Forest", as indicating that the latter endangered ecological communities did not occur. Secondly, Mr Venn claims that the Sainty Report says that all of the four communities that it identified were "dominated" by Melaleuca quinquenervia with the exception of the Foreshore Forest which was dominated by Melaleuca quinquenervia and Casuarina glauca . However, by the time of the Sainty Report in 1998, the Casuarinas in the Foreshore Forest were exhibiting dieback or had died. Hence, Mr Venn says that the Casuarinas would no longer have been dominant. Mr Venn says that this dominance of Melaleuca quinquenervia in the communities contrasts with the Scientific Committee's description in the Final Determination for Swamp Oak Floodplain Forest that Casuarina glauca is the dominant species (para 4 of the Final Determination).
154I will, therefore, consider the Sainty Report and its description of the sites surveyed.
155In order to assess the current impacts from subsidence and to monitor future impacts, Sainty & Associates undertook flora surveys on and either side of two permanent transects along existing survey lines and random sampling at four pre-determined sites. Transect 1 was outside and far to the west of Lot 1. Transect 2 started in Lot 1 (peg 83 on the survey line) and ran in a west, north-west direction, leaving Lot 1 around peg 108 and continuing across the neighbouring Lot 2 in DP 1029487 until peg 221 on the survey line. Eight quadrats were sampled along transect 2 with the first quadrat located at peg 109 (just outside and to the west of Lot 1 and a considerable distance from the Disturbed Area) and the other 7 quadrats along the survey line going away from Lot 1 in a west, north-west direction. The remoteness of these sites from the Disturbed Area in Lot 1 makes the flora surveyed at these sites of no proven relevance to the vegetation on the Disturbed Area of Lot 1.
156Three of the four predetermined sites were also outside Lot 1. Site 1 was to the south of the open water zone of the wetland area (probably in Lot 1 of DP 519335 but a considerable distance inland and to the west of Lot 1). Site 2 is to the west of the wetland where the open water zone changes to a shallower zone (in Lot 2 of DP of 1029487 and a considerable distance inland and to the west of Lot 1). Site 4 is to the north of the open water zone along the freshwater wetland margin and includes part of the weir separating the wetland from the lake. This site may be mostly in the north-eastern corner of Lot 1 but is to the west, northwest of the Disturbed Area on Lot 1. Site 3 is further to the north again of Site 4 in the low-lying foreshore region of Lake Munmorah that had been inundated by saline lake water (in Lot 3 in DP 1029487 and to the northwest of Lot 1).
157The Sainty Report used labels to describe the vegetation communities at each of the four predetermined sites. Site 1 was described by the label "Swamp Forest", Site 2 as "Rush/Sedge community"; Site 3 as "Foreshore Forest"; and Site 4 as "Wetland margin including 'Weir'". These are no more than shorthand labels and not determinative of the vegetation community to which the labels are applied. The Sainty Report describes each community so labelled in the report, with reference to the flora survey data collected. It is these descriptions and data, and not the labels, that are relevant. The assignment of labels in the Sainty Report can have no legal significance for the classification of the vegetation on Lot 1 as being Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest endangered ecological communities.
158The only site of potential relevance to understanding the vegetation in the Disturbed Area of Lot 1 is Site 3. Mr Venn relied upon the flora survey data and the analysis for Site 3 as being relevant. Mr Venn did not rely on the data and analysis of the vegetation in Site 4, presumably in recognition that Site 4, although in Lot 1, is a wetland buffer zone on the margin of the perched freshwater wetland and the weir between the freshwater wetland and the saltwater Lake Munmorah. The Disturbed Area of Lot 1 does not have these characteristics.
159The Sainty Report notes that for each site, including Site 3, three plots of 10mm x 10mm (100m ) were randomly selected and marked out to quantify the species composition and abundance of wetland vegetation. Further quantification of species richness and abundance, at a smaller scale, was made by sampling five quadrats of 2mm x 2mm (4m ) within each of the 100m plots.
160The Sainty Report classified Site 3 as a shore forest dominated by Melaleuca quinquenervia and Casuarina glauca with occasional Livistona australis . The site had been subject to inundation from saline lakewater. The understorey varied from ferns, grasses, to reeds and occasional sedges and rushes. Melaleuca trees were defoliated, indicating a high level of stress. The majority of Casuarina trees were exhibiting dieback or had died. The species recorded as present included characteristic species of Swamp Oak Floodplain Forest, being the trees of Melaleuca quinquenervia , Casuarina glauca and Glochidion ferdinandi , the sedges and rushes of Baumea juncea , Gahnia clarkei and Phragmites australis ; the grass Entolasia marginata ; and the perennial herb, Leptinella longipes (found in quadrat 3) which Dr Keith notes was listed in the descriptions of map units 106 and 107 which are defined as part of Swamp Oak Floodplain Forest in paragraph 8 of the Final Determination (Keith expert report, p 6). The composition of the ground stratum is consistent with that described as occurring on the fringes of coastal estuaries where soils are more saline.
161In the conclusion, the Sainty Report noted that:
"Impact on vegetation due to subsidence is clearly evident along the foreshore where a large area of foreshore forest is dead. Surviving trees will continue to die for a number of years after the changes in the hydrological regime have taken place. The trees will most likely remain standing after death ... Large areas of understorey that were formerly dominated by a number of fern species and grasses have died except where elevation is higher and inundation has not occurred." (Sainty Report, p 28).
162The Sainty Report also noted that:
"Inspection of an unaffected area of the foreshore adjacent to Colongra Point [which is in Lot 2] revealed a number of salt and semi-salt tolerant species. These species ( Sarcocornia quinqueflora , Baumea juncea , Juncus kraussii , Paspalum vaginatum , Leptinella longipes and Tetragonia tetragonoides are likely to expand their range and colonise where vegetation has been lost (p 28).
163As noted earlier, Baumea juncea and Juncus kraussii are each listed as characteristic species of Swamp Oak Floodplain Forest and Leptinella longipes occurs in communities mapped as Swamp Oak Floodplain Forest.
164The floristic descriptions in the Sainty Report of the vegetation at Site 3 and the affected foreshore area near Colongra Point do not support Mr Venn's submission that the vegetation in the Disturbed Area of Lot 1 prior to being cleared and filled was not Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest.
165First, Mr Venn has not established on the evidence that the vegetation recorded in the Sainty Report at Site 3 is or is not the same as the vegetation at the part of Lot 1 that was cleared and filled. Hence, it is not possible to draw an inference from the data and the analysis of the vegetation at Site 3 as to the vegetation in the Disturbed Area of Lot 1.
166Secondly, the Sainty Report's data and analysis of the vegetation in Site 3 does not speak against a conclusion that the vegetation could be part of Swamp Oak Floodplain Forest. To the contrary, the floristic descriptions are consistent with those for Swamp Oak Floodplain Forest, including the presence of three characteristic trees of Casuarina glauca , Melaleuca quinquenervia and Glochidion ferdinandi ; the occurrence of vines; and the ground cover of forbs, sedges and grasses with a composition reflecting the more saline conditions at Site 3.
167The statements in the Sainty Report concerning dominance of tree species do not preclude the vegetation being part of Swamp Oak Floodplain Forest. The vegetation at Site 3 was described as being dominated by both Melaleuca quinquenervia and Casuarina glauca . The description in the Scientific Committee's Final Determination of Swamp Oak Floodplain Forest does not preclude such co-dominance. As noted earlier, the Final Determination accepts that individual sites may exhibit differences in species composition and dominance. Dr Keith's evidence is that on the low-lying flat of the Disturbed Area, Casuarina glauca was the dominant tree (Keith expert report, p 5). Mr Venn's evidence was that the northern end of the foreshore land (which adjoins Lot 3 of DP 1029487) where the dead zone occurs was "always mostly Melaleuca quinquenervia , with the odd Casuarina here and there. The Melaleucas gradually thinned as you came south [into the Disturbed Area of Lot 1] ... I have always had Melaleuca and Casuarina around the Lot 2 boundary. I have observed that there have always been some small areas of Casuarina glauca up around the north-west of the Land as well, but otherwise they've just been scattered here and there among the Melaleucas, which dominate DP 509889." (Venn second affidavit of 11 May 2011, paras 73 and 74).
168Accordingly, the Sainty Report does not establish that the vegetation on the part of Lot 1 that was cleared and filled was not Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest.
169Mr Venn also relied on a document obtained from the NPWS, entitled "Summary of Vegetation Monitoring, March to November 2000" at the four sites surveyed by Sainty & Associates in 1998. For Site 3, the Foreshore Forest, the Summary of Vegetation Monitoring noted that:
"There had been little regrowth after initial subsidence and consequent flooding from lake. Few species have survived in this area of frequent inundation with conductivity readings over 25mS / cm ... These species are the Common Reed, Phragmites australis , and the grey rush, Baumea juncea . All Broad-Leaved Paperbarks, Melaleuca quinquenervia and Swamp She-Oak Casuarina glauca , have died within approximately 30 m line from the lake edge, as well as a majority of the paperbarks growing between 30-50 m distance from original lake edge." (Venn first affidavit of 16 February 2011, Tab 16, p 2).
170The Summary of Vegetation Monitoring noted that species lost from the area included saw-sedge, Gahnia clarkei , and cheese tree, Glochidion ferdinandi . On the other hand, the summary noted that there are some species recolonising in slightly higher spots, being Water Ribbons, Triglochin procera , and a wetland grass, Hemarthria uncinata , and also a salt marsh ground cover, Triglochin striata .
171Mr Venn relies on this document to demonstrate that, by 2000, few species had survived in and around the northern boundary of Lot 1 and all of the Melaleuca quinquenervia and some Casuarina glauca had died. (Respondent's submissions 1 June 2011, para 19). Accordingly, Mr Venn submits that the vegetation could not have been, at the time of the clearing and filling between May 2007 to July 2008, part of Swamp Oak Floodplain Forest.
172Again, I do not accept this submission. First, Mr Venn has not established that the inundation and adverse affects on vegetation on Site 3 were replicated on the Disturbed Area of Lot 1. Indeed, the satellite and aerial photography in December 2006 and June 2007, as well as other photographs taken in 2007, demonstrate a vast difference between the zone of dead trees, within which Site 3 was located, and the green trees and ground cover in and around the part of Lot 1 that was cleared and filled. As Dr Keith finds, before the relevant conduct of the clearing and filling of Lot 1, "trees were present in the Disturbed Area and open areas visible amongst the trees indicate that the site supported a mosaic of forest, woodland and reedland, consistent with the description of vegetation structure in the Final Determination" (Keith expert report, p 11). Lot 1 was, therefore, not in the condition and did not have the species composition described in the Summary of Vegetation Monitoring for Site 3.
173Secondly, the Summary of Vegetation Monitoring's record of species that had been lost or were recovering may provide evidence that the vegetation that did exist at Site 3 before being inundated and adversely affected might have been Swamp Oak Floodplain Forest. The site contains the dominant and subordinate tree species of Casuarina glauca , Melaleuca quinquenervia and Glochidion ferdinandi , and ground cover graminoids of Gahnia clarkei , Baumea juncea , and Phragmites australis . These are all listed as characteristic species in the Final Determination for Swamp Oak Floodplain Forest. In so far as Site 3 occurred on similar topography and soils on the lake foreshore as Lot 1, this may also corroborate, rather than speak against, the conclusion that the vegetation on Lot 1 was, prior to clearing and filling, and still is part of Swamp Oak Floodplain Forest.
Disturbance caused by Mr Venn's activities
174Next, Mr Venn submitted that his use of Lot 1 from around 1975-1976 until the commencement of the clearing and filling in May 2007, by clearing, removal of understorey, mowing and allowing the invasion of weeds, caused the vegetation on Lot 1 no longer to be part of either Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest.
175Mr Venn says he removed undergrowth but kept the tree cover and mowed along the foreshore until about August 1992 when subsidence and consequent flooding made use of the area for camping impossible (Venn first affidavit of 16 February 2011, para 64).
176Mr Venn relies upon the answer Dr Keith gave in his oral evidence to a question about the effects of mowing. Dr Keith said that mowing of reedland species, such as Baumea juncea and Juncus kraussii subsp australiensis , which grow on the low-lying flat on the lake foreshore, creates light at the ground surface which allows the entry of exotic species, which are shorter in stature, to establish and persist.
177However, this answer of Dr Keith does not establish that Mr Venn's past mowing resulted in the complete removal of all native species of ground cover, including reedland species. Dr Keith did not say so in his answer and he was not cross-examined further on his answer. Dr Keith's evidence in chief, including in his expert report, clearly establishes that native species of ground cover, including the reedland species, had persisted on Lot 1, nothwithstanding any past mowing before and after the clearing and filling on the Disturbed Area of Lot 1. The photographic and direct observational evidence of Dr Keith, Mr Bruce who undertook the clearing and filling, as well as other persons who visited the site, established that Lot 1 had a ground cover of native species before the clearing and filling in 2007 and 2008.
178Furthermore, Mr Venn's own evidence is that he ceased mowing the foreshore area after the subsidence in 1992, and again in 1998, because it was underwater or too wet (Venn first affidavit of 16 February 2011, para 4 and Venn second affidavit of 11 May 2011, para 39). Hence, if native species had been affected by mowing, there was time for them to recolonise before 2007.
179Mr Venn relies on the infestation of weeds, particularly Lantana camara , as evidence that the vegetation was not part of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest. Mr Venn says he recalls "the Lantana being very thick, tall and well established east of the Wetland [the inland freshwater wetland] from about the late 1970s when the electricity line went in". (Venn's second affidavit, para 76).
180Mr Venn refers to the statements in the Sainty Report concerning infestation of Lantana. First, along transect 2, the Sainty Report stated:
"Over 80% of the understorey is dominated by Lantana camara in large dense stands (in some cases Lantana was observed 10 m up trees)" (p 24, s 6.3.2).
181Secondly, in Site 3, the Sainty Report noted:
"The introduced Lantana camara is wide spread" (p 26, s 6.4.3).
182Thirdly, the Sainty Report expressed a general concern about the effects the adjacent properties were having on the wetland not related to subsidence impacts: "[l]arge areas of the wetland's buffer zone have been mowed and maintained as open grassed areas. This action has removed native vegetation cover and prevented its regrowth which, in effect, could be promoting feral predation and weed invasion typical of disturbed areas" (p 36, s 10.3).
183I do not accept that the presence of weeds means that the vegetation on Lot 1 before clearing and filling was not part of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest.
184First, the observations in the Sainty Report are at locations different to the Disturbed Area of Lot 1 that was cleared and filled. The 8 quadrats in which vegetation was surveyed along transect 2 were all located west of Lot 1. No inference can be drawn from the dominance of Lantana in the understorey in those quadrats to the condition of the understorey in the part of Lot 1 that was cleared and filled. Similarly, Site 3 is to the northwest of Lot 1 and no inference can be drawn from Lantana being widespread in Site 3 as to its abundance in Lot 1. The cleared areas in the wetland buffer zone are not limited to Lot 2 or Lot 1 and in any event are removed from the Disturbed Area of Lot 1.
185Secondly, Mr Venn's evidence is that Lantana did not grow on the foreshore area of Lot 1. Mr Venn says, until he had to stop after the subsidence in 1992, he mowed the foreshore areas, which kept any Lantana at bay. After the subsidence, Mr Venn's evidence is that the area was underwater or too wet and "not even Lantana grew, because it was so waterlogged and salty" (Venn's second affidavit, para 50). Lantana only became established after filling raised the level of the foreshore land. Mr Venn says that since early 2009, after the filling, he has mowed the area to "keep the resurgent Lantana and Bitou Bush at bay: it has come back since the hydrology has improved" (Venn's second affidavit, para 51). Mr Dalton, a volunteer Bush Regenerator working in the Colongra Swamp, said in his oral evidence that he observed Lantana growing as a dominant plant in the understorey on the higher level, but not on the lower part of the land which was more open.
186Thirdly, Dr Keith's evidence was that a close and careful analysis of the satellite and aerial photographs, particularly the colour and tone of the vegetation, reveals that areas where Lantana was established was inland and outside of the Disturbed Area of Lot 1 that was cleared and filled.
187Fourthly, the photographic evidence and the direct observational evidence of Dr Keith, Mr Bruce and others who visited the land reveals that Lantana was not widespread in the low-lying foreshore area.
188Finally, even if there had been Lantana and other weeds in the part of Lot 1 that was cleared and filled, this does not necessarily prevent characterisation of the vegetation as part of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest. The Scientific Committee in the Final Determinations for each of Swamp Oak Floodplain Forest and River-Flat Eucalypt Forest expressly notes that:
- " The species composition of a site will be influenced ... by its disturbance (including fire, grazing, flooding and land clearing) history" (para 2 of each Final Determination)
- "The composition and structure of the understorey is also influenced by grazing history, changes to hydrology and soil salinity and other disturbance, and may have a substantial component of exotic grasses, vines and forbs" (para 4 of Swamp Oak Floodplain Forest Final Determination)
- "The composition and structure of the understorey is influenced by grazing and fire history, changes to hydrology and soil salinity and other disturbance, and may have a substantial component of exotic shrubs, grasses, vines and forbs" (para 4 of River-Flat Eucalypt Forest Final Determination)
- "Very few examples of Swamp Oak Floodplain Forest remain unaffected by weeds. The causes of weed invasion include physical disturbance to the vegetation structure of the community, dumping of landfill rubbish and garden refuse, polluted runoff from urban and agricultural areas, construction of roads and other utilities, and grazing by domestic livestock. The principal weed species affecting Swamp Oak Floodplain Forest include ... Lantana camara " (para 13 of Swamp Oak Floodplain Forest Final Determination and the equivalent statement in para 12 of River-Flat Eucalypt Forest Final Determination).
189Hence, the Scientific Committee recognise that vegetation on a site can still be part of Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest endangered ecological communities notwithstanding infestation by weeds, including Lantana camara .
Disturbance caused by subsidence and changes to hydrology and salinity
190Finally, Mr Venn relies on the subsidence of Lot 1 and surrounding lands in 1992 and 1998 and the concomitant inundation by saline lake water. Mr Venn submits that this caused a change in the environment and vegetation with the consequence that the environment and vegetation existing prior to the clearing and filling in 2007 and which exists today on Lot 1, are artefacts and not natural. Hence, Mr Venn submits, the vegetation in 2007 and also today cannot be part of the Swamp Oak Floodplain Forest or River-Flat Eucalypt Forest endangered ecological communities. I do not accept this submission.
191First, whilst subsidence may have occurred and the low-lying flat may have become wetter, the factual evidence does not establish either extensive mortality or a change in species composition of the vegetation on the Disturbed Area of Lot 1. Obviously, the vegetation on the elevated area was and still is sufficiently high above the lake so as not to be affected by any inundation. As far as the vegetation on the low-lying flat, the satellite and aerial photography after the subsidence events in 1992 and 1998, including in 2006 and 2007, show green canopies of trees and green ground cover between trees in the Disturbed Area of Lot 1 in contrast to the dead trees and standing water between trees to the north of Lot 1 in Lot 3 of DP 1029487. The subsidence events caused the vegetation in the latter area, but not in the former area to die. Other photographic evidence and direct observational evidence of persons who were on Lot 1 in 2007 confirm that the trees and vegetation on Lot 1 were largely unaffected.
192The falling over and death of a Melaleuca quinquenervia on the foreshore towards the boundary of Lot 1 and Lot 2 (clearly visible on satellite and other photographs in 2006 and 2007) is the exception and is not evidence of widespread death of trees on Lot 1.
193I note the evidence of Mr Michael Shelly, an environmental consultant, who was personally involved in the work done by Environmental Resource Management (Australia) Pty Ltd ("ERM") in 1996 for Powercoal Pty Ltd at Colongra Point (on Lots 1 and 2) to rectify foreshore damage caused by subsidence. Mr Shelly says that the part of Lot 1 that was cleared and filled between May 2007 and July 2008 was "fully covered in native vegetation and undisturbed at the beginning and cessation of Powercoal's work [in 1996]. I recall that the vegetation in the 'new' area of disturbance [the area disturbed by clearing and filling by Mr Venn] was undisturbed and not affected by subsidence induced dieback at the time of my involvement in the rehabilitation of the foreshore on Lot 1, which was between late 1995 and 1996." (Shelly affidavit of 23 July 2010, para 32).
194I also note that the NPWS "Summary of Vegetation Monitoring March to November 2000," tendered by Mr Venn, recorded that:
"The lake reached a height of 0.58 m in April, May and July of 1999 and the lake covered the foreshore to a distance of approximately 80 m at its furtherest reach, reaching the survey line between Pegs Nos. 95-100 (which had subsided approximately 0.7 m)." (Venn first affidavit, Tab 12, p 37).
195The Summary records that in the area of inundation "much of the vegetation species was killed at this time".
196Pegs 95-100 on the survey line are along transect 2. They are close to the northern boundary of Lot 1 with Lot 3 of DP 1029487 and are to the west, northwest of the Disturbed Area of Lot 1. The summary corroborates that the subsidence and inundation by saline lake water that killed trees and vegetation in the dead zone in Lot 3 of DP 1029487 and the northern part of Lot 1 did not have the same effect on the balance of Lot 1 including the Disturbed Area.
197I do not accept Mr Venn's evidence stated in correspondence during 2007 and 2008 defending his actions and in his second affidavit that "the trees and other vegetation" in the part of Lot 1 that was later cleared and filled had died (Venn second affidavit, para 42); that "[i]t was waterlogged, detritus filled ooze and nothing was growing. It was a dead place." (Venn second affidavit, para 50); that the trees "had no branches, just dead sticks in the air" like those in the dead zone on Lot 3 of DP 1029487 (Venn second affidavit, para 50); and that the stand of Melaleucas and Casuarinas around the boundary of Lot 1 with Lot 2 "were the only ones left because those in the adjoining mid section of the Work Area had died." (Venn second affidavit, para 84). These statements are contradicted by the satellite and aerial photography in 2006 and 2007 and the photographic and direct observational evidence of persons who visited the site in 2007.
198Secondly, any increase in salinity of the groundwater as a result of subsidence and inundation would not necessarily cause vegetation to fall within or outside the description of a Swamp Oak Floodplain Forest. The Final Determination for Swamp Oak Floodplain Forest describes the ecological community at a level of generality so as to include vegetation under more and less saline groundwater conditions and more and less inundation and water logging. The composition of Swamp Oak Floodplain Forest is primarily determined by the frequency and duration of water logging and the level of salinity in the groundwater (see para 1 and also paras 4 and 6 of the Final Determination for Swamp Oak Floodplain Forest). Hence, any increase, caused by subsidence, in the frequency and duration of water logging or in the level of salinity of groundwater, may change, over time, the species composition or relative abundance of species on Lot 1, but it does not necessarily cause the vegetation to be or not to be part of the Swamp Oak Floodplain Forest endangered ecological community. Dr Keith's evidence is that on the low-lying flat the vegetation was, and still is, part of Swamp Oak Floodplain Forest. The subsidence and any concomitant inundation have not affected this classification of the vegetation.
199Thirdly, Mr Venn's submission is founded on the erroneous belief that ecological communities are static and not dynamic and hence that disturbance must cause the community to become a different community. An ecological community is a living entity, adaptively responding to disturbances in its environment. The disturbances may be due to natural events, such as fire, storms or floods or be human induced, such as clearing, increase in nutrients or introduction of alien species of plants and animals. At any point in time, an ecological community will be in a stage of response to whatever has been the disturbance history to that point in time. It would be impossible to have an ecological community that is not, in some way, disturbed. This dynamism of ecological communities is recognised in the Scientific Committee's Final Determinations of the Swamp Oak Floodplain Forest and River-Flat Eucalypt Forest endangered ecological communities.
200Prior to the 1992 and 1998 subsidence events, the vegetation on Lot 1 was responding to the disturbances caused by Mr Venn's various actions of clearing undergrowth, mowing and allowing the camping activities of Scouts, as well as bushfires and weed invasion and feral animals. The subsidence event simply introduced different disturbances. The vegetation adaptively responded to the changes caused by the subsidence in the hydrological regime or the salinity of the groundwater. The disturbances and adaptive responses might have differed, but the ecological community remained the same.
Conclusion on endangered ecological communities
201For these reasons, I find that: