Wollemi National Park standsWollemi National Park stands

Wollemi National Park stands

Following the success of the 2012 pilot translocation, two remote-area translocated stands were established in WNP in mid-2019, in deep, steep sided rainforest canyons with perennial watercourses (Mackenzie et al. 2021). Known respectively as T1 and T2, the aims of these translocations are to:

 use an adaptive management framework to experimentally address uncertainty in the optimal planting strategy to accelerate maturation and maximise longevity of translocated Wollemi Pine saplings (specifically, where to position saplings along gradients in vegetation, available light, fire and drought risk, and which type of source material – cuttings or seed-grown plants – to use)

 address knowledge gaps in the ecology of Wollemi Pine (including its persistence and regeneration niches) that are relevant to conservation management of the wild population

 ultimately, to increase the size and geographic distribution of the wild population (which requires the translocated stands to first become self-sustaining and is indicated by the appearance of second-generation seedlings).

These plantings extended the learnings from the 2012 pilot translocation and incorporated advances in propagation techniques and population genomics to produce large numbers of high quality and genetically diverse Wollemi Pine saplings. Additionally, the ecological experiments underlying the WNP translocations explicitly address the effects of disturbance regimes such as fire and drought on trade-offs between longevity, growth and lifetime reproductive output of translocated saplings over different timescales (Mackenzie 2021; Mackenzie et al. 2021).

Both T1 and T2 had an initial population size of 218 saplings each (Figure 5); however, they were heavily impacted by the 2019-20 fires soon after establishment and before the saplings had time to develop fire resistance. No saplings resprouted successfully post-fire at either site but 64 (30%) and 6 (3%) saplings escaped burning at T1 and T2, respectively.

In 2021 both T1 and T2 were augmented with c. 250 saplings each (Mackenzie et al., 2021), although 25% of the total population at T2 was impacted by a landslide in 2022, resulting in 13% mortality. As of May 2024, from the original 2019 planting, only 53 (24% pre-fire population) and 3 (1% pre-fire population) individuals persisted at T1 and T2, respectively (Mackenzie et al., unpubl. data). Survival of the 2021 augmentation cohort remains high, attributable in part to three years of favourable La Niña conditions from 2021 to 2023, with 210 (84%) saplings persisting at T1 and 187 (75%) saplings persisting at T2 as of May 2024 (Mackenzie et al., unpubl. data). These populations were augmented with c. 180 saplings each in April and June of 2024, bringing the total population size of T1 to 456 saplings and that of T2 to 379 saplings (Figure 5).