Fire regimes that cause declines in biodFire regimes that cause declines in biodiversity

Fire regimes that cause declines in biodiversity

While the Wollemi Pine has some capacity to resprout after low severity fires, this capacity varies markedly between life history stages (Mackenzie et al. unpubl. data) and the consequences of high severity fire are likely to be catastrophic. The species (especially smaller individuals) is vulnerable to high frequency fire (Mackenzie & Auld in press; Mackenzie et al. unpubl. data). Repeated short-interval fires will lead to increased rates of mortality due to reductions in protective tissues around meristems and reduced rates of resprouting due to reductions in availability of photosynthates for resprouting. Short fire intervals also mean less time for seedlings and juveniles to develop fire resistance and grow to heights beyond which their canopies may survive fire impacts (Mackenzie et al. unpubl. data).

The risk of unplanned fire in the wild population was substantially (albeit temporarily) reduced as a result of the 2019–20 fires which consumed surface fuels that had accumulated on site. This risk was expected to remain low for approximately five years (until 2024) until significant re-accumulation of surface fuels (Mackenzie et al., 2021). Beyond this, long-term fire exclusion in the order of 50–100 years is required to facilitate population recovery and persistence (Mackenzie et al. 2021).

The ongoing risk of fire is managed by NPWS, and the declaration of 5,000 hectares of the Wollemi Pine catchment as an AIS triggers the integration of spatial information into NPWS fire management systems. This facilitates the rapid identification and protection of environmental and cultural assets (such as the Wollemi Pine) during planned and unplanned fires.