Assessing impacts of the 2019–20 fires on nine rare plants: challenges and solutions for improved conservation responses

Context The 2019–20 fires in Australia burnt more than 5.5 million hectares in New South Wales, including the majority of populations for 5–8% of the state’s threatened and endemic plants. Desktop analyses immediately post-fire predicted serious declines in a subset of taxa, because of interactions between the fires and other threats. Aims We tested whether the fires caused a decline in nine rare, but not threatened, taxa considered at high risk, and whether the predicted threats to natural recovery occurred. Methods We collated pre-fire data from existing sources, and conducted field re-survey of known sites 1.6–2.6 years post-fire, collecting data on abundance, fire response and threats. Key results Three of the nine species declined post-fire, two others may have declined, although the data were inconclusive, two showed no apparent change, and two increased post-fire from germination of soil seedbanks. We found a low correlation of predicted and realised threats. The most common threat detected was erosion. Conclusions Our ability to detect an impact of the 2019 fires was hampered by the lack of pre-fire data, the small number of sites and plants, and variable responses. We attributed the low correlation between predicted and observed threats to high spatial variation, limitations of the predictive data used, and the difficulty in detecting some threats. Implications Future work should prioritise field surveys, including collection of key data to assess conservation status, improved data management, and active fire management for species most at risk from inappropriate fire regimes.