Springtail (Collembola) response to the 2019-2020 megafires in Blue Mountains swamps

Swamps are ecologically important environments where macroinvertebrates perform essential roles in nutrient cycling and maintaining interactions between different trophic levels. However, very little is known about how their diversity could be used as indicators of ecosystem health and recovery following disturbance. The recent 2019-2020 bushfires destroyed more than 50% of Blue Mountains swamps (NSW) and are expected to have severely affected macroinvertebrate communities. We, therefore, assessed the impact that the 2019-2020 bushfires had on collembola assemblages collected from Blue Mountains swamps using a DNA metabarcoding approach. Specifically, we assessed shifts in springtail (Collembola) taxonomic diversity, richness, and composition among swamps, between fire status (burnt and unburnt), and year (2019 and 2020). We found that the diversity of springtails was affected by fire disturbance and nearly all swamps showed a unique taxonomic composition of Collembola. While some taxonomic groups were not detected in burnt swamps after the fire, other taxa were found in greater abundance in both burnt and unburnt swamps after the fire. Overall, we found that the burnt sites had lower taxonomic richness and diversity of Collembola compared to the unburnt sites both before (2019) and after (2020) the fire. The results have implications for carrying out future assessments of the extent of taxonomic biodiversity shifts in invertebrates due to fire and providing the initial source of information for conservation and management indicating the need for considering actions to minimize the effects of climate change and future bushfire events on these critical ecosystems.