Quantifying the impact of severe bushfires on biodiversity to inform conservation

Abstract The unusually severe 2019-2020 Australian bushfire season destroyed large areas of habitat along the southeastern coast. We assess the differences between this fire season and previous ones to understand their impacts and potential recovery. We used thermal satellite data to quantify the extent of eastern Australian bushfires from 2012-2020. During the 2019-2020 anomalous fire season, 134 mega-fires, each over 10,000 ha, burned 62.5% of the total affected area, including critical forested landscapes. Previous fire seasons were characterized by smaller, scattered fires in mostly non-forested areas. The anomalous fire season had direct negative impacts on wildlife including grey-headed flying foxes, which experienced substantial declines in immediately available foraging forest habitat, particularly key winter resources. We identified important areas for managing wildlife resources and supporting ecosystem health in the coming decades. Our research also identifies key monitoring areas to improve our understanding of ecosystem recovery and resilience in changing fire regimes.