Responding to the biodiversity impacts of a megafire: A case study from south‐eastern Australia’s Black Summer

Abstract

Aim Megafires are increasing in intensity and frequency globally. The impacts of megafires on biodiversity can be severe, so conservation managers must be able to respond rapidly to quantify their impacts, initiate recovery efforts and consider conservation options within and beyond the burned extent. We outline a framework that can be used to guide conservation responses to megafires, using the 1.5 million hectare 2019/2020 megafires in Victoria, Australia, as a case study. Location Victoria, Australia. Methods Our framework uses a suite of decision support tools, including species attribute databases, ~4,200 species distribution models and a spatially explicit conservation action planning tool to quantify the potential effects of megafires on biodiversity, and identify species‐specific and landscape‐scale conservation actions that can assist recovery. Results Our approach identified 346 species in Victoria that had >40% of their modelled habitat affected by the megafire, including 45 threatened species, and 102 species with >40% of their modelled habitat affected by high severity fire. We then identified 21 candidate recovery actions that are expected to assist the recovery of biodiversity. For relevant landscape‐scale actions, we identified locations within and adjacent to the megafire extent that are expected to deliver cost‐effective conservation gains. Main conclusion The 2019/2020 megafires in south‐eastern Australia affected the habitat of many species and plant communities. Our framework identified a range of single‐species (e.g., supplementary feeding, translocation) and landscape‐scale actions (e.g., protection of refuges, invasive species management) that can help biodiversity recover from megafires. Conservation managers will be increasingly required to rapidly identify conservation actions that can help species recover from megafires, especially under a changing climate. Our approach brings together commonly used datasets (e.g., species distribution maps, trait databases, fire severity mapping) to help guide conservation responses and can be used to help biodiversity recover from future megafires across the world.

Animal mortality during fire

“…Efforts that reduce postfire predation pressure, such as the addition of artificial refuges to the landscape (e.g. Bleicher & Dickman, 2020) and targeted invasive predator control (Geary et al, 2021), and those that replace resources consumed by fire, such as supplemental food and water stations and nest boxes, could be leveraged to reduce the vulnerability of populations of threatened species following high severity wildfires.…”

“…The unprecedented scale of these recent fires (Boer et al, 2020;Duane et al, 2021) resulted in substantial proportions of many species' ranges-and in some instances entire geographic ranges-lying within the perimeter of a single fire (Ward et al, 2020). Understanding the likely proportional population toll of such fires is important in order to reassess the conservation status of species (Legge et al, 2020;Wintle et al, 2020), to help prioritize conservation management actions in the aftermath (Geary et al, 2021;Wintle et al, 2020), and to begin to grapple with the likely timescales of recovery. It is, therefore, timely to appraise what we know about the direct effects of fire on animal populations.…”

Design considerations for rapid biodiversity reconnaissance surveys and long‐term monitoring to assess the impact of wildfire

“…Spatial prioritization tools are commonly used to address questions such as where to establish conservation reserves, where to target habitat restoration or where to establish new developments while ensuring complementarity, adequacy and representativeness (Margules & Pressey, 2000;Scott et al, 1993). Such tools will likely become more important as the size of wildfires increase and because they have the capacity to explicitly include spatial layers, such as fire frequency and threats (Geary et al, 2021). There are surprisingly few examples where spatial prioritization tools have informed the design of post-wildfire surveys (Geary et al, 2021;Southwell et al, 2020) despite optimization approaches increasingly being used to design large-scale biodiversity monitoring networks (Amorim et al, 2014;Carvalho et al, 2016;Moran-Ordonez et al, 2018).…”

“…Such tools will likely become more important as the size of wildfires increase and because they have the capacity to explicitly include spatial layers, such as fire frequency and threats (Geary et al, 2021). There are surprisingly few examples where spatial prioritization tools have informed the design of post-wildfire surveys (Geary et al, 2021;Southwell et al, 2020) despite optimization approaches increasingly being used to design large-scale biodiversity monitoring networks (Amorim et al, 2014;Carvalho et al, 2016;Moran-Ordonez et al, 2018). A recent example that integrated SDMs and fire severity maps using spatial prioritization tools to inform post-fire survey design in presented is Box 1 and Figure 1.…”

“…The fires burnt more than 10 million hectares over seven months with exceptional severity (Boer et al, 2020;Ward et al, 2020), directly affecting an estimated three billion mammals, birds and reptiles (van Eeden et al, 2020). During and after the fires, many agencies at the state and national levels were quick to conduct on-ground surveys, set priorities, identify knowledge gaps and initiate recovery responses (Geary et al, 2021;Wintle et al, 2020).…”