Adverse fire regimes
The catastrophic 2019–20 Black Summer bushfires, which killed or displaced 3 billion animals, highlighted Australia’s long-term failures to prepare for and prevent extreme fire events. But biodiversity can also be chronically affected by ongoing patterns of less-severe fires, or by the absence of fires.
Adverse fire regimes vary widely – fires may be too frequent, too infrequent, too frequent in the late dry season (northern Australia), too frequent in autumn (southern Australia), too intense (Australia wide), not intense enough, outside the natural fire season, too large, too small, or lacking patchiness.
Adding to the complexity is that fire regimes interact with or exacerbate several other threats – particularly climate change (extreme heat and drought), invasive species (eg flammable invasive pasture grasses or increased predation by feral cats) and habitat destruction (eg post-fire logging). Community efforts to reduce fire hazards often exacerbates habitat destruction.
Adverse fire regimes imperil 24% of nationally listed threatened species (to a high or medium degree). Priorities to abate these threats include:
- preventing and preparing for extreme fire events and ensuring that biodiversity priorities are incorporated into all disaster arrangements
- identifying and applying preferred fire regimes for threatened species and ecological communities
- recognising an important role for Indigenous fire management.
Threats to Nature project / Invasive Species Council and Bush Heritage Australia. 2021. ‘Fire regimes that cause biodiversity decline’ as a key threatening process – comment on the listing assessment. Submission by the Invasive Species Council and Bush Heritage Australia. January 2022.