Beyond inappropriate fire regimes: a synthesis of fire-driven declines of threatened mammals in Australia

Abstract

Fire can promote biodiversity but changing patterns of fire threaten species worldwide. While scientific literature often describes inappropriate fire regimes as a significant threat to biodiversity, less attention has been paid to the characteristics that make a fire regime inappropriate. We go beyond this generic description and synthesize how inappropriate fire regimes contribute to declines of animal populations, using threatened mammals as a case study. We developed a demographic framework for classifying mechanisms by which fire regimes cause population decline, and applied the framework in a systematic review to identify fire characteristics and interacting threats associated with population declines in Australian threatened land mammals (n=99). Inappropriate fire regimes threaten 88% of Australian threatened land mammals. Our review indicates that intense, large, and frequent fires are the primary cause of fire-related population declines, particularly through their influence on survival rates. However, several species are threatened by a lack of fire and there is considerable uncertainty in the evidence base for fire-related declines. Climate change and predation are documented or predicted to interact with fire to exacerbate mammalian declines. This demographic framework will help target conservation actions globally and would be enhanced by empirical studies of animal survival, dispersal, and reproduction.

A demographic framework for understanding fire‐driven reptile declines in the ‘land of the lizards'

“…For example, Whelan et al (2002) proposed a demographic approach for understanding animal and plant population changes following fire events, with a focus on the life cycles of biota. Recent work has built on this approach and developed a demographic framework for classifying mechanisms by which fire regimes cause animal population decline, which was applied in a systematic review to identify fire‐regime characteristics and interacting threats driving declines in threatened Australian land mammals (Santos et al, 2022). Here, we apply this framework to squamate reptiles of conservation concern in Australia – a continent colloquially known as the ‘land of the lizards’ because of its high reptile diversity.…”