Fire and biodiversity in Australia

Abstract

Fire has a major influence on the management and conservation of Australian biodiversity. Notwithstanding a long history of fire on the continent, inappropriate contemporary fire regimes are a key threatening process for many Australian plant and animal species. Fire regimes vary appreciably across the continent, and different species and taxonomic groups respond in markedly different ways to different regimes. A set of case studies highlights the diversity of wildlife responses to fire, although we acknowledge that this set is inevitably far from a comprehensive assessment of the response of all biodiversity components to all fire regimes. Managing fires for biodiversity remains a challenge, particularly in the more remote parts of the continent or when management is driven mostly by human safety and economic assets. Some notable examples of local-and regional-scale fire management programs for biodiversity conservation are presented. Replicating the conservation benefits of these programmes across other parts of Australia will be difficult and will require improved understanding of the fire regimes required by biodiversity, significant effort in implementation and monitoring of outcomes and better understanding of fire by the Australian community. Introduction Australia is the most fire-prone continent. Fire has long shaped its ecosystem processes, the juxtaposition and extent of its ecological communities, the structure and floristics of its vegetation types, the ecology of many species, and the distribution, abundance or extinction of individual species. Much of this potency relates to Australian climatic regimes and Australia’s relative lack of topographic relief (and hence protection from extensive fire). Marked wet–dry (monsoonal) seasonality characterises Australia’s north, catalysing frequent (but relatively low-intensity) fire as the annual crop of tall savanna grasses cures during the long dry season. There is marked seasonality also in the Mediterranean and temperate climates of south-eastern and south-western Australia, and their hot summers prompt high-intensity wildfires. Seasonality is less pronounced in the arid inland areas, but recurring but irregular patterns of drought and wet periods drive infrequent but extensive fires as vegetation biomass built up in high-rainfall years dries when the rains disappear. These differences in environmental settings dictate that the frequency and impacts of fires vary very substantially across the Australian continent (Plate 14; Russell-Smith et al. 2007).