Fire regimes in arid hummock grasslands and 'Acacia' shrublands

Abstract

The flammability of arid 'Triodia' hummock grasslands and 'Acacia' habitats (shrublands and woodlands) was highlighted when wildfires swept across central Australia in 2001 and 2002 (Allan 2009) (Figure 9.1). These conflagrations constituted the most extensive 'fire event' in inland Australia since the mid-1970s, burning more than 500 000 km² in the southern Northern Territory alone. Such fires go largely unnoticed by the mostly urban Australian population and concern for potential 'environmental disaster' has not resonated with the general public. Since the last synthesis of fire in these landscapes (see Allan and Southgate 2002; Hodgkinson 2002) a steady flow of new research has focused on fire regimes and their impacts on species and habitat structure. Uncertainty still remains about how to manage fire regimes for biodiversity benefits, but we recommend a trait-based framework as a way forward. This approach differs from the overly simplistic dichotomisation of arid biota as 'fire tolerant' or 'fire sensitive' and moves towards the circumscription of demographic tolerance thresholds for focal species groups, with explicit emphasis on the interactions of climate and fire.