The effects of prescribed burning on epigaeic ant communities in eucalypt forest of South Australia

Abstract

Prescribed burning is commonly used in the management of fire prone vegetation in order to reduce the occurrence of large-scale wildfires as well as to maintain biodiversity values. We investigated the response and recovery of epigaeic ant communities in the Mount Lofty Ranges, South Australia, following prescribed burning by conducting pitfall trapping over three consecutive years (December 2006–2008) in recently burnt (prescribed burnt in spring seasons of 2004–2006) and unburnt vegetation (last burnt by wildfire in 1983). Of the 60 ant species collected, 53 and 49 occurred in burnt and unburnt habitat, respectively. Species richness, density and diversity were not different between burnt and unburnt habitat. Total ant abundance was higher in burnt habitat where five common species had significantly higher frequencies of occurrence in at least one sample year. No common species were found to be more prevalent in unburnt habitat. An analysis of ant functional groups found that Generalised Myrmicinae and Opportunists accounted for a larger proportion of the ant community in burnt habitat than in unburnt habitat, while the opposite was found for Cold Climate Specialists and for Specialist Predators. The composition of both ant species and functional groups differed significantly between habitat types and did not converge over three sample years. We found that ant communities in our study region are altered by single prescribed burns and suggest that monitoring them could be valuable in the appraisal of prescribed burning programs.