Long-term effects of frequent low-intensity burning on ant communities in coastal blackbutt forests of southeastern Australia

Periodic low-intensity fire (hazard-reduction burning) is a conspicuous man agement strategy in virtually all of Australia's dry forest communities whe re it is primarily used to reduce fuel levels with the intention of minimis ing the extent and severity of wildfires. Little is known, however, about t he effects of its repeated use on natural ecosystems over long periods of t ime. This study investigated the long-term effects of frequent low-intensit y fire on forest ant communities by comparing frequently burnt sites with l ong-unburnt control sites. While the richness of ant communities remained l argely unchanged, the composition of assemblages differed substantially bet ween treatments. Although frequent burning apparently resulted in the loss of a substantial number of species, the overall richness of frequently burn t areas was maintained by the addition of species not present on unburnt si tes. These changes in species composition were accompanied by major changes in community organisation (structure) and were considered to be a response to altered habitat conditions, particularly litter biomass, vegetation str ucture and patterns of insolation at ground level. Appropriate fire prescri ptions could therefore be applied to manipulate these habitat elements at a landscape scale to meet both management and conservation goals. A comparis on of pitfall trapping and litter extraction techniques revealed the import ance of a composite sampling strategy, with 22% of ant species detected onl y by litter extraction.