Community Organisation, Biogeography and Seasonality of Ants in an Open Forest of South-eastern Queensland

Abstract

The biogeography and structure of ant communities were examined over a 12-month period at a dry open eucalypt forest in south-eastern Queensland. Three sites were monitored, each with a distinct long-term burning history: burned annually since 1952, burned periodically since 1973, and unburned since 1946. A total of 89 species from 42 genera was recorded over all trapping periods, with the richest genera being Iridomyrmex, Camponotus and Pheidole, each with eight species. Site species richness was 74, 63 and 43, respectively, at the annually burned, periodically burned and the unburned site. We compared the ant community in this forest with those at other forested sites in eastern Australia. Overall, the south-eastern Queensland community was located on the overlap between the Bassian and Torresian zones (not dominated by either element), while the functional-group composition resembled those of both tropical savannas and cool-temperate woodlands. There were readily discernible differences between sites in terms of biogeographical and functional-group composition; and between the unburned site and both burned sites in terms of abundance and species richness. The relative abundance of Iridomyrmex spp. increased with burning frequency while the relative abundance of Bassian species decreased with burning frequency. Species richness and abundance at the burned sites were similar, but substantially higher than at the unburned site. The community characteristics of the three sites were readily distinguishable, indicating that ant communities may play a valuable role in detecting ecological changes in forested landscapes in south- eastern Queensland.