Ant community variation with rehabilitation and management history on a sand mine North Stradbroke island, south-east Queensland

Abstract

Ant communities at Bayside Mine on North Stradbroke Island were examined as bioindicators of rehabilitation success to provide further information on ecosystem health compared to that which is determined by vegetation monitoring. Three distinct assemblages were collected, with the ant fauna at unmined eucalypt forests characteristic of such habitats, with many arboreal, litter-dwelling and shade-preferring species. The community composition of ants at an unburnt 30-year old rehabilitated forest resembled these unmined reference forests, although abundance, species richness and diversity were intermediate between reference sites and younger rehabilitation areas. An adjacent 30-year old rehabilitated forest exposed to wildfi re was dissimilar to all sites, likely due to an incursion of the highly competitive pest ant, Pheidole megacephala. This species has been found in rehabilitation sites on the island previously and is thought to prefer areas with established vegetation where the microclimate at ground level has high humidity and lower temperature. Vegetation data from this study supports this suggestion, with a high understorey foliage projective cover and ground vegetation at this site compared to a paired adjacent unburnt site where the pest ant was absent. Ant communities at four 20-year old rehabilitated sites were similar to each other, regardless of management history, and contained mainly generalist species suggesting they were still recovering from the recent disturbances of management practices. Composition patterns, in relation to disturbance, were similar to previous research conducted on the island.