Persistence of ground-dwelling invertebrates in desert grasslands during a period of low rainfall – Part 2

Abstract

Current knowledge on the life history of Australia's arid zone invertebrates is sparse. From the studies conducted in arid zones globally, the primary drivers of invertebrates are thought to be climate, particularly temperature and rainfall. In Australia, a limited number of studies have shown vegetation and inter-species interactions are also highly influential. We investigated the effects of multiple potential drivers on ground-dwelling invertebrates in the spinifex sand plains of central Australia. The study was conducted during a period of low rainfall immediately following several years of higher than average rainfall. Results supported the trends found globally, with rainfall and temperature the most consistent drivers. Vegetation cover was not found to be an important driver; however increased abundance of large vertebrate predators coincided with greater abundance of many invertebrate orders. Areas supporting greater invertebrate abundances likely attract predators, particularly during periods when resources are low, and potentially play an important role in sustaining their populations during these periods. No suppressive effects were found, indicating many invertebrates can withstand the higher predator pressure apparent during low rainfall periods. This study highlights the important roles invertebrates play in ecosystem functioning and a need to gain a greater understanding of this little known group.