Altitudinally restricted communities of Schizophoran flies in Queensland's Wet Tropics: vulnerability to climate change

Abstract

The Australian Wet Tropics World Heritage Area (WTWHA) contains a number of highland vertebrates predicted to face extinction due to a warming climate, but little is known about risks to invertebrates, which are vital to ecosystem health. This study investigates the distribution and abundance patterns of the Dipteran sub-order Schizophora along an altitudinal transect in the Carbine Uplands of the WTWHA using Malaise traps. The season of peak abundance changed with altitude, with highland abundance peaking in October, and lowland abundance peaking in April. There was a high level of species turnover with altitude, and some evidence for distinct low-, mid-, and high-elevation assemblages, with the high-elevation assemblage containing the most restricted species. We would expect this high-elevation assemblage to be at risk of local extinction with 2-3° of warming, and the mid-elevation assemblage to be at risk with 4-5° warming. Future work should continue sampling to confirm patterns presented here and to monitor range shifts with climate change. A highland species-Helosciomyza ferruginea Hendel is suggested as a good indicator species for such monitoring.