Species composition and seasonal capture rates of terrestrial amphipods in a lowland and highland forest in Tasmania

Abstract

Composition of the amphipod fauna and seasonal changes in captures in pitfall traps were compared at a lowland forest in northeastern Tasmania and three sites in highland forest in central Tasmania. The number of species at the highland sites (five) was greater than for the lowland area (two), possibly due to the greater development of the litter habitat and the moister, more humid conditions at the highland sites. Capture rates were correlated with temperature, but not rainfall, at both the lowland and highland areas. However, minium temperature was most significant for the highland sites, and maximum temperature was most significant at the lowland area. Captures at the highland sites were proportionally greater in autumn and lower in summer and showed a peak in October which was not present at the lowland area. Capture rates are most likely influenced by both activity levels and population size, as determined by seasonal reproductive patterns. It is, therefore, possible that the differences in the seasonality of captures at the highland and lowland areas may be related to different patterns of reproductive activity at the different altitudes.