Assessing the abundance of seven major arthropod groups along an altitudinal gradient and across seasons in subtropical rainforest

Abstract

Changes in the abundance of seven major arthropod taxa with changes in altitude and season were investigated in a subtropical rainforest using both Malaise traps and flight intercept traps. Sampling was conducted as part of the IBISCA-Queensland Project at four plots established at each of five altitudes (300, 500, 700, 900 and 1100 m above sea level) within continuous rainforest. Trapping was carried out at four times throughout a 12 month period, comprising a dry season (winter) sample and samples in the early (spring), mid (summer) and late (autumn) wet season. Clear seasonal changes in the abundance of arthropods sampled were evident as well as changes in community assemblages. The winter sample in particular was different to all other seasons. Limited response to altitude was detected, with the greatest differences between altitudes along the gradient found in summer and winter samples. The limited altitudinal trend is likely the result of the scale of sampling with individual species and families expected to show contrasting responses. The clear influence of season, however, does demonstrate the sensitivity of these broad arthropod groups to climate variability and cues.