Research Abstract

Arachnid diversity along a transect of Lizard Island

This study addressed the diversity of arachnids among four different sites along a 1.75km transect in tropical Australia. Diversity in size was also considered, as were the similarities that existed between sites in species composition. Sampling was done in the coastal grassland, pandanus swamp, acacia grassland and the acacia heath using pitfall traps. To analyze the data collected, I used diversity indices and the Jaccard Similarity Index (Ludwig & Reynolds 1988). Thirty-three different arachnid species were found among the four sites. Greatest diversity was in the pandanus swamp. Highest diversity in size was found in the acacia heath. The acacia grassland and the acacia heath had the most species in common. The pandanus swamp was not similar to any other site in terms of species. It is quite clear in viewing the transect, that the pandanus swamp is dramatically different. This is reflected in the absence of common arachnid species found in other sites.