A phenological investigation of various invertebrates in forest and woodland areas in the south-west of Western Australia

Abstract

Invertebrates were collected in pitfall traps at 3 localities in the south-west of Western Australia: namely Perth (Reabold Hill), Dwellingup and Manjimup. The pitfall traps (diameter 1.8 cm) were spaced 3 m apart in a 6 x 6 grid at each locality. Between March 1976 and February 1977 collections were made once a month from traps exposed for a week. The groups reported on are: Araneida, Acarina, Scorpionida, Pseudoscorpionida, Phalangida, Diplopoda, Chilopoda, Isopoda, Annelida and Gastropoda.The differences in species richness and abundance between sites are discussed in terms of soil type, fire history and climatic pattern. Species richness of decomposers and predators is lowest at the most recently burnt site (Manjimup) suggesting that there is a period of decreased species richness of at least 3 years following fire. Decomposer abundance, and presumably rate of decomposition, is higher in the wetter months at Perth and Dwellingup although abundance is more closely associated with the warmer months at Manjimup. Predators are active throughout the year although, at Dwellingup and Manjimup, there is a decrease in activity associated with cool moist conditions.