Colonization of submerged twigs and branches of different wood genera by aquatic macroinvertebrates

Previous studies which investigated macroinvertebrate colonization of subme rged wooden substrates in streams and lakes did not consider the wood speci es. In this study, the genus of randomly collected twigs and branches from two streams was determined microscopically using morphological and structur al characteristics of the wood genera. The macroinvertebrate colonization o f the wooden substrates was analysed with respect to the different kinds of the twigs and branches. Additionally, an exposition experiment was conduct ed with the most commonly found wood genera, alder (Alnus) and oak (Quercus ), in two different stales of decay (freshwood and conditioned wood). The c olonization experiment stressed the results of the natural wood samplings t hat the wood genus plays only a minor role in the colonization by macroinve rtebrates.