Restoration of channelized streams — a benthological study

Summary

In the course of data analysis, calculation of Saprobic Index on the base of absolute numbers, SI_abs was helpful to characterize saprobic conditions. Among statistical methods of data analysis, Renkonen Identity of Dominances (RE), Spearman Rank Correlation (r_s), and cluster analysis proved to be most appropriate. Sørensen Quotient of Similarity (SO), diversity, and evenness provided less information.

At Bampfen, macroinvertebrate distribution patterns could be associated with anthropogenic influences on stream morphology like channelization, lack of shading, and homogeneous substrate composition. Similar investigations which have been carried out on two other brooks revealed impacts of sewage load and accelerated erosion due to channelization, additionally. On the basis of these results, limnological targets for the restoration of each small stream, adjusted to local conditions, could be defined in detail.