Distribution of macro-invertebrates in a ditch in relation to the vegetation

SUMMARY. 1. Quantitative fauna samples were taken from four differently structured vegetations in a ditch on three dates in the summer of 1980.
2. Cluster analysis of twenty-four samples showed that the vegetation pattern is probably the main factor in determining the spatial distribution of non-benthic macro-invertebrates in the ditch. Temporal heterogeneity arising from changes in the macro-invertebrate fauna during the summer, however, appeared to be of at least the same magnitude as the observed spatial heterogeneity. Different vegetation types differed considerably in total faunal density. Species that are taxonomically related tend to have a similar distribution in the ditch.