The relationship between habitat structure and biodiversity of the macrozoobenthos in the free-flowing section of the Danube in Austria - east of Vienna (preliminary results)
Fesl, C.; Humpesch, U. H.; Aschauer, A.
The habitat structure is described by the grain size distribution, whereas diversity indices were used to describe the biodiversity of the macrozoobenthos. At the sampling site, 112 species were identified, including 14 species of Mollusca, 32 of Clitellata, 5 of Crustacea and 49 of Insecta. Bootstrap and Jackknife techniques indicated that nearly all of the species which might occur in the sampling area were detected. Confidence intervals of the biodiversity of Mollusca and Oligochaeta were computed by Bootstrap procedure so that significant differences between sampling sites and dates could be obtained. For the analysis of further environmental variables, several water-flow variables were measured or calculated. The biodiversity of the Mollusca was positively correlated with sediment heterogeneity and negatively correlated with hydrological conditions, whereas the biodiversity of the Oligochaeta was negatively correlated with sediment heterogeneity and stress. Canonical Correspondence Analysis showed similar results for the Mollusca and described the relation of the species and the biodiversity with environmental gradients of selected variables.