Community analysis of Belarusian lakes: relationship of species diversity to morphology, hydrology and land use

In the glacial lake district of northern Belarus, limnologists collected extensive biological, chemical and physical data on 550 lakes (51% of all Belarusian glacial lakes). This large data set provided a unique opportunity to examine subtle relationships with great statistical power. Our purpose was to use multivariate and correlation analyses to explore relationships of species richness with morphological and hydrological parameters. A multivariate analysis of the environmental data suggests that the Belarusian lakes can be separated along gradients of size, hydraulic residence time and watershed development (land use). In most instances, species richness for major planktonic and benthic groups was correlated significantly with lake size and land use. Species richness values were correlated less with watershed size or hydraulic residence time. In each community, there was a group of species characterized by higher correlations with principal component analysis (PCA) axes. These groups are as follows: for phytoplankton-diatoms, for zooplankton-rotifers, and for zoobenthos-molluscs. For lakes both in pristine and developed watersheds, we found small but significant negative species-area correlations for littoral crustaceans. A survey of the relevant literature shows scale dependence for the correlation between species richness and lake size. For pelagic crustaceans, the species-area correlation was significant (and positive) for lakes with developed watersheds but not for pristine watersheds.