Affiliation: | (1) Department of Ecology, Karelian Institute, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland;(2) Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland;(3) Department of Biological and Environmental Sciences, University of Jyväskylä, P.O. Box 35, FIN-40351 Jyväskylä, Finland;(4) Finnish Environment Institute, P.O. Box 140, FIN-02251 Helsinki, Finland;(5) Present address: North Savo Regional Environment Centre, Research: Bioteknia, Neulaniementie 2L3, FIN-70100 Kuopio, Finland |
Abstract: | Biomass and species diversity (richness and evenness) of littoral organisms were explored in 27 sites in three basins of the large Lake Saimaa system in eastern Finland. The basins differed in degree of nutrient loading and trophic status. Six organismal groups, i.e., phytoplankton, periphyton, macrophytes, crustacean zooplankton, benthic macroinvertebrates and fish were studied. Factors affecting the biomass and diversity of these groups were explored by multiple stepwise regression analysis. The biomass of different groups was explained by the same variables, mainly nutrients, while diversity was associated with different environmental factors among the studied groups. The biomass of periphyton, phytoplankton, zooplankton, and fish correlated significantly with each other. There was also an apparent association between the biomass of macrophytes and that of benthic invertebrates. However, no significant correlations were found among the diversity of the studied groups. In accordance with previous studies, our results did not support the existence of species-rich hotspots or the possibility of using any surrogate taxon to reveal overall biodiversity. Thus, for conservation planning, biological surveys should include extensive collection of taxonomic groups and organisms at all trophic levels. |