Littoral diatoms in lakes with different degrees of dystrophy

摘要

Besides high dissolved organic carbon (DOC) content, humic lake waters typically have low pH, low conductivity and low alkalinity. With increasing concentration of dissolved organic matter, light climate changes towards long wavelength radiation and decreasing illumination simultaneously with increasing nutrient concentrations. Humic compounds reduce toxic effects of reactive metal ions like aluminium, which occur often in oligohumic acid waters in higher concentrations. Thus, the species richness in acid waters with low humic content is often rather low, and diatom community is characterised by acido-biontic and acidophilic taxa. The aim of this study was to investigate periphytic diatom communities in small boreal lakes with different degrees of dystrophy.