Pediastrum Meyen sensu lato (Chlorophyceae) in the phytoplankton of lowland and upland water bodies of Central Europe (Poland)

Abstract

Thirteen species and thirteen varieties of microscopic green algae from the genus Pediastrum were found in thirty one localities scattered in lowland and upland water bodies in Poland. Seven groups of localities are distinguished with cluster analysis. The groups differ from each other in terms of Pediastrum communities and environmental variables (pH, conductivity, carbonate hardness, nitrate and orthophosphate concentrations). The most distinct group contains five coastal lakes, which have high pH values and chloride concentration. Because the lakes have a high number of taxa, including a few rarely occurring worldwide, they are considered a hot spot for Pediastrum. Redundancy analysis revealed that the environmental variables account for ca thirty per cent of the variability of Pediastrum occurrence. Conductivity and pH statistically significantly explain the taxonomical variation of Pediastrum species and varieties. The genus Pediastrum as a whole is most positively correlated with conductivity. Individual taxa are influenced by different variables, except for P. tetras which is indifferent to them. The environmental preferences of the taxa can make inference on conditions in both recent and past water bodies more reliable.