Differentiation of periphyton and phytoplankton assemblages in anthropogenically transformed conditions of the littoral zone in a shallow urban lake (Lake Jeziorak Ma?y, Poland)

摘要

This study of periphyton (periphyton in separator pipes, epilithon and epiphyton) and phytoplankton (pelagial) assemb lage differentiation was conducted in Lake Jeziorak Ma.y within an anthropogenically transformed littoral zone.Analysis was conductedon thedifferences in abundance and biomass of these assemblages in relationship to the physico-chemical water parameters, species' similarity, diversity and environmental requirements of these assemblages, from April to October of 1997-2003 and in 2005.The periphyton in the pipes and epilithon were fo und to be the most similar assemblages. Despite similar substratum characteristics, changes in the physico-chemical water parameters, and especially those in PO4, Si and Cl, were found to affect these assemblages' develop ment. This was supported by correlations between the characteristic species and nutrients.While the growth of epiphyton was mainly related to changes in calcium and nitrogen concentration,phytoplankton depended more on conductivity, pH and Fe. The presence of seven algalgroups with different environmental requirements indicated considerable differentiation of the studied assemblages resulting fromanthropogenic transformation of this littoral zone. The installation of separators and also stone accumulations in this zone contributed to the creation of new habitats for periphytic algae whichutilized the commo n pool of nutrients. It may therefore have indirectly influenced phytoplankton dominated by cyanobacteria