ASPECTS OF THE ECOLOGY OF A FILAMENTOUS ALGA IN A EUTROPHICATED LAKE

In the eutrophic Lake Mikølajskie macrophytes disappearing from the deeper parts of the littoral are replaced by Vaucheria dichotoma Ag. This forms a belt at 3.0-4.5 m to which depth only 1% of surface light penetrates. The zone of V. dichotoma has a layered structure. Some filaments are covered in mud and receive no light, but are alive and photosynthesize when transferred to light. V. dichotoma prefers fertile environments with a high content of phosphate-phosphorus and ammonium-nitrogen. It is evergreen and its biomass changes relatively little during a year. © 1990 Kluwer Academic Publishers.