Changes in structure of macrophyte communities in the chosen lakes of Łęczna-Włodawa Lake District

Changes in the aquatic vegetation structure were analyzed in 4 lakes of Łęczyńsko-Włodawskie Lake District. The macrophytes’ structure has changed quite essentially in lakes in the last 10 years. A tendency of reduction the number of plant associations was observed in meso- and slightly eutrophic lakes, while an increase was observed in eutrophic ones. The range of macrophytes occurrence decreased in all investigated lakes.At first, phytocenoses of submerged macrophytes retreated from the lakes, especially charophyte communities. However, the number of phytocenoses of the rush vegetation grew up. The increase in Phragmitetum australis occurrence, was observed in each investigated lake. It is the typical phenomenon connected with successional changes in vegetation from mesotrophic to eutrophic lakes.