BIOCOENOTIC STRUCTURE OF TWO NEIGHBOURING WATER BODIES - A LAKE AND A POND 1

Summary. Two water bodies, differing in size and origin, were investigated in order to compare their aquatic vegetation and zooplankton community structure. In total, 25 macrophyte species (with Thelypteridi-Phragmitetum and Typhetum angustifoliae dominating) were found in the lake, while only 9 species (with Ceratophylletum demersi dominating) were recorded in the pond. Zooplankton was examined at one station in the pond (Ceratophyllum demersum) and at two in the lake (open water zone and Typha stand). Out of 64 identified zooplankton species only 25 (39%) were common for both examined water bodies. Only one species – cladoceran Chydorus sphaericus – dominated in both reservoirs. Analysing the distribution of zooplankton it was observed that in the case of rotifers and copepods their mean densities were the highest in the pond, while cladocerans prevailed in the cattail zone. Although both water bodies were very close to each other (10 m in distance) and the pond was supplied by the lake water, both aquatic vegetation and zooplankton community structure (including the taxonomical structure, zooplankton densities and dominating species) differed from each other.