Peculiarities of Phytoplankton Formation and Functioning in Small Water Reservoirs

Abstract

The patterns of phytoplankton formation and functioning in small reservoirs of Prypiat and Teteriv rivers basins were studied. Representatives of <i>Chlorophyta </i>species (32.7&#37; of the total number of species) and <i>Bacillariophyta</i> (24.6&#37;) were found to dominate these reservoirs in terms of species richness. It was established that with the increase in the area and volume of reservoirs, the species diversity of <i>Cyanobacteria </i>also increases, while <i>Euglenozoa</i> dominate in smaller reservoirs. The main abiotic parameters that lead to changes in the structural indicators of phytoplankton of the studied reservoirs, as well as the main differences in the structural and functional characteristics of phytoplankton of small reservoirs living in Polissia rivers were studied, in comparison with the large ones of the Dnieper and Volga rivers. A reliable correlation was established between phytoplankton biomass of small reservoirs and pH (<i>r</i> &#61; 0.55), phosphorus content of phosphates (<i>r</i> &#61; 0.46), color (<i>r</i> &#61; -0.36) and total nitrogen content (<i>r</i> &#61; -0.61). Abiotic factors that determine the amount of information diversity in water reservoirs are the phosphorus content of phosphates (<i>r</i> &#61; -0.73), pH (<i>r</i> &#61; 0.63), and watercolor index (<i>r</i> &#61; -0.62). Small reservoirs in comparison with large Dnieper and Volga reservoirs have a high level of photosynthesis intensity with a relatively small biomass of phytoplankton due to their significant optical depth and the peculiarities of the course of production processes of shallow waters, which occupy significant areas of the water areas of small reservoirs.