Analysis of the natural factors of biological productivity of water bodies in the different landscapes of Karelia

Abiotic environmental factors of biological productivity were studied in seven lakes with low water exchange and a few inflows in different landscapes of Karelia (Russia). Lakes are not exposed to human impact. An indicator of the biological productivity is the phytoplankton photosynthesis rate calculated on the concentration of phosphorus in water. The water bodies vary from oligotrophic to mesotrophic according to their trophic level. Cluster and component analysis of chemicals was carried out, hydrological, morphometric and landscape characteristics of the lakes were also determined. It was shown that in the absence of anthropogenic influence the availability of phosphorus and trophic level of the studied lakes in the humid zone are determined by the water exchange, effluent per unit of water column, color of water and landscape features. The most productive water bodies are located on the fluvioglacial and moraine plains dominated by podsolic soils, which have a good flashing regime and soluble humus substances. These lakes are distinguished by a larger inflow of phosphorus forming a part of humus substances originated from the water-collecting area per unit of water column. Oligotrophic lakes are located in moraine and selga landscapes dominated by podbours and brown soils with a lot of humus slightly transformed. These lakes are characterized by less water exchange and drainage factor, and, accordingly, low values of phosphorus input and water color.