Circulation of Biogenic Substances in the Kamionka River-Lake System

Reservoirs in river-lake systems play a dominant role in the circulation of biogenic substances. Their evolutional transformations, consisting in accumulation of substances, results it their ultimate disappearance. However, at a given moment, the roles played by reservoirs are far more diverse—they accumulate, perform a transit role or supply the system with biogenic substances. The assignment of roles played in the system to reservoirs performed on the basis of data of 2006 was verified in 2007 with respect to the durability of their roles. Some of the lakes consistently accumulated biogenic substances. Their performing of this function in the system was facilitated by favourable morphometric conditions accompanied by strong pressure, exceeding the value determined for critical load. A tendency of supplying the system by other lakes was visible when they were charged with a lower load than the critical values for phosphorus load. The reservoirs then utilised the opportunity to discharge a part of biogenic substance present in them, partially of internal origin.