Diagnosing of Biological Productivity in Lake Ecosystems

This work presents the system for biological productivity estimation in lake ecosystems. Input parameters of system (x – variables) are latitude, specific catchment area, average annual air temperature, annual sum precipitation, mean and maximum water body depth, water retention time in lake, average for growing season water color and daily assimilation number for phytoplankton chlorophyll. Under the conditions of lack of data on the water bodies' environmental status, the diagnostic system is often combined with modelling that enables to reconstruct the most important biological/production characteristics of water bodies. Diagnostic models are significant as with their help it is possible, with the appropriate database, to withdraw and concentrate all necessary information and present it in quantitative form. One of database was created for lakes and reservoirs located on the territory of the former Soviet Union and adjacent regions. Main data array was collected by Soviet scientists in 60–80's of the past century within the framework of the International Biological Program, UNESCO program “Man and Biosphere”, and a set of public and international projects. Summarizing and analysis of the collected data made it possible to reveal and represent in quantitative form a set of the regular ties between biotic and abiotic components in aquatic ecosystems. The goal of investigation was to develop the system of diagnosis for indicative biological characteristics – production of the key hydrobiont groups (producers, reducers, and consumers including fish). Abiotic factors that determine organisms' vital activities and aquatic ecosystems' functioning have been used as arguments. Some lakes of Russian Federation and Republic of Belarus related to humic zone of European continent have been the objects of the investigation.