TRANSFORMATION OF ZOOPLANKTON CENOSES IN REGULATION OF FLOW (IN A RESERVOIR) WITH THE AID OF SPECIES-DIVERSITY INDEXES

The initial phase of zooplankton formation in the Cheboksary reservoir was analyzed. Species diversity, estimated by Shannon's index, was chosen as the key parameter. It was found that in the first 3 years since the reservoir was built this index remained unchanged as a result of counter-directed variations of its two components: species richness and species equitability,. In this case, as an example of the effect of the factor of flow regulation. the conclusion is reached that the plasticity of a community is greater than that of its component species.