THE INFLUENCE OF EUTROPHYCATION UPON COMMUNITY STRUCTURE AND BIODIVERSITY OF MACROZOOBENTHOS

Comparative studies on community structure and biodiversity of macrozoobenthos were carried out in four lake areas with different trophic levels(mesotrophic, eutrophic and hypertrophic)in Lake Donghu. The results show that the higher the trophic level of the lake water is, the lower the species diversity(measured as K-dominant curves, diversity index and species number)of macrozoobenthos. The density of Limnodrilus Hoffmeisteri Claper閐e was positively correlated with the trophic level of the lake water, which was due mainly to its ability to tolerate low dissolved oxygen from eutrophication. The relation between Tanypus chinensis Wang and the trophic level of the lake water is firstly discussed, and the present study shows that T. chinensis is one of indicators of hypertrophication, however, it is less endurable to eutrophication than L. hoffmeisteri.