Studies on Community Characteristics and Biomass of Phytoplankton in Dongping Lake

Phytoplankton community structure and biomass variation of Dongping Lake in 2006 and 2007 were studied.The results showed that: 142 species of phytoplankton were collected,which were belonged to 8 phyla.Most of the phytoplankton community was composed by 64 species of Chlorophyta,which contributed the greatest accounting for 45.07% of the community species;then the phytoplankton community included 27 species of Cyanophyta,26 species of Bacillariophyta and 10 species of Euglenophyta,which contributed the greater accounting for 19.01%,18.31% and 7.04% of the community species,repectively;and the phytoplankton community also included 6 species of Pyrrophyta,4 species of Xanthophyta,3 species of Cryptophyta and 2 species of Chrysophyta,which contributed the least accounting for 4.23%,2.82%,2.11% and 1.41% of the community species.The density and biomass of phytoplankton were(0.10 ～13.84)×107ind./L and 0.45～37.23mg/L,respectively.The value of Shannon-Wiener's index and Pielou's index were 0.41～3.92 and 0.11～0.87 respectively,which showed that the community structure of phytoplankton was integrated and steady in Dongping Lake.