Characteristics of Phytoplankton Community Structure and Evaluation of Trophic State of Water Body in Bosten Lake

摘要

Bosten Lake was the largest inland freshwater lake in China. It is facing with a series of ecological problems nowadays. The phytoplankton and water samples of seventeen sampling sites in Bosten Lake were collected in September 2012. Results show that sixty-four species (genera) o1 phytoplankton, which belong to six phyla, are identified. The community structure of phytoplankton is dominated by Chlorophyta. The mean cell density of phytoplankton in whole lake is 8179.01×l0~4cellsL~(-1) and Cyanophyta accounts for 94.71%. The dominant species are Chroococcus sp. and Synedra acus. In terms of Shannon-Wiener diversity index, Margalef richness index, Pielou evenness index and total nitrogen content, it is ascertained that trophic state of water body in Estuary and Pumping Station is between mesotrophication and eutrophication. While in the other districts, the water body is eutrophic. In addition, the eutrophic degree of water body in District IV is higher.