RESUMO
By using canonical correspondence analysis (CCA), this paper studied the community structure of phytoplankton and its relationships with environmental factors in the drinking water source of Jinshu Bay, Taihu Lake. A total of 7 phylum and 58 genera were identified, and the phytoplankton community was dominated by Cyanophyta, Bacillariophyta, and Chlorophyta. The quantity of phytoplankton was slightly higher in summer (250 x 10(4) ind x L(-1)) than in spring (238 x 10(4) ind x L(-1)), but the community structure differed obviously between the two seasons. In spring, Cyanophyta was the dominant phylum, and Anabaena was the dominant genus; in summer, Chlorophyta was the dominant phylum, with no dominant genus but abundant quantity of Merismopedia and Scenedesmus. Besides temperature, the main environmental factors affecting the distribution of phytoplankton in spring were ammonium-nitrogen, total phosphorus, total nitrogen, and phosphate, while those in summer were total nitrogen, ammonium-nitrogen, phosphate, suspended solids, macrophytes, total phosphorus, and transparency.