Study on the Spatio-temporal Pattern of Plankton Community Structure and its Productivity in Chaihe Reservoir

The Spatio-temporal pattern of plankton community structure and the productivity in Chaihe Reservoir were studied in 2008.It studied species composition,density,biomass,dominant species and diversity index of plankton.The results shown that 135 species of phytoplankton were detected,and Bacillariophyta and Chlorophyta were the dominant species composition; The annual average density and biomass of phytoplankton were 11.58 × 106ind./L and 6.25 mg/L,respectively,and the dominant species were Chlorella sp.,Cyclotella meneghiniana and Fragilaria capucina.42 species of zooplankton,dominated by Rotifera and Protozoa,were detected; The annual average density and biomass of zooplankton were 358 ind./L and 3.49 mg/L,respectively,and the dominant species were Polyarthra trigla,Keratella cochlearis and Asplanchna brightwelli.The annual average diversity index of phytoplankton and zooplankton were 4.27 and 3.15,respectively.There was no obvious regularity in vertical distribution of plankton in the reservoir.