Community structure of plankton in Ning Xia of Jing River in summer
泾河宁夏段夏季浮游生物群落结构特征

The plankton community composition were investigated in Jing River of Ningxia section from July to August in 2010.The results showed that: 81 species (genera), 6 phylum of phytoplankton were observed in the whole paragraph. The density of phytoplankton was 1.1 × 104 ~ 11.6 × 104 cells L-1; the average density was 4.37 × 104 cells L-1; the range of biomass was 0.024 ~ 0.21 mg L-1, the average biomass was 0.057 mg L-1. At the same time, 54 species(genera),4 phylum of zooplankton were observed, the density was 60 ~ -185 ind L-1;the average density was 107.73 ind L-1; the range of Biomass was 0.02~ 0.662 mg L-1, an average was 0.24 mg L-1; the comprehensive index of plankton in Jing River showed that: In Jing River , the water quality was good; the composition and structure of community was instability, so, the plankton community composition was interferences by external environment susceptibility.