| 【Objective】The water environment factors and plankton compositions of six monitoring sections at 3
hydropower stations along the upstream, midstream and downstream of the Qiuxiang River were investigated, and the water
ecological status of the Qiuxiang River was clarified.【Method】The comprehensive nutritional status index, biodiversity
index and redundancy analysis were used to analyze the water quality status, the community structure characteristics of
plankton and the relationship between them, respectively.【Result】The water transparency, concentrations of Chla, total
phosphorus, total nitrogen and permanganate were 0.32-0.53 m, 0.10-0.43 mg/L, 0.6-5.3 mg/L, 1.39-4.33 mg/L and 0.70-
3.90 mg/L, respectively. The water quality status of the Qiuxiang River was at medium nutrition level according to the
comprehensive nutritional state index. A total of 53 species of phytoplankton and 62 species of zooplankton were identified.The abundance of the phytoplankton was ranged from 5.1×108 to 1.89×109 cells/L and that of the zooplankton was ranged
from 3.93 to 232.87 ind/L. Chlorophyta, Bacillariophyta, Cyanophyta, Protozoa and Rotaria were the dominant species among
phytoplankton and zooplankton. Based on the comprehensive plankton diversity index, the pollution of Qiuxiang River was at
the medium level.【Conclusion】The upper reaches of the Qiuxiang River has been polluted to a certain extent, and the degree
of pollution along the river is reduced. Dissolved oxygen is a key environmental factor affecting the structure of the plankton
community in the Qiuxiang River. |
