湘江长沙综合枢纽浮游动物群落结构及水质分析

Community dynamic structure of zooplankton and water quality in the comprehensive hub of Xiangjiang river,Changsha

为探讨湘江长沙综合枢纽上下游的浮游动物群落结构分布以及水质状况,2016年1—11月对研究水域进行6次采样分析。鉴定出浮游动物共计125种,包含轮虫60种、原生动物41种、枝角类13种、桡足类11种,物种组成上以轮虫和原生动物占据优势。优势种在时间尺度以原生动物占优势,其中球形砂壳虫为研究水域全年的优势种。单因素方差分析显示,浮游动物密度在时间尺度上具显著差异(P<0.05),空间尺度不具显著性(P>0.05)。主成分分析法(PCA)显示溶解氧、氟化物、Cu、Cd、Zn含量是影响浮游动物密度变化的主要环境因子;冗余分析(RDA)结果表明,重金属仍是影响群落结构的主要污染物,有机污染较严重。生物多样性指数评价显示,研究流域水质呈轻度至中度污染,上游的水质优于下游水质,流域水质符合Ⅱ至Ⅲ类水标准。

To explore the distribution of zooplankton community structure and water quality in the upstream and downstream of the comprehensive hub of Xiangjiang river, Changsha, the samples were collected 6 times and analyzed from January 2016 to November 2016. The results showed that 125 species of zooplankton, include 60 species of rotifers, 41 species of protozoa, 13 species of cladocera and 11 species of copepods were identified. Rotifers and protozoa occupy the dominant position in species composition. The protozoa was dominant species on the time scale, and spherical sand shell was the dominant species in the water whole year. One-way analysis of variance showed significant differences in zooplankton density on time scale (P<0.05), but not on spatial scale (P>0.05). The results of principal component analysis (PCA) showed that dissolved oxygen, fluoride, Cu, Cd and Zn were the main environmental factors affecting the community structure of zooplankton. Redundancy analysis (RDA) showed that heavy metals were still the main pollutants affecting the community structure, and were heavily polluted by organic pollutants. The biodiversity index evaluation showed that the water quality of the studied watershed was slight to middle level pollution, and the water quality of the upstream watershed was better than that of the downstream,and the water quality met the class II to III water standards.