河口区新建河道轮虫群落演替及与水环境的关系

于2011年12月~2012年11月对上海一河口性新建河道(临港新城B港河道)的轮虫群落结构进行为期1 a的调查研究,结果表明,调查期间该水体共检出轮虫23种,其中污染指示种19种;轮虫的种类数随河道建成时间的延长呈逐月上升趋势,从2种增加到13种;优势种在时间尺度上的演替明显,由开始的单一优势种螺形龟甲轮虫(Keratella cochlearis)向多种轮虫共同占优势转变,新建成的B港水体中的轮虫群落结构与外河水体(芦潮引河)存在明显的差异.相关性分析表明,B港水体中轮虫总密度与温度、叶绿素a显著正相关(P<0.05),但与盐度无显著相关性;除螺形龟甲轮虫外,其他主要种类的密度均与营养盐浓度、盐度呈负相关关系(P<0.05).临港B港河道轮虫各月间的相似性指数较低,说明临港B港河道水体生态系统尚未稳定,仍处于不断变化中;但是轮虫的丰富度Margalef指数、多样性指数Shannon-Wiener指数逐月增大、E/O值逐渐下降.

Succession of Rotifer Community and Its Relationship with Environmental Factors in a New Estuarial Landscape River, Shanghai

The community structures of rotifers were surveyed in Lin'gang B Gang River, a new estuarial river in Shanghai, from December 2011 to November 2012. A total of 23 rotifer species were identified, of which 19 species were the indicator of environmental pollution. Rotifer species' number rose monthly from 2 to 13. A conspicuous succession of dominant species was observed from a single dominant species (Keratella cochlearis) to several species. The rotifer community structure of Lin'gang B Gang River differs with that of the outer water body (Lu Chaoyin River). Pearson analysis showed that the rotifers' density had a significant correlation with water temperature and chlorophyll-a (P<0.05), but had no significant correlation with salinity; the densities of dominant species (except Keratella cochlearis) presented negatively correlations with concentration of nutrients and salinity (P<0.05). The low species similarity index between every month demonstrated that aquatic ecosystem of Lin'gang B Gang River was in the unstable state. However, the increase of Margalef index and Shannon-Wiener index of rotifers and the decline of E/O value monthly showed the water environment of Lin'gang B Gang. River was improved.