大纵湖大型底栖动物群落结构与水质生物学评价

Community Structure Investigation of Macrozoobenthos and Water Quality Biological Assessment of Dazong Lake

2013年1月中旬对大纵湖5个采样点的大型底栖动物进行调查,共采集底栖动物29种,其中DZ1的优势种为苏氏尾鳃蚓(Branchiura sowerbyi);其他各点的优势种为长角涵螺(Alocinma longicornis)。采用理化分析、Shannon-Wiener指数、Margalef指数、BPI指数对各点水质进行了综合评价。结果表明:DZ4属于β-中污染水质,其他各点属于α-中污染水质;对主要的环境因子与底栖动物密度进行相关性分析,发现DO与底栖动物群落未显著相关,NH3-N、NO-3-N、CODMn等因子更能代表水体的污染水平和营养状态,且随着营养状态的升高,耐污种类的颤蚓类数量呈现出增高趋势;寡毛类、蛭类、摇蚊幼虫、水生昆虫和软体动物5者之间除了寡毛类和蛭类存在极显著正相关性之外,其他无显著相关性。

We investigated macrozoobenthos at 5 sites of Dazong Lake in mid-January 2013 and a total of 29 taxa were identified,dominant species was Branchiura sowerbyi in DZ1 and was Alocinma longicornis in the other sampling points.Water quality was assessed using both physical and chemical analysis,including Shannon-Wiener index,Margalefindex and BPI index.These analysis indicated that DZ4 was β-mesotrophic,and the others was α-mesotrophic.Correlation analysis suggested：there was no significant correlation with DO and community structure of macrozoobenthos,instead that factors of NH3-N,NO3--N,CODMn were responsible for water pollution levels and nutritional status.With the rise of nutritional status,the number of tubificid worms was increasing.Except density of oligochaetes and hirudinea were extremely significant positive correlation,no correlations were found among the other species of zoobenthos.