官厅水库底栖动物的群落结构及其时空格局

于2007年3—12月对官厅水库底栖动物的群落结构及其时空格局进行了研究。结果表明：共检出底栖动物43种,隶属于4门24科42属;优势种为霍甫水丝蚓Limnodrilus hofmeisteri、刺铗长足摇蚊Tanypus punctipennis和大红德永摇蚊Tokunagayusurika akamusi;底栖动物的年平均密度为5 037个/m2,年平均生物量（湿重或带壳湿重）为39.80 g/m^2,底栖动物的密度和生物量在冬季最高、夏季最低;采样水域冬季冰下摇蚊幼虫的密度和生物量很高,12月在五棵树采样点,大红德永摇蚊幼虫的密度和生物量高达9 136个/m^2和64.39 g/m^2;底栖动物的年平均密度和生物量在下营采样点最高;Shannon-Wiener多样性指数的年平均值为2.03,Pielou均匀度指数的年平均值为0.56。耐污种霍甫水丝蚓、刺铗长足摇蚊和大红德永摇蚊为优势种,表明水库富营养化较严重。分析了底栖动物的密度、生物量与环境因子之间的关系,结果表明：底栖动物的密度与总磷、水温呈极显著负相关（P〈0.01）,与叶绿素a呈显著负相关（P〈0.05）,与硝态氮、pH呈极显著正相关（P〈0.01）,与磷酸盐、亚硝态氮、透明度、水深呈显著正相关（P〈0.05）,与总氮相关不显著（P〉0.05）;但底栖动物的生物量与各环境因子的相关性均不显著（P〉0.05）。

Community structure and spatio-temporal pattern of zoobenthos in Guanting Reservoir, Beijing, China

The community structure and spatio-temporal pattern of zoobenthos in Guanting Reservoir were studied from March,2007 to December,2007.The results showed that a total of 43 species were identified,belonging to 4 phyla,24 families and 42 gena;The dominant species were Limnodrilus hofmeisteri,Tanypus punctipennis and Tokunagayusurika akamusi,with annual average density of 5 037 ind./m^2 and biomass of 39.80 g/m^2.The maximal and minimal densities and biomasses of the zoobenthos were observed in winter and summer.The density and biomass of chironomidae were found high below ice,Tokunagayusurika akamusi being 9 136 ind./m^2 and biomass of 64.39 g/m^2 in Wukeshu sampling station in December.The maximal annual average density and biomass of zoobenthos were found in Xiaying sampling station.The annual average value of Shannon-Wiener diversity index was 2.03 and that of Pielou index 0.56.The polluted-tolerance species L.hofmeisteri,T.punctipennis and T.akamusi overwhelmed the community,indicating that the reservoir was seriously in eutrophication.The density of zoobenthos with total phosphorous level（TP） and temperature were to be significant negatively correlated（P〈0.01）,with chlorophyll-a significant negatively correlated（P〈0.05）,with NO-3-N and pH significant positively correlated（P〈0.01）,with PO4^3--P,NO2^--N,SD,and water depth significant positively correlated（P〈0.05）,with TN not significant correlated（P〈0.05）.Correlation between biomass of zoobenthos and environment factors was not significant（P〈0.5）.