太湖流域大型底栖动物生物完整性研究

于2009年8月对太湖流域32个采样点的大型底栖动物和水环境因子进行了调查采样.选取太湖流域大型底栖动物的物种数、物种相对丰度、敏感-耐污类群组成、功能摄食类群和多样性指数等共22个参数作为构建太湖流域大型底栖动物生物完整性评价体系的候选参数.通过对候选参数在参考点位(8个)和受损点位(19个)之间的比较,最终确定了总分类单元数(total taxa)、摇蚊科分类单元数(chironomidae taxa)、甲壳+软体动物分类单元数(crustaceanmollusc taxa)、前3位优势分类单元相对丰度(top three of dominant taxa)以及香农威纳多样性指数(shannon-wienerindex)为构建评价体系的参数.通过比值法计算得到太湖流域各个采样点的生物完整性得分.在太湖流域监测的站点中7个为健康,7个为亚健康,6个为一般,5个为较差,3个为极差.Pearson相关性分析显示,B-IBI得分同亚硝酸氮、氨氮呈显著性负相关(P0.05).

ON BIOLOGICAL INTEGRITY OF MACROINVERTEBRATE IN TAIHU BAISN

Investigation was conducted on macroinvertebrate and environmental parameters at 32 sampling sites in Taihu Basin in August 2009.Twenty two(22) candidate metrics belonging to five types(richness of species,relative abundance,composition of tolerance and intolerance taxa,functional feeding groups and biodiversity index) were chosen to establish benthic index of biological integrity system in Taihu Basin.Five core metrics were selected to build biotic integrity system,which were total taxa,Chironomidae taxa,Crustacean & Mollusc taxa,top three of dominant taxa and Shannon-wiener index by comparision between eight reference sites and 19 degraded sites.Ratio method was used to calculate biological integrity score for all selected sites.Data showed that 7 sites were excellent,7 sub-excellent,6 normal,5 bad and 3 very bad.The result of Pearson test between B-IBI score and environmental factors showed that B-IBI scores were negatively correlated to nitrite nitrogen and ammonium nitrogen significantly(P<0.05).