高邮湖大型底栖动物群落结构及影响因素

跨流域调水工程沿线调蓄湖泊生态状况直接决定工程能否顺利实施。基于2018年4和9月高邮湖底栖动物调查数据，对底栖动物区系组成、群落结构及主要影响因子进行了研究。调查期间共鉴定出底栖动物42种，隶属3门7纲22科；软铗小摇蚊（Microchironomus tener）、霍甫水丝蚓（Limnodrilus hoffmeisteri）、齿吻沙蚕（Nephtys sp.）、苏氏尾鳃蚓（Branchiura sowerbyi）、厚唇嫩丝蚓（Teneridrilus mastix）为调查期间优势物种，相对丰度分别为24.0%、17.7%、8.1%、7.2%和6.5%；两次调查期间底栖动物优势物种组成存在较大差异。密度、物种丰度、香浓指数在4月份显著高于9月份；非度量多维标度排序（NMDS）和多响应置换过程（MRPP）从群落层面证实了两次调查期间底栖动物群落结构的差异性。指示物种分析表明，软铗小摇蚊、霍甫水丝蚓和有栉管水蚓（Aulodrilus pectinatus）是造成两次调查底栖动物群落差异的关键物种。基于距离的冗余分析（dbRDA）表明，高邮湖底栖动物群落在4月份主要受硅酸盐和总磷影响；9月份主要受水深和叶绿素a影响。

Macroinvertebrate community structure and its relationships with environmental factors in the Gaoyou Lake, eastern China

Ecological condition of the regulating and storing lakes along inter-basin water diversion project directly determines whether the project can be carried out smoothly. Based on the survey data in April and September 2018, macroinvertebrate species composition, community structure and its relationships with environmental factors were studied in the Gaoyou Lake. A total of 42 species, belonging to 3 phylum, 7 class and 22 families, were identified during the investigation period. Microchironomus tener, Limnodrilus hoffmeisteri, Nephtys sp., Branchiura sowerbyi, Teneridrilus mastix were the dominant taxa, with relative abundance were 24.0%, 17.7%, 8.1%, 7.2% and 6.5%, respectively. The dominant species compositions of the two surveys were seriously different. Macroinvertebrate density, species richness, Shannon index were all significantly higher in April than in September; non-matric multi-dimensional scaling (NMDS) and multi-response permutation procedures (MRPP) analyses confirmed the difference of macroinvertebrate community structure at community level. Indicator species analysis showed that Microchironomus tener, Limnodrilus hoffmeisteri and Aulodrilus pectinatus were the key taxa that caused community differences. Distance-based redundancy analysis (dbRDA) showed that macroinvertebrate communities in the Gaoyou Lake were mainly affected by Si(OH)₄ and total phosphorus in April, and water depth and chlorophyll a in September.