巢湖水向湖滨带底栖动物群落结构研究

COMMUNITY STRUCTURE OF MACROZOOBENTHOS IN THE LITTORAL ZONE OF THE CHAOHU LAKE

2009年6月和11月对巢湖水向湖滨带底栖动物进行群落结构调查。共采集到底栖动物33种,隶属9科29属,以寡毛类和水生昆虫为主,合计占总种类数的79%。底栖动物的平均密度和生物量分别是506ind./m2和115.34g/m2。巢湖水向湖滨带底栖动物群落结构趋于单一化,敏感种(光滑狭口螺、长角涵螺等)减少或消失,而耐污种(苏氏尾鳃蚓、霍甫水丝蚓、环棱螺、淡水壳菜等)成为优势种。水向湖滨带底质是影响底栖动物分布及现存量的主要因素,堤岸间接影响其组成和分布,淤泥底质中底栖动物密度最高,砾石底质中生物量最高,而较硬的粘土底质中现存量最低。在功能摄食类群方面,巢湖水向湖滨带以直接收集者和过滤收集者为主。依据本研究结果,对巢湖水向湖滨带生态修复提出了建议。

Investigations of macrozoobenthos in the littoral zones of the Chaohu Lake were carried out twice in June and November of 2009.Altogether 33 species belonging to 9 families and 29 genera were recorded,in which oligochaetes and insectesa counted 79% of the total species.The mean density and biomass of macrozoobenthos were 506 ind./m2 and 115.34 g/ m2,respectively.The study showed that the diversity of macrozoobenthos in the littoral zones of the Chaohu Lake decreased seriously because sensitive species(e.g.Stenothyra glabra,Alocinma longicornis) decreased or disappeared,while tolerance species(e.g.Branchiura sowerbyi,Bellamya sp.,Limnodrilus hoffmeisteri,Limnoperna lacustris) dominated in the littoral zone of the Chaohu Lake.We also found that substrate played an important role in structuring macrozoobenthic assemblages,and bank types also indirectly had effects on the composition and distribution of macrozoobenthos.The maximal density and biomass of macrozoobenthos were found in the clay and gravel substrate,respectively.Collector-gatherers and collector-filters were the dominant functional feeding groups in the littoral zones of the Chaohu Lake.Based on the research,recovery and utilization propositions were made for macrozoobenthos in the littoral zones of the Chaohu Lake.