嘉兴南湖浮游动物群落结构及影响因素研究

Characteristics of Zooplankton Groups in Nanhu Lake Catchment and Its influencing Factors in Jiaxing City

通过对嘉兴市南湖及南湖水系16个样点进行调查采样分析,明确了南湖浮游动物群落现状,探讨了影响南湖浮游动物群落结构的主要影响因子。结果显示,南湖水系共检出浮游动物种类49种;优势种有13种,其中轮虫、原生动物、桡足类和枝角类分别有3种、4种、2种和4种。南湖水体中浮游动物总丰度和总生物量均低于7条南湖主要出入湖河流和南湖出入湖口;Margalef物种丰富度指数、Shannon-Wiener物种多样性指数、Pielou均匀度指数分布显示南湖水体浮游动物多样性指数最低,说明南湖水体浮游动物多样性水平较低。RDA分析结果显示,南湖水系浮游动物群落主要受颗粒物含量、总氮以及亚硝态氮等影响,而不同种类浮游动物与水环境因子的相关性也不同。进一步分析表明,悬浮颗粒物含量、水体富营养化水平、水温以及鱼类摄食等均可对南湖水系浮游动物群落产生影响,造成南湖水系浮游动物小型化。

Characteristics of zooplankton groups in Nanhu Lake and its river systems were studied by field investigation,and redundancy analysis(RDA)analysis was conducted to clarify the relationship between zooplankton abundance and environmental factors.The results showed that totally 49 zooplankton species were identified and 13 zooplankton species were recognized as dominant species in the study areas.Density and biomass of zooplankton in Nanhu Lake were lower than that in Nanhu lake river systems.Results of 3 diversity index including Shannon-Wiener index,Margalef index and Pielou’s index displayed in Nanhu Lake were lower than that in inlet/outlet of Nanhu Lake and Nanhu lake river system,implying that zooplankton diversity in Nanhu Lake was the lowest.The results of RDA and correlation analysis showed that suspended solid,total nitrogen and nitrite were the major environmental factors that determined zooplankton distribution in Nanhu Lake catchment,and various factors including suspended solid,eutrophication status of Nanhu Lake,water temperature and fish feeding may cause the dominance of rotifers over cladocerans in the research field.