上海世博园后滩湿地枝角类群落结构的周年动态

Annual dynamics of cladocera community structure in Backshore Wetland of Expo Garden,Shanghai

上海世博园后滩湿地是中国2010年上海世界博览会规划区的重点项目.于2009年9月—2010年8月对后滩湿地枝角类群落结构的组成和现存量的时空变化及其主要影响因子进行研究.共鉴定枝角类36种,隶属于5科13属.优势种12种,主要为圆形盘肠溞、卵形盘肠溞、长肢秀体溞和晶莹仙达溞等.枝角类年均生物密度和生物量分别为5.7ind·L-1和0.3559mg·L-1;现存量的周年变化模式均呈双峰型,密度和生物量的主高峰分别出现在4月和7月,次高峰分别出现在7月和5月.枝角类的Shannon指数、Pielou指数和Margelf指数均呈现夏秋季高、春冬季低的格局.枝角类群落结构和环境因子的典型对应分析表明,水温、pH、DO和NO-2-N是世博园后滩湿地枝角类群落结构变化的主要影响因子.

The Backshore Wetland of Expo Garden,Shanghai was one of the key parts of the World Expo construction project in 2010.From September 2009 to August 2010,a monthly investigation was conducted to understand the spatiotemporal dynamics of cladocera community structure （including species composition and standing crop） and related main affecting factors in the Backshore Wetland.A total of 36 cladocera species in 13 genera of 5 families were identified through the year.There were 12 dominant species,mainly Chydorus sphaericus,C.ovalis,Diaphanosoma leuchtenbergianum,and Sida crystalline.The mean annual abundance and biomass of the cladocera were 5.7 ind·L-1 and 0.3559 mg·L-1,respectively,and the annual dynamics of the standing crop showed bimodal,with the main peak in April and July,and the second peak in July and May,respectively.The Shannon index,Pielou index,and Margelf index were high in summer and autumn,but low in winter and spring.The canonical correspondence analysis （CCA） showed that water temperature,pH,dissolved oxygen,and nitrite nitrogen were the main factors affecting the community structure of cladocera in the Backshore Wetland.