博斯腾湖枝角类群落结构特征及其影响因子

Cladocera in Bosten Lake: Community characteristics and driving factors

2010—2013年对博斯腾湖17个站位的枝角类及其影响因子进行了11次季度采样调查,阐述了枝角类群落结构特征及其演替动态,分析了博斯腾湖枝角类物种和多样性对环境变量的响应.结果表明：1）调查期间共鉴定枝角类14种,其中优势种3种.与历史数据比较,喜贫营养型水体的种类减少甚至消失,喜富营养型水体的种类逐步占据群落优势地位.2）枝角类密度时空变动较大,调查期间各站位密度变幅为0-567.0 ind·L^-1,总平均为30.0ind·L^-1;年际变动上2011年最高（82.5 ind·L^-1）,之后逐年递减;水平分布上密度差异显著,主要呈沿岸浅水区高、中心深水区低的特点.3）水温是影响枝角类群落最重要的生态因子;种类分布对水深的响应表现在长刺溞在深水区分布较多,长额象鼻溞多集中在浅水区;食物限制和食浮游动物鱼类的捕食可能是影响博斯腾湖枝角类群落结构变动的重要原因.

Cladocera of 17 sampling locations in Bosten Lake were investigated 11 times from 2010 to 2013. Their community structure and succession dynamics were elaborated,and their responses to environment factors were analyzed. The results showed that a total of 14 species were identified and3 of them were the dominant species. Compared with history data,species preferring oligotrophic conditions were decreasing or even disappeared,and species preferring eutrophic conditions had occupied the dominant position gradually. Spatial and temporal distribution of Cladocera densities changed greatly. Densities of the 17 sampling locations varied from 0-567.0 ind·L^-1with an average of 30. 0 ind · L^-1. Annual density of 2011 was the highest（ 82. 5 ind · L^-1）,and then decreased year by year. Horizontal distribution of Cladocera showed a significant difference,and it was higher in shallow water area along the coast than in deep water area in the center. Temperature was the main ecological factor affecting the Cladocera community. Species distribution changed with water depth,and Daphnia longispina was common in the deep water while Bosmina longirostris was common in shallow water. Food limitation and fish predation might be the important reason that caused the variation of community structure.