金沙江干流浮游甲壳动物群落结构特征及其与环境因子的关系

Characteristics of crustacean zooplankton community structure and its relationship to environmental factors in the main stream of the Jinsha River

为了解金沙江浮游甲壳动物群落特征及其与环境因子间的关系,对2017-2019年春季和秋季采集自金沙江干流的浮游甲壳动物样品进行了定量分析。结果表明,共鉴定浮游甲壳动物31种,其中枝角类11种,桡足类20种。优势种主要为长额象鼻溞(Bosminida longirostris)、广布中剑水蚤(Mesocyclops leuckarti)和特异荡镖水蚤(Neutrodiaptomus incongruens)。金沙江干流浮游甲壳动物的平均密度和生物量分别为(0.97±0.12)ind./L和(0.069±0.011)mg/L。密度和生物量的时空变化特征均为春季高于秋季,中下游高于上游。浮游甲壳动物的Shannon-Wiener多样性指数和Pielou均匀度指数的均值分别为0.75±0.08和0.59±0.07,表明金沙江干流甲壳动物群落结构简单。聚类分析显示,金沙江干流浮游甲壳动物可分为2个类群。典范对应分析(CCA)表明,影响金沙江干流浮游甲壳动物群落结构的主要环境因子为pH、流速和化学需氧量。研究结果可为金沙江干流水域水生态管理和保护提供科学依据。

There are few reports on the crustacean zooplankton research in the main stream of Jinsha River.We collected crustacean zooplankton and water samples in spring and autumn from 2017 to 2019,and revealed the relationship between crustacean zooplankton community structure and environmental factors through canonical correspondence analysis to identify the pattern of crustacean zooplankton communities structure and the critical environmental impact factors in the mainstream of Jinsha River and provide a theoretical basis for water aquatic ecological protection,.Rusults showed that 31 Crustacean zooplankton species were identified,including 11 Cladocera species and 20 Copepoda species.The dominant species were Bosminida longirostris,Mesocyclops leuckarti,and Neutrodiaptomus incongruens.The average density and biomass of crustacean zooplankton were(0.97±0.12)ind./L and(0.069±0.011)mg/L,respectively.Spatial and temporal variations were higher in spring than autumn and higher in the middle and lower reaches than downstream.The community structure of crustacean zooplankton was simple,with a mean Shannon-Wiener diversity index of 0.75±0.08 and a Pielou evenness index of 0.59±0.07.Cluster analysis divided the communities into two groups.Canonical correspon-dence analysis indicated that pH,FV,and COD were the community structure main ecological factors.These findings provide important basic data for managing and protecting aquatic ecology in the mainstream of Jinsha River.