新丰江水库浮游动物群落结构特征

Zooplankton Community Structure in Xinfengjiang Reservoir

分析华南大型饮用水源水库浮游动物群落结构特征及主要环境影响因子,为水库生态环境保护提供基础资料和参考依据。于2019年8月至2020年6月在新丰江水库设置12个采样站点进行每2个月1次的浮游动物监测,设置采样站点12个。结果显示,调查期间共采集到浮游动物19属30种,其中轮虫8属17种,枝角类5属7种,桡足类6属6种,夏季出现的种类数最多(25种),春季最少(14种);各站点浮游动物密度和生物量月均值分别为11.52~161.52个/L和0.92~17.65 mg/L,具有极显著的季节差异(P<0.01),表现为夏季高、冬季低的特点;空间分布上呈现为上游和下游河道型库区高,中心敞水区低的分布趋势;浮游动物Shannon-Wiener多样性指数为0.87~1.19,Margalef丰富度指数为0.97~1.53,Pielou均匀度指数为0.54~0.93。浮游动物密度与环境因子的相关分析和冗余分析(RDA)结果表明,水温、叶绿素a和pH是影响新丰江水库浮游动物群落结构的主要环境因子。

Xinfengjiang reservoir is the largest reservoir in Guangdong Province,serving both as a drinking water source for the Pearl River Delta region and as the water volume regulation hub for Dongjiang River.In this study,we explored the community structure and spatiotemporal variation of zooplankton in Xinfengjiang reservoir based on zooplankton monitoring at 12 sampling sites once ev-ery two months from August 2019 to June 2020.Then,combined with the results of water quality monitoring,we analyzed the relationship of the zooplankton community with water environmental pa-rameters and discussed the primary environmental factors in large drinking water source reservoirs of South China.The aim was to accumulate baseline data for a study of long-term ecosystem variation in Xinfengjiang reservoir and provide a reference to support the protection of water resources and aquatic ecology.A total of 30 zooplankton species from 19 genera were observed including 17 rotifer species from 8 genera,7 cladoceran species from 5 genera and 6 copepod species from 6 genera.There were 8 dominant species(Y≥0.02)identified during the investigation,consisting of 4 cladoceran species and 4 copepod species.The number of zooplankton species was highest(25 species)in sum-mer and lowest(14 species)in spring.The ranges of zooplankton density and biomass were 11.52-161.52 ind/L and 0.92-17.65 mg/L,with extreme seasonal variation(P<0.01),and both were generally higher in summer and lower in winter.Spatially,zooplankton density and biomass were higher in the riverine sections,upstream and downstream,and lower in the central lacustrine area.The ranges of the Shannon-Wiener diversity index,Margalef richness index and Pielou evenness index were,respec-tively,0.87-1.19,0.97-1.53 and 0.54-0.93.Correlation and redundancy analyses of zooplankton den-sity and water environmental parameters show that water temperature,Chl-a and pH were the primary environmental factors affecting zooplankton community structure.