农业面源污染对莫力达瓦旗某水库浮游生物和底栖动物群落结构的影响

Effect of Agricultural Non-point Source Pollution on Plankton and Zoobenthos Communities in a Reservoir in Morin Dawa Daur Autonomous Banner

2018年7月采用常规方法调查了莫力达瓦旗某水库浮游生物和底栖动物的群落结构。本次调查共鉴定出浮游植物6门15属18种及变种,其中硅藻门种类最多,蓝藻门的丰度、生物量高于其他藻类。浮游植物的总平均丰度为45.36×10~4ind./L,总平均生物量为15.3192mg/L;共鉴定出浮游动物13属16种属,其中桡足类种类较多,生物量较高;原生动物和轮虫种类很少,但丰度较高。浮游动物的总平均丰度为787.19ind./L,总平均生物量为0.3914mg/L。仅在两个采样点发现底栖动物2目3科3种,都为优势种。底栖动物的总平均丰度为83.2ind./m^2,总平均生物量为0.240g/m^2。水库水质浑浊,浮游生物和底栖动物物种较单一,优势种多为耐污种类,Shannon-Wiener多样性指数(H’)和Margalef丰富度指数(D)结果表明,水库水环境质量属于α-中度污染。浮游生物和底栖动物与环境因子的典范对应分析结果表明,水温、透明度和磷酸盐含量是影响浮游生物和底栖动物群落结构及其分布的主要环境因子。通过研究该水库受农业面源污染影响后的水生态特征,可为保护与合理利用呼伦贝尔水资源提供基础数据.

The community structures of plankton and zoobenthos were investigated in a reservoir affected by agricultural non-point source pollution in Morin Dawa Daur Autonomous Banner in July of 2018 in order to study the effects of agricultural non-point source pollution on water ecological characteristics in a reservoir,and to provide basic data with the protection and application of HulunBuir water resources.A total of 18 phytoplankton species(belonging to 15 genera and 6 phyla)were found,with the maximal species number in Bacillariophyta,and higher abundance and biomass of Cyanophyta than the others.There were average total phytoplankton abundance of 45.36×10~4 ind./L,and the average total phytoplankton biomass of 15.3192 mg/L.A total of 16 zooplankton species(belonging to 13 genera)were observed,total average abundance of 787.19 ind./L,and the total average biomass of 0.3914 mg/L,with the most diverse group and biomass of copepods,and rare species of protozoa and rotifer whch they had a high abundance.A total of 3 zoobenthos species(belonging to 3 Family and 2 Order)were recorded only at 2 sampling points,and all dominant species,with total average abundance of 83.2 ind./m^2,and the total average biomass of 0.240 g/m^2.The Shannon-Wiener diversity index(H’)and the Margalef diversity indices(D)indicated that the reservoir,which had turbid water and the plankton and rare dominant species of zoobenthos,was underα-moderate pollution.Analysis of the plankton and zoobenthos and environmental factors’CCA showed water temperature,transparency and phosphate content were the main environmental factors affecting the community structure and distribution of plankton and benthic fauna in the reservoir.