基于通径模型对比分析水泊渡水库和倒天河水库后生浮游动物群落结构

Comparsion of community structure of zooplankton in Shuimodu Reservoir and Daotianhe Reservoir based on the path model

于2015年的枯水期(1月)和丰水期(8月)进行浮游动物采样,使用通径分析法分析浮游动物群落结构与环境因子的关系。研究结果表明:(1)群落结构特征方面,轮虫在两座水库的物种种类组成中占比最大,水泊渡水库和倒天河水库中轮虫分别占各自总物种数的50.00%和72.73%。两个水库的浮游生物的丰度和生物量均存在显著的时空差异,时间上最高值出现在丰水期,空间上最高值出现在大坝。相同水库不同水情的优势种有所不同,相同水情期不同水库优势种也不完全一样:枯水期水泊渡水库优势种为螺形龟甲轮虫(Keratella cochlearis)、长额象鼻溞(Bosmina longirostris),丰水期水泊渡水库优势种为刺盖异尾轮虫(Trichocerca capucina)、中剑水蚤(Mesocyclops)、无节幼体(Nauplius)、长额象鼻溞(Bosmina longirostris);枯水期倒天河水库优势种为螺形龟甲轮虫(Keratella cochlearis)、长额象鼻溞(Bosmina longirostris),丰水期倒天河水库优势种为螺形龟甲轮虫(Keratella cochlearis)、中剑水蚤(Mesocyclops)、长额象鼻溞(Bosmina longirostris)。(2)通径分析表明,对水泊渡曲腿龟甲轮虫(Keratella valga)生物量产生主要影响的关键环境因子为无机氮(DIN)、水柱相对稳定性(RWCS)和电导率(EC);对水泊渡螺形龟甲轮虫(Keratella cochlearis)生物量产生主要影响的环境因子为总氮(TN)、真光层深度(Zue)和电导率(EC);对水泊渡中剑水蚤(Mesocyclop)生物量产生主要影响的关键环境因子为总磷(TP)、无机氮(DIN)和深度(H)。对倒天河螺形龟甲轮虫(Keratella cochlearis)生物量和长额象鼻溞(Bosmina longirostris)生物量产生主要影响的环境因子分别为混合层深度(Zmix)和酸碱度(pH)。研究表明,对不同浮游动物的生物量产生主要的环境因子不完全相同,不同的水库中对同种浮游动物的生物量产生主要影响的环境因子也不完全相同,可以根据浮游动物优势种以及现存量(丰度、生物量)大小等进行分析,判定水库产生主要影响的环境因子,并且进行控制。

In order to study the characteristics of the zooplankton community structure in the Shuibodu Reservoir and the Taotianhe Reservoir in Guizhou Plateau,zooplankton were sampled during the dry season(January)and the wet season(August)in 2015 respectively,and the path analysis was used to analyze the relationship between community structure and environmental factors.The results are as follows.(1)As for the community structure,Rotifer accounted for the largest proportion of species in the two reservoirs,with that of the Shuibodu Reservoir and the Taotianhe Reservoir accounting for 50.00%and 72.73%respectively.The temporal and spatial differences in the plankton abundance and biomass in the two reservoirs varied considerably,with the peak temporal value appearing in the wet season,and the highest spatial value in dams.The dominant species in different water regimes of the same reservoir were different,while the dominant species in different reservoirs in the same water regime were also different:the dominant species in Shuibodu Reservoir during the dry season were Keratella cochlearis and Keratella cochlearis,while the dominant species in Shuibodu Reservoir during the wet season were Trichocerca capucina,Mesocyclops,Nauplius and Bosmina longirostris;the dominant species in Daotianhe Reservoir during the dry season were Keratella cochlearis and Keratella cochlearis,while the dominant species in Daotianhe Reservoir during the wet season were Keratella cochlearis,Mesocyclops and Bosmina longirostris.(2)Path analysis showed that inorganic nitrogen(DIN),water column relative stability(RWCS)and electrical conductivity(EC)were the key environmental factors that had a major impact on the biomass of Keratella valga in the Shuibodu Reservoir;total nitrogen(TN),true light depth(Zue)and electrical conductivity(EC)were the main environmental factors affecting the biomass of Keratella cochlearis in Shuibodu Reservoir;total phosphorus(TP),inorganic nitrogen(DIN)and depth(H)were the key environmental factors influencing the biomass of Mesocyclop in Shuibodu Reservoir.The key environmental factors affecting the biomass of Keratella cochlearis and Bosmina longirostris were the depth of mixed layer(Zmix)and pH(pH)respectively.Studies showed that the main environmental factors that produce the biomass of different zooplankton were different,and the environmental factors affecting the biomass of the same species of zooplankton in different reservoirs also had differences.Environmental factors affecting the reservoir can be determined and controlled by analyzing the dominant species of zooplankton and the amount,biomass and size of existing ones.