重庆东河上游浮游植物和底栖动物群落结构特征

Community Structure of Characteristics Phytoplankton and Zoobenthos in the Upper Reaches of Donghe River in Chongqing

为了解重庆东河上游浮游植物、底栖动物群落结构特征,于2017年4月25日-28日在重庆市开州区东河上游设置采样点,对水质理化参数、浮游植物和底栖动物进行调查。水质检测结果显示,各河段水质良好。浮游植物共鉴定出5门121种,生物量及生物多样性在S6河段最高,S2河段最低;底栖动物共鉴定出3门23种,密度及生物量在S6河段最高,S2河段最低。相较于S1河段以及有正常生态流量的S6河段来说,其余河段或因引水式电站的修建形成水库,水流状态由急流变为缓流甚至静水,或因拦河坝无下泄生态流量,形成减脱水河段,浮游生物群落结构受到一定影响。库区河道部分地带受泥沙淤积影响,生境多样性和异质性降低,底栖动物的栖息密度及生物量较其他河段偏低。

From 25th to 28th of April in 2017,sampling sections had been set up in the upper reaches of Donghe River in Chongqing to survey the current situation of water quality parameter and understand the community structure of phytoplankton and zoobenthos.The results of water quality test show that the water quality of each river section is good.A total of 121 species and 5 phylum of Phytoplankton are identified and the biomass and biodiversity are the highest in S6 and the lowest in S2;a total of 3 phylum and 23 species of zoobenthos are identified,and the density and biomass are the highest in S6 and the lowest in S2.Compared with S1 and S6 that have normal ecological flow,the other reaches of the river have changed the flow state from rapids to slow flow or even still water because of the reservoirs formed after building the diversion hydropower station,and the community structure of plankton is under certain influence as a result of the dewatering reaches due to the lack of ecological flow discharge.In reservoir section affected by sediment deposition,the diversity and heterogeneity of habitat are reduced and the inhabit density and biomass of zoobenthos are lower than those in other reaches.