Phytoplankton community structure and driving mechanism of its construction process in autumn in Zhelin Reservoir, Lake Poyang Basin

研究环境过滤过程和空间扩散限制过程在构建水生浮游植物群落结构中的作用是了解这些因素如何驱动物种分布和影响群落结构的关键步骤.为了揭示鄱阳湖流域柘林水库浮游植物群落结构特征与环境因子的关系，以及明确环境因子和空间扩散限制性因子在浮游植物群落构建过程中的影响机制，于2020年10月，对柘林水库33个采样点的浮游植物和水质理化进行调查分析.共鉴定浮游植物7门122种，其中，以绿藻门种类最多，为34属62种，占总物种数的50.81%，硅藻门次之，为11属27种.柘林水库浮游植物优势种类主要是蓝藻门中的伪鱼腥藻属（Pseudoanabaena）、浮鞘丝藻属（Planktolyngbya）、小尖头藻属（Raphidiopsis）以及硅藻门中的针杆藻属（Synedra）.柘林水库浮游植物细胞丰度的变化范围为0.93×106~172.12×106 cells/L，平均值为95.42×106 cells/L，生物量的变化范围为0.95~22.35 mg/L，平均值为9.35 mg/L.上游修河水域浮游植物生物多样性指数显著高于库心和库湾水域，库心与库湾水域之间浮游植物生物多样性指数差异性不明显.柘林水库上游修河水域浮游植物群落结构与库心和库湾水域存在明显分离，群落结构的差异性主要受水体透明度、电导率、氨氮和硝态氮的影响.变差分解结果显示，空间扩散限制性作用在驱动柘林水库浮游植物群落构建过程中占据主导地位.;Evaluation of the relative influences environmental and spatial processes in structuring aquatic phytoplankton metacommunities is an essential step for understanding species spatio-temporal distributions. To reveal relationships between community structures environment as well clarify driving mechanism factors diffusion limiting on structure Zhelin Reservoir, Lake Poyang Basin, water quality physicochemical characteristics 33 sampling sites were investigated analyzed October 2020. A total 122 belong to 7 genera identified, with 62 34 Chlorophyta, accounting 50.81% species, followed by Bacillariophyta 27 11 genera. The dominant Reservoir are Pseudoanabaena, Planktolyngbya Raphidiopsis Cyanophyta Synedra Bacillariophyta. cell abundance varied from 0.93×106 172.12×106 cells/L average 95.42×106 cells/L, biomass 0.95 22.35 mg/L 9.35 mg/L. biodiversity index upstream Xiuhe tributary area was significantly higher than that center reservoir bay area, while no significant difference found. tributaries separated bay, differences mainly affected transparency, electrical conductivity, ammonia nitrogen nitrate nitrogen. results variation partitioning showed effect Reservoir.