Seasonal changes of phytoplankton community structure and its influencing factors in lakes and reservoirs adjacent to water sources in Shanghai

为改善城市水源地及毗邻水域的水质管理,2019年11月至2020年11月分别在青草沙水库中央沙水域和金泽水库南白荡水域开展了4个季度的采样调查.运用综合营养状态指数(TLI(Σ))对水体营养状态等级进行综合评估,并采用主成分分析(PCA)、冗余分析(RDA)和相关性分析等方法研究了浮游植物群落特征与环境因子的关系.结果表明:中央沙和南白荡水域TLI (Σ)范围分别为57.5~59.0、54.1~56.1,2个水体均处于轻度富营养状态;两者分别鉴定出浮游植物7门104属184种、8门96属172种;蓝藻门是中央沙水域全年浮游植物构成的主要门类,其次为硅藻门、绿藻门,而南白荡浮游植物群落结构季节性演替明显,优势门类由硅藻门/隐藻门-蓝藻门-隐藻门/硅藻门变化,浮游植物细胞密度季节平均值变化范围分为3.00×107~1.61×108 cells/L、4.29×106~6.59×107 cells/L;鉴定出2个水体浮游植物的优势类群分别有4门17属、5门13属,中央沙水域全年的主要优势类群为假鱼腥藻属(Pseudanabaena)和长孢藻属(Dolichospermum),而南白荡春冬季的主要优势类群为小环藻属(Cyclotella)、隐藻属(Cryptomonas)和蓝隐藻属(Chroomonas),夏秋季主要优势类群为假鱼腥藻属、平裂藻属(Merismopedia)和微囊藻属(Microcystis);中央沙水域浮游植物群落结构变化主要与总氮、总磷、水温等环境因子有关,而南白荡主要与水温、总溶解性盐等环境因子有关,水体流通性差异对此起关键作用.;In order to improve water quality management for urban sources and their adjacent waters, sample were collected in Zhongyangsha Reservoir Lake Nanbaidang four seasons from November 2019 2020. The comprehensive trophic level index (TLI(Σ)) was used assess the state levels of bodies, relationship between characteristics phytoplankton communities environmental factors studied using principal component analysis (PCA), redundancy (RDA) correlation analysis. It is shown that theTLI(Σ) ranged over 57.5-59.0 54.1-56.1 Nanbaidang, respectively, both bodies a mildly eutrophic state. species identified with 184 7 phyla 104 genera, 172 8 96 genera respectively. Cyanophyta major group throughout year Reservoir, followed by Bacillariophyta Chlorophyta, while seasonal succession community structure changed mainly Bacillariophyta/Cryptophyta-Cyanophyta-Cryptophyta/Bacillariophyta. mean density 30.0 million-161 million cells/L 4.29 million-65.9 cells/L. dominant as 4 17 5 13 main Pseudanabaena Dolichospermum year, Cyclotella, Cryptomonas Chroomonas spring winter, Pseudanabaena, Merismopedia Microcystis summer autumn. results also indicated changes related such total nitrogen, phosphorus, temperature, dissolved solids etc., differences circulation played key role.