晋城市沁河流域秋季浮游植物群落结构特征及其与环境因子的关系

为了摸清晋城沁河流域浮游植物的空间分布及关键驱动因子，于2020年10~11月对山西省晋城市沁河和丹河的62个采样点的浮游植物及环境因子进行调查分析.鉴定出浮游植物7门47种，由隐藻门、绿藻门、甲藻门、金藻门、硅藻门、蓝藻门和裸藻门组成.沁河的优势种为小球藻、啮蚀隐藻、尖尾蓝隐藻、具星小环藻、绿球藻和绿色裸藻.丹河的优势种为啮蚀隐藻、史密斯胸隔藻、绿色裸藻、具星小环藻、小球藻和矩圆囊裸藻.Shannon-Wiener多样性指数（H''）的范围0.35~3.15，均值为1.40，Pielou均匀度（J）的范围是0.24~1.00，均值是0.68.丹河浮游植物多样性指数高于沁河，沁河晋城段中游和丹河晋城段中下游浮游植物均匀度指数最低.典范对应分析结果表明：河岸缓冲区林地面积比例是影响沁河绿藻门绿球藻分布的主要驱动因子，绿色裸藻的分布主要受硝态氮、总磷和河岸林地面积比例的影响，具星小环藻的分布主要受城镇建设用地的面积比例和温度的影响，小球藻、啮蚀隐藻和尖尾蓝隐藻主要分布受农村聚落用地和耕地面积比例的影响.丹河啮蚀隐藻和具星小环藻的分布主要受pH和硫酸盐影响，绿色裸藻主要受河岸城镇建设和草地面积影响，矩圆囊裸藻主要受林地面积比例和Cl^-影响最大，史密斯胸隔藻的分布主要受水温和耕地面积比例影响最大，小球藻主要受氨氮和耕地面积影响最大.

Characteristics of Phytoplankton Community Structure and Their Relationships with Environmental Factors in Autumn in Qinhe River Basin of Jincheng Region

In October-November 2020, the phytoplankton and the aquatic environment from 62 sites in the mainstream of the Qinhe River and the largest tributary of the Qinhe River (Danhe River) in the Jincheng region were investigated to clarify the spatial pattern of phytoplankton communities and their driving factors. A total of 7 phyla and 47 species of phytoplankton were identified in the Qinhe River basin and were composed of Cryptophyta, Chlorophyta, Pyrrophyta, Chrysophyta, Bacillariophyta, Cyanophyta, and Crytophyta. Six dominant species in the Qinhe River included:Chlorella vulgaris, Cryptomonas erosa, Chroomonas acuta, Cyclotella stelligera, Chlorococcum, and Euglena viridis. Six dominant species in the Danhe River included:C. erosa, Frustulia vulgaris, E. viridis, C. vulgaris, Trachelomonas oblonga Lemm, and C. stelligera. The Shannon-Wiener diversity index (H'') varied from 0.35 to 3.15, with a mean value 1.40. The Pielou evenness index (J) varied from 0.24 to 1.00, with a mean value of 0.68. H'' values in the Qinhe River were higher than those in the Danhe River. J values were relatively low in the middle reaches of the Qinhe River and middle-low reaches of the Danhe River. The results in the Qinhe River through a canonical correspondence analysis (CCA) showed that the percent of forest land at a 300 m buffer was the driving factor of Chlorococcum in Chlorophyta, and nitrate, total phosphorus, and the percent of forest land at the 300 m buffer were the driving factors of E. viridis. Cyclotella stelligera was mainly influenced by the percent of urban land and water temperature, whereas C. vulgaris, C. erosa, and C. acuta were mainly influenced by the percent of farmland and residential land at the 300 m buffer. The results in the Danhe River via CCA showed that C. erosa and C. stelligera were mainly influenced by pH and sulfate, E. viridis was mainly influenced by the percent of urban land and grass land, T. oblonga Lemm was mainly influenced by chloride and the percent of forest land, F. vulgaris was mainly influenced by water temperature and the percent of farmland, and C. vulgaris was mainly influenced by ammonia and the percent of farmland.