Study on the phytoplankton community structure and its driving factors in Furong Creek during spring and autumn under the influence of cascade weirs  

梯级堰作用下芙蓉溪浮游植物春秋季群落结构及其驱动因素研究

作　　者：REN Jiangshan YU Jun LI Jingjuan LYU Jianzhang WANG Xiaogang 任江山;余俊;李景娟;吕建璋;王晓刚(南京水利科学研究院水工水力学研究所,江苏南京210029;江西交通职业技术学院,江西南昌330013)

机构地区：[1]Hydraulic Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu,China [2]Jiangxi Vocational and Technical College of Communications,Nanchang 330013,Jiangxi,China

出　　处：《水利水电技术(中英文)》2025年第3期171-185,共15页Water Resources and Hydropower Engineering

基　　金：国家重点研发项目(2022YFC3204200,2022YFC3204204);国家自然科学基金青年科学基金项目(52409100)。

摘　　要：[Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore the nonlinear response relationship between phytoplankton community structure and its driving factors in spring and autumn in Furong Creek under the construction of cascade weirs.[Methods]The structure of phytoplankton communities and related environmental factors were investigated in Furong Creek from 2023 to 2024.This study focused on the analysis of the changes of nutrient concentrations and biomass of phytoplankton in autumn and spring within the same dry season in Furong Creek.Redundancy analysis was used to identify the key factors influencing the structure of phytoplankton communities.The MIKE 11 model was employed to simulate the hydrodynamic changes in the river.Combined with total nitrogen and permanganate index,a GAM model of phytoplankton diversity index and hydrodynamic factors was developed,and the change of phytoplankton diversity after the optimized layout of the cascade weirs was fitted.[Results]The result showed that the annual average value of Shannon-Wiener diversity index of phytoplankton in Furong Creek was 2.79,which was in a state of mild pollution.A total of 239 species from 95 genera in 8 phyla were identified.Among the phytoplankton,Chlorophyta was the dominant group throughout the year in Furong Creek,followed by Bacillariophyta and Cyanophyta.The cell abundance of phytoplankton ranged from 3.11 to 20.64 mg/L and from 0.23 to 6.31 mg/L in spring and autumn,which indicated a clear seasonal succession of phytoplankton community structure.Compared with autumn,the relative abundance of Cyanophyta significantly decreased in spring across the whole river section,while Chrysophyta and Dinophyta showed significant increase at some monitoring sites,leading to water bloom phenomenon and a noticeable decline in the diversity of phytoplankton.The dominant species in the water bodies t【目的】筑堰改变河流水力特性,影响河流浮游植物群落结构以及水生态系统健康水平。为探究梯级堰建设下芙蓉溪浮游植物春秋季群落结构及其驱动因素的非线性响应关系。【方法】于2023-2024年在芙蓉溪开展了浮游植物群落结构及相关环境要素的调研,重点分析了芙蓉溪同一枯水期内秋春两季浮游植物营养物质浓度及生物量变化状况,通过冗余分析筛选影响浮游植物群落结构的关键影响因子,使用MIKE 11模型拟合了河道内水动力变化状况,结合总氮和高猛酸盐指数,构建了浮游植物多样性指数与水动力因子的GAM模型,拟合了梯级堰优化布置后的浮游植物多样性变化状况。【结果】结果显示:芙蓉溪浮游植物Shannon-Wiener多样性指数全年均值为2.79,整体处于轻度污染状态,鉴定出浮游植物8门95属239种:绿藻门是芙蓉溪全年浮游植物的主要构成门类,其次为硅藻门和蓝藻门,浮游植物春秋两季细胞丰度变化范围为3.11~20.64 mg/L和0.23~6.31 mg/L,浮游植物群落结构季节性演替明显,相较于秋季,春季蓝藻门的相对丰度在全河段显著降低,而金藻门和甲藻门在部分点位显著上升,并形成水华现象,造成浮游植物多样性水平显著下降。全年水域优势种为链形小环藻(Cyclotella catenata)、小球藻(Chlorella vulgaris)、双对栅藻(Scenedesmus bijuga)、四尾栅藻(Scenedesmus quadricauda)、尖尾蓝隐藻(Chroomonas acuta)、卵形隐藻(Cryptomonas ovata)和啮蚀隐藻(Cryptomonas erosa)。冗余分析(RDA)表明,水动力因子(v、h)和水体环境因子(TN、COD_(Mn))是浮游植物种群结构的显著影响因子。【结论】结果表明:芙蓉溪春季的水环境营养物质浓度、浮游植物生物量和密度远高于秋季,结合水动力因子和环境因子构建的GAM模型可以有效地反应浮游植物多样性指数与驱动因素间的非线性关系,在春季营养物质浓度提升的情况下,溢流堰�

关 键 词：cascade weirs MIKE 11 model redundancy analysis GAM model influencing factors 

分 类 号：X43[环境科学与工程—灾害防治]