| 摘要: |
| 揭示水生生态系统中浮游植物群落的构建机制,是有效预防藻类水华以及科学管理水生态系统的重要条件。为了揭示长江中下游通江湖泊之一—鄱阳湖浮游植物群落的构建机制,以及明确驱动该湖泊浮游植物群落结构变化的具体影响因子,于2020年8月,对全湖38个采样点的浮游植物及其功能群组成,以及环境因子进行调查分析。共检出7门59属91种,其中绿藻门(27属46种)、硅藻门(13属22种)和蓝藻门(8属11种)分别占总藻类种数的50.5%、24.2%和12.1%,其它门类占13.2%。浮游植物可划分为23个功能群,其中N、G、P、W1和LO为鄱阳湖优势功能群,它们所指示的生境特征表明鄱阳湖存在富营养化风险。鄱阳湖湖湾水域浮游植物群落结构与主航道水域存在明显差异,湖湾水域浮游植物Shannon-Wiener多样性指数、Simpson 多样性指数和Pielou均匀度指数均显著高于主航道水域(Mann-Whitney U,p < 0.001)。群落距离与环境距离和地理距离的相关关系结果显示,环境过滤作用和空间扩散限制作用共同影响了鄱阳湖浮游植物及其功能群群落的构建,而变差分解分析、C-score分析和校正随机率分析结果进一步明确了确定性过程(环境过滤作用)占据主导地位且其对功能群群落影响更大。约束性排序分析结果显示,浊度、高锰酸盐指数和电导率是驱动鄱阳湖浮游植物群落结构变化的最重要环境因素,温度、盐度、电导率和高锰酸盐指数是影响鄱阳湖浮游植物功能群群落结构的主要环境因素。 |
| 关键词: 鄱阳湖 浮游植物 功能群 群落结构 环境因子 空间因子 确定性过程 |
| DOI： |
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| 基金项目:国家自然科学基金（42161016）, 江西省水利科学院江西省鄱阳湖水资源与环境重点实验室开放研究基金（2022SKSH05）, 国家重点研发计划项目（2023YFC3209000，2023YFC3208700-05）和江西省重大科技专项 （20213AAG01012） |
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| Mechanisms and driving factors of phytoplankton community construction during wet season in Poyang Lake |
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WU Qiang1, LIU Jutao2, WEN Chunyun2, YANG Ping2, LIU longlingfeng3, WANG Fei3
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1.: Jiangxi Academy of Water Science and Engineering，Nanjing Institute of Geography and Limnology，Nanchang Institute of Technology;2.: Jiangxi Academy of Water Science and Engineering;3.: Nanchang Institute of Technology
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| Abstract: |
| It is of great significance to reveal the mechanism of phytoplankton community structure in aquatic ecosystem for effective prevention of harmful algal blooms and scientific management of aquatic ecosystem. In order to reveal the construction mechanism of phytoplankton community and to clarify the specific influencing factors driving the structural changes of the phytoplankton community in Poyang Lake, one of the river-connected lakes in the middle and lower reaches of the Yangtze River, the phytoplankton and its functional groups in Poyang Lake and the environmental factors of 38 sampling sites were investigated in August 2020. A total of 91 species in 59 genera from 7 phyla were detected, among which Chlorophyta (27 genera and 46 species), Bacillariophyta (13 genera and 22 species) and Cyanobacteria (8 genera and 11 species) accounted for 50.5%, 24.2% and 12.1% of the total species respectively, and others accounted for 13.2% of the total species. Phytoplankton can be divided into 23 functional groups in Poyang Lake. Among them, N, G, P, W1 and LO were the dominant functional groups, indicating that Poyang Lake was at the risk of eutrophication. There was a significant difference between the phytoplankton community structure in Poyang Lake bay and the main channel area, and the Shannon-Wiener diversity index, Simpson diversity index and Pielou evenness index of phytoplankton in the bay area were significantly higher than those in the main channel area (Mann-Whitney U, p < 0.001). The results of the correlation between the community distance and the environmental and geographic distances showed that environmental filtering and spatial dispersal constraints jointly influenced the construction of phytoplankton and its functional groups in Poyang Lake, while the results of variation partitioning analysis, C-score analysis and modified stochasticity ratio analysis further clarified that the deterministic process (environmental filtering) was dominant and had a greater influence on the functional groups. The results of constrained ordination analysis showed that turbidity, CODMn and conductivity were the most important environmental factors driving the change of phytoplankton community structure in Poyang Lake, while temperature, salinity, conductivity and CODMn were the main environmental factors influencing the community structure of phytoplankton functional groups in Poyang Lake. |
| Key words: Poyang Lake phytoplankton functional groups community structure environmental factors spatial factors deterministic process |
