长江中游浅水湖泊磷赋存形态特征及其对浮游植物群落结构的影响:以湖北省长湖为例OA
Characteristics of phosphorus fractions and their effects on phytoplankton community structure in the middle reaches of the Yangtze River:A case study of Lake Changhu,Hu-bei
磷是湖泊生态系统的关键营养元素和初级生产力的主要限制因子,水体磷的赋存形态及其含量可显著影响浮游植物群落结构.为解析典型长江中下游浅水湖泊——湖北省长湖水体磷的赋存形态特征及其对浮游植物群落结构的影响,并为长湖水生态修复和精细化管理提供科学依据,于 2024年3、5、9月和12月在长湖设置10个采样点,系统调查了水体中磷赋存形态、其他环境因子及浮游植物群落结构.结果表明:长湖水体总磷年均值为0.117 mg/L,均值为9月＞3月＞5月＞12月,自西向东呈降低趋势.总体而言,溶解态总磷(均值为0.060 mg/L)对总磷的贡献略高于颗粒态磷(均值为0.056 mg/L).就具体形态而言,3月以颗粒态磷为主,5月颗粒态磷在总磷中的占比略高于溶解态总磷,9月和12月则以溶解态总磷为主,其中9月溶解态总磷主要以溶解态有机磷形态存在,12月则以溶解态无机磷为主;9月水体溶解态有机磷含量显著高于其他时期.长湖浮游植物优势门类为蓝藻门、绿藻门、硅藻门和隐藻门.非度量多维尺度排序和置换多元方差分析结果显示,浮游植物群落结构在不同时期差异显著,且呈现一定的季节演替特征.3-12月,群落结构表现为硅藻门+隐藻门+绿藻门→蓝藻门+绿藻门→蓝藻门→隐藻门+硅藻门+蓝藻门+绿藻门的变化.其中,3、5和12月分别以硅藻门小环藻(Cyclotella sp.)、蓝藻门细小平裂藻(Merismopedia minima)和隐藻门具尾逗隐藻(Komma caudata)优势度最大;9月则以水华蓝藻微囊藻(Microcystis spp.)占据显著优势,该种在5月也为优势种.冗余分析和偏最小二乘路径建模分析结果进一步表明,溶解态有机磷、水温、溶解态总磷和悬浮物对浮游植物群落结构的影响最为显著,且磷赋存形态对浮游植物群落结构具有显著的直接效应,其中溶解态有机磷的影响最大,对微囊藻丰度的正向作用尤为突出.综上,本研究结果表明磷赋存形态显著影响了长湖浮游植物群落结构,突出了在富营养化浅水湖泊中定量识别不同形态磷,尤其是溶解态有机磷风险的重要性.
Phosphorus is a key nutrient in lake ecosystems and a primary limiting factor for primary productivity,with its speciation and concentration significantly influencing phytoplankton community structure.To investigate the characteristics of phosphorus frac-tions and their effects on phytoplankton assemblages in Lake Changhu,a typical shallow lake in the middle and lower reaches of the Yangtze River,and to provide a scientific basis for its ecological restoration and precision management,we conducted seasonal sampling in March,May,September,and December 2024 at 10 sites,analyzing phosphorus forms,environmental variables,and phytoplankton community composition.Results showed that the annual average total phosphorus(TP)concentration was 0.117 mg/L,with levels ordered as September＞March＞May＞December and a decreasing gradient from west to east.Dissolved total phosphorus(DTP;mean of 0.060 mg/L)contributed slightly more to TP than particulate phosphorus(PP;mean of 0.056 mg/L).Seasonal variation in phosphorus forms was observed:PP dominated in March;PP slightly exceeded DTP in May;DTP prevailed in September and December,with dissolved organic phosphorus(DOP)predominant in September and dissolved inorganic phos-phorus(DIP)in December.DOP in September was significantly higher than in other months.Phytoplankton were dominated by Cyanophyta,Chlorophyta,Bacillariophyta,and Cryptophyta.Non-metric multidimensional scaling and permutational multivariate analysis of variance revealed significant temporal variation in community structure,showing a clear seasonal succession:from Bacil-lariophyta+Cryptophyta+Chlorophyta in March to Cyanophyta+Chlorophyta in May,then Cyanophyta in September,and finally Cryptophyta+Bacillariophyta+Cyanophyta+Chlorophyta in December.Dominant species included Cyclotella sp.(Bacillariophy-ta)in March,Merismopedia minima(Cyanophyta)in May,Komma caudata(Cryptophyta)in December,and Microcystis spp.(Cyanophyta)—a bloom-forming genus—in September,which was also dominant in May.Redundancy analysis and partial least squares path modeling identified DOP,water temperature,DTP,and suspended solids as the most influential factors on phyto-plankton community structure,with phosphorus fractions exerting significant direct effects.DOP showed the strongest effect,par-ticularly promoting Microcystis spp.abundance.These results demonstrate that phosphorus speciation significantly shapes phyto-plankton community structure in Lake Changhu and highlight the importance of quantitative assessment of different phosphorus forms—especially DOP—for evaluating ecological risks in eutrophic shallow lakes.
杨新宇;郭祉宾;向邈;李学梅;朱挺兵;魏念
中国水产科学研究院长江水产研究所,武汉 430223||华中农业大学水产学院,武汉 430072中国水产科学研究院长江水产研究所,武汉 430223中国水产科学研究院长江水产研究所,武汉 430223中国水产科学研究院长江水产研究所,武汉 430223中国水产科学研究院长江水产研究所,武汉 430223中国水产科学研究院长江水产研究所,武汉 430223
磷赋存形态浮游植物长湖
Phosphorus fractionphytoplanktonLake Changhu
《湖泊科学》 2026 (3)
955-969,15
国家重点研发计划项目(2023YFD2400904)和中国水产科学研究院中央级公益性科研院所基本科研业务费专项资金项目(2023TD61)联合资助.
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