摘要: |
2019年对南通市中央创新区新建湖泊紫琅湖的浮游植物进行了4个季度的调查,旨在研究典型城市新建景观湖泊的浮游植物群落结构特征及其与环境因子关系。紫琅湖全年共鉴定出浮游植物种类7门186种,春季种类数最多,共6门113种,其中蓝藻门(Cyanophyta)占17.7%,绿藻门(Chlorophyta)占19.5%,硅藻门(Bacillariophyta)占39.8%;夏季种类数最少,共7门43种,其中蓝藻门占32.6%,绿藻门占30.2%,硅藻门占16.3%;冬季和春季则硅藻种类多。从丰度来看,各季节浮游植物组成均以蓝藻为主,冬、夏、秋季蓝藻的丰度分别为(26.81±6.70)×106 ind./L、(12.77±1.02)×106 ind./L和(31.99±10.23)×106 ind./L,显著高于其他藻类(P<0.05)。典范对应分析(CCA)表明透明度、pH、总磷和浊度是与浮游植物群落相关性较强的4个环境因子,其中透明度是最主要的环境因子。冬季和春季浮游植物主要与透明度正相关,夏季主要与总磷和浊度呈正相关,秋季主要与pH呈正相关。紫琅湖的浮游植物优势类群以蓝藻门为主,其中伪鱼腥藻(Pseudoanabaena sp.)为全年唯一的优势藻类(优势度指数分别为Y冬=0.66,Y春=0.10,Y夏=0.16,Y秋=0.26)。综合营养指数表明湖泊处于轻度富营养水平,浮游植物多样性水质评价表明夏季水体污染相对严重。城市新建景观湖泊紫琅湖营养水平较高、透明度低、浮游植物群落结构波动大,暴发蓝藻水华的可能性较高,研究结果可为城市新建景观湖泊水质改善和健康生态系统的构建提供科学依据。 |
关键词: 新建湖泊 浮游植物 群落结构 环境因子 生态系统构建 |
DOI:10.14188/j.ajsh.2021.06.001 |
分类号:S932.7 |
基金项目:国家重点研发计划项目(2019YFD0900601);国家大宗淡水鱼产业技术体系项目(CARS-45);中国科学院青年创新促进会人才项目(2019331)和南通市中央创新区紫琅湖生态水处理项目 |
|
Phytoplankton community structure and its relationships with environmental factors in a new urban landscape lake |
LI Shiqi1,2, LI Wei1, GUO Chao1,2, MAI Zhan1,2, LIAO Chuansong1, LIU Jiashou1, GE Xuanchen3, YIN Wenwen3, FAN Yutao3
|
1.State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China;2.University of Chinese Academy of Sciences, Beijing 100049, China;3.Management Office of Nantong Innovation Zone, Nantong 226000, Jiangsu, China
|
Abstract: |
To study the phytoplankton community structure and its relationship with environment of newly built urban lakes, we used Zilang Lake as a model ecosystem and conducted a seasonal investigation in 2019. We found that there were a total of 186 species of phytoplankton from 7 phyla in Zilang Lake. The species number was the most in spring (6 phyla, 113 species), among which Cyanophyta accounted for 17.7%, Chlorophyta 19.5%, and Bacillariophyta 39.8%. The species number was the least in summer (7 phyla, 43 species), among which Cyanophyta accounted for 32.6%, Chlorophyta 30.2% and Bacillariophyta 16.3%. There were many diatoms in winter and spring, and many blue-green algae in summer and autumn. The abundance of cyanobacteria was (26.81±6.70)×106 ind./L, (12.77±1.02)×106 ind./L and (31.99±10.23)×106 ind./L in winter, summer and autumn, respectively, significantly higher than that of other algae (P < 0.05). CCA analysis showed that transparency, pH, total phosphorus and turbidity were four environmental factors strongly correlated with phytoplankton community, among which transparency was the most important environmental factor. The structure of phytoplankton was positively correlated with transparency in winter and spring, with total phosphorus and turbidity in summer, and with pH in autumn. The dominant alga species in the newly built lake were mainly cyanobacteria, among which Pseudoanabaena sp. was the only year-round dominant algae(YWinter=0.66,YSpring=0.10,YSummer=0.16,YAutumn=0.26). Comprehensive nutrient index showed that the lake was in a mild eutrophication level, and the evaluation of phytoplankton diversity showed that the water pollution level was relatively serious in summer. Our study indicates that the blue-green algae bloom easily in new-built urban landscape lakes, with higher nutrient level, lower transparency and vulnerable phytoplankton community. The results can provide scientific basis for improving water quality and constructing healthy ecosystem in newly built urban landscape lakes. |
Key words: newly built lake phytoplankton community structure environment factor ecosystem construction |