东莞生态园浮游植物群落结构特征、功能类群及其与环境因子的关系

Phytoplankton community structure,functional groups and their relationship with environmental factors in Dongguan Ecological Park

为探究东莞城市湿地公园浮游植物群落结构特征、功能类群及其与环境因子的关系,于2019年4—12月按季度在东莞生态园中央岛群水域和月湖湖区设置7个采样站点,采用传统分类法、功能群分类法及综合营养状态指数法等对该园区水环境中浮游植物群落结构和环境因子进行了调查分析。结果表明:在东莞生态园共鉴定出浮游植物7门137种(属),其中,绿藻门物种数最多,全年优势种均来自蓝藻门;浮游植物年平均丰度和生物量分别为(16.83±1.97)×10^(7)ind./L和(23.00±3.00)mg/L,丰度和生物量在季节间存在显著性差异(P<0.05),且季节和湖区间存在显著交互作用(P<0.05);聚类分析(CA)显示,浮游植物物种组成在季节间存在显著性差异(P<0.05);东莞生态园浮游植物可划分为24个功能群,其中D、F、H1、J、Lo、MP、P、S1、SN、W1、X1和Y为优势功能群,且存在季节演替;RDA分析显示,水温(WT)、磷酸盐(PO_(3)^(-)-P)、氨氮(NH_(4)^(+)-N)、pH和总磷(TP)是影响浮游植物优势种和优势功能群的主要环境因子;结合单因子水质评价法、综合营养状态指数(TLI)、功能群Q指数、浮游植物现存量、叶绿素a和浮游植物多样性指数对东莞生态园进行水质评价综合分析显示,水体有机污染严重,主要污染物质为氮。研究表明,东莞生态园浮游植物群落以蓝藻为优势种,水环境处于中度富营养状态或中污染状态,需严格控制外来污染并加强水体自身净水能力。

To investigate the structural characteristics of phytoplankton communities,functional groups and their relationship with environmental factors in Dongguan Urban Wetland Park,the phytoplankton community structure and environmental factors in the water environment were quarterly investigated at 7 sites in the Central Islands and Moon Lake of Dongguan Ecological Park from April to December 2019 by the traditional classification method,functional group classification method and comprehensive nutrient status index method.The results showed that 137 species(genera)of phytoplankton were identified in Dongguan Ecological Park,with the most species number in Chlorophyta and all the dominant species in Cyanophyta throughout the year.There were annual average phytoplankton abundance of(16.83±1.97)×10^(7)ind./L and biomass of(23.00±3.00)mg/L,with significant differences in abundance and biomass among seasons(P<0.05),and significant differences between seasons and lake areas(P<0.05).Cluster analysis(CA)showed that there were significant changes in the composition of phytoplankton species between seasons(P<0.05).Phytoplankton in Dongguan Ecological Park was divided into 24 functional groups,with dominant functional groups D,F,H1,J,Lo,MP,P,S1,SN,W1,X1 and Y,and seasonal changes.Redundancy analysis(RDA)revealed that water temperature(WT),phosphate(PO_(3)^(-)-P),ammonia nitrogen(NH_(4)^(+)-N),pH and total phosphorus(TP)were the main environmental factor affecting the dominant phytoplankton species and functional groups.A comprehensive analysis of the water quality evaluation by single factor evaluation method,trophic level index(TLI),functional group Q index,phytoplankton standing crop,chlorophyll-a and phytoplankton diversity indices showed that Dongguan Ecological Park was in a moderately eutrophic or polluted state,with severe organic pollution and nitrogen as the main pollutant.The phytoplankton community in Dongguan Ecological Park was shown to be dominated by Cyanophyta,and the water environment to be in a moderately eutrophic or moderately polluted state.It is necessary to strictly control external pollution and strengthen the water purification capacity of the water itself.