广州海珠国家湿地公园河湖连通水系浮游植物功能群特征及其对环境因子的响应

Characteristics of phytoplankton functional groups and their responses to environmental factors in the connected river-lake system of Guangzhou Haizhu National Wetland Park

为了解广州海珠国家湿地公园河湖连通水系浮游植物功能群对不同水体连通性和异质性的响应,于2021年对石榴岗河-海珠湖连通水系浮游植物群落结构和环境特征进行季度调查。共鉴定浮游植物6门76属168种,以绿藻门、硅藻门、裸藻门和蓝藻门为主;海珠湖浮游植物的平均丰度(64.76×10^(6)cells·L^(-1))显著高于石榴岗河(24.09×10^(6)cells·L^(-1))(P<0.05),石榴岗河Shannon多样性指数和Pielou均匀度指数均显著高于海珠湖(P<0.05);依据浮游植物的生态功能,连通水系划分为28个浮游植物功能群,优势功能群主要是以平裂藻属(Merismopedia)为代表的Lo功能群、以栅藻属(Scenedesmus)为代表的J功能群和以沟链藻属(Aulacoseira)为代表的P功能群;冗余分析表明,水温、铵态氮和总磷是影响浮游植物优势功能群的主要环境因子;海珠湿地河湖连通水体已达到富营养化水平。

To understand the responses of phytoplankton functional groups to connectivity and heterogeneity in the connected river-lake system of Guangzhou Haizhu National Wetland Park,we conducted a quarterly survey on the phytoplankton community structure and environmental characteristics in ihe Shiliugang River and Haizhu Lake in 2021.A total of 168 phytoplankton species belonging to 6 phyla and 76 genera were detected,mainly consisting of Chlorophyta,Bacillariophyta,Euglenophyta,and Cyanophyta.The average abundance of phytoplankton in Haizhu Lake(64.76×10^(6)cells.L^(-1))was significantly higher than that in Shiliugang River(24.09×10^(6)cells·L^(-1))(P<0.05),while Shannon diversity index and Pielou evenness index in the Shiliugang River were significantly higher than those in Haizhu Lake(P<0.05).The phytoplankton in the connected river-lake system of Guangzhou Haizhu National Wetland Park could be classified into 28 functional groups according to their ecological functions.The dominant functional groups were group L。,group J,and group P,which was represented by Merismopedia,Scenedesmus,and Aulacoseira,respectively.Water temperature,ammonium nitrogen,and total phosphorus were the main environmental factors affecting the dominant functional groups.The results indicate that the connected riverlake system has reached the level of eutrophication.