巢湖流域春季浮游植物群落结构特征及其与环境因子的关系

Spring community structure of phytoplankton from Lake Chaohu and its relationship to environmental factors

采用野外调查的方法,结合趋势对应分析(DCA)及典范对应分析(CCA)的手段,研究春季巢湖流域河湖水体浮游植物群落结构特征及其与环境因子的相关性.结果表明,共鉴定出浮游植物73种,分属8门(硅藻门、绿藻门、蓝藻门、隐藻门、金藻门、甲藻门、裸藻门和黄藻门).在巢湖水体中,硅藻门、蓝藻门及绿藻门的数量之和占总数量的93.5%,为优势种群;蓝藻门中的项圈藻占总数量的21.9%,成为优势种.巢湖流域出入湖河流水体中,硅藻门、蓝藻门及绿藻门的数量也最多,占总数量的82.6%,为优势种群;蓝藻门中的席藻和束丝藻数量分别占总数量的38.3%、32.6%,成为出入湖河流水体中的绝对优势种.DCA分析表明巢湖流域水体浮游植物群落存在明显的空间差异.CCA分析表明巢湖水体浮游植物空间分布主要受水温、浊度和硝态氮浓度的影响;南淝河和柘皋河浮游植物空间分布受叶绿素a和硝态氮浓度的影响;而裕溪河、兆河和白石山河、杭埠河和丰乐河、派河浮游植物空间分布则受叶绿素a和磷酸根浓度的影响.

Spring community structure of phytoplankton from rivers and wetlands in Lake Chaohu catchment was investigated by means of field sampling,and it＇s relationship with environmental factors was analyzed by detrended correspondence analysis （DCA） and canonical correspondence analysis （CCA）.The results showed that 73 species （genera） of phytoplankton have been identified in water from Lake Chaohu,which belonged to Bacillariophyta,Chlorophyta,Cyanophyta,Cryptophyta,Chrysophyta,Pyrrophyta,Euglennophyta and Xanthophyta,respectively.In the water of Lake Chaohu,93.5%of the phytoplankton belonged to the phylum Bacillariophyta,Cyanophyta and Chlorophyta,which constructed the dominant population.Notably the number of Anabaenopsis from the phylum Cyanophyta,the most dominant species,is 21.9%of the numbers of the phytoplankton.In some rivers discharged to Lake Chaohu,the dominant species are also of the phylum Bacillariophyta,Cyanophyta and Chlorophyta,which constitute 82.6%of the phytoplankton.The number of Phormidium （the species of the largest population） reaches as high as 38.3%of the number of the phytoplankton,while the number of Aphanizomenon （the species of the second largest population） reaches 32.6%,both of which belong the phylum Cyanophyta.These two species construct the absolute dominant species.A significant discrepancy in spatial distribution of phytoplanton in the lake was observed.Phytoplankton community structure and spatial distribution in the water were remarkably affected by temperature,turbidity and NO-3-N.However,concentrations of Chl.a,NO-3-N and PO3-4-P were the main environmental variables affecting phytoplankton community structure and spatial distributions in water from rivers discharged to the lake.