鄱阳湖浮游植物功能群的长期变化特征(2009-2016年)

Long term dynamics of phytoplankton functional groups in Lake Poyang during 2009-2016

鄱阳湖是中国最大的淡水湖,每年都有剧烈的季节性水位变化.为了解鄱阳湖浮游植物功能群特征及其与环境因子的关系,2009—2016年每季度在鄱阳湖15个采样点采集水样,分析鄱阳湖的水质和浮游植物群落结构,并对浮游植物进行功能群划分.研究结果表明,鄱阳湖共检出浮游植物8门106属. 2009—2016年平均生物量分别为0.044、0.252、0.335、6.379、3.945、2.912、3.562和1.550 mg/L.硅藻门为鄱阳湖浮游植物的优势门类.鄱阳湖浮游植物可划分为27个功能群,其中15个功能群(C、D、G、H1、J、Lo、M、MP、N、P、S1、Tc、Wo、W1和Y)为优势功能群. 2009—2011年,功能群P、Y、MP、D为优势类群,2012—2016年,功能群P、Y、MP、H1、Lo为优势类群.鄱阳湖浮游植物优势功能群不同水文阶段的演替规律为:枯水期P、MP、Y、Lo、D,涨水期P、Y、D、MP、H1,丰水期P、Y、D、MP、Lo、H1,退水期P、Y、MP、G. RDA分析结果显示,水位变化、水温、透明度、电导率、悬浮物浓度和亚硝态氮浓度是影响鄱阳湖浮游植物功能群的主要环境因子.

Lake Poyang is the largest freshwater lake in the Yangtze floodplain in China,with dramatic seasonal water level changes each year.The objective of the paper is to show the characteristics of phytoplankton functional groups and their relationship with environmental factors.Samples of water quality and phytoplankton were quarterly taken and analyzed at 15 sampling stations of Lake Poyang from 2009 to 2016.The phytoplankton function groups of phytoplankton were analyzed.The phytoplankton community structure and functional group characteristics of Lake Poyang were analyzed from 2009 to 2016.The results show that the phytoplankton in Lake Poyang can be divided into 27 functional groups,15 of which (C,D,G,H1,J,Lo,M,MP,N,P,S1,Tc,Wo,W1 and Y) are dominant.Functional groups P,Y,MP,and D were dominant in 2009 to 2011.Functional groups P,Y,MP,H1,and Lo were dominant in 2012 to 2016.The successional routine of dominant phytoplankton functional groups in different phases are P,MP,Y,Lo,D in low water level phases,P,Y,D,MP,H1 in increasing water level phases,P,Y,D,MP,Lo,H1 in high water level phases and P,Y,MP,G in decreasing water level phases.RDA results showed that water level changes,water temperature,transparency,conductivity,suspended solids and nitrite are the most important environmental factors of phytoplankton functional groups in Lake Poyang.