抚仙湖、洱海、滇池浮游藻类功能群1960s以来演变特征

Historical changes of phytoplankton functional groups in Lake Fuxian,Lake Erhai and Lake Dianchi since 1960s

作为主要的初级生产者,浮游植物在水生生态系统中扮演着重要的角色,浮游植物的时空分布反映了生态环境的变化.依据浮游植物的形态、生理、生态特点而定义的浮游藻类功能群对藻类的耐受性和敏感性进行了描述,因而浮游藻类功能群的组成是生境特征的良好指示者.对1960s至今抚仙湖、洱海、滇池3个高原湖泊的浮游藻类组成进行分析,并首次将功能群理论运用到这3个湖泊.结果表明,3个湖泊的浮游藻类优势功能群组成在近50～60年间发生了明显的改变：抚仙湖的浮游藻类优势功能群演变过程为C、X2、Lo、F、P（1960s）-H1、C、P（1980s）-P、C、T（1990s）-T（2000年以后）;洱海的浮游藻类优势功能群演变过程为J、Lo、MP、C、H1（1960s）-C、H1（1980s）-C、H1（1990s）-C、H1、M（2000年以后）;滇池的浮游藻类优势功能群演变过程为J、N、P、MP、Lo（1960s）-J、P、MP、M（1980s）-J、M（1990s）-M（2000年以后）.抚仙湖、洱海、滇池水体内的藻类功能群演替趋势特征,即耐低温物种的减少以及喜营养物种的增加,表明3个高原湖泊在近几十年可能受到了气候变暖和营养程度增加的影响.

Phytoplankton is one of the major primary producers and plays important roles in the aquatic ecosystems.The temporal and spatial variations of the algae could reflect the environmental dynamics.In light of the morphological,physiological and ecological characteristics of algae,phytoplankton functional groups theory was applied first time for these lakes to describe the tolerance and preference of algae in detail.The phytoplankton assemblages were considered to be good indicators of environmental conditions.The data of phytoplankton composition dated from the 1960s was collected and analyzed for Lake Fuxian,Lake Erhai and Lake Dianchi,respectively.Great changes have taken place in phytoplankton assemblages in the three lakes during the past 60 years.The historical change of dominant phytoplankton functional groups was demonstrated as C,X2,Lo,F,P （1960s）-H1,C,P （1980s）-P,C,T （1990s）-T （after 2000） for Lake Fuxian; J,Lo,MP,C,H1 （1960s）-C,H1 （1980s）-C,H1 （1990s）-C,H1,M （after 2000） for Lake Erhai; J,N,P,MP,Lo（1960s）-J,P,MP,M （1980s）-J,M （1990s）-M （after 2000） for Lake Dianchi.The reduction of low-temperature tolerance species and increase of high-nutrition preference species dated from the 1960s might give some indication of the environmental changes of warmer temperature and nutrients increases in the three lakes.