【摘要】 富营养化和风浪是影响大型浅水湖泊浮游植物群落的重要因素,本文于2003年10月至2004年9月对太湖梅梁湾和五里湖理化环境因子(水温、透明度值、悬浮质浓度和氮、磷营养盐浓度)和浮游植物群落进行了逐月监测,通过对两个湖区理化因子和浮游植物群落结构在周年内季节变化的比较研究,探讨富营养化程度以及风浪对浮游植物群落结构的影响,结果为:(1)梅梁湾由于受风浪影响悬浮物含量较高,五里湖则富营养化水平更高.(2)周年内五里湖浮游植物平均生物量(6.85 mg/L)高于梅梁湾的平均生物量(4.99 mg/L),两个湖区都呈现夏秋高峰、冬季低谷的变化特征.梅梁湾浮游植物群落季节演替的模式基本为:冬季硅藻(小环藻属Cyclotella spp.)和隐藻(隐藻属Cryptomonas spp.)-春季绿藻(细丝藻属Planctonema sp.)-夏季绿藻(绿球藻目Chlorococcales种类)和蓝藻(微囊藻属Microcystis spp.和浮游蓝丝藻属Planktothrix spp.)-初秋蓝藻(微囊藻属)和硅藻(浮游直链硅藻Aulacoseira spp.)-秋季隐藻(隐藻属).五里湖的季节演替模式没有梅梁湾明显,全年隐藻(隐藻属)都占优势,在此基础上,秋冬季硅藻(小环藻属和浮游直链硅藻属)占优势,裸藻(裸藻属Euglena spp.)在冬春季占优势,绿藻(绿球藻目种类和团藻目衣藻属Chlamydomonas spp.)在整个春季和初夏的优势地位在夏季被蓝藻(微囊藻属和浮游蓝丝藻属)所取代.群落构成的差异是浮游植物对两个湖区不同风浪条件和富营养化水平的响应结果.(3)通过与PEG(Plankton Ecology Group)模式的比较,梅梁湾和五里湖浮游植物群落的季节演替主要受水温、光照、营养盐(氮、磷)浓度和浮游动物牧食等因子的影响,因此,大型富营养化浅水湖泊浮游植物群落演替规律需要进一步的研究.更多还原

【Abstract】 Eutrophication and wave action caused by wind are two important factors determining the phytoplankton structures in large shallow lakes.Based on the investigations from October 2003 to September 2004 in Meiliang Bay and Lake Wuli,situated in the northwest of Lake Taibu,the third large shallow lake in China,the spatial distribu- tion and seasonal variation of environmental variables and phytoplankton community were analyzed to test if trophic level and wave action caused by wind were important for phytoplankton community.The results showed that:(1) Meiliang Bay and Lake Wuli were different in trophie states and wave action caused by wind,the former was more severely affected by wind and the latter was more eutrophic.(2)The annual mean of the total phytoplankton bio- mass in Lake Wuli(6.85 mg/L)was much higher than that in Meiliang Bay(4.99 mg/L).The monthly mean reached the maximum in summer and autumn while the minimum in winter in both hays.Seasonal variation of domi- nant phytoplankton assemblages and species in Meiliang Bay was as follows:Bacillariophyta(Cyclotella spp.)and Cryptophyta(Cryptomonas spp.)in winter,Chlorophyta(Planctonema sp.)in spring,Chlorophyta(genera of Chlo- rococeales order such as Scenedesmus spp.and Pediastrum app.et al.),Cyanobacterias(Microcystis app.and Planktothrix spp./Oscillatoria spp.),Bacillariophyta(Aulacoseira spp./Melosira spp.)in summer,Cryptophyta (Cryptomonas spp)in autumn,while the seasonal succession in Lake Wuli was somehow vague.Cryptophyta (Cryptomonas spp.)dominated throughout the year.Sub-dominant or co-dominant species are Bacillariophyta(Aul- acoseira granulate and CycloteUa spp.)in winter,Chlorophyta(genera of Chlorococcales order and Chlamydomonas spp.)in spring,Cyanobacterias(Planktothrix spp.and Microcystis spp.)and Euglenophyta(Euglena spp.)in summer,Bacillariophyta(Aulacoseira spp.)in antumn.The difference of phytoplankton community between two bays was resulted mainly from their eutrophic station and wave action caused by wind.(3)Compared with classical PEG(Plankton Ecology Group)model,the seasonal succession of phytoplankton community in Meiliang Bay and Lake Wuli showed some similar rules and they were mainly affected by water temperature,light,nutrient(nitrogen and phosphorus)and the grazing of zooplankton.However,the succession may fluctuate due to the effect of eu- trophication and wave action caused by wind.More studies are needed to understand seasonal succession of phyto- plankton community in large eutrophic shallow lakes.更多还原