红枫湖水库浮游植物演变(1980—2006年)和富营养化趋势研究

根据1980年、1990年、1995年、1997年、1998年、2005年、2006年等年份对红枫湖的调查资料,总结了过去26年来红枫湖水库浮游植物种类组成、数量、优势种类、多样性指数等的主要变化:浮游植物年平均数量在26年内由每毫升几百个增为几万个,夏季为藻类数量的高峰期,蓝藻数量始终占优势,绿藻和硅藻数量变化不大。种类上始终以绿藻和蓝藻占优势,硅藻次之,藻类种类趋于小型化。以浮游植物群落的生态学变化作为主要指标,对红枫湖水库的富营养化过程进行了生物学评价。红枫湖水库26年来的富营养化过程是贫营养至中度富营养—富营养—重富营养,污染过程是轻污染至β-中污染之间—中污染—重污染状态变化,近年红枫湖水库水体有向中污染转变的趋势。

Ecological changes of phytoplankton(1980-2006) in Hongfeng Lake and the study of eutrophica trend

Summarizing the data of surveys made in Hongfeng Lake in 1980,1990,1995,1997,1998,2005 and 2006,this paper discusses the main ecological changes of species composition,biomass,seasonal variation and biodiversity index of past 26 years.The average annual abundance of planktonic algae increased from hundreds to ten thousands of cells per ml of water.There was a highest biomass in summer and a marked biomass increase of Cyanophyta.The dominance of biomass was Cyanophyta from 1980 to 2006;the change of biomass of Chlorophyta and Bacillariophyta was not large.The species of Chlorophyta and Cyanophyta was dominant from 1980 to 2006,then Bacillariophyta.The species of phytoplankton tended to be miniaturized.Based on ecological changes of phytoplankton association as the main parameter,a biological assessment of eutrophication process in Hongfeng Lake at its present stage can be regarded as medium eutrophication—eutrophication—severe eutrophication,The process of pollution was light pollution to β-middle pollution—medium pollution—heavy pollution from 1980 to 2006.The trend of pollution was medium pollution in recent years.