乐安江重金属污染对浮游植物群落结构的影响

１９９３年和１９９４年对乐安江６个采样站浮游植物的两次调查结果表明，藻类的群落结构因不同河段水质状况不同而不同：未受矿山废水污染的上游海口站，藻类多样性指数较高，密度较低，优势种多为清洁神和耐中污的种类，水质较好；接纳大量矿山及采矿化工废水和生活污水的沽口站，藻类受到明显抑制，多样性指数极低，耐污种占绝对优势，水质极差；随流程和净化时间的延长，下游各站藻类的种类、数量、多样性指数、种类数比均不断上升，优势比不断下降，体现出明显的水质净化趋势．乐安江水体Ｃｕ２＋浓度与藻类的种类、数量、种类多样性指数、种类数比呈负相关的关系，Ｃｕ２＋浓度与藻类的优势比呈正相关关系；ｐＨ值与上述指标关系正好与Ｃｕ２＋所呈现的关系相反．藻类群落结构在春季丰水期与秋季枯水期的变化表明，春季乐安江水质好于秋季．

A STUDY ON THE EFFECT OF HEAVY METAL POLLUTION ON PHYTOPLANKTON COMMUNITY STRUCTURE IN THE LEAN RIVER

The algal communities and water quality in the different perts of the Lean River polluted by heavy metals due to mining activities were studied in May of 1993 and October of 1994,respectively.The results indicated that 6 sampling sites with different water quality showed a great difference in algal communitystructure.Haikou site with clean water in the upper reaches showed high species richness,low individual abundance,hish biodiversity index and many indicator species as clean water plants.In Gukou station with very poor water quality polluted by mining,alsal speces richness and diversity index declined obviously and tolerant species became absolutely dominant.The dramatic increases in number of species,individual abundance and biomass were found at the two stations in the lower reaches as compered with the polluted station.The species richness)individual abundance,diversity index and dominant ratio were well correlated with the concentration of heavy metals and pH value in the water.