于2009年1月至12月对淀山湖浮游藻类生物量及水体中N、P营养元素含量进行连续监测,并利用典范对应分析(CCA)对浮游藻类种类分布与环境营养因子间的相关性进行研究.结果表明:淀山湖全年藻类生物量呈现两次大规模增长时期,分别为春季的4月份(以绿藻为主)和初秋的8月份(以蓝藻为主),其中春季藻类群落最大生物量(39.68 mg/m3)明显高于秋季(29.86 mg/m3);不同季节藻类生物量与水体氮、磷营养物质含量间具有一定的相互影响关系,冬季(11-1月)以硅藻和绿藻为优势种群的藻类群落,其生物量与水体总磷含量呈显著相关性,夏季(5-8月)蓝绿藻种群占优势时,藻类群落生物量则与水体氨氮浓度变化显著相关,然而在春季(2-3月)及秋季(9 10月)藻类的两次大规模增长时期,水体N、P含量的增加却并不能明显促进藻类生长,总磷与硝态氮之间存在一定的交互作用.
The phytoplankton biomass and concentrations of N and P in Lake Dianshan were investigated from January to December, 2009, and relationship between phytoplankton distribution and nutritional factors was correlated by Canonical Correspondence Analysis. The results showed that there were two biomass peaks of phytoplankton within a year in Lake Dianshan. The one peak was in spring (March and April), and the other in autumn (August). The biomass of phytoplankton in spring (39.68 mg/m3 )was higher than that in autumn ( 29.86 mg/m3 ). There were significant relationships between the nutrient concentrations and algae biomass in different seasons. The growth of phytoplankton was limited by phosphorus when the baeillariophyta and ehlorophyta were dominant in Lake Dianshan from November to January. However, the growth of phytoplankton was limited by ammonium when the eyanophyta and chlorophyta were dominant in the lake from May to August. The higher nitrogen and phosphorus concentrations cannot significantly accelerate the growth of phytoplankton during the two outbreak periods of February-March and September-October, because there were interacted effects between nitrate and phosphorus.