南太湖水体叶绿素a含量与氮磷浓度的关系

在2007年6月-2008年4月对南太湖近岸水域4个航次生态环境调查的基础上,进行了叶绿素a含量（CHL-a）与总氮（TN）、总磷（TP）浓度及氮磷比（N/P）关系的统计分析。结果表明：南太湖水体中CHL-a含量与TN浓度的关系存在显著的季节差异,在蓝藻水华大范围爆发的2007年6月和2008年4月两者呈高度显著的正相关,而2007年10月和2008年1月两者无显著性关系;CHL-a含量与TP浓度在4次调查中皆无显著性关系;岭回归分析显示,N/P在10~25之间是南太湖水体中附着藻类的最佳生长范围,此时总氮、总磷浓度及氮磷比与CHLa含量呈显著的正相关,四者的多元回归关系为（CHL-a）=-0.001 2＋0.0064×（TN）＋0.0215×（TP）＋0.0005×（N/P）（R=0.543,P〈0.023）。总体来说,南太湖水体中的总氮、总磷浓度及氮磷比皆在藻类生长的适宜范围内,氮磷浓度处于较高水平,已经不是藻类生长的限制因素,在不同水温、光照等环境因子的作用下,加入本水域复杂的水文、季风共同影响下形成了蓝藻水华爆发的季节性差异。

Relationship Between Chlorophyll a Content and TN and TP Concentrations in Water Bodies of South Taihu Lake

The relationships between the chlorophyll a（Chl-a） content and total nitrogen（TN）,total phosphorus（TP） concentrations and The ratio of TN vs TP（N/P） in water bodies of south Taihu lake were investigated in the south of Taihu lake.Seasonal variations in the relationship between the Chl-a content and TN was observed in the statistic.The Chl-a content increased with increasing TN concentration when they in June 2007 and April 2008,and had no significant correlation in October 2007 and January 2008.The Chl-a content had no significant correlation with TP in all season.Ridge regression analysis showed that the Chl-a content increased with increasing TN concentration,TP concentration and N/P,when the favorable water body′s ratio of nitrogen vs phosphorus for algae growth in south Taihu lake（between 10 and 25）,the relationship as follows：（Chl-a）=-0.001 2＋0.006 4×（TN）＋0.021 5×（TP）＋0.000 5×（N/P）（R=0.543,P0.023）.As a whole,there had the favorable water body′s TN and TP concentrations for algae growth in south Taihu lake,and observed Seasonalvariations in the relationship between the biomass of algae and nutrient by envionment factors such as temperature,light,hydrological and monsoon.