长江中下游地区湖泊中蓝藻及其与氮磷浓度的关系

Cyanobacteria Genus and its Relationship with Nitrogen and Phosphorus Concentration in Lakes along the Middle and Lower Reaches of the Yangtze River

根据对长江中下游地区30个浅水湖泊的调查,分析了蓝藻的群落结构特征及其与环境中氮磷浓度的关系。研究显示蓝藻生物量生长季节比非生长季节高很多,生长季节最大值出现在三角湖(5.719 mg/L),最小值出现在天鹅洲(0.001 mg/L)。半通江湖泊蓝藻生物量高于其他类型湖泊;生长季节,蓝藻生物量占浮游植物总生物量比例在半通江湖泊和城郊湖泊均大于40%,而在通江湖泊和城市湖泊均不到20%;半通江湖泊最大,之后依次为城郊湖泊、通江湖泊和城市湖泊。氮磷比无论生长季节还是非生长季节在大部分湖泊均低于40。对蓝藻优势类群与氮磷浓度进行Pearson相关性分析结果显示,在生长季节仅集胞藻属(Synechocystis)与总磷极显著正相关(P<0.01);在非生长季节,集胞藻属与氨氮、亚硝酸盐氮、总磷极显著正相关(P<0.01),与硝酸盐氮显著相关(P<0.05),蓝纤维藻属(Dactylococcopsis)与氨氮、亚硝酸盐氮、总磷极显著正相关(P<0.01)。

According to the investigation on the thirty shallow lakes in the middle and lower reaches of the Yangtze River, the community structure characteristics of cyanobacteria in these lakes and its relationship with the concentration of nitrogen and phosphorus were analyzed .The results showed that the biomass of cyanobacteria in growth season was higher than non-growth season, with the maximum value （5.719 mg/L） in Sanjiao Lake and the minimum value （0.001 mg/L） in Tian′ezhou.The biomass of Cyanobacteria in lakes half-connected with river was sig-nificantly higher than other types of lakes .In half-connected lakes and suburban lakes , the biomass accounted for more than 40%of the total phytoplankton biomass during growth season , while which was less than 20% in connected and urban lakes , with the order of lakes from high to low as follows：half-connected lakes , suburban lakes , connected lakes and urban lakes .The N/P ratio in most of the lakes was lower than 40 both in growth season and non-growth season .Pearson correlation analysis of cyanobacteria dominant groups and concentration of nitrogen and phosphorus showed that only Synechocystis presented significantly positive correlation with total phosphorus （P〈0.01） in growth season, while in non-growth season, Synechocystis and Dactylococcopsis both presented significantly positive correlation with ammonia nitrogen , nitrite nitrogen and total phosphorus （P〈0.01）, furthermore, Synechocystis also had positive correlation with nitrate nitrogen （ P〈0 .05 ） .