苏州城市河道滞流水体浮游植物常见属生态位研究

Study on phytoplankton predominant species niche in stagnation water of Suzhou City

采用Colwell公式、余世孝和Pianka公式计算了苏州城市河道滞流水体浮游植物常见属的生态位宽度、二维（TN，TP）生态位中心点、一维（NH3-N）生态位中心点及生态位重叠。结果表明：重污染河道中蓝纤维藻、十字藻、卵囊藻、栅藻、小环藻的生态位宽度值较大，色球藻和蓝隐藻的生态位宽度值较小；蓝纤维藻、十字藻、卵囊藻、栅藻、小环藻、隐藻和蓝隐藻占据二维（TN，TP）生态空间的中心，而色球藻、颤藻和直链藻占据生态空间边缘；色球藻和颤藻的生态位重叠值最小，蓝纤维藻和十字藻生态位重叠值最大。在苏州城市河道中，氮磷浓度偏高，氨氮含量较大的情况下，绿藻门的生态位宽度普遍较大，各属种与其它各门的生态重叠值也均较高，与蓝藻相比具有竞争优势。

In this paper, niche breadth, two-dimensional （TN, TP） niche center point, one-dimensional （NH3-N） niche centerl point and niche overlap of the phytoplankton dominant species in the Suzhou city River stagnation water were measured using Colwell, Shi-Xiao Yu and Pianka formula. The results showed that： the niche breadth of Raphidiopsis sp., Crucigenia, OOcystis, Scenedesmus, Cyclotella was greater and Chroococcales and Chroomonas was smaller in the heavily polluted fiver; Raphidiopsissp sp., Crucigenia, Oocystis, Scenedesmus, Cyclotella Chroomonas, Crypromonas occupied two-dimensional （TN, TP） ecological space center, and Chroococcales, Dactylococcopsis and Melesira occupied brink; the niche overlap of Chroococcales and Dactylococcopsis was the smallest, the niche overlaps of Raphidiopsis and Crucigenia was the largest. In the Suzhou city river, under the situation of high concentration of nitrogen and phosphorus, high ammonia nitrogen content, the niche breadth of green algae was generally larger, and the ecological niche overlap was also higher, and they had competitive advantage as compared with blue-green algae.