不同温度条件下徒骇河沉水植物腐烂对上覆水体中营养盐浓度的影响

Impacts of decomposition of submerged plants on nutrient concentrations in overlying water in Tuhai River under different temperatures

通过实验室模拟方法,研究高、低温条件下徒骇河两种优势沉水植物腐烂对上覆水体中营养盐浓度的影响。结果表明:菹草和金鱼藻的腐烂分解导致水体的pH值呈现下降→上升的变化趋势;沉水植物腐烂分解使上覆水体中总氮、总磷浓度增加;在27℃下,上覆水体中的氮磷浓度均表现为上升→下降趋势;而在10℃下,上覆水体中的氮浓度持续上升,磷浓度表现为上升→下降趋势,在低温条件下氮磷含量的累积均明显高于高温条件。

Using the method of laboratory simulation,the impacts of the decomposition of two dominant submerged plants in Tuhai River on the nutrient concentrations in the overlying water under different temperatures were studied.The results show that in the decomposition process of Potamogeton crispus and Ceratophyllum demersum,the pH value of the overlying water declines and then rises,and the concentrations of total nitrogen and total phosphorus in the overlying water significantly increase.At the high temperature of 27℃,the concentrations of nitrogen and phosphorus in the overlying water both increase at the beginning of the decomposition and then decline.At the low temperature of 10℃,the concentration of phosphorus in the overlying water also increases firstly and then decreases.However,the nitrogen concentration continuously increases,and the accumulation of both phosphorus and nitrogen in the overlying water at 10℃ is obviously higher than that at 27℃.