菹草生长对沉积物间隙水中各形态磷浓度的影响

摘要

通过人工构建湖泊生态系统,用湖泊沉积物的上层泥和下层泥分别代表清淤前后的2种基质,研究菹草(Potamogeton crispus)生长对沉积物不同层次间隙水中各形态磷浓度的影响.垂直方向上,将2种基质中的间隙水分为表层、中层和底层3个层次.结果表明,菹草生长能够不同程度地降低各层间隙水中磷浓度,上层泥和下层泥2种基质均表现为表层间隙水溶解性总磷(DTP)和溶解性活性磷(SRP)含量降低幅度最大,DTP含量分别降低68.97％和83.09％,SRP含量分别降低54.57％和96.02％.菹草的吸收作用使得各层间隙水中磷浓度均低于无沉水植物的对照组.试验结束时,2种沉积物中TP含量降低幅度差异不显著,说明疏浚前后种植菹草均可有效控制湖泊内源磷污染.%Phosphorus in the interstitial water of sediment is a major nutrient supply for submerged macrophytes. To study effects of Potamogeton crispus growth on concentrations of different species of phosphorus in the interstitial water of sediments , an artificial lake ecosystem was established using the upper layer and lower layer of lacustrine sediments as the two substrates before and after desilting and Potamogeton crispus was cultured in winter. The interstitial water in each of the two substrates was vertically divided into three layers, I. E. Overlying layer, middle layer and bottom layer. Results show that growth of Potamogeton crispus reduced phosphorus concentrations in the interstitial water in all the layers to a varing degree. The decrease rate in dissolved total phosphorus (DTP) and soluble reactive phosphorus (SRP) was the most significant in the overlying layers of the two substrates, reaching 68. 97% and 83. 09% for DTP, and 54. 57% and 96. 02% for SRP, respectively. At the end of the experiment, the decrease in total phosphorus (TP) was not significant in the two substrates, indicating that Potamogeton crispus can effectively control phosphorus pollution in lake with or without dredging-