Abstract: 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 cripus 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,reching 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 the Potamogeton cripus can effectively control phosphorus pollution in lake with or without dredging.

Key words: Potamogeton crispus, sediment, interstitial water, phosphorus form