In order to explore the migration and transformation of phosphorus in sediments and variation of water quality from beach plants.The mechanisms of root exudates to the phosphorus in the sediments

the phosphorus exchange of the beach plants-sediment system at different water level

the speciation of phosphorus in the sediments at different growth phases of beach plants

the number and types of microorganisms from the rhizosohere

the adsorption of phosphorus by the Fe and Mn plaques

the absorption and transformation of phosphorus when plants growing would be studied.Then the effects of beach plants on the exchange of phosphorus in the sediments would be revealed.Theoretical basis and technical support for restoring the eutrophicated lakes and the damaged lake wetlands would be provided.