Effect of Aquatic Macrophytes in Tidal Wetlands on the Total Nitrogen and Total Phosphorus

The field experimental region which was 9 048 m2 was built in the inner river of Zhengjiang on August in 2006 and different types of aquatic macrophytes containing emergent plant community,submerged plant community and floating plant community were introduced in order to monitor and research the effects of different types of aquatic macrophytes on removing the total nitrogen and the total phosphorus in water body.The result shows that total nitrogen content in the inflow side was 1.13 mg/L and in the different outflow side was 0.67 mg/L,0.52 mg/L,0.43 mg/L respectively.The removal efficiency was different in three aquatic macrophytes community and the order was the emergent plant communityfloating plant communitysubmerged plant community.The total phosphorus of water body was influenced significantly by aquatic macrophytes.The total phosphorus content after running through the emergent plant community,floating plant community and submerged plant community was 0.13 mg/L,0.09 mg/L,0.06 mg/L respectively.In general,aquatic macrophytes could remove the total nitrogen and the total phosphorus obviously,and different plant communities have played a positive role in prevention of water eutrophication.