Seasonal Dynamics of Nitrogen,Phosphorus and Biomass of Phragmites commuis at Mengqingyuan Garden Artificial Wetland in Shanghai

Dynamics of nitrogen,phosphorus and aboveground biomass of Phragmites commuis were studied in pilot-scale in Shanghai Mengqingyuan surface flow wetland.Dynamics of nitrogen,phosphorus and the aboveground biomass of Phragmites communis showed single-peak curve and seasonal change obviously.The maximum values of nitrogen,phosphorus in leaf and aboveground parts of Phragmites commuis appeared in late October or early November,but the contents of nitrogen,phosphorus in stem of Phragmites commuis reached peak values in middle December.The aboveground biomass of Phragmites commuis was biggest in late October or early November too,being 6 624 g·m-2 at October 21st.So,it was the best time to harvest Phragmites commuis in late October or early November when the content of nitrogen and phosphorus and the aboveground biomass of Phragmites commuis reached maximum values.