Dynamic changes of the retention capacity for phosphorus by emergent macrophytes in the Yeyahu Wetland
野鸭湖湿地挺水植物磷素截留量动态变化分析

The Yeyahu Wetland is located upstream of the Guanting Reservoir, which plays a significant role in reducing nutrient inputs and preventing eutrophication. In this paper, the distributions of four dominant emergent macrophytes communities in the wetland were investigated, and the seasonal dynamics of plant biomass and phosphorus contents were also analyzed. The dynamic changes of total phosphorus retention capacities by four emergent macrophytes were accordingly determined. Results show that Zizania aquatica. presented the highest phosphorus content in shoots, followed by Typha latifolia., Scirpus planiculmis. and Phragmites australis., while the phosphorus contents in roots ranked as Zizania aquatica.>Scirpus planiculmis.>Typha latifolia.>Phragmites australis.. The phosphorus contents in roots and shoots of the four macrophytes both decreased through the plant life cycle. Significant disparity was shown among the phosphorus storage capacities of the four macrophytes, which were 4910 g·m-2 of Zizania aquatica., 4140 g·m-2 of Typha latifolia., 2190 g·m-2 of Scirpus planiculmis. and 1390 g·m-2of Phragmites australis., respectively. The total phosphorus retention capacities in the study area showed a maximum value of 2210.8 kg in summer and a minimum value of 1263.5 kg in winter. The mean value of the phosphorus retention capacities decreased gradually along the upper, middle, and lower reaches of the wetland.