野鸭湖湿地挺水植物磷素截留量动态变化分析

野鸭湖湿地位于官厅水库上游,在截留养分、预防水库水体富营养化方面发挥着重要作用.通过野鸭湖湿地中4种优势挺水植物(茭白、扁秆藨草、香蒲、芦苇)的分布区域研究,分析了植物生物量及养分元素磷含量随季节的动态变化特征,得到了研究区域内4种挺水植物对磷素截留总量的动态变化.结果表明,研究区域内4种优势挺水植物地上部分磷含量为茭白>香蒲>扁秆藨草>芦苇;地下部分磷含量呈现茭白>扁秆藨草>香蒲>芦苇的分布特点;4种植物的地上部分和地下部分磷含量均随生长季节而降低;4种植物的单位面积磷素蓄积能力存在明显差异,表现为茭白>香蒲>扁秆藨草>芦苇的规律,其单位面积蓄积峰值依次为4910、4140、2190和1390g.m-2;研究区域内挺水植物磷素蓄积总量在夏季达到峰值2210.8kg,最小值出现在冬季,为1263.5kg;区域内上、中、下游挺水植物的磷素截留总量依次递减.

Dynamic changes of the retention capacity for phosphorus by emergent macrophytes in the Yeyahu Wetland

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.