生活污水处理场主要湿地植物吸氮纳磷的生态功能

The Ecological Function of Nitrogen and Phosphorus Accumulations for Six Wetland Plants in Domestic Sewage Treatment Plant

利用原位定点观测方法,研究梭鱼草、鸢尾、美人蕉、芦苇、菖蒲和香根草6种人工湿地植物的根、茎、叶氮、磷浓度及其化学计量的季节变化。结果表明:(1)6种植物体不同部分氮、磷浓度分别介于14～51mg/g和1.4～6.2mg/g,均具有较强的氮、磷吸收能力,除香根草外,其它植物地上部分氮、磷浓度均高于地下部分(P<0.05);(2)植物体单位面积根、茎和叶的氮、磷贮量与植物生物量呈正比,且地上部分高于地下部分,故收割植物地上部分是去除生活污水氮、磷含量的有效途径;(3)鸢尾叶片N∶P比值大于16,梭鱼草在14～16,其余小于14,且芦苇、菖蒲和香根草氮、磷贮量较高,故推荐后3种植物为该生活污水处理场的优先选择物种。

Seasonal variations of N and P concentrations and N：P ratios in roots,stems and leaves were studied on six wetland plant species including Pontederia cordata,Iris germanica,Canna indica,Phragmitas communis,Acorus calamus Linn and Vetiveria zizanoides using in situ observation method. The results showed：（1） The N and P concentrations in different parts of the six plant species are between 14~51 mg/g and 1.4~6.2 mg/g,respectively. All the selected species have strong ability of N and P accumulation. The N and P concentrations are higher in the aboveground part than in the under ground part except Vetiveria zizanoides （P0.05）. （2） The N and P storages per m2 of all the plants are positively related with their biomass and higher in the aboveground part than in the under ground part,which indicates that it is an effective pathway to remove N and P accumulations with harvesting the plant above ground parts in domestic sewage.（3）The N：P ratio of Iris germanica is higher than 16,the ratio of Pontederia cordatais is between 14 and 16,while the ratios of other species are lower than 14. Additionally,the N and P storages are higher in Phragmitas communis,Acorus calamus Linn and Vetiveria zizanoides than in Iris germanica and Pontederia cordatais. Thus the authers suggest that the three species mentioned afore would be preferential species to plant in this domestic sewage treatment plant.