黄河三角洲湿地盐生植物氮和磷的根际效应

通过比较黄河三角洲湿地三种盐生植物柽柳(Tamarix chinensisLour).、盐地碱蓬(Suaeda salsa Pall).和白茅(Imperata cylindrica Beauv.)的根际与非根际土壤中氮、磷的根际效应,分析了不同植物种类根际效应差异的原因。研究结果表明,三种盐生植物根际土壤总氮、速效氮以及有效磷的含量与非根际土壤相比均显著增加(p0.01),根际土壤的总磷含量也高于非根际土壤。柽柳植株对氮、盐地碱蓬植株对磷的富集作用最强,并表现出明显的根际累积效应,这一结果对于滨海湿地氮、磷污染截留的植物修复技术建立具有重要的指导意义。同时,造成不同植物种类的根际效应差别的原因不同,pH值是影响柽柳根际速效氮累积效应的主要原因,而盐地碱蓬根际有效磷累积主要受到根际微生物和盐度变化的共同影响。

Rhizosphere Effect of Three Halophytes in the Yellow River Delta on Nitrogen and Phosphorus

Rhizosphere effect of Tamarix chinensis Lour,Suaeda salsa Pall. and Imperata cylindrica Beauv. in the Yellow River Delta on nitrogen and phosphorus in rhizosphere was compared,and the differences were analyzed as well. Results showed that total nitrogen,available nitrogen and available phosphorus increased significantly in rhizosphere compared to those in bulk soils. Total phosphorus in rhizosphere was also higher than that in bulk soils. Nitrogen accumulated most strongly in Tamarix chinensis Lour. and its rhizosphere,while the phosphorus accumulated most strongly in Suaeda salsa Pall,and its rhizosphere. Results provided fundamental basis for the phyremediation of coastal wetlands,where the nitrogen and phosphorus could be intercepted by plants. Reasons for rhizosphere effect of three plants were not the same. The value of pH in rhizosphere was main factor affecting the cumulative effect of available nitrogen in rhizosphere of Tamarix chinensis Lour,while the activity of rhizospheric microorganism and salinity were the main factors for the cumulative effect of available phosphorus in rhizosphere of Suaeda salsa Pall.