黄河口滨岸潮滩不同类型湿地土壤氮素分布特征

对黄河口滨岸潮滩不同类型湿地土壤氮分布特征进行了对比研究。结果表明,湿地土壤氮以有机氮为主,无机氮所占比例较低且以铵态氮为主。土壤氮水平分布特征明显,TN、NH4+-N和NO3--N含量较高的分别是芦苇湿地、碱蓬-柽柳湿地(过渡带)湿地和芦苇湿地;土壤氮垂直分布特征亦明显,表现为表层土壤氮含量大于下层,其中,TN、NH4+-N和NO3--N含量垂直变化最明显的分别是三棱蔗草-朝天委陵菜湿地、碱蓬湿地和芦苇湿地。影响土壤氮分布的主要因素有水分条件、植被类型及微生物活动等。相关分析表明TN与有机氮、有机质呈极显著正相关(P<0.01),NH4+-N与TP呈显著负相关(P<0.05)。研究发现,植被对调整湿地氮的空间分布有一定作用,从而为湿地生态修复提供了理论依据。

Spatial Distribution of Nitrogen in Different Wetlands' Soils in Intertidal Flat of Yellow River Estuary

A comparative study was carried out on soil nitrogen distribution characteristics in different wetlands in the Intertidal Flat of Yellow River Estuary.Results showed soil nitrogen in different wetlands was dominantly composed of organic nitrogen,while inorganic nitrogen content was low and mainly consisted of ammonium nitrogen.Soil nitrogen obviously distributed horizontally,and the contents of TN,NH4+-N and NO3——N were separately higher in Suaeda salsa-Tamatix chinensis Lour wetland(transition zone) and Phragmites australis wetland.The vertical distribution characteristics of soil nitrogen were also obvious,and surface layer was higher than subsoil.The most significantly vertical variation of total nitrogen was in Sparganiacea-P.supina L wetland,and ammonium nitrogen was in Suaeda salsa(L.)Pall wetland,and nitrate nitrogen was in Phragmitas communis Trin wetland.The main factors affecting the spatial distribution of nitrogen were moisture content,plant types and microorganisms.Correlation analysis showed total nitrogen was significantly positively correlated with organic nitrogen and soil organic matter(P < 0.01),ammonium nitrogen was negatively correlated with total phosphorus(P < 0.05).The research result showed that the distributions of N in wetland soils were affected by plants,and the research could provide theory for the restoration of ecosystem in wetlands.