三江平原典型湿地土壤腐殖质的剖面分布及其组成特征

以三江平原腹地挠力河、别拉洪河、浓江河流域自然沼泽湿地为研究对象,研究了典型湿地土壤腐殖质的剖面分布及其组成特征,并探讨了土壤腐殖质与植被类型及土壤全氮含量的关系。三江平原典型湿地土壤草根层和泥炭层中胡敏酸(HA)和富里酸(FA)的累计含量在整个剖面总量中的比例均大于70%,各组分相对含量分别高于35%总有机碳和23%总有机碳,其剖面分布与土壤有机碳(SOC)的变化趋势一致,由表层向下层逐渐减少。除小叶章湿地土壤草根层HA/FA值为0.97外,三江平原典型湿地土壤HA/FA均大于1,其剖面均值为1.4~2.5,表明三江平原湿地为胡敏酸型土壤.腐殖质各组份含量及其HA/FA值因植被类型而异,而与土壤全氮含量呈显著线性相关(p<0.05)。

Humus Distribution and Fraction of Typical Marsh Soil Depth Profiles in the Sanjiang Plain

The distribution of humus in typical marsh soil sections and the characteristic of humus fraction were studied in the drainage basins of the Naoli River,Bielahong River and Nongjiang River in the hinterland of the Sanjiang Plain.The relationship between marsh soil humus,vegetation,and soil total nitrogen(TN) were also discussed in this paper.The relative contents of humic acid(HA) and fulvic acid(FA) of root layer and peat layer were more than 35% and 23% of total soil organic carbon(SOC),respectively,and the accumulative contents of HA and FA of two soil layers exceed 70% of whole profile contents.As the changes of SOC in the soil profiles,soil humus contents trended to reduce from top layer to sublayer.Besides root layer of Calamagrostis angutifolia marsh soil with an average of HA/FA being 0.97,the mean values of HA/FA in other marsh soil sections were 1.4-2.5,which indicates that marsh soil in the Sanjiang Plain belongs to a humic acid enriched soil.Humus fractions and HA/FA were different among the marshes with different vegetations and it was significantly related to TN(p<0.05).