不同生态带下盐城滩涂湿地土壤颗粒和矿物结合有机碳特征

通过对比不同生态带下盐城滩涂湿地表层土壤中颗粒有机碳(POC)和矿物结合有机碳(MOC)含量与分布,探讨不同生态带下滩涂植被对土壤环境特别是土壤有机质组分分布及其累积的影响。结果表明:不同生态带的滩涂湿地表层土壤总有机碳(TOC)和总氮(TN)含量分布规律为:芦苇地互花米草滩盐蒿滩光滩,反映了盐城滩涂湿地土壤由海向陆土壤质地由砂到粉砂,最后为粘土的变化规律;互花米草滩对土壤有机质有着比光滩和盐蒿滩更高的富集能力,芦苇地的颗粒有机碳(POCf+POCo)含量为4.17 g/kg,互花米草滩的POC含量为2.14 g/kg,远高于盐蒿滩(1.92 g/kg)和光滩(0.31 g/kg)。互花米草的引种从有机碳物理分级组分上改变了TOC的分配,有利于提高土壤中游离态颗粒有机物、闭蓄态颗粒有机物的含量以及占土壤有机碳的比例。该研究能够为沿海滩涂湿地碳存储和固碳潜力以及评价和保护湿地生态系统提供一定的科学依据。

Organic Carbon Characteristics of the Particulate Organic Carbon and Mineral-associated Organic Carbon in Yancheng Soils in Different Ecological Zones

The contents and distribution of the particulate and mineral-associated organic carbon(POC and MOC) in Yancheng soils in different ecologic zones were investigated,and the effects of vegetation on soil environment,especially the organic matter composition and accumulations were also discussed.Results indicated that the total organic carbon(TOC) and total nitrogen(TN) in Phragmiues auszradis marshes were higher than those in other ecological zones,and decreased from Phragmiues auszradis marshes to Spartina alterniflora marshes,Artemisia schrenkiana marshes and sandy marshes.This trend of distribution and accumulation shows changes in soil texture with sandy-silty sandy-clays from sea to continent.Particulate organic carbon(POCf + POCo) was 4.17 g/kg in Phragmiues auszradis marshes and 2.14 g/kg in Spartina alterniflora marshes,which were far higher than 1.92 g/kg in Artemisia schrenkiana marshes and 0.31 g/kg in sandy marshes.The introduction of Spartina alterniflora in coastal wetland changed the distribution of TOC in physical fractions,which is benefitial to the increase of the concentrations of soil POCf and POCo and the ratio of soil organic carbon compositions.This research can provide a certain scientific basis for further study of carbon storage and sequestration potential in coastal wetland as well as for the evaluation and protection of wetland ecosystems.