Particulate Organic Carbon and Mineral-Associate Organic Carbon in Soils of Different Ecologic Zones of a Coastal Wetland

Abstract

Concentration and distribution of particulate organic carbon (POC) and mineral organic carbon (MOC) in soils of different ecological zones of Yancheng coastal wetland were investigated, and the effects of vegetation on soils environment, such as the accumulations and characteristics of soil organic carbon, were also discussed. Results indicated that total organic carbon (TOC) and total nitrogen (TN) in Phragmiues auszradis marshes were higher than those in other ecological zones, and decrease from Phragmiues auszradis marshes to Spartina alterniflora marshes, Artemisia schrenkiana marshes and sandy marshes. This trend of distribution and accumulation reflected the changes of soil texture with sandy-fine sandy-silty from sea to continent; Particulate organic carbon was 4.17g Kg-1 in Phragmiues auszradis marshes and 2.14g Kg-1 in Spartina alterniflora marshes, which were far higher than 1.92g Kg-1 in Artemisia schrenkiana marshes and 0.31g Kg-1 in sandy marshes. The introduce of Spartina alterniflora in coastal wetland changed the distribution of TOC in physical fractions, which benefited to increase the concentrations of soil free POCf and occluded POCo and the ratio of soil organic carbon compositions.