Characteristics of Soil Organic Carbon Mineralization in Different Plant Communities in Typical Grasslands

Taking Leymus chinensis community, Stipa grandis community, Cleistogenes squarrosa community and Leymus chinensis + Stipa grandis + Cleistogenes squarrosa mixed community as the dominant species of soil as the research object, and taking the soil without aboveground plants as the control, the organic carbon mineralization culture method was adopted.The characteristics of carbon dioxide（CO₂） emission from soil of different grain size under different plants in the typical grassland of the southwest edge of Xilingol Grassland in Inner Mongolia were studied, in order to find out the mineralization characteristics of soil organic carbon under different dominant plants in this area.The results showed that different plant communities had stimulating effects on organic carbon mineralization,among which,Stipagrandis had the greatest stimulating effect on organic carbon mineralization,and when the soil aggregate size was the same,the organic carbon mineralization under Stipagrandis was the same.The rate and accumulation amount were the highest.Meanwhile,soil organic carbon,alkalihydrolyzed nitrogen and pH had significant correlations with soil organic carbon mineralization.