川西北高寒地区土壤有机碳密度的垂直分布特征

Vertical Distribution of Soil Organic Carbon Densities in the Arctic-Alpine Region of Northwest Sichuan

为掌握川西北高寒地区不同土壤类型碳储量的变化,选择了川西北红原县的3种典型土壤（亚高山草甸土、泥炭草甸土、冲积土）进行有机碳密度的垂直分布特征研究。结果表明：随土壤深度的增加,亚高山草甸土和冲积土的土壤有机碳密度降低;泥炭草甸土的有机碳密度在40～60 cm达到最大。整个土壤剖面（1 m）有机碳密度最高的是泥炭草甸土（72.06 kg/m2）,其次是冲积土（26.58 kg/m2）,最小的是亚高山草甸土（17.05 kg/m2）;冲积土、亚高山草甸土的表层土壤（0～20 cm）的有机碳密度分别占整个剖面的41%、58%,而泥炭草甸土的表层土壤（0～20 cm）的有机碳密度仅占整个剖面的15%。

A study was conducted on the vertical distribution of organic carbon densities in three typical soils （sub-alpine meadow soil,turfy meadow soil,and alluvial soil） in Hongyuan County,northwest Sichuan of China. Organic carbon densities were decreasing in sub-alpine meadow soil and alluvial soil along with going deeper into the soils,and that in turfy meadow soil reached a maximum at layers 40-60 cm deep.In the whole soil profiles（1 metre thick）,organic carbon densities in turfy meadow soil were the highest（72.06 kg/m^2）,followed by alluvial soil（26.58 kg/m^2） and then sub-alpine meadow soil（17.05 kg/m^2）,whilst that in 0？？20 cm thick top layers accounted for 41%and 58%of the whole profiles of alluvial soil and sub-alpine meadow soil,respectively,and only 15%for turfy meadow soil.