中文摘要：

土壤有机碳是反映土壤质量以及土壤缓冲能力的一个重要指标,对于温室效应与全球气候变化具有重要的控制作用。研究以陕西省第二次土壤普查数据为主要资料,结合多年的相关研究数据,对陕西省土壤碳密度及储量进行估算,并分析了陕西省土壤有机碳密度的空间分布特征。结果表明：榆林、延安地区北部以及商洛等地区分布的风沙土、黄绵土、石质土等土壤有机碳密度最小,小于4 kg m-2;陕西南部地区的土壤有机碳密度主要在4~9 kg m-2之间;咸阳地区及渭南地区土壤有机碳密度也较高,主要在9~12 kg m-2之间;关中地区渭河及其两岸、秦岭部分山区土壤有机碳密度最大,最高达30 kg m-2以上;陕西省平均土壤有机碳密度为6.87 kg m-2,在全省的22个土壤类型中,有13个土壤有机碳密度低于全国平均水平,占全省土壤总面积的77.42%,全省土壤有机碳储量约为1.41×1012kg。本研究为我国土壤碳库和碳平衡的研究提供基础数据。

英文摘要：

Soil organic carbon（SOC） is an important indicator of soil quality and soil buffering capacity,which affects greenhouse effect and global climate change.The second soil survey data of Shanxi Province were used as the main data,combining with years of relevant research data,the SOC density was estimated and extensively discussed.Results showed that the SOC density of sandy soil,loessal soil in north Shanxi,and lithosoil in Shangluo was the lowest（less than 4 kg m-2）,whereas the highest SOC density was mainly presented in Guanzhong Plain and Qinling Mountains（up to or even more than 30 kg m-2）.In addition,the SOC density in south Shanxi ranged between 4 and 9 kg m-2.It was found that SOC density varied widely among 22 soil types of Shanxi Province,in which the SOC density of 13 soil types was lower than the national average level.The mean SOC density and storage of Shanxi Province were 6.87 kg m-2 and 1.41 × 1012 kg,respectively.