Abstract: A clear understanding of the spatial and temporal variation characteristics of soil organic carbon can provide an important guarantee for the dynamic monitoring of soil quality and the scientific utilization of land resources. The geostatistic was used to analyze the temporal and spatial variation of SOC content in Aohan Chifeng based on soil survey data. The result showed that the mean contents of SOC in 1985 and 2014 were 6.91 and 7.49 g·kg-1. And the spatial distribution characteristics gradually decreased from south to north. In 1985, soil organic carbon content had a strong spatial autocorrelation in the research scale. After 30 a of change, the average increase of soil organic carbon in agriculture, forestry and grassland was 5.92%, 10.22% and 8.47%, respectively. The soil organic carbon content was significantly improved after the restoration of forest return, grass and sandy vegetation.The spatial autocorrelation distance of soil organic carbon was shortened. The soil organic carbon content was significantly improved after the restoration of forest return, grass and sandy vegetation.

Key words: soil organic carbon, spatio-temporal variability, geostatistics, semi-arid region

摘要： 清晰地认识区域土壤有机碳的时空变异特征，能够为土壤质量动态监测和科学利用土地资源提供重要保障。选择赤峰市敖汉旗作为研究区，在实测调查数据的基础上，对比分析了敖汉旗在1985—2014年土壤有机碳的时空变异特征。结果表明： 1985年和2014年土壤有机碳含量分别为6.91和7.49 g·kg-1，且在空间上均呈现由南向北逐渐降低的分布特征。1985年，土壤有机碳含量在研究尺度内具有较强的空间自相关性，经过30 a的变化，农、林、草3种土地有机碳含量平均分别增长5.92%、10.22%与8.47%，土壤有机碳的空间自相关距离缩短。退耕还林、还草以及沙地植被恢复后，土壤有机碳含量均有显著提升。

关键词: 土壤有机碳, 时空变异, 地统计学, 半干旱区