土壤有机碳是土壤养分评测和质量分析的重要指标之一,研究不同草原类型土壤有机碳的空间分布规律有利于草地的生态恢复和土地的合理利用。以锡林郭勒草原为研究对象,运用克里格插值法、相关性分析法、一元线性回归法和主成分分析法探讨土壤有机碳的空间分异规律,以期揭示不同影响因素对草原土壤有机碳的影响程度。结果表明：（1） 在草甸草原中,土壤有机碳含量在0~10 cm、20~30 cm、40~50 cm土层的含量依次为23.28 g·kg^-1、12.71 g·kg^-1、9.28 g·kg^-1;在典型草原中,含量变化依次为16.75 g·kg^-1、10.75 g·kg^-1、7.20 g·kg^-1;在荒漠草原中,含量依次为1.62 g·kg^-1、2.00 g·kg^-1、1.73 g·kg^-1。表明草甸和典型草原土壤有机碳含量随土壤深度增加而逐渐降低,而荒漠草原不同土层间无显著性差异。（2） 不同草原类型对土壤有机碳含量的影响程度不同,对于同一土层深度,基本表现为草甸草原>典型草原>荒漠草原。水平方向上有机碳含量与植被盖度分布相一致,呈由东南向西北逐渐递减的趋势。（3） 在对影响因素的分析中,土壤有机碳与海拔、气温、pH均呈极显著负相关关系（P<0.01）,与降水、土壤含水量、速效氮、速效磷呈极显著正相关关系（P<0.01）,与坡度、坡向、速效钾无明显相关性关系（P>0.05）。（4） 影响土壤有机碳的主要因子为速效氮、降水量和气温,次要因子为土壤含水量和速效钾,因此,应注重对不同草原氮素的摄入以及水热条件的把控。

Soil organic carbon (SOC) is an important indicator of soil nutrient content and quality. The study of SOC in different steppe types assists ecological restoration and rational land use projects. This study was conducted in the Xilin Gol steppe, and used the Kriging interpolation, correlation analysis, unary linear regression, and principal component analysis to explore the spatial differentiation of SOC and identify its influencing factors. The results showed that: (1) In the meadow steppe, SOC content in 0-10 cm, 20-30 cm, and 40-50 cm soil layers was 23.28 g·kg^-1,12.71 g·kg^-1, and 9.28 g·kg^-1, respectively; in the typical steppe it was 16.75 g·kg^-1, 10.75 g·kg^-1, and 7.20 g·kg^-1, respectively; in the desert steppe, the content was 1.62 g·kg^-1, 2.00 g·kg^-1, and 1.73 g·kg^-1, respectively. Also, results showed that the SOC content in the meadow and typical steppes gradually decreased with the increase of soil depth, while there was no significant difference between different soil layers in the desert steppe. (2) Different steppe types had different influences on SOC content. For the same soil layer depth, the SOC content order was basically meadow steppe>typical steppe>desert steppe. The SOC content in the horizontal direction was consistent with the distribution of vegetation coverage, showing a trend of gradual decrease from southeast to northwest. (3) Correlation analysis showed that SOC was significantly (P<0.01) and negatively correlated with altitude, temperature, and pH; and significantly (P<0.01) and positively correlated with precipitation, soil water content, available nitrogen, and available phosphorus. It had no significant correlation (P>0.05) with slope, aspect, and available potassium. (4) The main factors affecting SOC were available nitrogen, precipitation, and temperature; the secondary factors were soil water content and available potassium. Therefore, attention should be paid to the control of nitrogen intake and hydrothermal conditions in different steppe types.