中文摘要：

基于我国第二次土壤普查数据,利用Arc GIS和GS＋地统计软件,分析东北地区土壤有机碳含量（SOCC）和土壤全氮含量（STNC）空间分布特征,并从8个自然因子和土地利用方式（LUT）中辨析主控因素及人类活动和自然因素影响的相对重要性。结果表明：东北地区SOCC、STNC属于养分分级的中等偏上水平;SOCC、STNC的最优半方差函数模型均为高斯模型,块金效应分别为36.56%和43.76%,具有中等强度空间自相关性;SOCC、STNC空间分布为从东北向西南方向逐渐降低。SOCC、STNC与土壤阳离子交换量（CEC）、经度（Lo）、纬度（La）、海拔高度（H）呈显著正相关,与年均温（MAT）、p H、土层厚度（d）均呈显著负相关,而与年均降水量（MAP）相关性均不显著（P〉0.01）;东北地区影响SOCC、STNC的主控因素为CEC、Lo、LUT、p H和MAT;所有相关性因子共同解释SOCC、STNC变异性的30.10%和29.20%,其中LUT解释部分分别占总解释程度的10.96%和5.82%。自然因素特别是土壤性质对该区土壤碳氮空间分布的影响仍然起到主导作用,但耕地条件下农业生产活动可能在一定程度上削弱自然因子对土壤碳氮的影响。

英文摘要：

The spatial distribution characteristics of soil organic carbon content and soil total nitrogen content in Northeast China were analyzed with the data of Second National Soil Survey using Arc GIS and GS ＋ geostatistics softwares. Simultaneously,we explored the controlling factors and relative importance between human activities and natural factors from 9 natural factors and land use types. The content of soil organic carbon and soil total nitrogen were in the medium level according to the national soil nutrition classification. The semivariogram models of soil organic carbon and total nitrogen were best described by Gaussian model,the Nugget / Sill of them were36. 5% and 43. 76%,respectively,having moderately dependent spatial correlation. Spatial distribution of carbon and nitrogen content decreased gradually from northeast to southwest in this region. Soil organic carbon and total nitrogen had significant positive correlation with cation exchange capacity,longitude,latitude and elevation,had significant negative correlation with average annual temperature,p H and soil thickness,and had no significant correlation with average annual precipitation（ P〉0. 01）. The main controlling factors which affect the spatial variation of soil organic carbon and total nitrogen in the Northeast China were cation exchange capacity,longitude,land use types,p H and average annual temperature. All factors explained 30. 20% and 29. 10% of the organic carbon and total nitrogen content variation,and explanation of land use types represented 10. 96% and5. 82% of total explanation,respectively. Natural factors,especially soil quality,were dominant compared with land use types. Furthermore,human activities including land use may weakened influence of natural factors to some extent in cultivated land.