省域土壤有机碳空间分布的主控因子——土壤类型与土地利用比较

MAIN FACTOR CONTROLLING SOC SPATIAL DISTRIBUTION AT THE PROVINCE SCALE AS AFFECTED BY SOIL TYPE AND LAND USE

基于河北省第二次全国土壤普查数据,运用方差分析和回归分析对比了河北省土壤类型和一级土地利用类型对0～20 cm深土壤有机碳空间分布的影响,探讨了省域土壤有机碳空间分布的主控因子。研究结果表明,土壤类型和土地利用是河北省表层土壤有机碳密度空间分布的重要影响因子。其中土壤类型对土壤有机碳密度空间分布的影响与土壤分类级别相关,土壤分类级别越低,对土壤有机碳密度空间变异的反映能力越大。与土壤类型相比,土地利用对表层土壤有机碳密度空间分异的解释能力要大于土类,但小于亚类和土属。为此,在省域尺度对土壤有机碳密度进行区域预测和估算时应将土地利用和土壤类型结合起来作为土壤有机碳空间分布的主控因子,优先考虑土地利用后,在相同土地利用类型内再尽量以低级土壤分类进行空间预测或估算。

Effects of soil type and type of first-class land use on spatial distribution of SOC at the depth of 0 - 20 cm in Hebei Province were explored based on the data of Hebei Province of the Second National Soil Survey and using variance analysis and regression analysis. It was found that they were the major factors controlling SOC spatial distribution. The effect of soil type was related with soil classification. Soils in lower soil categories of the soil classification were more capable of reflecting SOC spatial distribution. Land use explained SOC spatial distribution better than soil type at the soil group level, but not at the soil subgroup and soil family levels. Therefore, it is advisable to use soil type and land use in combination as main controlling factors in predicting or assessing SOC spatial distribution at the provincial scale, giving prior consideration to land use, then to soil type in the lower categories of soil classification under the same land use.