地形因子与人工林土壤有机碳密度的关系——以晋西黄土丘陵区为例

Ralationship of Topographic Factors and Soil Organic Carbon Density under Plantations: A Case in Loess Hilly Region in Western Shanxi Province,China

为了探究晋西黄土丘陵区不同人工林下土壤有机碳密度的性质,在该区选取了4种典型人工林配置模式,对其土壤上层(0～20 cm)和下层(20～40 cm)的有机碳密度进行了测定和比较,分析了不同人工林下土壤有机碳密度分布的特性。借助普通最小二乘法(OLS),对地形因子与土壤有机碳密度之间的量化关系进行了分析。结果表明:土壤碳密度与全N、水解性N均在0.01水平上显著正相关。林下的土壤碳密度排序为针阔混交林>人工针叶林>人工阔叶林>灌木林。土壤碳密度在不同地形条件下存在差异,但地形差异只能解释土壤碳密度差异的18.4%。土壤碳密度随着坡度的增大而减少,从阳坡到阴坡不断增加,坡面位置的分布特征则为坡顶<坡面<坡脚。

Four typical plantations were selected to explore the nature of soil organic carbon （ SOC ） density under different plan- tations of the Loess Hilly Region, in Western Shanxi Province, China. SOC densities in upper layer （0-20 era） and lower layer （20-40 cm） were measured and compared to analyze the distribution of SOC density accordingly. By ordinary least squares （OLS） , the quantitative relationship between the topographic factors and SOC density was analyzed. The result shows that there are positive correlations between SOC density and total N, and available N at 0.01 level. SOC density un- der four plantations is ranked as： mixed wood〉coniferous plantation〉artificial broad-leaved forests〉shrubs. There is SOC density difference, accounting for 18.4% of the differences in SOC density, in different topographic conditions. SOC den- sity decreases with the increasing of slope. As aspects changes from sunny to shady, its distribution characteristics of dif- ferent slope position is as slope top〈slope surface〈slope base.