黄土高原不同土地利用方式下土壤颗粒体积分形特征

Fractal characteristics of soil particle volume size distribution under different land use on the Loess Plateau

通过对黄土高原长武地区的野外调查与采样、室内粒度分析和土壤容重测定,利用土壤颗粒体积分维模型,分析了该区域苹果人工经济林地和耕地土壤颗粒体积分形特征,探讨了颗粒体积分形特征与颗粒体积含量、容重的关系。研究结果表明:土壤体积分形维数可以作为区域苹果林地土壤质量评价指标,土壤体积分形维数Dv在2.401～2.704之间,其大小主要由粘粒(﹤0.001mm)决定,并且与﹤0.01mm各粒级体积含量呈正相关,与﹥0.01mm各粒级体积含量呈负相关。土壤体积分形维数受土地利用的影响明显,主要表现在表层土壤中耕地Dv大于林地Dv,而深层土壤相反。三个剖面中,土壤体积分形维数与土壤容重的关系不一致。

Based on field investigation,sampling and laboratory analysis of soil particle size and bulk density and the soil particle volume fraction dimensional model,fractal characteristics of soil particle volume size distribution under different land-use condition were analyzed.The results showed that soil volume fractal dimension should be greater than soil weight fractal dimension,soil volume fractal dimension can be used as regional indicators for soil quality evaluation;volume fractal dimension Dv is at the 2.401～2.704 in soils at XCG,XCL91 and XCL86,it mainly determined by clay of the size 0.001,and it positively correlats with 0.01mm and negatively with 0.01mm;soil volume fractal dimension is deeply impacted by land-use,Dv is lower in manifested land XCL91 and XCL86 than cultivated land XCG in the surface soil and opposite in deep soil;Among the three profiles,soil volume fractal dimension has inconsistent relationship with soil bulk density.