黄土高原刺槐人工林地土壤颗粒分形特征研究

采用分形理论,研究黄土高原刺槐人工林地不同树龄和不同深度的土壤颗粒的分形特征.结果表明,在刺槐人工林凋落物和根系等的作用下,人工林能够提高林地土壤的团聚能力,降低土壤的分形维数;不同树龄刺槐人工林地的土壤颗粒分形维数在土壤剖面的不同深度上趋于均一,而且小于同种质地的其他土壤;土壤颗粒分形维数可以反映森林土壤粒径分布的变化,因而可作为评价森林土壤生态特征的指标.

Fractal characteristics of soil particle of Robinia pseudoacacia L. plantation forestland in loess plateau

The present paper aims to report the author's analysis on the fractal characteristics of soil particle of Robinia pseudoacacia L. plantation forestland in loess plateau. The author used fractal theory for analyzing the soil structure and the soil particle-size distribution at different ages and different depths. The conclusion the paper has gained is: in the long-term works of roots and humus, the soil aggregate ability has been enhanced, the low content of clay may lead to the lower fractal dimension of soil particle. However, the fractal dimension of soil particles is nearly the same at different soil depths and different ages, but not quite the same with soil texture on the other places. All this indicates that the soil aggregating ability has been enhanced and in turn the soil fractal dimension had been reduced by the effect of litters and root of Robinia pseudoacacia L. And finally, the fractal dimension of soil particle can reflect the distribution degree of soil particle in forestland, and, therefore, it can be taken as assessing index for forest ecological property.