不同起源格式栲林地的土壤分形特征

土壤结构性是影响土壤肥力的一个重要因素.本文运用分形模型对不同起源格氏栲林分表层土壤团粒结构进行研究,探讨了分形维数与土壤肥力的关系.研究结果表明格氏栲天然林结构多层,土壤粒径分布的分形维数小,水稳性团聚体即＞0.25nn的团粒含量高,土壤养分除水解性总酸度外,其它含量均较高,土壤团聚体水稳性能良好,土壤具有良好的渗透性、自动调节及抗逆性能,非毛管孔隙发达,土壤肥力较高;格氏栲纯人工林,林分结构单一,其土壤粒径分布的分形维数较低,土壤养分含量、水分状况及土壤通透性低于天然林,土壤肥力下降;分形维数为不同起源格氏栲林分表层土壤肥力特征描述提供新尺度、新方法.

Study on Fractal Feature of Soil Fertility under Different Original Castanopsis Kanakamii Stands

The condition of soil structure is a important factor to effect soil fertility. In this paper, the fractal model is used to study the soil aggregate structure under different original C. kanakamii stands, to inquiry the relation between fractal dimension and soil fertility. The study results indicate that, the stand structures for the natural forest of C. kanakamii are complex, the fractal dimension of soil aggregate is little, which the more content of the particle >0.25 millimeter aggregate is, the more content of other soil nutrient elements excepting for total hydrolysable acid is, the more splendid the capacity of stable aggregate composition under water and permeability of soil is, the better performance of self_regulation and resistant is, the more flourishing non_capillary pore of soil is, and the higher the soil fertility is. The forest stand of the pure plantation C. kanakamii is single, which the fractal dimension of soil aggregate composition, the content of soil nutrients, soil water, soil permeability are smaller than the natural forest , and the soil fertility is dropping. It is clear that fractal model will provide a new tool for describing character of soil fertility in different original C. kanakamii stands.