西双版纳橡胶林土壤颗粒体积分形维数特征

土壤粒径分布影响土壤质地均匀程度和土壤肥力等,是重要的土壤物理特征之一。运用土壤颗粒体积分形维数模型计算了西双版纳不同林龄橡胶林土壤剖面各层(共计105个土壤样品)的分形维数D值。结果表明,分形维数D值介于2.636 2~2.885 0之间,分形维数与0.002 mm的黏粒体积百分含量呈极显著正相关关系,与0.002~0.05 mm的粉砂和0.05~2.00 mm的砂砾呈极显著负相关关系;不同林型的土壤颗粒体积分形维数随土层深度增加变化不同,10龄和22龄橡胶林土壤粒径分布曲线的波动性较32龄橡胶林的小,各层颗粒之间的差异性较32龄的大;分形维数和土壤黏粒体积百分含量与全钾含量和自然含水率都在p0.05水平呈显著正相关关系,粉砂体积百分含量除与上述土壤基本性质呈显著负相关关系外,还与土壤有机质、全磷呈显著负相关,而分形维数和土壤黏粒体积百分含量与土壤有机质、全磷、全氮、土壤容重、总孔隙度的相关性未达到显著水平。

Fractal Dimension of Soil Particle Volume in Rubber Forest of Xishuangbanna

Soil particle size distribution affects soil texture uniformity and soil fertility,which is one of the important soil physical characteristics.In this paper,fractal dimension D (value) of soil layers (105 soil samples in total) of rubber forest in Xishuangbanna was calculated by using the fractal dimension model of soil particle volume.The results showed that the fractal dimension D was between 2.636 2 and 2.885 0,and the fractal dimension had a significant positive correlation with the percentage of clay volume of ＜0.002 mm,had a negetive correlation with 0.002-0.050 mm silt and 0.05-2.00 mm,and the fractal dimension of soil particle volume varied with soil depth.The fluctuation of soil particle size distribution curve of 10yr and 22yr rubber forest was less than that of 32yr rubber forest.The difference between the fractal dimension and the soil clay volume percentage and the total potassium content and the natural water content were all significant at the p ＜0.05 level.The percentage of the silt volume was negatively related with soil organic matter and total phosphorus,while the correlation of porosity of total nitrogen,soil bulk density,soil bulk density,soil bulk density and soil organic matter,total phosphorus,total nitrogen,soil bulk density and total soil did not reach a significant level.