植被恢复过程中土壤团聚体分形特征研究

Fractal Characteristics of Soil Aggregates in Vegetation Recovery Process

通过野外调查和室内分析,运用分形理论,研究了典型黄土丘陵沟壑区安塞纸坊沟流域植被恢复过程中土壤团聚体含量及分形特征,以期为黄土高原植被恢复和生态建设提供科学指导.研究结果表明:(1)恢复早期(7年)有利于大团聚的形成,但<0.16 mm粒级的团聚体含量在各恢复年限中都占有最大比例.(2)分形维数随年限在2.68~2.89间变化,其中恢复7年分形维数最小,但仅有15年和24年恢复年限差异显著.土层间分形维数值为2.75~2.83,以表层0~10 cm分形维数最小.(3)分形维数与平均质量直径和>0.25 mm团聚体均呈极显著负相关,与<0.16 mm团聚体含量呈极显著正相关关系.

Through the field investigation and laboratory analysis,we use the fractal theory to research the vegetation recovery process soil aggregate content and the fractal dimension feature in typical loess hilly region soil aggregate content Ansai Zhifanggou Valley that aim to provide scientific guidance for vegetation restoration and ecological construction. The results show that:Firstly,vegetation reiterate early in favor of large aggregates is formed,but less than the 0.16 mm grain size of aggregate content in the period of rehabilitation occupies the largest proportion.Secondly,the fractal dimension changes between 2.68 and 2.89,and the restore 7 years have the smallest fractal dimension,but only 15 years and 24 years of restoration period have the significantly different. Among the different soil fractal dimension changes between 2.75 and 2.83,we find the surface of 0 cm to 10 cm have the minimum fractal dimension. Thirdly,fractal dimension and mean mass diameter and larger than 0.25 mm aggregates are significantly negatively correlated. And with the size fraction less than 0.16 mm aggregate content and fractal dimension is significantly positively correlated.