对汶川地震灾区震后典型植被受损治理区和未受损区(对照)不同坡位土壤的基本性状指标(包括颗粒结构、分布和组成及主要养分含量)进行了测定和比较,并运用分形模型计算这些指标的分形维数;在此基础上对土壤分形维数与土壤基本性状指标间的相关性进行了分析。结果表明:震后植被受损治理区和未受损区不同坡位的土壤均以粒径0. 002 ~0. 050 mm 的颗粒为主,粒径0. 500 ~1. 000 mm 的颗粒较少;土壤分形维数为2. 59 ~2. 68,且治理区各坡位的土壤分形维数均高于未受损区。治理区各坡位土壤中的黏粒含量均显著高于未受损区,而2 个区域中坡位和下坡位的粉砂粒和砂粒含量无显著差异。治理区各坡位土壤的有机质和全氮含量均显著低于未受损区,而碳氮比差异不显著;在治理区,仅下坡位有机质和全氮含量的恢复率超过30%,上坡位和中坡位有机质和全氮含量的恢复率均在30%以下。相关性分析结果显示:土壤分形维数与土壤颗粒粒径的相关系数均大于0. 9,说明颗粒越大土壤的分形维数越高;土壤分形维数与黏粒含量呈极显著正相关,与砂粒含量呈显著负相关,与粉砂粒含量则无显著相关性;土壤分形维数与有机质和全氮含量总体上呈显著或极显著负相关,而与土壤碳氮比呈正相关。研究结果表明:震后植被受损治理区的植被恢复有利于土壤养分的积累以及土壤团聚体的形成和改善,但土壤养分的恢复需要较长时间;土壤分形维数与土壤颗粒含量、有机质含量和全氮含量均呈高度线性相关,因此可将土壤分形维数作为震后受损植被土壤恢复程度的评价指标之一。

The basic characters ( including structure, distribution and composition of particle and contents of main nutrient components) of soil at different slopes in destroyed vegetation management region and undestroyed region (the control) in Wenchuan earthquake disaster area after earthquake were  determined and compared, and the fractal dimension of these indexes was calculated by fractal model. On this basis, correlation between soil fractal dimension and soil basic character indexes was analyzed. The results show that particles with diameter of 0. 002 -0. 050 mm are main in soil at different slopes in destroyed vegetation management region and undestroyed region after earthquake, while particles with diameter of 0. 500-1. 000 mm are less. The soil fractal dimension is 2. 59-2. 68, and that at  different slopes in management region all are higher than that in undestroyed region. The clay content in soil at different slopes in management region is significantly higher than that in undestroyed region, while there are no significant differences in silt and sand contents in soil at middle and lower slopes between two regions. Contents of organic matter and total N in soil at different slopes in management region are significantly lower than those in undestroyed region, but there is no significant difference in C/ N ratio. In management region, only the recovery rate of contents of organic matter and total N in soil at the lower slope is over 30%, while that at the upper and middle slopes all are below 30%. The correlation analysis result shows that the correlation coefficient between soil fractal dimension and soil particle diameter all are above 0. 9, meaning that the bigger soil particle, the higher soil fractal dimension. Soil fractal dimension has an extremely significantly positive correlation with clay content in soil, has a significantly negativecorrelation with sand content in soil and has no significant correlation with silt content in soil. And in general, soil fractal dimension has significantly or extremely significantly negative correlations with contents of total N and organic matter in soil, but has positive correlation with C/ N ratio in soil. It is suggested that vegetation restoration in destroyed vegetation management region is beneficial to soil nutrient accumulation and formation and improvement of soil aggregate, but soil nutrient recovery needs a longer term. And there is a highly linear correlation between soil fractal dimension and contents of particle, organic matter and total nitrogen in soil, so soil fractal dimension could be used as one of assessment indexes for restoration degree of destroyed vegetation soil after earthquake.