中文摘要：

运用分形模型,对云南东川蒋家沟不同植被类型土壤颗粒的分形特征及其与土壤养分的相关性进行分析,结果表明：1.5种植被类型土壤的分形维数不同,介于2.47～2.59,大小顺序依次为：花生〉石榴〉新银合欢〉草地〉坡柳,花生和石榴所代表的坡耕地的分形维数显著大于新银合欢、草地和坡柳所代表的植被恢复用地。2.分形维数与粘粒（〈0.002 mm）、粉粒（0.002～0.05 mm）的含量呈极显著的正相关关系,坡耕地的粘粒、粉粒含量高于植被恢复用地。分形维数与土壤的有机质、全氮、水解氮含量呈显著负相关关系,与有效磷含量呈显著的正相关关系。植被恢复用地的有机质、全氮、水解氮含量均高于坡耕地,新银合欢的有机质、全氮、水解氮含量低于坡柳和草地,花生、新银合欢和石榴的有效磷含量高于坡柳和草地。3.分形维数能够反映土壤的颗粒粒径分布及养分状况,可作为评价蒋家沟土壤结构稳定性与土壤肥力的一个重要指标。因此,蒋家沟应减少耕作,加强植被恢复,植被类型以改善土壤结构、提高土壤肥力效果较佳的草本和灌木为主。

英文摘要：

This paper studied the fractal characteristics of the soil particle and the correlation analysis between fractal features and soil fertility under different vegetation types in the Jiangjiagou Gully of Dongchuan, Yunnan, China by using fractal model. Results showed that： 1. The fractal dimension of different vegetation types was different, and the fractal dimension of five kinds of vegetation types ranged from 2.47 to 2.57. The fractal dimension of the soil particle of Arachis hypogaea land（AHD） was the highest, followed by Punica granatum land（PGL）, leucaena leu- cocephala land（ LLL）, grassland（ GL）, dodonaea viscose land（DVL）. The fractal dimension of slope cropland re- presented by the AHD and PGL was significantly bigger than that of vegetation restoration land represented by the LLL, GL and DVL. 2. There were highly significantly positive correlations between fractal dimension and contents of clay（ 〈0. 002 mm） and particle（0. 002 -0.05 mm）. The content of clay and silt of slope cropland was higher than vegetation restoration land. And there were significantly negative correlations between fractal dimensions and contents of soil organic matter, total - N, and alkali-hydrolysable - N, however the correlation between fractal di- mension and contents of available - P is significantly positive. The contents of organic matter, total - N and alkali- hydrolysable -N in vegetation restoration land were higher than farmland with the trend of LLL 〉 DVL and GL, but the contents of available - P for AHD, LLL and PGL were higher than DVL and GL. 3. The distribution of the soil particle size and nutrient status can be reflected by the fractal dimension, and the fractal dimension can be an important indicator used to evaluate the stability of soil structure and soil fertility in the area with Jiangjiagou Gully. So we should focus on reducing the number of tillage and enforcing vegetation restoration. The effects that we opti- mized the soil structure and improved the soil fertility by DVL a