江子河小流域不同植被类型土壤粒径的多重分形特征

Multifractal analysis on soil particle size distribution for different vegetation types in Jiangzihe small watershed

为探讨植被类型对土壤粒径分布非均匀性和土壤结构异质性的影响,运用激光粒度分析方法和分形理论,研究桐柏大别山区江子河小流域5种植被类型的土壤颗粒组成及其多重分形特征。结果表明:1)土壤颗粒单分形参数D、多重分形参数Δα、Rf、[α(-1)]-f[α(0)]和f[α(1)]/f[α(0)]均与土壤黏粒体积分数显著正相关,即土壤中细颗粒物质体积分数越高,土壤颗粒分布的非均匀性和奇异性越大;2)不同植物群落土壤颗粒分形维数D和多重分形参数表现为杂木林和针阔混交林(马尾松+栓皮栎)>茶园>竹林和水稻田,即森林(防护林)植被可以增加土壤中黏粒和粉粒等细粒物质体积分数、改善土壤质地的均匀性和增强土壤颗粒结构的异质性。

For exploring the effect of vegetation types on heterogeneity characteristics of soil particle size distribution and soil structure,the composition of soil particles and its multi-fractal characteristic for five vegetation types of Jiangzihe small watershed were studied with laser particle-size analysis method and multi-fractal theory.The results show that： 1） The volume fractal dimension D and multi-fractal parameters Δα,R,f[α（-1）]-f／ and f／/ f／ are significant positively correlated with the content of clay particles,i.e.,the higher the content of soil fine particles,the more heterogeneous the soil particle distribution and the greater singularities.2） The fractal dimension and multifractal parameters of different vegetation types are give as the following order： the spinney and mixed forest（Pinus massoniana＋Quercus variabilis）tea plantation（Camellia sinensis）bamboo forest（Phyllostachys pubescens）paddy field,which means that the forest vegetation（protective forest） could improve the heterogeneity of soil texture and soil structure by raising the content of clay particles.