沂蒙山林区不同植物群落的土壤颗粒分形与水分入渗特征

为探索沂蒙山林区不同植被对土壤分形结构及入渗性能的改良作用与机制,运用土壤分形学和水文学原理与方法,研究沂蒙山林区7种植物群落下的土壤颗粒组成和入渗过程。结果表明：1）植物群落具有显著改善土壤颗粒结构和入渗性能的作用,其改善程度为针阔叶（赤松＋麻栎）混交林依次高于阔叶林（刺槐纯林、麻栎纯林）和针叶林（赤松纯林）;2）研究区土壤颗粒组成具有石质山地典型粗骨土的结构特征,其分形维数与土壤入渗速率呈明显的正相关关系;3）植物群落改良土壤分形结构和入渗性能的分形学机制,是通过增加土壤粉粒与黏粒等细粒物质含量而提高土壤分形维数,进而改善土壤团粒结构和孔隙结构,提高土壤质地均匀程度和入渗能力的。研究成果可为沂蒙山区水土保持植被类型的合理选择与配置提供参考。

Fractal features of soil particle size distribution and infiltration characteristics under different vegetation communities in the forestland of Yimeng mountains area

For exploring the improving effect and the mechanism of the forest vegetation to soil fractal structure and infiltration property in Yimeng mountainous area,composition of soil particles and infiltration under seven vegetation communities of Yimeng forestry area are studied according to the theories and means of soil fractal geometry and hydrology.Results indicate that: 1) All kinds of forest communities have obvious function of meliorating soil particle structure and characteristics of infiltration,the improved degree of coniferous and broad-leaved mixed forest（Pinus densiflora & Quecus variabilis Carr.） is higher than broad-leaved forest（Robinia pseudoacacia,Quecus variabilis Carr.） and coniferous forest（Pinus densiflora）.2) Soil particle composition which is positive correlativity obviously between the soil fractal dimension and soil infiltration rate displays a typical fragment of rocky mountainous area.3)Fractal geometry mechanism of forest communities meliorating soil fractal structure and infiltration property is that by raising the content of fine-grained soil particles to increase the soil fractal dimension,thereby improving both aggregate structure and pore structure,the degree of soil texture uniformity and the infiltration capacity is advanced.The research findings can provide reference for scientific selection and distribution of water conserving vegetation types in Yimeng mountainous area.