凤阳山主要林分类型土壤优先流特征及其影响因素

发布时间：2018-05-20 11:01

本文选题：优先流 + 土壤细根　；参考：《南京林业大学》2015年硕士论文

【摘要】：土壤优先流不仅在土壤水源涵养方面有重要作用,同时在加重地下水污染、山体滑坡、泥石流的发生等方面也存在一定的负面影响,因此土壤优先流越来越被人们重视。本研究以浙江凤阳山4个典型森林类型为对象,通过野外测定、染色示踪试验,研究土壤孔隙、土壤结构、土壤有机质含量、根系特征、石砾质量及表面积等对土壤优先流的影响及作用机制,研究结果如下:(1)林木细根(根径:0.6mm、0.6mm~1.2mm、1.2mm~1.8mm和1.8mm)的根长密度基本表现为随土层深度的增加而减少,根表面积和根体积分布也表现出相同的变化规律。(2)土壤总孔隙度、非毛管孔隙度随着土壤深度的增加而减小,土壤有机质含量、土壤大团聚体数量随土层深度的增加而减少,土壤结构变差。(3)相邻微区域,根径0.6mm的根长密度、根表面积、根体积、根尖数、根分叉数、石砾质量、石砾表面积和非毛管孔隙度基本表现出优先流区基质流区。(4)基于主成分分析,第一主成分反应出根系特征指标对有优先流路径的影响作用,第二主成分反应出石砾含量对优先流路径的影响作用,第三主成分分反应出非毛管孔隙和石砾含量对优先流路径的综合影响作用,第四主成分反应出分形维数对优先流路径的影响作用。通过进一步的计算检验,发现75%样地综合得分表现为优先流区基质流区。可以认为根径0.6mm的根长密度、根表面积、根体积、根尖数、根分叉数、石砾质量、石砾表面积、非毛管孔隙度为影响优先流的主要因素。
[Abstract]:Soil preferential flow not only plays an important role in soil water conservation, but also has some negative effects on the aggravation of groundwater pollution, landslides and debris flow. Therefore, the soil preferential flow has been paid more and more attention. This study is based on 4 typical types of forest types in Fengyang mountain, Zhejiang. The effects and mechanisms of soil porosity, soil structure, soil organic matter content, root characteristics, gravel quality and surface area on soil priority flow were studied. The results were as follows: (1) the root length density of the tree root (root diameter: 0.6mm, 0.6mm~1.2mm, 1.2mm~1.8mm and 1.8mm) decreased with the increase of soil depth, and the root table The area and root volume distribution also showed the same change law. (2) the total porosity of soil, non capillary porosity decreased with the increase of soil depth, the content of soil organic matter, the number of soil aggregates decreased with the increase of soil depth, and the soil structure became worse. (3) the root length density, root surface area and root body of the root diameter 0.6mm in adjacent microregions. Product, root tip number, root bifurcation number, gravel quality, gravel surface area and non capillary porosity basically show the matrix flow area in the priority flow area. (4) based on the principal component analysis, the first principal component reacts the effect of the root characteristic index on the preferential flow path, and the second main components reverse the effect of the gravel content on the priority flow path, and third main main components. The effects of non capillary pores and gravel content on the preferential flow path are synthesized. Fourth main components reflect the effect of fractal dimension on the preferential flow path. Through further calculation and test, it is found that the comprehensive score of the 75% samples is the matrix flow area of the priority flow area. The root length density and the root surface can be considered as the root diameter 0.6mm. Product, root volume, root tip number, root fork number, gravel quality, gravel surface area and non capillary porosity are the main factors affecting preferential flow.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714

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