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题名	蒋家沟泥石流源区新银合欢根系固土效应实验研究
作者	郭灵辉
学位类别	硕士
答辩日期	2011-05-24
授予单位	中国科学院研究生院
授予地点	北京
导师	王道杰
关键词	新银合欢 根系动态 根系分布 固土效应
其他题名	Experimental study on the effect of Leucaena leucocephala root on the soil reinforcement in Debris flow source area in Jiangjia Gully
学位专业	自然地理学
中文摘要	我国泥石流分布广、数量多、危害严重。新银合欢作为区域性泥石流防治的先锋树种，在我国南方地区广为引用。然而，对于抑灾植物新银合欢根系生态适应特征、根系固土效应尚无细致的研究。基于此，本研究以典型泥石流沟——蒋家沟泥石流区新银合欢林为研究对象，采用分层分段挖掘法和三维坐标法，主要研究了不同龄级新银合欢根系时空动态特征、新银合欢根系对坡位条件的敏感性和适应性，并且在此基础上，运用粗根锚固原理和细根加筋原理，对新银合欢根系固土能力、固土范围进行评估。主要结论如下： 1.新银合欢细根质量密度随树龄的增大而增加，但增加幅度先大后小；各龄级新银合欢细根质量密度都呈现明显的表聚特征，但随树龄的增加，集中化特征增强；坡中部位比坡顶部位新银合欢细根质量密度大，且表聚程度高；细根质量密度垂直方向遵循对数函数递减，水平方向呈抛物线变化趋势。 2.新银合欢各级粗侧根数量和直径随树龄增大都有所增加，5年生至10年生粗侧根数量增加较快，10年生至15年生则侧重于粗侧根直径增加；不同坡位间新银合欢各级粗侧根差别不大。 3.新银合欢单根抗拉强度与根径呈幂函数相关关系，根径越小根系的抗拉强度越大。 4.新银合欢根系固土能力随深度的增加而减小，5年生至10年生新银合欢根系中细根加筋作用增长较快，而10年生至15年生粗根锚固力增加幅度大，锚固深度深；坡中部位根系固土能力较坡顶大。
英文摘要	Debris flow is widely distributed in our country, with high frequency and serious destruction. Leucaena leucocephala is widely cultivated in the south area in our country, as the regional pioneer species to prevent debris flow occurring. However, there are only few careful researches on its ecological adoption features, the effect and range on the soil reinforcement of its roots so far. Basing on this, Leucaena leucocephala forest in the typical debris flow gully—Jiangjia Gully were chose in our study. Digging out from up to down at different distances from the stem in three directions and three-dimensional coordinate method were used to analyze its roots dynamic and spatial characteristics, its ecological adoption under different slope position. Then, the ability and range on the soil reinforcement of its roots was estimated according to fiber reinforcement theory and anchoring theory. Subsequently. The result showing: 1. The weight densities of fine roots are increasing as tree growing, but the increasing rate is faster at first and then slower in the same ranged profile. All of the weight densities of fine roots of different aged Leucaena leucocephala are completely appeared an obvious accumulation trait in the topsoil layer and an intensifyingly centralized trend with growth. There are more fine roots with greater accumulation trait in the topsoil layer in the middle slope position. Fine roots decrease at a logarithmic function with increases of soil depths and change by parabolic function with distances from the stem. 2. The average number and diameter of coarse lateral roots rise with the tree growth. The former increases faster from five years old to ten, while the latter grows quicker from ten years to fifteen. There is not very different about coarse lateral roots between slope positions. 3. Root tensile strength increased significantly with decreasing diameter, following the power law relationship. 4. The capability of the roots on the soil reinforcement reduces with the increasing depth. From five years old to ten, the fiber reinforcement of fine roots grows faster, and the coarse roots anchoring force rise quicker with deeper anchoring depth, from ten years to fifteen. The whole soil reinforcement of roots in the middle slope position is lager than that in top.
语种	中文
公开日期	2013-01-19
内容类型	学位论文
源URL	[http://192.168.143.20:8080/handle/131551/4831]
专题	成都山地灾害与环境研究所_山地灾害与地表过程重点实验室
推荐引用方式 GB/T 7714	郭灵辉. 蒋家沟泥石流源区新银合欢根系固土效应实验研究[D]. 北京. 中国科学院研究生院. 2011.

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