摘要
以蒋家沟泥石流区不同龄级新银合欢根系为研究对象,在分析其垂直分布与构成特征的基础上,运用加筋原理研究其固土效应。结果显示,不同龄级新银合欢根系表聚现象明显,随土层深度的增加呈减少趋势,约80%集中在0—120cm土层范围内;细根(D≤1mm)在整个细根根系中所占比例较大,决定着整个细根的分布趋势;10年生新银合欢D≤1mm细根较5年生增幅明显,15年生1mm<D≤2mm细根较10年生增幅显著。根径越小,根系的抗拉强度越大,根径与根系的抗拉强度呈幂函数相关关系,不同深度、不同树龄新银合欢根系固土能力变化较大,与细根(D≤1mm)关系密切。
Variously aged Leucaena leucocephala in debris flow area of Jiangjia gully were chosen and the fine root systems were dug out from the surface to the bottom layers at different distances from the stem in three directions.Basing on the analysis of fine root vertical distributions and composition,the effect of fine roots on the soil shear strength were estimated according to reinforcement theory.The result show that fine roots exhibited an obvious accumulation trait in the topsoil layer,which reduced with depth.Approximately 80% of the fine root materials were found in the layer between 0—120 cm depths.Fine roots were mainly composed of smaller ones（D≤1 mm）and determined the development of root distribution.The 10-year stands had more fine roots（D≤1 mm） than 5-year ones,and the 15-year stands had obviously more intermediate roots（1 mm≤D≤2 mm） comparing to the 10-year stands.Root tensile strength decreased significantly with increasing diameter,following a power law function.The soil shear strength enhanced by fine roots was highly variable among depths and ages,largely depended on the smaller roots（D≤1 mm）.
出处
《水土保持通报》
CSCD
北大核心
2011年第5期85-89,214,共6页
Bulletin of Soil and Water Conservation
基金
国家自然科学基金项目"固氮植物防治泥石流的抑灾作用机制研究"(40771025)
中国科学院知识工程重要方向课题"震裂坡地暴雨型泥石流滑坡区生态恢复理论与技术"(kzcx2-yw-332)
关键词
蒋家沟
新银合欢
细根分布
固土效应
Jiangjia gully
Leucaena leucocephala
fine root distribution
soil reinforcement effect
