黄土高原土质边坡林木根系表观黏聚力空间异质性研究

To investigate the spatial variability of root additional cohesion on loess slope, this paper takes monospecific stands of Robinia pseudoacacia and Platycladus orientalis grown on slopes in the semiarid Loess Plateau of northern China as case study. Root distribution could be described by root area ratio (RAR). Root tensile strength was determined with laboratory mechanical tests. Finally, spatial variability of root additional cohesion was analyzed. The results showed that biomechanical characteristics of R. pseudoacacia roots were significantly different from P. orientalis roots. RAR and root additional cohesion were significantly different among species, slope locations and depth. The analyses of R. pseudoacacia and P. orientalis root spatial heterogeneity indicated that root reinforcement was not evenly distributed along slope in the Loess Plateau, which could provide a basic theory of afforestation mode in spatial distribution and hence control soil erosion and shallow landslide.      

林木根系单根的生物力学特性

以黄土高原半干旱区17年生的刺槐(Robinia pseudoacacia)人工林和17年生的侧柏(Platycladus orientalis)人工林为对象,通过单根拉伸试验研究了根系的抗拉强度和杨氏模量.结果表明,刺槐根与侧柏根的生物力学特性表现出显著的尺度效应.根系的抗拉强度与杨氏模量都随直径的增大而减小,且刺槐根的强度约是侧柏根的2倍.