摘要:生态建设是"一带一路"可持续发展的基础，甘肃省陇南市位于"一带一路"核心区域，地处浅层滑坡多发区，地质灾害频发。通过单根抗拉试验和重塑土直接剪切试验对该区域四种典型灌木杠柳、胡枝子、酸枣和石榴的土壤及根系进行研究，探讨灌木根系对土壤物理性质和浅层滑坡的改善效应。结果表明，灌木根系能显著提高土壤含水率，改善孔隙结构；抗拉强度与根径间存在显著幂函数关系（P < 0.01），根径<1 mm的毛细根抗拉强度最强，单根抗拉强度依次为胡枝子 > 石榴 > 酸枣 > 杠柳；重塑土抗剪强度随土壤含水率升高而降低，土壤粘聚力（C）和内摩擦角（φ）均随含水率增加而减小，在10%的最优含水率下，抗剪强度依次为石榴 > 酸枣 > 杠柳 > 胡枝子；随根系密度增加，杠柳和胡枝子的根-土复合体抗剪强度减小，酸枣和石榴在1.5倍天然根系密度下对土壤抗剪强度增强效果最强。通过评价浅层滑坡多发区不同灌木护土固坡效应，为"一带一路"沿线展开生态修复提供理论依据。



Abstract:Ecological construction is the foundation of sustainable development in "the Belt and Road" region. Longnan, Gansu Province, is an important water conservation region in the core area of "the Belt and Road" region, and frequent natural disasters, such as shallow landslides and debris flows are major geographical features of this area. The soil and root systems of four typical shrubs (Periploca sepium, Lespedeza bicolor, Ziziphus jujube and Punica granatum) were studied by single tensile test and direct shear test of remolded soil to explore the improvement of soil physical properties and shallow landslides. The results showed that the root system of these shrubs could significantly improve the soil water content and pore structure of the soil. There was a significant power function relationship between the tensile strength and root diameter (P < 0.01), and the tensile strength of the capillary root with diameter < 1 mm was the highest. The tensile strength of a single root was in the order of L. bicolor > P. granatum > Z. jujube > P. sepium. The shear strength of remolded soil decreases with an increase in water content, and the soil cohesion (C) and internal friction angle (φ) decreased with an increase in water content. At the optimal moisture content of 10%, the shear strength was in the order of P. sepium > Z. jujube > P. sepium > L. bicolor. With increasing root density, the shear strength of root soil composite system of P. sepium and L. bicolor decreased. The shear strength of P. sepium and Z. jujube reached the highest while it was under 1.5 times that of the natural root density. This study could provide a theoretical basis for vegetation restoration in "the Belt and Road" region by evaluating the effects of different shrub slopes in shallow landslide-prone areas.





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