中文摘要：

为进一步探讨寒旱环境植物护坡力学效应,本项研究在自建试验区选取了适宜于当地气候条件下生长的乡土草本和灌木植物共5种作为供试种,并分别对其进行了单根拉伸试验,较为系统地分析了5种草本和灌木植物根系的强度特征。试验结果表明：5种草本和灌木植物其单根抗拉力分别随根径增大而增大,两者之间呈幂函数关系;同时,其单根抗拉强度表现出随根径的增加呈减小的规律,且两者间具有幂函数关系;草本植物垂穗披碱草单根抗拉强度大于细茎冰草,而灌木单根抗拉强度由大至小依次为柠条锦鸡儿、霸王、白刺。此外,对比分析生长期为1a和2a的3种灌木单根拉伸试验的应力-应变关系曲线得出,灌木植物单根在拉伸试验阶段初期,应力-应变之间呈线性关系,表现出弹性材料特性;至试验的中期和后期阶段时应力-应变之间呈非线性关系,表现出弹塑性材料特性;进一步研究表明灌木单根的最大伸长率随着生长期的增加呈下降趋势。该研究成果在防治研究区浅层滑坡、水土流失等地质灾害,以及保护区域生态地质环境等方面具有重要理论研究价值和实际指导意义。

英文摘要：

This paper is to further explore the mechanical effects of plants in slope protection in cold and arid environments. It selects five kinds of native herbs and shrubs as the test samples. They are suitable for the local climate conditions. They are planted in the self-built test area in this research. The single tensile tests are carried out to systematically analyze the strength characteristics of plant roots of the five kinds of herbs and shrubs. The results show the follows. The single root tensile resistances increases with the diameter increasing. Power relations exist between single root tensile resistances and root diameters of the herbs and shrubs respectively. Meanwhile,the single root tensile strengths increase with the diameter decreasing. Power relations exist between single root tensilestrengths and root diameters of five kinds of herbs and shrubs respectively. The single root tensile strength of Elymus nutans Griseb is bigger than that of Agropyron trachycaulum（ Linn.） Gaertn,while the sequence of the single tensile strengths of shrubs from big to small is Caragana korshinskii Kom,Zygophyllum xanthoxylon（ Bunge） Maxim. and Nitraria tangutorum Bobr. Besides,some phenomena are shown by comparing and analyzing the stress-strain relationship curves of tensile tests of three kinds of shrubs in the vegetative period of 1a and 2a. That is,in the early single root tensile test of shrubs,there is a linear relationship between stress and strain,which shows the elastic material properties. Until the middle and late stage of the test,the relationship between stress and strain is nonlinear and shows the elastic-plastic material properties. Further research shows a downward trend of the largest elongation of the shrub single root with the increasing of vegetative period. The results of the study have a theoretical researching and practical guiding significance in the prevention and treatment of geological disasters such as shallow landslide and soil erosion in the study area and in the protection of the re