中文摘要：

以青藏铁路沱沱河取土场草本植物种植区为例,在野外和室内分别对生长期为5a的6种草本做了原位拉拔试验、室内拉伸试验和剪切试验,分别得到了试验区梭罗草、碱茅、冷地早熟禾、赖草、垂穗披碱草、星星草等6种草本根系抗拔力为187.34～57.89N、抗拉力为4.44～2.99N,抗剪力为4.33～3.85N.同时,对取土场试验区6种草本地上茎叶、地下根系15种化学元素进行了分析.结果表明,地上茎叶和地下根系主要含有Al、Ca、Mg、K、Fe、Sr、Zn、Mn等8种元素,其中Al、Ca、Mg、K等4种元素较其余元素含量显著;此外,6种草本其根系所含Ca、Fe、Zn、Sr、Ni、Cu等6种元素含量均显著大于相应草本种的茎叶部分.试验区6种草本抗拔力由大至小依次为梭罗草、赖草、冷地早熟禾、垂穗披碱草、碱茅、星星草,6种草本其根系所含的其中前8种主要化学元素依次为Al、Ca、Mg、K、Fe、Zn、Mn、Sr等元素,这说明了取土场试验区6种草本根系固土力学强度与根系所含化学元素具有一定的关系.

英文摘要：

The Tuotuohe earth-borrowed area along the Qinghai-Tibet Railway,where there are various dominant vegetation species,was taken as a testing area.In the area in situ pull-out test,single root tensile and shear tests were carried out to study the roots-reinforcing capability of six herbs with growth period of five years.The testing results show that the roots pull-out resistance is 187.34-57.89 N,single root tensile resistance is 4.44-2.99 N and single root shear resistance is 4.33-3.85 N.The chemical elements of the six herbs（Al,K,Ca,Mg,Fe,Zn,Sr,Mn,Na,P,Li,Cr,Ni,Co and Cu） within both stems and leaves upon surface and beneath surface were determined,of which 15 chemical elements and their contents were analyzed individually.There are eight chemical elements（Al,Ca,Mg,K,Fe,Sr,Zn and Mn） within stems and leaves and roots being proven to be dominant,among them the contents of Al,Ca,Mg,and K are obviously rich.Besides,the contents of Ca,Fe,Zn,Sr,Ni and Cu within underground roots are more than those within stems and leaves upon surface.The experiment of pull-out resistance on the six herbs with growth period of five years under slope protection found that roots-reinforcing strength ranks as follows： Kengyilia thoroldianaLeymus secalinusPoa crymophilaElymus nutansPuccinellia distansPuccinella tenuiflora.According to the above sequence,of the fifteen elements,the principal ones are Al,Ca,K,Mg,Fe,Zn,Mn and Sr.From the above mentioned,it is clear that a close relationship exists between the roots-reinforcing strength and the containing of chemical composition within roots.