摘要
通过对试验区草本植物根系的力学强度试验,研究了黄河源玛沁地区高寒草地植物护坡的力学效应,即通过研究未退化、轻度退化、重度退化的草地的主要优势种植物的单根抗拉力、抗拉强度和根-土复合体的抗剪强度等评价其固土护坡能力与贡献。研究所选取的未退化草地的优势种植物主要有小嵩草(Kobresia pygmaea C.B.Clarke)、紫花针茅(Stipa purpurea Griseb.),轻度退化草地的优势种植物包括矮火绒草(Leontopodium nanum(Hook.f.et Thoms.)Hand.-Mazz.)、二裂委陵菜(Potentilla bifurca L.),重度退化草地的优势种植物为细叶亚菊(Ajania tenuifolia(Jacq.)Tzvel.)、盐地风毛菊(Saussurea salsa(Pall)Spreng)。由单根拉伸试验结果表明,单根抗拉强度平均值由大至小依次为紫花针茅>小嵩草>矮火绒草>二裂委陵菜>细叶亚菊>盐地风毛菊;室内根-土复合体原状试样直接剪切试验表明,根-土复合体的抗剪强度由大至小依次为小嵩草>紫花针茅>矮火绒草>二裂委陵菜>细叶亚菊>盐地风毛菊。研究成果对进一步探讨黄河源高寒地区植物固土护坡机理,以及试验区及其与试验区条件相似的其他地区,科学防治坡面水土流失、浅层滑坡等地质灾害的发生具有重要理论指导意义。
Mechanical strength tests have been conducted on grass roots of alpine grassland plants in Maqin County to study their mechanical effects in soil fixation and slope protection in the source area of the Yellow River. Three representative sampling plots were selected according to the degradation degrees which were marked as non-degraded grassland, lightly degraded grassland and heavily degraded grassland. The root tensile strength and shear strength of the dominant plants in this alpine grassland was studied to estimate the contribution to soil fixation and slope protection. The selected dominant plants in non-degraded grassland were Kobresia pygmaea C. B. Clarke and Stipa purpurea Griseb. , in lightly degraded grassland Leontopodium nahum （ Hook. f. et Thorns. ） Hand. - Mazz. and Ajania tenuifolia （Jacq.） Tzvel were chosen, Potentilla bifurca L. and Saussurea arenaria Maxim were the dominant in heavily degraded grassland. The result of single root tensile test shows that the descending order of single root strength of these plants is Stipa purpurea Griseb. 〉 Kobresia pygmaea C. B. Clarke 〉 Leontopodium nahum （ Hook. f. et Thoms.） Hand. - Mazz. 〉 Potentilla bifurca L. 〉 Ajania tenuifolia （ Jacq. ） Yzvel. 〉 Saassurea salsa （Pall） Spreng, while the result of direct shear test shows that the descending order of root-soil composite systems shear strength is Kobresia pygmaea C. B. Clarke 〉 Stipa purpurea Griseb. 〉 Leontopodium nanum （ Hook. f. et Thorns. ） Hand. - Mazz. 〉 Potentilla bifurca L. 〉 Ajania tenuifolia （ Jacq. ） Tzvel 〉 Saussurea salsa （ Pall ） Spreng. The study has theoretical significance in investigating the mechanism of the alpine grassland plants for slope protection and in prevention and control of geological disasters such as water and soil loss, and shallow landslide in the region and other regions with the similar environmental conditions.
出处
《山地学报》
CSCD
北大核心
2014年第5期550-560,共11页
Mountain Research
基金
国家国际科技合作计划资助项目(2011DFG93160)
国家自然科学基金资助项目(41162010
41302258)
长安大学西部矿产资源与地质工程教育部重点实验室开放基金资助(CHD2011SY016)~~
关键词
黄河源区
高寒草地
植物护坡
根-土复合体
抗拉强度
抗剪强度
力学效应
the source area of the Yellow River
alpine grassland
slope protection with vegetation
root-soil composite systems
tensile strength
shear strength
mechanical effects
作者简介
李光莹（1989-）,男,硕士研究生,主要从事地质工程等方面的研究工作.E—mail：liguangying11@mails．ucas．cn
通信作者：胡夏嵩（1965-），男，教授。E-mail：hxs@mail．tsinghua．edu．cn
