植物枝叶与根系固土抗蚀差异性研究

发布时间：2018-03-06 22:20

本文选题：根系　切入点：固土　出处：《内蒙古农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以3-4年生(4年生为主)5种内蒙古中西部地区常见的水土保持植物：柠条(Caragana microphylla Lam.)、沙柳(Salix psammophila C.wang et Ch.Y.Yang)、沙地柏(Sabina vulgaris Ant.)、白沙蒿(Artemisia sphaerocephala Krasch.)和沙棘(Hippophae rhamnoides Linn.)为研究对象,对饱和含水率条件下5种植物根-土复合体抗剪特性、影响5种植物根系固土主导力学因素、5种植物根系固土能力差异性和除沙地柏以外的4种植物枝叶与根系固土抗蚀差异性进行研究,得出以下结论：(1)针对春季土壤干旱和夏季土壤饱和含水两种条件,对影响5种植物根系固土的10项指标(直根抗拉强度、代表根本构特征、代表根弹性模量、侧根分支处抗拉强度、累计根表面积、拉拔摩阻特性、根-土界面摩擦系数、累计根长、根-土复合体粘聚力、根-土复合体内摩擦角)进行主成分分析。结果表明,根系抗拉力学特性是影响植物根系固土的主导力学因素,其次为根-土界面摩阻特性,最后是根-土复合体抗剪特性。(2)在主成分分析结果基础上,对两种条件下5种植物根系固土能力的差异性进行评价,结果显示,根系固土指数为：春季土壤干旱,柠条(0.834)沙柳(0.303)＞沙地柏(-0.066)白沙蒿(-0.206)沙棘(-0.864)；夏季土壤饱和含水,柠条(0.876)＞沙地柏(0.218)沙柳(0.065)白沙蒿(-0.404)沙棘(-0.755)。建立根系固土理想模型,对10项指标的最优值进行评价,结果显示,春季土壤干旱和夏季土壤饱和含水条件理想模型的固土指数分别为1.415和1.485。(3)针对春季大风和夏季土壤饱和含水两种条件,在10项根系固土指标的基础上增加3项防风指标(单株防风效能、林带防风效能、群落防风效能)。两个时期4种植物枝叶与根系固土抗蚀的差异性评价结果表明,枝叶与根系固土抗蚀指数为：春季大风,沙柳(0.841)柠条(0.454)白沙蒿(-0.466)沙棘(-0.829)；夏季土壤饱和含水,柠条(0.841)沙柳(0.474)白沙蒿(-0.470)沙棘(-0.844)。春季大风和夏季土壤饱和含水条件下,理想模型固土抗蚀指数分别为1.393和1.442。(4)饱和含水率条件下,根-土复合体抗剪强度在5种植物间差异显著。5种植物根-土复合体的抗剪强度在4种垂直荷载下均高于素土。在根系密集分布层内,根-土复合体抗剪强度的大小排序依次为：沙柳沙地柏沙棘柠条白沙蒿。5种植物根-土复合体粘聚力值均高于素土,变化范围为14.76%-21.50%,内摩擦角变化规律不明显,变化范围为-4.90%-5.16%。
[Abstract]:In this paper, 3-4 years old (4 years old, 5 species of common soil and water conservation plants in central and western Inner Mongolia: Caragana microphylla Lam.Zhang, Salix psammophila C. Wang et Ch.Y.Yang, Sabina vulgaris Ant., Artemisia sphaerocephala Krasch.) and Hippophae rhamnoides Linn. were studied. The shear resistance of five plant root-soil complexes under saturated water content was studied. The main mechanical factors affecting the soil fixation of five plant roots were studied. The differences of soil fixation ability of five plant roots and the soil fixation resistance of four plants except cypress were studied. The following conclusions can be drawn as follows: (1) in view of the soil drought in spring and saturated water in summer, 10 indexes (tensile strength, root tensile strength, root elastic modulus and elastic modulus of root) affecting the consolidation of 5 plant roots are studied. The principal component analysis was carried out on the tensile strength, cumulative root surface area, pullout friction characteristics, friction coefficient of root-soil interface, cumulative root length, adhesion of root-soil complex and internal friction angle of root-soil complex at lateral root branch. Root tensile properties are the dominant mechanical factors affecting the soil fixation of plant roots, followed by the root-soil interface friction characteristics, and finally the root-soil complex shear resistance. 2) based on the results of principal component analysis, The difference of soil fixation ability of root system of five plants under two conditions was evaluated. The results showed that the soil fixation index of root system was: spring soil drought, Caragana korshinskii 0.834) Saussuliu 0.303) > Phellodendron spp. -0.066) Artemisia artemisia-0.206) Hippophae rhamnoides in summer, the saturated water content of soil in summer. Caragana korshinskii 0.876) > Phellodendron korshinskii 0.218) Sagittio (0.065)) Artemisia albicans (-0.404)) Hippophae rhamnoides L. ideal model of soil fixation by root system was established, and the optimum values of 10 indexes were evaluated, the results showed that, The soil consolidation index of the ideal model of soil drought in spring and saturated water in summer is 1.415 and 1.485.53 respectively. On the basis of 10 soil fixation indexes of root system, there were 3 wind-proof indexes (wind-proof efficiency of single plant, wind-proof effect of forest belt, wind-proof effect of community). The results showed that the difference of erosion resistance between branches, leaves and roots of four plants in two periods was significant. The soil erosion resistance index of branches, leaves and roots were: spring gale, Phyllostachys korshinskii (0.841)) Caragana korshinskii (0.454)) Hippophae rhamnoides, (-0.466) Hippophae rhamnoides, summer soil saturated water content, Caragana korshinskii (0.474)) Hippophae rhamnoides (-0.844). Under the condition of saturated water content of the ideal model, the corrosion resistance index of the solid soil is 1.393 and 1.442.t4, respectively. The shear strength of root-soil complex was significantly higher than that of plain soil under four vertical loads, and the shear strength of root soil complex was higher than that of plain soil under four vertical loads. The order of shear strength of root-soil complex is as follows: the cohesion of 5 species of Artemisia korshinskii is higher than that of plain soil, the range of variation is 14.76 -21.50, and the change of internal friction angle is not obvious, ranging from -4.90 to 5.16.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S157

【参考文献】