夏季干旱时期根系固土主导力学因素分析与差异性评价

Analysis of the Mechanical Factors of Soil Reinforcement by Roots and Evaluation of the Differences Between 5 Kinds of Plants

以3~4年生（4年生为主）5种内蒙古干旱、半干旱地区常见的水土保持植物[柠条（Caragana microphylla Lam.）、白沙蒿（Artemisia sphaerocephala Krasch.）、沙棘（Hippophae rhamnoides Linn.）、沙柳（Salix psammophila C.Wang et Ch.Y.Yang.）和沙地柏（Sabina valgaris Ant.）]为研究对象,利用SAS 9.0软件对夏季土壤干旱时期影响5种植物根系固土的10项指标进行主成分分析。结果表明：根系的抗拉力学特性是影响5种植物根系固土的主导因素,其次为根-土界面摩阻特性,最后为根-土复合体抗剪特性;在此基础上,运用层次分析法对5种植物根系固土差异性进行评价,为了减少主观因素所带来的误差,将主成分分析所得3个力学特性的方差贡献率作为权重,5种植物根系固土指数分别为：柠条（0.954）〉沙地柏（0.084）〉沙柳（0.041）〉白沙蒿（-0.315）〉沙棘（-0.764）。

Taking 3-4year-old of Caragana microphylla Lam.,Salix psammophila C.wang et Ch.Y.Yang.,Sabina vulgaris Ant.,Artemisia sphaerocephala Krasch.and Hippophae rhamnides Linn.that were common used in soil and water conservation in the arid and semi-arid regions of Inner Mongolia as materials,the test was to explore the dominant mechanical factors of roots and the differences of soil reinforcement by roots between plants,and ten indicators of the mechanical properties of roots were analyzed by the principal component analysis（PCA）with the software of SAS 9.0.The results showed that the dominant factors of summer drought were in the sequence of the tensile mechanical property,the root-soil surface friction property,and the root-soil composite shear property.On this basis,five plants were evaluated by the method of analytic hierarchy process（AHP）.In order to reduce the error caused by subjective factors,the variance contribution rate of PCA of the three mechanical properties were used as evaluation weight of AHP.The index of soil-reinforcement by roots were Caragana microphylla Lam.（0.954）〉Sabina vulgaris Ant.（0.084）〉Salix psammophila C.wang et Ch.Y.Yang.（0.041）〉Artemisia sphaerocephala Krasch.（-0.315）〉Hippophae rhamnides Linn.（-0.764）.