关键词: 白桦, 根系形态, 抗拉强度, 根土复合体, 三轴剪切

Abstract: The roots of Betula platyphylla, one of common tree species in the rocky mountain area of northern China was selected as the research object. The full excavation method was used to compare root length, root diameter and soil depth, and the root morphology model was established by using Sketchup Pro 8 software. The root tensile strength and shear strength of the soilroot composites was tested in the laboratory. The results showed that roots of Betula platyphylla vertical distribution was concentrated in the soil depth of 0-60 cm, playing an important role on slope shallow soil and water conservation. The root morphology simulated using software was closer to the actual. The root tensile strength and the diameter were proportional to the tensile strength, and decreased with the increasing diameter. The root system of Betula platyphylla can significantly enhance soil shear strength, and roots crossed in different ways, the shear strength of the root soil complex was also different．

Key words: Betula platyphylla, root morphology, tensile strength, soilroot composites, triaxial shear