The effect of Persian oak species (Quercus persica) in soil reinforcement (Case Study: Tabarok, Bazaft basin)

Vegetation enhances the soil resistance against instability and erosion through increasing the soil cohesion. The main effect of vegetation in stability improvement is soil reinforcement by roots. The amount of reinforcement depends on distribution and strength of roots. The aim of this study was to assess the quantity of these two parameters of Persian oak roots and also comparing the tensile strength and reinforcement effect of roots in winter and summer seasons. Damage survey method was used to assess the distribution of roots. The diameters of all roots in trenches were measured by a digital caliper. Some root specimens were randomly selected from five tree samples and their tensile strengths were measured using a standard Instron. The range of root diameter and corresponding force and tensile strength were 0.1-5.5 mm, 1.3-411.3 N and 0.93-1217.39 MPa, respectively. Maximum and minimum root densities were in 0-10 and 50 cm soil horizons. The maximum reinforcement effect was belong to winter and 0-10 cm horizon. Minimum and maximum reinforcement effects for winter season were 0.0001 and 3.37 and 0.0004 and 2.87 MPa for summer.