Evaluating mechanical properties of seedling roots of some tree species

Abstract

The mechanical behavior of vegetation roots significantly affects the mechanism of soil reinforcement and slope stability. The aim of the present study was to determine the mechanical properties of seedling roots of some tree species in the second district of Kheyrud forest. Ten samples of each species (beech (Fagus orientalis Lipsky.), hornbeam (Carpinus betulus L.) and, maple (Acer velutinum Boiss.)) completely extracted from soil and all roots were collected, then their mechanical properties were measured in the labratory. The results showed that in all species, the relation between root diameter and tensile force, was positive power law whereas the relation was negative power law for root diameter and tensile strength and also Young’s modulus. Results of ANCOVA showed that tensile force, tensile strength, and Young’s modulus were significantly different among species. Accordingly, the average tensile force and tensile strength for hornbeam species were 48 and 40% higher than beech and maple species, respectively and the average Young's modulus of beech species was 38% higher than hornbeam and maple species. The findings of this work show that the mechanical properties of the roots can be used as an indicator in selecting species for soil bioengineering purposes. Therefore, it is recommended that these properties be considered in soil reinforcement modeling.

Keywords

• soil protection
• tree species seedling
• young’s modulus of roots
• root mechanics