ABSTRACT
Roots have been adopted for soil mechanical reinforcement for centuries (Smith and Snow, 2008). Plant roots provide tensile strength to soil, and thus, understanding the biomechanical properties of roots, such as tensile strength and Young’s modulus, is crucial for estimating the extent to which plant roots can mechanically reinforce soil (Wu et al., 1979; Mickovski et al., 2007). The recent state of the art in slope stability improvement can be found in many books (e.g., Coppin and Richards, 1990; Barker, 1995; Gray and Sotir, 1996) and four conference proceedings for the International Conference of Soil, Bio- and Eco-Engineering: The Use of Vegetation to Improve Slope Stability (Stokes et al., 2004, 2007; Hubble et al., 2017). Most of these studies focused on the root biomechanical behaviour of plant species native to America and Europe, and in general, they adopted the negative power (or power decay) law as an empirical expression to explain the relationship between root tensile strength (or sometimes root Young’s modulus) and root diameter. This chapter provides an update on the root biomechanical properties of some of the plant species native to Asia and also evaluates the applicability of the negative power law to a wide range of root diameters. The possibility of using microorganisms (fungi) to enhance root biomechanical properties is also explored.
