Root biomass and root morphological traits of three shrub species: Implications for the soil anti-scouring resistance of the ecological slope

The purpose of this study was to determine which shrub species will enhance soil anti-scouring resistance on an ecological slope. Root traits and soil anti-scouring resistance of three shrubs (Amorpha fruticosa Linn (AFL), Swida alba Opiz (SAO) and Lespedeza bicolor Turcz (LBT)) were measured. Results showed that root biomass and root morphological traits of three shrubs were significantly correlated with the soil anti-scouring resistance index. According to the composition characteristic values, root morphological traits among the three shrubs had a high contribution rate. Under two slopes and two rainfall conditions, when root biomass and root morphological traits (e.g., root length, root volume and root surface area) were identical, AFL had the highest soil anti-scouring resistance index. These results suggested that root biomass and morphological traits of AFL had more significant effects on soil anti-scouring resistance comparing with SAO and LBT. Therefore, in engineering practice, AFL with stronger soil anti-scouring resistance can be selected as slope plants.