Root System Traits and Mechanical Properties of Three Shrub Species: Implications for the Structural Stability of the Ecological Slope

The purpose of this paper is to find the shrub species more suitable to enhance the structural stability of the ecological slope in the study area. Through the investigation, we found three common shrubs, there are Amorpha fruticosa Linn. (AFL), Syringa oblata Lindl. (SOL) and Forsythio mandshurica Uyeki. (FMU). In this study, the root system traits and mechanical properties were characterized and described using reliable experimental approaches. The results shown that the root withdrawal force was proportional to diameter (from 0.6-6 mm). The mean specific root length, individual length, surface area, and mean diameter of fine roots in different slopes were higher for AFL and SOL than for FMU, especially for high root orders. Although previous studies have focused on the relevant content, the reinforcement ability of different shrubs is rarely quantitatively compared under the same road conditions. Moreover, the morphology traits of the fine root were considered in this study. These results suggested that the root system traits and mechanical properties of AFL would enable more effective consolidated slopes structure than SOL and FMU, revealing that planting AFL might be a better way for enhancing ecologicalslope structure stability.