Effects of the root morphological characteristics of different herbaceous species on soil shear strength and soil anti-scourability in the dry-hot valley region of South-western China

Abstract

Planting vegetation in the dry-hot valley region of South-western China has proven to be an effective measure for controlling the development of gullies. However, the mechanisms responsible for this effectiveness remain unclear. In this study, five plots, each containing a different herbaceous species, were chosen to explore the effects of their root morphological characteristics on soil shear strength and soil anti-scourability. Our results showed a significant difference among the root morphological characteristics of the five species. In addition, the soil shear strengths of the vegetated plots were greater than that of the bare plot. This study demonstrated a significant positive correlation for root weight density among the different plots. Moreover, the runoff sediment was logarithmically related to time, and the root volume density was linearly related to soil anti-scourability, although exponentially related to soil detachment rate. These findings improve the understanding of the effects of different root morphological characteristics on soil shear strength and soil anti-scourability. We expect that these research results will provide a theoretical background for further study of plant species selection during the practice of soil and water conservation in the dry-hot valley region of South-western China.