Effects of different types of vegetation recovery on runoff and soil erosion on a Wenchuan earthquake-triggered landslide, China

Abstract

In order to find suitable vegetation types for wider earthquake-triggered landslide rehabilitation in the eastern Longmenshan, we chose six vegetation types, which included three artificial restoration vegetation types (shrub <i>Paeonia decomposita,</i> deciduous tree <i>Betula albo-sinensis,</i> and evergreen tree <i>Cryptomeria fortunei</i>), two natural restoration vegetation types (middle and high coverage of grasses), and one residual vegetation. Soil quality, runoff, and soil loss were evaluated for the six vegetation types. We found that high coverage of grass prevented surface runoff and soil erosion more effectively than other vegetation types, and the deciduous tree and shrub were more suitable for soil quality recovery than the evergreen tree after the landslide. Among the three artificially planted vegetation types, the roots of the deciduous tree had stronger expansion ability than those of the shrub and evergreen tree. Our results indicated that high coverage of grass and deciduous trees could complement each other to achieve a good restoring effect, which would not only help reduce surface runoff and soil erosion but also facilitate the formation of fertile islands and enhance the stability of subsurface soils. Therefore, the two vegetation types could be used to form an effective vegetation restoration pattern for wider earthquake-triggered landslide rehabilitation in this region.