Effects of precipitation and restoration vegetation on soil erosion in a semi-arid environment in the Loess Plateau, China

Abstract

Soil erosion is a critical environmental problem of the Loess Plateau, China. As an important project for soil and water conservation in the semi-arid environment, the Grain-for-Green extensively transformed a wide range of farmland into vegetated land after the 1980s. Yet, the effects of vegetation restoration on soil erosion reduction are not well understood. In this study, we monitored runoff and sediment yield at sites restored with six typical restoration vegetation types including shrubs (Armeniaca sibirica, Spiraea pubescens and Artemisia coparia), grasses (Andropogon), and shrub-grass-compounds (Andropogon and A. coparia) in the Loess Plateau. We employed structural equation modelling (SEM) to systematically analyze the relative effects of precipitation and vegetation on soil erosion. The results showed that the runoff and sediment yield at the grasslands were significantly higher than other cover types. The shrub cover had the strongest soil conservation capacity of all restoration vegetation. SEM results showed varying impacts of precipitation (i.e., total amount and erosive rainfall intensity) on runoff and soil erosion under different vegetation types owing to differences in canopy structure and surface litter layer. Our study quantitatively revealed the interactive effects of precipitation and vegetation on runoff and sediment, which may be beneficial to conserving available water and soil resources in the semiarid environment. (C) 2015 Elsevier B.V. All rights reserved.