Effect of Land Use on Water Erosion Override Impacts Associated with Climate

Abstract

Anthropogenic activities have dramatically changed land uses over the last century, which has considerably increased soil disturbance. Despite considerable attention paid to the effects of land use on soil erosion, it remains controversial as to how much land use and climate contribute to erosion. In this study, we conducted a comprehensive meta-analysis of 1,380 measurements from published studies using the 137 Cs method to examine the responses of erosion to land uses and climatic variables across terrestrial ecosystems in China. Our results showed that land use had significant impacts on the rate of erosion, with the lowest rates on natural and bamboo forests and the highest rates on farmland. Land use change of forest and grassland to farmland significantly increased erosion. Erosion rates respond significantly but differently to climatic variables in varying land use types. Correlations of erosion rates with mean annual temperature and precipitation were negative in forest ecosystems, positive in farmland, and nonsignificant in grassland. Variance partition analysis showed that land use types explained more of the variation in erosion rates than did environmental variables at a broad geographic scale, such as climate. This study highlights the importance of land use in affecting erosion rate. Incorporating these evidences into global erosion models may improve the simulation of long-term soil dynamics.