Hydrologic and aeolian controls on vegetation patterns in arid landscapes

Hydrological and aeolian processes redistribute sediments and nutrients within arid landscapes with important effects on the composition and structure of vegetation. Despite the relevance of wind and water erosion to the dynamics of arid and semiarid ecosystems, the interactions between these two processes remain poorly understood. In this paper we present the results of an intensive set of infiltration experiments from the Chihuahuan Desert, showing that in this system the infiltration capacity under the shrub canopy is lower than that at the outer edges of the vegetated patches. Hence, runoff is more likely to occur from the middle of these shrub-dominated areas to the edges. These experimental results show that the differential rates of soil deposition and removal by aeolian processes result in differential rates of hydrological processes such as infiltration and runoff with important implications for the formation and expansion of mesquite dunes in arid landscapes.