Characterizing grass root exposure due to wind erosion in the Chihuahuan Desert

Drylands account for roughly 40% of the Earth's net primary productivity (NPP). Land use change in arid environments, particularly from woody shrub encroachment, has the potential to change NPP. Aeolian processes and vegetative composition are intrinsically coupled in arid environments. Our study examines this dynamic by posing the question: how does the density of grass cover influence root exposure? We collected data at six sites in the northern Chihuahuan Desert with varying densities of grasses (Bouteloua eriopoda, Sporobolus spp., and Aristida spp.). Line point intercept transects were used to determine the density of grass cover. Then, the direction and degree of root exposure was measured by using modified gap and belt transects. Our results suggest that lower vegetative coverage is associated with increased levels of upwind facing root exposure. These results will shed light on how wind erosion affects NPP, and the longevity of arid grasslands undergoing woody shrub encroachment.