The potential for using soil carbon, soil texture, and elevation as indicators of grass-cover response in Chihuahuan Desert grassland restoration practices

Abstract

Estimating how effective shrub removal treatments will be in desert grassland restoration is a significant challenge for land managers. We investigated whether soil and site-level properties could serve as indicator variables for grass response following shrub removal in the Chihuahuan Desert. Our study took place in southwest New Mexico, at shrub removal sites established by the Restore New Mexico (RNM) program 10 years before our sampling efforts. At each site, we sampled soils and analyzed them for organic carbon (SOC), texture (% sand, silt, and clay), and pH. Site-level grass % cover data from before and after shrub removal was used to calculate grass response (GGS) to shrub removal treatment relative to controls. GGS was positively related to SOC, with a stronger relationship for soils from under shrub canopies. GGS was also strongly related to soil texture (% sand and % silt), and positively correlated with site average annual rainfall and elevation. Elevation was also related to SOC, soil texture (% sand and silt), and average annual rainfall. Our study found that soil and site properties, such as soil carbon, soil texture, and elevation, could potentially serve as useful indicators of grass response to shrub removals and suggest further exploration of these possibilities in Chihuahuan Desert restoration practices.