Responses of wind erosion to climate-induced vegetation changes on the Colorado Plateau

TitleResponses of wind erosion to climate-induced vegetation changes on the Colorado Plateau
Publication TypeJournal Article
Year of Publication2011
AuthorsMunson SM, Belnap J, Okin GS
JournalProceedings of the National Academy of Sciences
Volume108
Issue10
Pagination3854-3859
Accession NumberJRN00582
Keywordsarid, climate change, Colorado Plateau, horizontal flux, land use, national park, threshold shear velocity, vegetation change, wind erosion
Abstract

Projected increases in aridity throughout the southwestern United States due to anthropogenic climate change will likely cause reductions in perennial vegetation cover, which leaves soil surfaces exposed to erosion. Accelerated rates of dust emission from wind erosion have large implications for ecosystems and human wellbeing, yet there is poor understanding of the sources and magnitude of dust emission in a hotter and drier climate. Here we use a two-stage approach to compare the susceptibility of grasslands and three different shrublands to wind erosion on the Colorado Plateau and demonstrate how climate can indirectly moderate the magnitude of aeolian sediment flux through different responses of dominant plants in these communities. First, using results from 20 y of vegetation monitoring, we found perennial grass cover in grasslands declined with increasing mean annual temperature in the previous year, whereas shrub cover in shrublands either showed no change or declined as temperature increased, depending on the species. Second, we used these vegetation monitoring results and measurements of soil stability as inputs into a field-validated wind erosion model and found that declines in perennial vegetation cover coupled with disturbance to biological soil crust resulted in an exponential increase in modeled aeolian sediment flux. Thus the effects of increased temperature on perennial plant cover and the correlation of declining plant cover with increased aeolian flux strongly suggest that sustained drought conditions across the southwest will accelerate the likelihood of dust production in the future on disturbed soil surfaces.

URLfiles/bibliography/JRN00582.pdf
DOI10.1073/pnas.1014947108