title: Biogenic crust dynamics on sand dunes.
abstract: Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in model studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fixed crusted dunes and fixed vegetated dunes at low wind power; and fixed vegetated dunes and active dunes at high wind power. These results suggest a crossover between two different forms of desertification.
authors.affiliation: Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel.
authors.forename: Shai
authors.initials: S
authors.lastname: Kinast
authors.forename: Ehud
authors.initials: E
authors.lastname: Meron
authors.forename: Hezi
authors.initials: H
authors.lastname: Yizhaq
authors.forename: Yosef
authors.initials: Y
authors.lastname: Ashkenazy
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D003889:Desert Climate; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D010944:Plants / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003102:Colloids; D012822:Silicon Dioxide