QUANTIFYING DUNE FIELD REACTIVATION POTENTIAL: EXPERIMENTS AND ANALYSES FROM THE NORTHERN GREAT PLAINS
We ask: will these dunes reactivate in the near future? We first develop a framework to define the reactivation state of dune fields. We split the role of vegetation in dune fields into: (i) suppression of blowout advance, and (ii) resistance to disturbance. These two roles are mechanistically distinct and can be evaluated separately. Together, the two variables yield 4 reactivation states: (i) stable, (ii) blowout dominated, (iii) reactivating, or (iv) stable but disturbance susceptible. We detail experiments to artificially reactivate blowouts in the Middle Sand Hills (Canada), demonstrating the roles of various types of disturbance. Finally, we demonstrate a GIS methodology to quantify the present capacity of the dune field to resist disturbance. We explore how the dune field’s ‘ability to heal from disturbance’ changes under different climates and the implications for the future.
Reactivation of even a portion of Great Plains dune fields (total area ~ 182,000 km2) could result in dramatic economic losses. Our work helps develop some basic prediction tools to evaluate the future vegetation cover of this substantial and valuable land base.