Feedbacks between vegetation and morphology on barrier islands

Vegetation is a key contributor to the development of topographic relief on barrier islands, and thus can be influential in determining barrier island susceptibility to overwash. As global temperatures increase, cool-weather grasses that build continuous dunes in the mid-Atlantic coastal zone may be replaced by warm-weather grasses that create hummocky, discontinuous dunes—a change which will likely affect spatial variability in overwash vulnerability. Furthermore, as overwash events become more frequent, dune-building grasses (which increase topographic relief and thrive at high elevations) may be replaced by overwash-adapted maintainer species (which stabilize flat topography and thrive at low elevations), thereby increasing the likelihood of future overwash and reinforcing continued disturbance. We are using both field-based and numerical modeling approaches to investigate the complex, interacting roles of vegetation, sediment, and external physical drivers in barrier island evolution and response to changing climate conditions.