Ecomorphodynamic Feedbacks and Couplings Between Landscape Subsystems Influence Barrier Island Response to Changing Climate
Wednesday, 17 December 2014: 3:10 PM
Because barrier islands are low-lying and dynamic landforms, their habitats are especially sensitive to changing environmental conditions. The continued existence of barrier island landforms will depend on the degree to which islands can maintain elevation above sea level while also responding to changes in forcing by migrating landward. We are increasingly learning that ecomorphodynamic interactions (i.e., interactions between ecological and morphodynamic processes) as well as couplings between island and back-barrier marsh environments play a critical role in determining how barrier island systems will evolve as sea level rises, storm intensity increases and the species composition of coastal vegetation changes in the future. Here, we present an overview and synthesis of recent and new model experiments and observations that illustrate the importance of feedbacks between vegetative and sediment transport processes as well as the importance of ecomorphodynamic couplings between landscape units in influencing 1) the rate of formation, maximum height and morphology of coastal dunes; 2) overall island state (high vs. low) and the potential for rapid transitions in state to occur in response to gradually changing forcing; and 3) the persistence of back-barrier marshes, and thus the influence of back-barrier marshes on the rate of migration of barrier island-marsh systems.