POST-HURRICANE INTERACTIONS BETWEEN VEGETATION DYNAMICS, DUNE RECOVERY, AND PHYSICAL GRADIENTS ON BARRIER ISLANDS

Northwest Florida has been exposed to many extreme storm events during the past few years, resulting in varying impacts on the dune morphology of the barrier island. Post-hurricane dune recovery depends on the establishment of vegetation which in turn depends on sediment mobility, exposure to salt spray and topography. In this study the environmental gradients on Santa Rosa Island were examined after significant morphological changes during Hurricanes Ivan and Dennis. Wind speed, salt spray and sediment movement were measured for a one month period at sites that are representative of the range of hurricane changes to the island morphology (from low impact to breeches). Preliminary results suggest that strong environmental gradients exist and that the gradients are different between sites, largely in response to the pattern of vegetation. This suggests that the level of impact, and the resulting distribution of vegetation, affects the rate and pattern of dune recovery.