Saltwater intrusion from Hurricane Sandy induced tree mortality in tidal freshwater swamps on the Delmarva Peninsula, Mid-Atlantic coast, USA
After hurricanes, coastal freshwater swamps damaged by saltwater surge may have a different trajectory than those damaged by wind. This study compares salinity versus wind-driven effects of hurricanes by comparing structural damage and regeneration dynamics in Taxodium distichum swamps following Hurricanes Sandy versus Katrina, with landfalls on the Atlantic Coast in October 2012 and Gulf of Mexico in August 2005, respectively. Ground surveys of downed and standing tree structure (height and dbh), mortality and canopy coverage were conducted.
After Hurricane Sandy, certain study swamps long the Pocomoke River (MD) within 6 km of Chesapeake Bay had elevated salinity so that many individuals of salinity intolerant species died (e.g., T. distichum). In contrast, tree damage was wind-related after Hurricane Katrina along the Pearl River (MS), where T. distichum had little structural damage and high levels of conspecific regeneration. The long-term consequences of hurricane–related disturbances depend on the specific tolerances of tree species to salinity intrusion versus wind breakage, as well as post-hurricane environments for regeneration. Future forest composition is likely to be very different following wind versus salinity impacts related to hurricanes.