Hurricanes are important forces that sculpt landforms within coastal wetlands and influence their ecology through effects on physical, chemical, and biological processes. In addition, sea-level rise and land subsidence are long-term processes that affect coastal areas, as in the Mississippi River Delta Complex (MRDC), which contains >40% of the Nation's wetlands. Intertidal plants, like mangroves and salt marsh grasses, are important in promoting accumulation of sediments and organic matter, thereby building the soil resource and maintaining wetland elevation as sea level rises. Species shifts may make wetlands more vulnerable to sea-level rise, depending on the species' capacities to build marsh elevation. This project will take advantage of recent hurricane events, Hurricanes Gustav and Ike that made landfall in September 2008 near Port Fourchon, Louisiana to compare the capacity of mangrove and salt marsh ecosystems to capture sediment, create a barrier to sediment delivery, stimulate organic matter contributions to soil, and increase elevation in coastal areas. This information becomes increasingly important if sea-level rise and hurricane intensity and frequency increase with global climate change as predicted.
Understanding how hurricanes interact with processes controlling coastal elevations is essential to developing sound plans to conserve and protect these ecosystems and the services they provide. The sustainability of coastal wetlands in the MRDC is critical not only as a natural resource and for seafood production, but also for their key role in protecting the ports of New Orleans and Port Fourchon, through which nearly 30% of the nation's energy resources and foreign imports pass.
