PARENT SESSION
Poster Session #13: Salt Marshes.
Monday, August 5. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC
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Functional equivalency of created to natural salt marshes in southwest Louisiana.
EDWARDS, KEITH*,1, PROFFITT, CHARLES2, 1 McNeese State University, Lake Charles, Louisiana2 National Wetlands Research Center, Lafayette, Louisiana
ABSTRACT- Louisiana is losing coastal wetlands at a rapid rate. To combat these losses, dredged material is being used to restore and create coastal salt marsh habitat in Louisiana and this technique is expected to become more common as a restoration method throughout the Gulf of Mexico coast. However, it is questionable whether this method is successful in producing salt marsh systems whose functions mirror those of natural, nearby wetlands. We compared biotic and abiotic factors between created salt marshes, formed by the pumping of dredged material into formerly open water areas, and natural salt marshes in the Hog Island area of the Sabine National Wildlife Refuge in southwest Louisiana. The created marshes range in age from 5 to 19 years. As the created marshes aged, their species cover came to resemble that of the natural marshes, but only in the lower elevation zones of these older created marshes. Likewise, decomposition rates of Spartina alterniflora, the most common plant species, were similar in natural marshes and the lower elevational areas of the created marshes, but were slower in the high elevation zones of the created marshes, regardless of marsh age. Above and belowground production also differed between natural and created marshes. Percent soil organic matter was significantly lower, while soil bulk density was much higher, in all of the created marshes compared to the natural marshes. How quickly dredge-filled salt marshes begin to resemble functionally natural salt marshes appears to be influenced by marsh elevation as well as age. In addition, it appears that soil properties will take longer than vegetative factors to become similar between the created and natural salt marshes.
KEY WORDS: Dredged material, Spartina alterniflora, Salt marsh