Elevation and Salinity Effect on Vegetation in a Created Tidal Marsh in Eastern North Carolina

摘要

The goal of wetland restoration/creation projects is to construct a wetland that exhibits the same beneficial functions as the targeted wetland community in the most efficient manner possible. Research conducted on a recently completed seven-hectare (17 acres) tidal marsh in Carteret County, North Carolina helped to quantify planting success of common North Carolina tidal wetland vegetation within the first growing season. A review of literature and surveys of local reference tidal marshes indicatednative plants in these areas were distributed at distinct elevation ranges, but little information was available on the success of these species when planted at these elevations during marsh creation or restoration. Some specific research objectives were1. To quantify the success of greenhouse-propagated Spartina alterniflora, Spartina patens, Juncus roemerianus and natural regeneration in each target elevation range 2. To quantify hydrology and salinity gradients between the specified elevation rangesand 3. To determine if a relationship exists that affects vegetation success. The experimental design for this research included three-4x4 Latin square replicates at three distinct elevation ranges along the newly constructed tidal stream. Each of the nine squares included S. alterniflora, J. roemerianus, S. patens, and an unplanted control. In each square, one water table monitoring well and two water quality wells, used to monitor salinity, were installed. Preliminary results indicated that plantinggreenhouse-propagated vegetation yielded a more rapid marsh establishment than depending on natural regeneration. Aerial photographs and stem counts have indicated that J. roemerianus and S. patens both established well in the mid elevation (0.67 m -0.8m MSL) and high elevation squares (0.8 m - 0.91 m MSL). Spartina alterniflora established well in the lower elevation squares (0.5 m - 0.67 m MSL). The success of vegetation at these elevations has been affected by the tidal fluctuations and precipitation patterns. All of these factors continue to be studied.