A bare coastal georgian spoil area located in a smooth cordgrass(spartina alterniflora loisel.) Salt marsh was channelized by usingan amphibious rotary ditcher to evaluate its use in marsh restoration. The method has been found to offer an inexpensive and rapid, yetsafe, technique of wetland mitigation in salt marshes that exhibit the proper hydrological and elevational characteristics. Amphibious rotary ditching has been found to have less of an impact on the marsh than excavation, which usually requires large earth-moving equipment, earth mats, site access, and traffic control. The surcharge is dispersed evenly to either side of the ditcher onto the marsh; thus, an upland dispoal site is not required. In this case, the impact from the rotary ditcher's tracks and sidecast material to the existingsalt marsh communities surrounding the spoil was temporary. Recovery and even enhancement of existing s. Alterniflora communities has been rapid. Compared with an unchannelized (reference) spoil area, the marsh restoration channel has increased tidal frequency, duration, and flushing during ebb tide. In spite of drought, s. Alterniflora coverage on the channelized spoil zone more than doubled over the first 2 years after the construction of the channel. Remote sensing using aerial photography has revealed a 42% decrease in unvegetated area on the channelized site. This paper appears in transportation research record no. 1224, Rest areas, wetlands, and hydrology.
Samenvatting