In developing conservation policy, identifying the main threats and quantifying the current status of key resources is fundamental. Forested wetlands in the southeastern U.S. provide a suite of critical ecosystem services (habitat/biodiversity, water quality, protection from extreme events), yet, relative to a pre-settlement baseline is been poorly understood at present. Not only is the original extent of forested wetlands is only partially captured by geographic databases such as the National Wetlands Inventory, but the current condition (impounded, cleared for agriculture, converted to pine silviculture, developed, recently harvested) is also difficult to determine with confidence from existing data sources such as the U.S. Forest Service’s Forest Inventory and Analysis. As such, there is a need for better quantification of both the likely baseline extent and of the current management of this ecosystem. Using the Coastal Plain of Georgia as a pilot region, we use a species distribution modeling approach to identify the probable historic extent of forested wetlands from known forested wetland locations. Then using this modeled extent as a mask, we classify Landsat imagery to quantify current land use and land cover within the mask.
Results/Conclusions
Our results suggest that the original extent of forested wetlands in the Georgia Coastal Plain may have been >10% larger than currently. Based on our classification of Landsat imagery, major threats to forested wetlands appear in order of magnitude to be impoundment, conversion to pine silviculture, agricultural conversion, and coastal development. Thus, conservation of forested wetlands is best promoted by restoring hydrology (in the case of the first three threats) and by better regulation of future coastal development.