Identification of temperate rainforest environments in the Southern Appalachians

The natural vegetation of the Southern Appalachian region included exceptional cove forests exhibiting characteristics typically associated with temperate rainforest formations. Human impacts over the past few centuries have almost completely eliminated these exceptional forests. The distribution of environments capable of supporting these forests is controlled regionally by climate, and locally by topography. The Thornthwaite climatic classification is applied in the context of a GIS to identify the regional extent of the temperate rainforest (perhumid) climate under both average and drought conditions. A GIS database incorporating manually-derived topographic data and land use and forest vegetation data derived from a 1990 Landsat Thematic Mapper (TM) satellite image is developed for a local study area. The local GIS database is analyzed to determine if a spectral signature can be identified from the TM image that can be used to identify temperate rainforest environments. The perhumid climate area of the region covers approximately 5200 square miles and persists, though reduced in extent, even during extreme drought conditions. Twenty percent of the local study area is characterized by topographic sites favorable to the development of temperate rainforest communities. Analysis of the selected TM image did not identify a spectral signature that could be used to identify temperate rainforest environments. Extrapolation of the results from the local study area to the broader region suggests that 1000 square miles of the Southern Appalachian region are temperate rainforest environments. The conservation and restoration of the Appalachian temperate rainforest formation will contribute significantly to maintaining the biodiversity of the region.