Last of the Wild of the Northern Appalachian/Acadian

The Last of the Wild (LTW) of the Northern Appalachian/Acadian ecoregion are the 120 largest and wildest areas remaining in the ecoregion. The LTW are derived by taking the 10 largest areas in each ecological subregion (12) that have a Human Footprint score equal to or less than 10 (HF <= 10).The Human Footprint (HF) of the Northern Appalachian/Acadian ecoregion measures the extent and relative intensity of human influence on terrestrial ecosystems at a resolution of 90 m using best available data sets on human settlement (population density, dwelling density, urban areas), access (roads, rail lines), landscape transformation (landuse/landcover, dams, mines, watersheds), and electrical power infrastructure (utility corridors). The Human Footprint is calculated by assigning Human Influence (HI) scores of 0 to 10 to geographic data layers that map features of human activity. Where 0 is no human influence (no conversion from natural state) and 10 is maximum human influence (complete conversion e.g. urban areas, road surfaces). HI scores from assigned to data layers are combined together to calculate the Human Influence Index (HII), that measures total direct human impact.The Human Footprint is a relative measure of human impact - relative to the ecological context. The Human Footprint is calculated by normalizing the Human Influence Index (HII) within ecological subunits within the study area using the equation HFi = [(HIIi - HIImin_j) * 100] / (HIIma_j - HIImin_j) where i represents the cell and j represents the ecologic subunit of which the cell is a member.