Fig. 2. The example discussed in the text is based on land cover and roads near Raleigh-Durham airport (North Carolina). The two maps at the top of the figure illustrate Method 1, and the two maps at the bottom of the figure illustrate Method 2. Upper left: generalized land-cover map. The labeled features are: (A) Research Triangle Park, (B) Raleigh-Durham airport, (C) interstate highway 40, (D) William B. Umstead State Park, (E) U.S. highway 70, and (F) the residential district of Raleigh. Lower left: land cover with road map superimposed. Upper right: forest vs. nonforest from map of generalized land cover. Lower right: forest vs. nonforest from map of land cover with roads superimposed. The fragmentation indices shown in Table 1 were calculated from the forest-nonforest maps (upper right and lower right).