The edge disturbance zone is the region along the polygon's periphery that can be influenced, and possibly degraded, by the external environment. The width of these edge disturbance zones varies with the issue or species of study. In the ecological literature, the edge widths can range from 25 meters to several hundred meters depending on species and the land cover type of the surrounding environment. Timber harvest may be affected by edge zones since areas directly adjacent to developed areas are typically not suitable for harvest. For general purpose studies, we typically use 100 meters as the width of the edge disturbance zone.