Secondary conservation areas, consisting of those elements of the natural landscape that are not protected by law, but the maintenance of which in their natural state would provide environmental, aesthetic, pastoral, historical, or other value to the environment or community, such as flood hazard areas, floodplains, steep slopes (typically greater than 25%), mature woodlands [noninvasive trees with caliper of 20 inches or greater (measured at four feet)], wetland buffer zones, vernal pools, prime farmland, large open meadows, stone walls, critical wildlife habitats, priority habitats (as designated by Natural Heritage and Endangered Species Program) and important cultural features such as historic and archaeological sites, heritage landscapes and scenic views.