Some ecosystems depend on periodic fires to maintain the habitats which make up the ecosystem. In these fire adapted areas, fire promotes plant and wildlife diversity and burns away accumulations of live and dead plant material (leaves, branches, trees).

FIRE DEPENDENT ECOSYSTEM MAP
• Oak-hickory forests are common in Pennsylvania, West Virginia, Kentucky, Tennessee, and many other states. • Natural fires occurred in oak-hickory forests at intervals of 25 years or less. • Native Americans burned some of these forests very often, possibly every year or two. • Most oaks have thick bark so they can survive surface fires. Both oaks and hickories sprout from the base of the trunk after fire. • Fires remove shade and deep litter on the forest floor, creating perfect conditions for oaks and hickories to reproduce. • Oaks and hickories don't reproduce well in shade, so other tree species take over if the forest doesn't burn for a long time.