Historically, wildfires played a central role in the creation and / or maintenance of prairie and savanna conditions. In the Midwest due to the fragmentation of the landscape through developement, wildfires are infrequent and quickly suppressed. Prescribed burns mimic this lost natural process. Since fire impacts the above ground growth of woody species where they have stored energy reserves that are combusted, herbaceous species are favored since their perennial growth is below ground in the Midwest. Many species of oaks have thick bark that protects them from the effects of fire relative to other tree species. Elemental to conductng prescribed burns is the creation of a Burn Plan. It is important to protect sections of any given remnant from fire so that the entire is never burned at once since many insects overwinter on the above ground plant tissue, amongst other reasons.