Effects of Fire on Succession

Fires affect vegetation by altering and/or maintaining successional stages. When fire was more frequent in the southern Appalachians, forest succession was maintained in the yellow pine (high fire frequency) or yellow pine-hardwood (moderate fire frequency) seral stages (Quartenman and Keever 1962, Komarek 1974, Hartnett and Krofta 1989) and fire-dependent or fire-associated species dominated many forest stands. In the absence of fire and other similar disturbances, forests in the southern Appalachians have gradually changed composition from pine and pine-hardwoods to communities dominated by hardwoods and some hemlock and white pine. When fire is excluded or suppressed, fire-intolerant hardwoods compete with pine species, lowering their survival until the next recruitment opportunity or fire (Clark 1991). In this way, fire drives forest succession by stabilizing or changing community composition (Buckner and Turrill 1999).