Are Crown Fires Necessary For Table Mountain Pine?
Ridgetop pine communities of the southern Appalachian Mountains have historically been maintained by lightning- and human-caused fires. Because of fire supression for several decades, these stands are entering later seral stages. Such stands typically have an overstory of Table Mountain Pine (Pinus pungens) that is being replaced by shade tolerant chesnut oaks (Quercus prinus). The shrub layer consists of dense mountain laurel (Kalmia latifolia). Previous research suggests that restoration of these communities can be accomplished with high-intensity fires that open the forest canopy and expose mineral soil. Three recent studies examined plant-community response to high-intensity prescribed fires. A series of four supporting studies helps to explain some of the results of these field studies. High- and medium-high-intensity fires provided adequate sunlight for pine seedlings, whereas medium-low- and low-intensity fires did not. Post-burn duff was deep (<5 cm) and did not vary by fire intensity. We observed sufficient seedling densities to restore pine-dominated stands (<9,000/ha) after all but the highest intensity fires. Many seedlings survived the first growing season as their roots penetrated duff to reach mineral soil. Hardwood rootstocks resprouted on sites treated with all fire intensities and may out-compete pine seedlings. High-intensity fires may have reduced mycorrhizal abundance and moisture availability for new germinants. Fires of lower intensity than previously recommended or multiple fires of very low intensity may provide the best conditions for pine regeneration.