Stand Dynamics and Fire History of a Southern Appalachian Pine-Hardwood Forest on Rainy Mountain, Chattahoochee National Forest, Georgia, U.S.A.

In the American Southeast, forest managers and conservationists are interested in evaluating how forest composition is changing in response to both human and natural disturbances. This study explored the stand dynamics of a pine-hardwood forest on Rainy Mountain in the Chattahoochee National Forest of Georgia over the last 115 years and analyzed the role fire has had as a disturbance in the forest. Increment cores were collected from trees in 30 plots, each 0.01 ha in area. The cores were used to determine date of establishment of each tree and create age structure charts for each plot and for the study area as a whole. Based on calculated importance values, blackgum, pitch pine, and red maple are currently the dominant species in the forest. However, seedling and sapling surveys showed an absence of yellow pine regeneration along with a relative abundance of red maple and blackgum, indicating that these trees will dominate the future forest. A concurrent fire history was also constructed using logs, stumps, remnant wood, and living trees with fire scars. Small sections were collected from each and analyzed to determine how frequently fires occurred in the Rainy Mountain area. The resulting fire chronology, the first developed for the state of Georgia using dendrochronology, spans from 1904 to 2012 and includes 36 individual dated fire scars from 20 trees. Fires occurred as recently as 2010, and the mean fire interval of the chronology indicates a fire event approximately once every four years. Several old stumps with fire scars were also collected, but could not be dated in many cases because of the lack of a sufficiently long master tree-ring chronology. Similar to other research conducted in the southern Appalachian Mountains, this study shows a change in forest composition from a pine-oak dominated forest to a red maple-blackgum dominated forest, a change that has previously been linked to fire suppression management policies beginning in the 1930s. However, the fire chronology at Rainy Mountain shows an actual increase in fire frequency after the 1930s accompanied by a concurrent change in forest composition.