Authors: William T Flatley*, University of Central Arkansas, Lillian E McDaniel, University of Central Arkansas, Don C Bragg, USDA Forest Service, Southern Research Station
Topics: Biogeography, Physical Geography, Anthropocene
Keywords: fire history, Ouachita Mountains, shortleaf pine, dendrochronology, forest dynamics
Session Type: Virtual Paper
Start / End Time: 9:35 AM / 10:50 AM
Room: Virtual 30
Presentation File: No File Uploaded
Forest conditions characterized during initial EuroAmerican settlement are often used as reference conditions for restoration. However, fire history reconstructions demonstrate that fire frequency increased during the initial arrival of EuroAmericans in portions of the eastern United States. Early shifts in the fire regime or “fire waves” likely drove changes in forest conditions prior to more extensive impacts of agricultural clearance and logging. We conducted a dendroecological study in an unlogged shortleaf pine forest in the Ouachita Mountains with the objective of developing a multi-century record of fire occurrence, tree establishment, and growth releases. Our results demonstrate that the forest experienced a fundamental shift in the fire regime, forest composition and structure that coincided with the initial arrival of EuroAmericans. During the 1700s, fire frequency was moderate (13.7-year mfi), tree establishment was a mix of oak and pine, and forests experienced episodic canopy releases that aligned with fire events. Following the arrival of EuroAmericans in the 1830s, fire frequency increased (2.9-year mfi), tree establishment shifted to pine, and the forest recorded a period of growth releases indicative of extensive canopy disturbance. Forest change initiated during the first decade of settlement, suggesting that EuroAmericans at low population densities used fire to alter forest conditions. Considering that similar fire waves have been documented across the Interior Highlands and other regions of the eastern US, it is likely that forests conditions in these regions have been highly dynamic in response to shifts in anthropogenic burning for at least 200 years and likely longer.