Changes in Fire Regimes and the Successional Status of Table Mountain Pine (Pinus pungens Lamb.) in the Southern Appalachians, USA

Table Mountain pine is a tree species endemic to the southern Appalachians that is heavily dependent on repeated surface fires for successful regeneration. Since the implementation of fire suppression as a forest management tool in the early 1900s, the fire frequency in Great Smoky Mountains National Park and surrounding National Forests has been dramatically altered. Without fire, Table Mountain pine will not persist in the southern Appalachian Mountains. I used dendrochronology to analyze the fire history and current age structure of Table Mountain pine populations. This approach provided baseline information on the current successional status of Table Mountain pine stands and their relationships with past fire. Cores were collected from a minimum of 75 trees at each of five study sites in Great Smoky Mountains National Park. Additionally, samples were taken from fire-scarred snags, stumps, and downed logs. Results indicated that the age structure of Table Mountain pine populations in the park exhibits a generally J-shaped distribution with the last major recruitment event occurring around 70 years ago. Fire history analysis indicated that the pre-park Weibull Median Fire Interval was 6.8 years, while the Maximum Hazard Interval, the longest fire-free period that can occur before burning is highly probable, was 80.6 years. These results indicate that the pre-park fire regime was characterized by frequent fires. Because the post-park fire interval has been dramatically increased by approximately 70 years of fire suppression, Table Mountain pine is being slowly extirpated from the southern Appalachian landscape. Data provided by the dendrochronological techniques used in this study are essential for the successful reintroduction of fire to regenerate Table Mountain pine in the region.