Four Decades of Table Mountain Pine Demography on Looking Glass Rock (Transylvania Co., North Carolina, USA)

Published:

January 2020

Author

Lawrence S. Barden

Additional Authors

James T. Costa

Table Mountain pine (Pinus pungens) is an Appalachian endemic that requires canopy-opening disturbance such as fire or logging for successful regeneration. The infrequency and typically moderate intensity of Appalachian lightning-ignited fires combined with Table Mountain pine’s requirement for canopy disturbance for successful recruitment posed an ecological question: How did Table Mountain pine (TMP) persist in North America for almost 1.5 million years without anthropogenic fires? An early monograph on TMP suggested that the species might have persisted without fire on extremely xeric and sterile rock outcrops. Motivated by this suggestion, in 1976 the first author located a small TMP population on a xeric rock outcrop in western North Carolina where no fires had occurred since 1889. Three longitudinal censuses in 1976, 1986, and 1996 showed that the population had perpetuated itself without fire for more than 100 years. The current study extends this record of self-maintenance an additional 20 years and compares decadal variations in age structure with 120 years of drought records from western North Carolina. An unexpected observation of this 40- year study was a slow invasion of the TMP study site by ericaceous shrubs, a terminal transition that was predicted in a 2010 model of oak-pine-heath succession without fire.

Keywords

drought, lightning-ignited fire, pine-heath succession, Pinus pungens, rock outcrop