SREL Reprint #3310

Thresholds of Disturbance: Land Management Effects on Vegetation and Nitrogen Dynamics

Beverly Collins

Savannah River Ecology Laboratory, Aiken, SC 29802

Abstract: Land at Fort Benning is used for multiple purposes. Use for military training ranges from light disturbance by foot and occasional light vehicle traffic to heavy disturbance by repeated armored vehicle traffic. Upland mixed pine/hardwood forests have been managed over the last 25 yr, by periodic thinning and burning, to promote longleaf pine (Pinus palustris) savanna for the endangered red-cockaded woodpecker (Picoides borealis). These military and forestry land uses occur over a heterogeneous environment. The installation’s location in the Fall Line Sandhills region is an ecotone between the Piedmont and Coastal Plain provinces. Vegetation and soils are influenced by topography, drainage, periodic fires, and a long history of human use. Some combinations of land uses may not be sustainable over upland environments at Fort Benning. The ecosystem may lose nutrients or fail to regenerate desirable species. Objective 3 of FY2000 SON (CSSON-00-03) requested research to ‘determine whether there are thresholds in spatial extent, intensity or frequency above and/or below which the natural system cannot sustain identified ecological and/or land use disturbances.’ The Savannah River Ecology Laboratory (SREL) conducted a field experiment to evaluate the ecological effects of military training and forest management for longleaf pine at Fort Benning, to determine if there are thresholds beyond which upland ecosystems cannot sustain the combined effects of these land uses.

Keywords: SEMP, Fort Benning, Land Management, Ecology, Disturbance, Longleaf Pine, Red Cockaded Woodpecker, Sandhills, Fall Line

SREL Reprint #3310

Collins, B. 2005. Thresholds of Disturbance: Land Management Effects on Vegetation and Nitrogen Dynamics. SERDP Project RC-1114E.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).