In the southeastern United States, the Department of Defense (DoD) has extensive land holdings in the Fall Line ecoregion, which occurs along the interface between the Coastal Plain and Piedmont provinces. Throughout this region exist extensive areas of sandhills, which support a unique flora and fauna that includes a suite of threatened and endangered plant and animal species (TES). Forests on military installations along the Fall Line are managed to promote open pine woodlands as habitat for the federally endangered red-cockaded woodpecker (Picoides borealis; RCW). It is not known whether management efforts directed primarily toward RCW populations also are beneficial, or possibly harmful, for other sandhills TES. A more holistic and efficient approach may be needed to integrate the effects of land management, military training demands, and ecosystem sensitivities into management of sandhills communities and associated TES that occur in these habitats
This study evaluated the effects of forest management practices and military training activities on the Fall Line sandhills communities and the suite of TES that they contain. Specific objectives were: (1) at the landscape level, to assess whether military training and forest management to promote RCW habitat (e.g., burn season and frequency; use of herbicides) are appropriate for managing sandhills communities and (2) at the species population level, to determine how these combinations of forest management and training activities affect individual TES, such as select sandhills plant species.
For this project spatially explicit landscape-level and species-based habitat models were combined with field surveys and experiments to evaluate potential conflicts among management scenarios for selected TES. Geographic information systems (GIS) were used to discriminate sandhills communities and to describe the spatial extent and intensity of forest management practices and military training at the primary study sites, Fort Benning and Fort Gordon, Georgia and the Department of Energy's Savannah River Site, South Carolina. Probability-based habitat models, nested within the landscape models, were developed for selected TES and used to identify areas with habitat conditions that could support multiple species or habitat conditions where conflicts among species might otherwise occur. Field surveys and experiments also were used to quantify the impacts of forest management practices across the array of military conditions on sandhills communities and TES.
Results suggest that burning at intervals of several years to maintain an open understory for RCW habitat is compatible with the occurrence of most sandhill plant species, but other understory control treatments (especially herbicide application) are detrimental. In general, rare plants of the sandhills persist under moderate disturbances associated with forest management and military activities. Furthermore, habitat models and GIS maps of potential suitable habitat for TES plants are useful in conservation efforts and in identifying sites for transplantation if conflicts in land use and TES species occurrence arise.
This research has provided information on the occurrence and distribution of southeastern Fall Line sandhills and related xeric woodland communities, on the occurrence of rare plants in these communities, and on the effects of forest management practices and disturbances that may be associated with military activities.