SREL Reprint #2505




Rare plants of southeastern hardwood forests and the role of predictive modeling

Donald W. Imm1, Harry E. Shealy Jr.2, Kenneth W. McLeod3, and Beverly Collins3

1U.S. Forest Service, Savannah River, P.O. Box 700, New Ellenton, SC 29809 USA
2University of South Carolina-Aiken, 471 University Parkway, Aiken, SC 29802 USA
3Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802 USA

Abstract: Southeastern hardwood forests burn infrequently and are characterized by high habitat and microsite diversity. Rare plants of these forests are mostly herbs associated with specific habitats (e.g., hardwood coves, wetlands) or other geographic regions. Habitat prediction models for rare plants can be useful when large areas must be surveyed or populations must be established. We developed a habitat prediction model for four species of southeastern hardwood forests: Nestronia umbellula, Carex chapmanii, Rhododendron flammeum, and Habenaria lacera. The model suggests that the Carex has strong affinity to habitat resource and vegetation conditions. In contrast, Nestronia umbellula is not strongly associated with habitat characteristics. The model did not accurately predict N. umbellula habitat, possibly because it did not account for this plant's clonal and partially parasitic habit or its tolerance of periodic burning. Rhododendron flammeum is strongly associated with specific topographic variables, and the model fairly accurately predicted its habitat. Although H. lacera is strongly associated with habitat resources and vegetation, its habitat is small in area and was not well predicted by the GIS-based model. These four examples suggest that models based on resource and vegetation characteristics can accurately predict habitat, but only when plants are strongly associated with these variables and the scale of modeling coincides with habitat size. Habitat prediction models can be useful tools for managing rare plants of southeastern hardwood forests, especially when combined with information gained through research and monitoring.

Index terms: Carex chapmanii, Habenaria lacera, Nestronia umbellula, Rhododendron flammeum, southeastern hardwood forests

SREL Reprint #2505

Imm, D. W., H. E. Shealy, Jr., K. W. McLeod, and B. Collins. 2001. Rare plants of southeastern hardwood forests and the role of predictive modeling. Natural Areas Journal 21:36-49.

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