Dr. Gary L. Walker


  • Ph.D., University of Tennessee at Knoxville

My current research interests are involved with different aspects of cliff-face ecology in the Southern Appalachians. This research began as a spin-off of my doctoral research investigating the population biology of a glacial relict tree in the Southern Appalachians, Northern White Cedar, Thuja occidentalis L. These glacial relict populations exist primarily on cliff systems in the Ridge and Valley province of the Southern Appalachians and harbor high levels of genetic variation for the species. We found several other glacial relict species associated with white cedars in southern disjunct ranges normally found in bogs in the boreal forests of North America. After beginning my academic career here at Appalachian State University, I have conducted research on cliff-face plant communities in Linville Gorge Wilderness Area, in additional sites in the Ridge and Valley and on the Oak Ridge National Laboratory, and at the Obed Wild and Scenic River National Park and Cumberland Gap National Historic Park on the Cumberland Plateau. My cliff-face research group currently includes Dr. Mike Madritch, an ecosystem ecologist and Dr. Coleman McCleneghan, a mycologist/lichenologist, both from ASU Biology, as well as three graduate students, Laura Boggess, Justin Harkey and Eric Purdy. We are currently engaged in research projects back at Cumberland Gap, at the Big South Fork of the Cumberland National Park and Recreational Area, in the Great Smoky Mountains National Park and recently finished a vegetational survey of cliff faces in the Ocoee River Gorge. Many of these grant-supported studies are related to determining the impacts of rock climbing on the plant and lichen communities of cliff-face communities toward developing management plans for state and federal agencies. In the course of these studies we are finding rare, disjunct and restricted plants and lichens on cliff faces, ancient trees, and occasionally new species in these systems. From a more theoretical approach we are interested in the physical factors the influence plant and lichen community structure on cliff faces. We also intend to use this information toward developing a predictive GIS model that can be used by land managers to evaluate cliff systems that may support significant vegetation or be attractive to rock climbers.

a cliff-face population of northern white cedar in the southern Appalachians; levels of heterozygosity in populations of norther white cedar

Publications, Peer Reviewed:

  • C.N. Wells, R.S. Williams, G.L. Walker and N.M. Haddad. 2009. Effects of corridors on genetics of a butterfly in a landscape experiment. Southeastern Naturalist, 8(4): 709-722.
  • Bresowar, Gerald, G.L. Walker 2011. Patterns of Genetic Distribution of Sibbaldiopsis tridentate (Rosaceae) in the Eastern United States. Castanea 76(2): 210-221.

Publications, Technical Reports:

  • Walker, Gary L. 2005. An Evaluation of a Dye-Marking Technique for Wild Ginseng, Panax quinquefolius L., for the National Park Service." U.S. Department of the Interior, National Park Service, Great Smokey Mountains National Park, Shenandoah National Park.
  • Walker, Gary L. 2005. "Investigation of Existing and Potential Marking and Forensic Techniques for Plant Population Protection." U.S. Department of the Interior, National Park Service, Great Smokey Mountains National Park, Shenandoah National Park.
  • Walker, Gary L., David Ballinger. 2007. "Physical Variables and Community Structure of the White Rocks Cliff System, Cumberland Gap National Historic Park." U.S. Department of the Interior, National Park Service, Cumberland Gap National Historic Park.
  • Walker, Gary L., Bal Krishna Nepal, Peter Soule'. 2010. "Characterization of Ancient Red Cedars Communities in the Obed Wild and Scenic River Gorge," U.S. Department of the Interior, National Park Service, Obed Wild and Scenic River Gorge National Park, Wartburg, TN.

Publications, Books as Contributing Author:

  • Walker, G. L. 2012. Chapter 4: "A Necessary Social Understanding of the Natural Sciences," in Environmental Crime, Enforcement, Policy, and Social Responsibility, edited by Mary Clifford and Terry Edwards, Jones & Bartlett Learning, LLC. Burlington, MA 01803


  • Distinguished Graduate Faculty Mentor Award, Appalachian State University, October 1, 2009.
  • Faculty Excellence in Mentoring Graduate Students Award, Conference of Southern Graduate Schools, February 27, 2010.
  • Induction into the Academy of Outstanding Graduate Mentors, Inaugural Inductee, October 1, 2010.
Title: Professor Emeritus, Cliff-Face Ecology
Department: Department of Biology

Email address: Email me