1. University Program in Ecology, Southern Center for Sustainable Forests, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
2. The Nature Conservancy, Pennsylvania Forest Conservation Program, Williamsport, PA 17701, USA.
3. Resource Professionals Group, Durham, NC 27707, USA.
4. Pratt School of Engineering, Duke University, Durham, NC 27708, USA.
5. State and Private Forestry, USDA Forest Service, Morgantown, WV 26505, USA.
6. Austrian Chamber of Agriculture, Department of Forestry and Energy, A-1014 Vienna, Austria.