Affiliation: | School of Forestry and Wood Products, Michigan Technological University, Houghton, MI 49931, USA;;Forest Nutrition Cooperative, North Carolina State University, Raleigh, NC 27695, USA;;USDA Forest Service, South-east Experiment Station, Research Triangle Park, NC 27709, USA;;Department of Botany, Duke University, Durham, NC 27708, USA;;Westvaco, PO Box 1950, Summerville, SC 29484, USA |