1. School of Environment and Natural Resources; The Ohio State University; Columbus OH 43210 USA
2. School of Forest Resources and Environmental Sciences; Michigan Technological University; Houghton MI 49931 USA
3. Department of Forest Resources; University Minnesota; St Paul MN 55108 USA
4. Nelson Institute for Environmental Studies; University of Wisconsin; Madison WI 53706 USA
5. Department of Forest Ecosystems and Society; Oregon State University; Corvallis OR 97331 USA