1. U.S. Department of Agriculture Economic Research Service, Washington, DC 20024, USA.
2. U.S. Department of Agriculture Forest Service, Northern Research Station, Morgantown, WV 26505, USA.
3. Forestry and Wood Sciences, Czech University of Life Sciences Prague, Praha 6 - Suchdol, Czech Republic.
4. Institute for Agro-Environmental Sciences, NARO (NIAES), Tsukuba, Japan.
5. Environmental Science and Policy, University of California, Davis, Davis, CA 95616, USA.