1. Northern Research Station, USDA Forest Service, 359 Main Road, Delaware, OH 43015, USA.
2. Pacific Northwest Research Station, USDA Forest Service, 204 Siginaka Way, Sitka, AK 99835, USA.
3. Forest Products Program, University of Alaska-Fairbanks, Palmer Research and Extension Station, 533 E. Fireweed Avenue, Palmer, AK 99645, USA.