1. Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, U.S.A.
2. Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Canada
3. Department of Plant, Soil and Microbial Sciences and the Department of Forestry, College of Agriculture & Natural Resources, Michigan State University, East Lansing, U.S.A.
4. Department of Forest Engineering, Resources and Management, College of Forestry, Oregon State University