1. Department of Recreation, Park and Tourism Management, Pennsylvania State University, University Park, PA 16802, USA
2. Forestry Division, Food and Agriculture Organization of the United Nations, 00153 Rome, Italy
3. Faculté des Sciences Agronomiques, Université du Bas-Uélé, Buta, Democratic Republic of the Congo
4. Institut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC J9X 5E4, Canada