1. Département Génie Rural, Eaux et Forêts, Faculté d’Agronomie, Université Abdou Moumouni de Niamey, Niamey BP 10960, Niger
2. African Forest Forum (AFF), Nairobi P.O. Box 30677-00100, Kenya
3. Kenya Forestry Research Institute, Taita Taveta Research Centre, Wundanyi P.O. Box 1206-80304, Kenya
4. Department of Forest Economics, Swedish University of Agricultural Sciences (SLU), Box 7060, 750 07 Uppsala, Sweden