1. CSIR-Forestry Research Institute of Ghana, Kumasi, Ghana
2. Department of Geosciences and Natural Resource Management, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
3. Société de Développement defs Forêts (SODEFOR), Abidjan, Côte d’Ivoire
4. CIRAD, Forest Department, Research Unit 39, Diversity and Breeding of Forest Tree Species, TA 10C, Montpellier Cedex, France