1. Arba Minch University, College of Agricultural Sciences, Natural Resources Management, P.O. Box 21, Arba Minch, Ethiopia
2. Addis Ababa University, College of Natural Sciences, Plant Biology and Biodiversity Management, P.O. Box 3434 Addis Ababa, Ethiopia
3. World Agroforestry Centre (ICRAF), UN Avenue, P. O. Box 30677, Nairobi, Kenya