Diversification of products and services from diverse on-farm trees allowed the traditional agroforestry systems of southern Ethiopia to be considered as sustainable farming systems over a timescale of centuries. But their sustainability has been threatened in recent years, owing to the increasing pressure from a rapidly growing population. Investigation of the diverse tree species on agroforestry for various products and services is beneficial to explore the relationships of some farm characteristics with tree species diversity. Very little academic literatures exist on the agroforestry systems of on-farm tree species diversity. This book, therefore provides a new findings on the characterization of tree species diversity, how the diversity of trees and shrub species are linked to farm characteristics and composition of tree species under agroforestry land use system. It also provides new ideas on the importance value index and use-diversity of different tree species. A complete inventory of on-farm tree species and farm characteristics is analyzed. The analysis should give some knowledge and should be primarily useful to professionals in fields of agroforsetry and agriculture.