The monoculture systems that have been encouraged by governments since the 1960s have led to major socio-economic and environmental crises. Now the diversification of tree crop systems is advancing throughout the tropics. Why and when does diversification take place? What categories of farmers diversify? What obstacles do they have to overcome, and how do public and private policies interfere in this process? How do land use systems and landscapes evolve as a result of this diversification? According to the authors of this volume, diversification is certainly a response to market risks, but also to the depletion of environmental resources. Ecological changes such as declining soil fertility and increasing pressure from pests, diseases and weeds intensify at the end of monoculture cycles, driving crop change and diversification of farming systems. Meanwhile, diversification is encouraged by governments but increasingly also by the private sector that offers free seedlings, credit, technical assistance and market outlets to farmers to encourage the adoption of certain crops in a context of increasing competition for land resources. Social changes such as the return of young people to the villages, investments of urban middle classes in plantation agriculture, aging of the rural work force and increasing population pressure also play a role in this process. Through 15 case studies from Africa, Latin America, Asia and the Pacific, the authors provide us with in-depth insights into the economy and ecology of family agriculture and its recent developments. The book targets professionals of the tropical tree crop sector, students and scientists working on economic and ecological questions of tropical land use, and anyone interested in sustainable rural development. While the case studies are from tropical contexts, the methodological approaches and discussions are also relevant to temperate agriculture.