Introduction - Economic and ecological aspects of diversification of tropical tree crops -- Chapter 1. Diversification of cocoa farms in Côte d'Ivoire: complementarity of and competition from rubber rent -- Chapter 2. Coconut farmers and lethal yellowing disease: a case study in two villages in Ghana's Central region -- Chapter 3. From the coffee-cocoa combination to oil palm cycles: the case of Dabou and Aboisso in Côte d'Ivoire -- Chapter 4. Development of oil palm plantations and orange groves in the heart of the cocoa territory in eastern Ghana -- Chapter 5. Rubber in the kingdom of cocoa. The south-west of Côte d'Ivoire in the 1990s -- Chapter 6. Rubber: natural rent, capitalization rent? West-central Côte d'Ivoire and southern Thailand -- Chapter 7. From Firestone to Michelin, a history of rubber cultivation in a cocoa-growing country: Ghana -- Chapter 8. Extensive fish farming, a complementary diversification of plantation economies -- Chapter 9. Determinants in the choice of perennial crops in diversified production systems of rubber growers in south-western Cameroon -- Chapter 10. Socio-economic conditions of horticultural diversification in cocoa production systems in southern Cameroon -- Chapter 11. Agroforestry-based diversification for planting cocoa in the savannah of central Cameroon -- Chapter 12. Diversifying Central American coffee agroforestry systems via revenue of shade trees -- Chapter 13. Coconut- and cocoa-based agroforestry systems in Vanuatu: a diversification strategy in tune with the farmers' life cycle -- Chapter 14. The place of cocoa and coconut cultivation in family plantations in peninsular Malaysia -- Chapter 15. Diversification and perennial-crop cycles in Aceh, Indonesia.