Acknowledged world leaders in various aspects of tropical agroforestry were invited at a one-day symposium to present state-of-the-art reviews of the developments in their respective research areas

Large areas of the warm, humid tropics in Southeast Asia, the Pacific, Latin America, the Caribbean, and Africa are hilly or mountainous. Jackson and Scherr (1995) estimate that these tropical hillside areas are inhabited by 500 million people, or one-tenth of the current world population, many of whom practice subsistence agriculture. The region most affected is Asia which has the lowest area of arable land per capita. Aside from limited areas of irrigated terraces, most of the sloping land, which constitutes 60% to 90% of the land resources in many Southeast Asian countries, has been by-passed in the economic development of the region (Maglinao and Hashim, 1993). Poverty in these areas is often high, in contrast to the relative wealth of irri gated rice farms in lowland areas that benefited from the green revolution. Rapid population growth in some countries is also exacerbating the problems of hillside areas. Increasingly, people are migrating from high-potential lowland areas where land is scarce to more remote hillside areas. Such migra tion, together with inherent high population growth, is forcing a transforma tion in land use from subsistence to permanent agriculture on fragile slopes, and is creating a new suite of social, economic, and environmental problems (Garrity, 1993; Maglinao and Hashim, 1993).

Agroforestry is recognized as a sustainable land-use management in the tropics, as it provides environmental-friendly ecosystems; it also provides people with their every day need for food and cash. Since the recognition of agroforestry as a science, curricula have been developed for agroforestry programs for undergraduate and graduate trainings in Universities. Therefore, there is an urgent need to develop and make available educational material. This textbook strives to provide up-to-date information on tropical agroforestry to serve as educational material in the tropical context. The authoritative textbook of Nair (1993) on agroforestry was published 18 years ago, and before the advent of tree domestication, an important agroforestry practice today. In addition, many other research activities, such as carbon sequestration and integrated pest management, have been included in the agroforestry agenda. This textbook is intended for agroforestry students, teachers, and practitioners.

Introduction of the seminar; Acknowledgements; State of art in agroforestry; Highlights in agroforestry research and practice; Significance of social organization and cultural attitudes for agroforestry development; Classification of agroforestry systems; Economics in agroforestry; Silvicultural concepts in agroforestry; Ergonomics and its possible applications in agroforestry; A critical analysis of an agroforestry project in Acosta and Puriscal, Costa Rica; Criteria for the evaluation of organic matter and nutrient cycling in agroforestry systems; Agroforestry system interactions: man-tree-crop-animal; Case studies: soil and plant aspects of agroforestry systems; Response of hybrid Theobroma cacao to two shade associations in Turrialba, Costa Rica; Associations between cacao (Theobroma cacao) and shade trees in southern Bahia, Brazil; Nutrient cycling in agroforestry systems of coffee (Coffea arabica) with shade trees in the central experiment of CATIE; Experiences with coffee shade trees in Costa Rica; Coffee and cacao plantations under shade trees in Venezuela; The pejibaye palm (Bactris gasipaes H.B.K.) as a potential agroforestry species; Agroforestry systems with Gliricidia sepium; Alley cropping of annual food crops with woody legumes in Costa Rica; Results from the CATIE "Central Experiment": pasture and shade tree associations; Experiences with fence line fodder trees in Costa Rica and Nicaragua; Priorities for research on nitrogen fixation in agroforestry systems; Population dynamics of guava (Psidium guajava L.) in pastures; Case studies: diagnosis and technologies for agroforestry; The ICRAF agroforestry farming systems approach international council for research in agroforestry; Farmer'attitudes towards trees; Factors affecting the adoption of agroforestry innovations by traditional farmers; Development and application of agroforestry practices in tropical Asia; Agroforestry in Africa: potentials and constraints to technical and socio-economic development; Agroforestry experiences in southern Sudan with special reference to small farmers; Characteristics of farms producing basic grains in four areas of Central America; Case studies: economics and ergonomics in agroforestry; Economics of agroforestry systems in Africa; Economics of agroforestry systems in Asia; Advances in economic studies of agroforestry plantations in Central America; Ergonomic and biological aspects of human work in agroforestry productions systems; Reports of working groups: evaluation and specific recommendations; Working group A: soil and plant aspects of agroforestry systems; Working groupo B; Diagnosis and technologies for agroforesry; Working group C: Economics and ergonomics in agroforestry; Organization; Seminar committee; Participants; Programme.

This volume comprises a selection of original contributions presented at a workshop held in Montpellier, France, in June 1997. The two main objectives of the workshop were, firstly, to bring together what is understood about the processes underlying agroforestry practice, and, secondly, to provide a forum to explore relevant models and modelling approaches. The workshop was also able to play a role in examining the agroforestry systems encountered in temperate and Mediterranean areas, including both traditional and more innovative agroforestry practices. The main aspects discussed were: ecological interactions amongst components, environmental impact, economics and policy modelling.