The Role of Ecosystem-level Models in the Design of Agroforestry Systems for Future Environmental Conditions and Social Needs

Forestry is the art (skill), practice, science, and business of managing forest ecosystems to sustain an ecologically possible and socially desirable balance of forest resources and other ecosystem services and values. Agroforestry could be defined similarly, but in reference to agro-ecosystems and tree-crop-animal resources. When practiced by indigenous cultures, agroforestry has been based on their experience-based wisdom about what works and what does not (Hsiung 1996). However, if a different set of agroforestry values (e.g. a new crop or tree species) and/or a new agroforestry system for which there is little or no experience are to be sustained, this experience-based approach must be supplemented with an understanding of the ecological processes that underlie both the traditional systems and the new set of values. Because social unrest, wars, diseases, natural disasters, and the continuing urbanization of the world's population result in the loss of traditional rural knowledge, the design of future agroforestry systems will have to be based as much or more on an understanding of the processes responsible for production and sustainability of multiple values and environmental services as it has on traditions and experience in the past. When properly implemented, the approach of experience + process-level understanding can capture the benefits of traditional systems but also have the flexibility to respond to the changing needs and desires of individuals and societies, and to changing social and environmental conditions.