tional barriers are overcome, and new mechanisms developed, development projects increasingly bring together a wide array of public and private organizations.

In 1984, for example, the Cooperative for American Relief Everywhere, the New York Zoological Society, the U.S. Agency for International Development (USAID), and the Ugandan Forestry Department initiated the Village Forest Project in southwestern Uganda. The goal of the Village Forest Project is to improve living conditions for local farmers through the introduction of agroforestry techniques while simultaneously reducing pressures on the Kibale Forest Reserve, a protected area of moist lowland forest (Cooperative for American Relief Everywhere, 1986; Struhsacker, 1987). The International Center for Research in Agroforestry provides on-site technical assistance. The Sustainable Agriculture and Natural Resource Management program of USAID is attempting to bring the same collaborative spirit to a full range of sustainable resource management issues in developing countries (National Research Council, 1991a).

Dissemination of Information Through Extension Services The implementation of sustainable agriculture systems and practices in the humid tropics will require the active involvement of extension services. Decentralization, local adaptation, and innovation are key to the successful adoption and refinement of these systems, and extension services can be adapted to meet these needs. Working together with NGOs and others in the private sector, extension personnel can link farmers, researchers, resource agencies, community officials, and development officials. Through them, agencies should promote relevant research findings, develop demonstration projects and networks, and disseminate the information, management practices, plant materials, and tools necessary for the wider application of sustainable agricultural systems. Information, however, must flow both ways: extension workers should assist researchers in identifying the socioeconomic, environmental, and agronomic constraints that small farms and rural communities face.

Sustainability begins with an approach that is attuned to these environmental, social, and cultural realities, to local belief systems, and to traditional methods and knowledge. Accordingly, future extension services need to adopt an interdisciplinary approach. Extension personnel may require exposure to and training in aspects of land use and the environmental sciences that they have not previously received, including forestry and agroforestry, land use planning and zoning, and the conservation of biological diversity. In addition, the social aspects of rural development must become a more