This highly topical study of tropical deforestation in Mexico reports on the first phase of the Land-Cover and Land-Use Change in the Southern Yucatan Peninsular Region Project (LCLUC-SYPR): a large, multi-institutional, and team-based study designed to understand and project land changes in a development frontier that pits the rapidly growing needs of smallholder farmers to cut down forests for cultivation against federally sponsored initiatives committed to various international programmes of forest preservation and complementary economic programmes. The SYPR project is a response to inderdisciplinary defined research themes deemed critical to global environmental change and complementary international research agendas (e.g. environment and development, ecosystem assessment, biotic diversity). Pivotal among these agendas are those posed by the Land-Use/Cover Change (LUCC) effort of the International Geosphere-Biosphere Programme and the International Human Dimensions of Global Enviro