Résumé
Despite its isolation from land communications networks and colonization frontiers, the regions of the Upper and Middle Negro River are characterized by increasing connectivity between rural or forest areas, pertaining to communities, and urban areas, i.e. small towns along the river. Population movement between these two poles, on a temporary or permanent basis, results in expanded periurban agriculture, in the context of new social and ecological arrangements. A comparative approach is proposed to cultivated plants diversity, based on a sample of 14 and 18 families in these urban and forest contexts. Relations among the diversity of managed spaces, biological diversity and social networks involved in access to phytogenetic resources were analyzed. The analysis shows a recomposition of agricultural systems with high crop diversity, at times higher than in the context of forests, albeit subject to more system vulnerability due to reduced fallow periods and available manual labor. In urban areas, traditional agricultural resource management strategies are combined with another objective, farmed lands access. This analysis also points out the need for reflection about the conservation of a biocultural heritage.