Résumé
In Amazonia, shifting cultivation is the main farming system, and it is practiced in heterogeneous environments and with different degrees of sustainability. In the lower Rio Negro (Amazonas, Brasil), nearby the city of Manaus, the complex swidden-fallow systems need adaptations to cope with the lack of land rights and of labor force, wich is due to rural-urban mobility, extractivism, schooling and turism. We analyze the innovations developed by indigenous people in order to maintain their production and the flexibility of their agricultural system, by conserving agrobiodiversity and influencing the spatiotemporal dynamics of their cultivated areas within these permanent instability conditions.