The question of how smallholders of the Amazon estuary, locally known as cabolcos, have adapted their land use systems to produce resources during booms and busts is analyzed in this article. We draw upon more than 50 years of census data and more than 30 years of remotely sensed land-cover data to reconstruct these dynamics from World War II to the present. We found that smallholders are highly flexible in their land use decisions and livelihood strategies and that such flexibility has helped them to adapt their land-use systems to produce resources in demand during market booms and conserve forests. Smallholder mosaic landscapes contain forest fragments that enhance socioecological resilience to floods and other events produced by changes in the local hydro-climatic regimes due to sea-level rise and other climate-related changes. We argue that flexibility is a tool to reduce livelihood vulnerability by facilitating adaptation to global market and climate driven changes over the long term.