Land use transitions and the decline of family farming in Southeastern Brazil: Patterns, pressures, and environmental trade-offs

The expansion of monocultures and urbanization has reshaped rural landscapes in Brazil. We evaluated how land use has changed in São Paulo state, since a decree defining family farming in the country was issued, and how it contributed to climate change and the ability to adapt to it. We analyzed land use changes between 1985 and 2023 across 601 municipalities, focusing on the dynamics of family farming and its environmental implications. Using data from Brazilian Agricultural Censuses and MapBiomas platform, we classified municipalities according to increases or decreases in the area under family farming, assessed their land tenure patterns, associated changes in land cover, and calculated carbon stock and sequestration values based on land use, to assess the relationship between them and the presence of family farming. Land tenure and land regularization processes affected family farming distribution, and agrarian reform processes have contributed to an increase in family farming areas and halted monocultures advance. Greater homogenization of local agriculture was observed, contributing to lower carbon sequestration where the reduction in family farming was more pronounced. Results show that municipalities with expanding family farming areas have higher forest cover, better pasture quality, greater carbon stock and sequestration values. Conversely, municipalities with declining family farming areas experienced higher growth in soybean monocultures and landscape simplification. These patterns underscore territorial and ecological impacts of agricultural concentration, and displacement of small-scale diversified systems. Our results show that policies targeting family farming can promote greater diversification, reduce landscape homogenization, and increase carbon sequestration capacity.