The Brazilian Forest Code and riparian preservation areas: Spatiotemporal analysis and implications for hydrological ecosystem services

The Brazilian Forest Code (BFC) requires the preservation and restoration of forests in riparian preservation areas (RPAs). The total area in RPAs and the impacts of changes in the BFC on RPA requirements are uncertain due to lack of clarity about how RPAs are defined in practice. We reconstruct the history of the RPA rule, use a recent cadastral database (CAR) of the state of Rondônia to quantify the area of RPA by stream size and to document the impact of the 2012 changes in RPA requirements, and review the literature on hydrological ecosystem services (HES) in light of RPA rules. We find that most (64%) of the area in RPAs in the state of Rondônia was illegally deforested by 2017, and the 2012 regulations require restoration of only half of that cleared area. Most of the RPA is located along small streams (< 10 m wide) that were typically missing in previous assessments. As of 2017, 66% of the RPA along small streams was deforested, while most (70–95%) RPA along large streams (> 200 m wide) was forested. Current restoration requirements (5 m regardless of stream width) for very small properties (< 60 ha) are likely inadequate to restore HES. Preservation of forest along large streams remains important, but policy and management should also emphasize the preservation and restoration of forest along small streams because they account for most of the riparian preservation area, with important implications for humans and ecosystems.