No evidence of local deforestation leakage from protected areas establishment in Brazil's Amazon and Atlantic Forest

Establishing Protected areas (PAs) could displace or cause ‘leakage’ of deforestation into adjacent areas. Such leakage would potentially offset PAs' conservation effort by jeopardizing forest conservation goals and impeding financial mechanisms such as Reducing Emissions from Deforestation and forest Degradation - REDD+. Here we investigate forest loss inside PAs' borders and whether leakage occurred following the establishment of new PAs (n = 425) within the Amazon and the Atlantic forests in Brazil between 2004 and 2017. We applied a Before-After-Control-Intervention statistical design with a matching approach to evaluate deforestation leakage from PAs' establishment using a spatial (inside and outside PAs)– temporal (before and after PA establishment) measure of deforestation rates. We also used “Random Forest” to investigate the drivers of the effect of PAs' establishment on their surrounding areas. We found that when PAs' establishment led to reducing deforestation inside their boundaries, their surrounding also experienced a reduction in deforestation (“blockage”). Similarly, when PAs' establishment could not reduce deforestation inside their boundaries, their surroundings also experienced increased deforestation. Such a pattern was most common for Indigenous territories, especially in the deforestation arch in the Amazon. However, we did not find significant evidence for leakage as PAs' surroundings with a significant increase in deforestation were associated with PAs unable to significantly reduce deforestation within their boundaries. Therefore, “leakage” should not limit the establishment of new PAs. Instead, greater investments into reinforcement are needed for existing PAs, with high priority given to Indigenous Territories.