Carbon sequestration and riparian zones: Assessing the impacts of changing regulatory practices in Southern Brazil

Despite the consensus that riparian zones are important for the conservation of biological diversity and many other ecosystem services, there are no consistent regulations for how, or if, riparian areas should be used and the size of buffer zones required. Recently, controversial revisions to the Forest Code in Brazil have been implemented which include a reduction in the width of protected riparian buffer zones required along rivers. In order to model the impact of legislative changes on ecosystem services, we used the integrated valuation of environmental services and tradeoffs (InVEST) tool to assess a 30,000 ha watershed in southern Brazil and carbon sequestration as an indicator for ecosystem services. The results demonstrate that the adoption of improved agriculture practices, development of secondary forests and especially the conversion of land into more restrictive types of land-use has a significant and positive impact on the levels of carbon sequestered. On the other hand, the easing of riparian zone requirements shows an important potential loss in carbon sequestration. More importantly, reducing the size of the buffer zone might result in land-conversion into agriculture or pasture, impacting both carbon sequestration and other ecosystem services. However, the easing of restrictions on riparian areas under the revised Forest Code might be overshadowed by changes to Legal Forest Reserve provisions which could have a much greater impact on carbon sequestration. Despite the restrictions imposed by various pieces of legislation, the loss of ecosystem services due to a reduction in the protected riparian area, as well as possible land conversion due to changes in Legal Forest Reserves, are possible unless efforts involving narrowing the gap between research and policy, effective law enforcement, and implementing attractive payment for ecosystem services programs, are put in place. We believe that introducing incentives to farmers to maintain the protection of riparian areas by implementing agroforestry systems, such as erva-mate (Ilex paraguariensis), would be beneficial socioeconomically and ecologically and should be integrated into the Forest Code.