Soil Carbon Stocks in the Brazilian Pampa: An Update

The grasslands in Southern Brazil have been been used for cattle ranching for more than 300 years. More recently, it has been recognized that these ecosystems provide key environmental services. Dramatic land use changes in the last decades, notably the conversion to cropland and silviculture, have brought about the risk of land degradation. We applied a combination of bibliographic research and geoprocessing operations to revise and update an earlier SOC stock estimate for the Brazilian Pampa. The calculated SOC stocks obtained in this study were compared with our original study and other SOC stock estimates. Our results were 7–27% higher than these estimates and approximately 8% lower than our previous estimate. Given the limited information on biome-wide soil C status, our soil C stock dataset and derived maps provide a useful assessment of SOC stocks in Pampa. Refining this approximation would require additional soil sampling and land use mapping to cover data gaps. This is a crucial research topic deriving from the Brazilian commitment to pursue sustainable agriculture systems in the context of mitigation of human-induced changes in the terrestrial C cycle.