A rapid evidence assessment on the impact of climate change on peatland carbon dynamics in South America

Peatlands are vitally important ecosystems characterized by a diversity of services spanning species, ecosystem, landscape, and global scales. Peatlands store globally significant amounts of carbon, making it critical to understand how peatland carbon stocks will respond to climate change and development pressures. South America is estimated to contain approximately 10–13% of the world’s peatlands, representing a globally significant carbon reservoir. Knowledge of peatlands and their carbon storage and cycling in South America remains poorly synthesized, despite their diversity across elevation and climatic gradients, and their disproportionate importance in the global peatland carbon pool. We conducted a rapid evidence assessment (REA) of carbon dynamics in South American peatlands, emphasizing differences between high- and low-elevation systems and the effects of climate change and disturbance. Using predefined inclusion criteria, we reviewed 272 peer-reviewed studies published between 2000 and 2024. The majority of the literature was paleoecological (n = 47), and short-duration carbon flux studies (n = 15), yet fewer than 1% of studies investigated long-term peat decomposition rates that could be used as inputs for future climate scenario modeling. High-elevation peatlands generally exhibit long-term carbon accumulation but show high sensitivity to warming and hydrological change, whereas low-elevation peatlands contain large carbon stocks that are vulnerable to drought, flooding, fire, and land-use disturbance. Across elevations, climate variability frequently amplifies disturbance-driven carbon losses. Major gaps remain in long-term monitoring, decomposition measurements, and climate scenario modeling. Our synthesis highlights the need for coordinated research, monitoring, and conservation strategies to protect South American peatlands and their critical role in the global carbon cycle under future climate change.