A Review of Global Wetland Carbon Stocks and Management Challenges

Wetlands have unique soil, vegetation, and biogeochemistry that arises from their landscape position and wetland hydrology, which creates low oxygen levels in the soil. With reduced oxygen availability, plants develop adaptations to survive, such as aerenchyma, that allow transport of atmospheric oxygen to their roots, and soil microbial communities become dominated by anaerobic respiration processes that are less efficient in oxidizing carbon. Combined, the above- and belowground carbon stocks of wetlands play a key role in the global carbon cycle at varying time scales. This chapter provides a comprehensive assessment of wetland carbon stocks, research methodologies, and their historical and future trajectories. We estimate wetland carbon stocks range between 520–710 PgC (and 1792 to 1882 PgC with permafrost carbon) globally.