Carbon Dynamics in Wetland Ecosystems

Wetland ecosystems are among the most potent natural carbon reservoirs on Earth, sequestering large quantities of organic carbon in water-saturated soils and sediments. These environments mediate the balance between carbon uptake through plant productivity and carbon release via microbial decomposition and greenhouse‐gas fluxes. Key processes include peat formation in peatlands, carbon burial in mineral wetlands and methane generation under anaerobic conditions. Hydrological regime exerts a primary control on redox potential, affecting both aerobic and anaerobic pathways of organic matter breakdown. Vegetation composition, soil texture and nutrient availability further shape the rates of carbon accumulation and loss. Globally, wetlands store an estimated 20–30 % of terrestrial soil organic carbon while occupying less than 6 % of land area. This disproportionate role underlines their significance for climate regulation and highlights the vulnerability of carbon stocks to land‐use change, drainage and restoration efforts. Emerging research seeks to map previously unrecognised carbon pools, understand microbial controls on greenhouse-gas fluxes and develop management practices that enhance long-term carbon sequestration.

Research from Nature Portfolio

Recent studies have revealed vast quantities of previously unmapped soil organic carbon in forested wetland-upland transition zones, substantially increasing estimates of regional carbon stocks. High-resolution mapping along gradient transects demonstrated that so-called “cryptic” wetland carbon may boost current wetland soil carbon inventories by up to 480 %. Foundational work in North America has quantified national wetland carbon reserves, showing that inland freshwater systems store nearly ten times more carbon than tidal saltwater wetlands and highlighting the disproportionate importance of freshwater habitats for regional carbon sequestration. A meta‐analysis of wetland restoration and creation efforts indicates that, even after two decades, restored soils accumulate carbon at significantly slower rates than natural wetlands, with recovery strongly influenced by wetland type, temperature regime and hydrological connectivity. These insights point to the need for targeted restoration strategies that prioritise hydrological regimes and site-specific conditions to accelerate carbon recovery.

Carbon Dynamics in Wetland Ecosystems publication trend

The graph below shows the total number of articles in carbon dynamics in wetland ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Soil organic carbon (SOC): The carbon component of organic compounds in soil, representing the primary pool of carbon in wetland sediments.

Particulate organic carbon (POC): The fraction of SOC composed of larger, partially decomposed organic matter particles that contribute to soil structure and long-term carbon storage.

Dissolved organic carbon (DOC): Low-molecular-weight organic molecules dissolved in pore water, readily available for microbial metabolism and transport.

Redox potential: A measure of the oxidative or reductive conditions in soil, governing the pathways of organic matter decomposition and greenhouse-gas production.

Carbon sequestration: The process by which carbon dioxide is fixed from the atmosphere and stored in vegetation, soils or sediments over ecological timescales.

Methanogenesis: The microbial production of methane under strictly anaerobic conditions, a key pathway of carbon release in water-logged soils.

References

1. Revealing the hidden carbon in forested wetland soils. Nature Communications (2024).
2. Carbon storage in US wetlands. Nature Communications (2016).
3. A synthesis of soil carbon and nitrogen recovery after wetland restoration and creation in the United States. Scientific Reports (2017).
4. Reducing Emissions From Degraded Floodplain Wetlands. Frontiers in Environmental Science (2020).
5. Enhancing soil organic carbon, particulate organic carbon and microbial biomass in semi-arid rangeland using pasture enclosures. BMC Ecology and Evolution (2018).