Carbon Dynamics in Riparian and Floodplain Ecosystems

Riparian and floodplain ecosystems play a central role in the terrestrial carbon cycle by mediating the exchange of carbon between land and water bodies. These dynamic interfaces are shaped by periodic inundation, sediment deposition and vegetation growth, which together govern the storage, transformation and flux of carbon. In riparian zones, flood frequency and hydrological gradients control the distribution of soil organic carbon and the allocation of carbon among biomass compartments, including litter, roots and woody tissues. Floodplains accumulate both surface and buried carbon pools, with sediment burial processes sequestering organic matter in subsurface horizons. Microbial decomposition and redox conditions in waterlogged soils further influence carbon turnover, while restoration of native vegetation can enhance sequestration rates. Understanding the interplay of geomorphology, hydrology and ecology in these systems is crucial for improving global carbon budgets, informing land management and optimising restoration strategies that harness the natural carbon-sink potential of these vulnerable landscapes.

Research from Nature Portfolio

Recent studies have revealed that floodplain soils contain substantial carbon stocks well below the upper metre of the profile, challenging conventional accounting frameworks. Analyses of deep soil cores extending to several metres have shown that buried horizons resulting from historical sedimentation can hold significantly greater amounts of organic carbon than surface layers alone. Restoration of native vegetation on former agricultural floodplains further promotes carbon accumulation in both surface and subsurface soils, emphasising the importance of management practices that support natural flood regimes. These findings have led to revised estimates of global carbon storage and underscored the need to incorporate deep carbon pools into carbon modelling and policy decisions.

Carbon Dynamics in Riparian and Floodplain Ecosystems publication trend

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

Technical terms

Riparian zone: The transitional area between terrestrial and aquatic ecosystems along watercourses, characterised by distinct vegetation and soil conditions.

Floodplain: The low-lying land adjacent to a river that is subject to periodic inundation, facilitating sediment deposition and nutrient exchange.

Soil organic carbon (SOC): Carbon component of soil organic matter derived from decomposed plant and animal residues, a key indicator of soil fertility and carbon storage.

Carbon sequestration: The process by which carbon dioxide is captured from the atmosphere and stored in carbon pools such as vegetation, soils or sediments over long timescales.

Hydrological gradient: Variation in water availability, depth or flow frequency across a landscape that influences soil moisture and carbon processes.

Buried carbon pools: Subsurface carbon stocks beyond typical sampling depths (often >1 m), representing long-term sequestration reservoirs in floodplain soils.

References

1. Drivers of carbon sequestration by biomass compartment of riparian forests. Ecosphere (2015).
2. Impacts of Floods on Organic Carbon Concentrations in Alluvial Soils along Hydrological Gradients Using a Digital Elevation Model (DEM). Water (2016).
3. Distribution of Soil Organic Carbon in Riparian Forest Soils Affected by Frequent Floods (Southern Québec, Canada). Forests (2017).
4. Deep carbon storage potential of buried floodplain soils. Scientific Reports (2017).
5. Carbon Stocks of Hardwood Floodplain Forests along the Middle Elbe: The Influence of Forest Age, Structure, Species, and Hydrological Conditions. Water (2021).
6. What Factors Shape Spatial Distribution of Biomass in Riparian Forests? Insights from a LiDAR Survey over a Large Area. Forests (2021).