The use of re-created wetlands as a way to mitigate nitrogen pollution has become popular in Denmark. However, although the re-creation of wetlands is efficient in removing nitrogen, it may also increase the emission of methane and nitrous oxide which are two greenhouse gases. Therefore we studied the effect of a riparian wetland restoration on greenhouse gas emissions. Additionally we quantified the emission of greenhouse gas from natural wetlands and investigated the factors influencing the fluxes of gas.

Main findings

• Conversion of agricultural soils into wetland does not increase the overall emission of greenhouse gas.
• Emission of greenhouse gas from restored wetlands is comparable to that of natural wetlands.

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When a wetland is drained and used for agricultural purposes, the soil rapidly decomposes and this lead to large emissions of carbon dioxide (CO₂) and nitrous oxide (N₂O).  This increases atmospheric pollution and  contribute to global climate change. Wetland restoration can greatly diminish or even suppress CO₂ and N₂O emissions but it will increase methane (CH₄) emission. Nevertheless the increase in CH₄ is compensated by the decrease in CO₂ and N₂O.

International papers

• Methane emissions in Danish riparian wetlands: ecosystem comparison and pursuit of vegetation indexes as predictive tools
• Greenhouse gas emissions from a Danish riparian wetland before and after restoration
• Nitrate removal capacity and nitrous oxide production in soil profiles of nitrogen loaded riparian wetlands inferred by laboratory microcosms
• Nitrous oxide fluxes in undisturbed riparian wetlands located in agricultural catchments: Emission, uptake and controlling factors