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.
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.