Constructed wetlands (CW) are developed during the 1950th. CWs are an engineered and thus more controllable wetland environment to utilize natural turnover processes. To remove excess reactive N from the ecosphere denitrification is the most common biochemical process. Establishing a constructed wetland by restoring the natural hydraulic conditions of a low land fen using nitrate laden drainage runoff water will create a semi-natural environment with increased denitrification rates. We conducted a long term and large scale mesocosm experiment that allows for upscaling to an establishing CW.<eng>
