Methane emissions from Dutch peatlands measured by a national eddy covariance network

Drained peatlands need to be rewetted to reduce carbon dioxide (CO2) emissions caused by microbial peat oxidation and to limit soil subsidence. Raising groundwater levels will subsequently increase the chance of methane (CH4) emissions, a much more potent greenhouse gas (GHG) gas than CO2. While intact peatlands are long-term carbon sinks and have a net cooling effect, despite the CH4 emissions, how disturbed peatlands will respond to rewetting is less certain. There are several rewetting strategies outside of returning the land to unproductive uses, such as paludiculture (agriculture on inundated soils) and installing water infiltration systems (WIS) in pastures.In the Netherlands, more than 85% of the peatlands are used for agriculture and have been extensively drained. Rewetting these peatlands is necessary to reduce CO2 emissions, however the effect this will have on CH4 emissions needs to be understood such that optimal rewetting strategies can be chosen to minimise GHG emissions. In this presentation, we report our efforts into monitoring CH4 emissions across Dutch peatlands with a network of eddy covariance (EC) systems since 2020 for the Netherlands Research Programme on Greenhouse Gas Dynamics in Peatlands and Organic Soils (NOBV) project. Fluxes of CO2 and CH4 have been observed across 20 field sites that cover the current Dutch peatland extent using a combination of permanent and mobile (alternating between two paired sites) EC towers that measured the land uses of paludiculture, semi-natural, pastures with WIS, pastures with high and low groundwater levels, and a lake. We focus on the main drivers of CH4 emissions in Dutch peatlands, evaluate the impact of land use on annual CH4 emissions, and emission upscaling.