Greenhouse-gas balance of a drained peatland in western Iceland

The uptake and emissions of the greenhouse gasses (GHGs) CO₂, CH₄, and N₂O are strongly linked to terrestrial land use. According to Iceland’s National Inventory Report to the UNFCCC, the single largest component of Iceland‘s overall greenhouse gas (GHG) emissions is the release of GHGs from drained peatland. On the other hand, foreign studies have shown peatland restoration to be a promising measure for reducing emissions of drained areas. Therefore, studies on the GHG-balance of drained and rewetted peatlands are now a very hot topic internationally.

Within Iceland, the use of peatland- and other wetland restoration as a GHG mitigation measure is hampered by a lack of more country-specific data on GHG balances of such ecosystems. Therefore, there is an urgent need to increase the research on this topic in Iceland.

In this project, the main aim is to gather high-quality data on the GHG dynamics of a drained and restored peatland. The site is located at the farm Lækjarnes in W-Iceland and was drained ca. 50 years ago, but has never been cultivated. That is the land use category of most drained peatland in Iceland, they mostly remain uncultivated and are used for livestock grazing. 

In this Research, we are using an Eddy covariance system to collect CO₂ and CH₄ flux data, while N₂O fluxes are measured with a static chamber method. The eddy covariance technique has become a “standard method” in ecosystem flux- and process-based research worldwide. We are also measuring auxiliary parameters, such as full energy balance, climatic variables, groundwater levels, soil water and temperature, and more. Our eddy system was installed at the research site in Jan 2023. 

The site is currently drained and will remain so for the first two years, but then it will be rewetted and the measurements will continue after the rewetting. The specific research goals I have chosen to address in my PhD project are: a) Determine the diurnal, seasonal, and annual CO₂, CH₄, N₂O, water, and energy balances of a drained wetland and b) Determine the initial change in those fluxes following ecosystem restoration (rewetting).  The first preliminary data on CO₂, H₂O, and CH₄ winter fluxes from the drained peatland will be presented at the conference.