CO₂, CH₄, and Water Fluxes of a Drained Peatland in W-Iceland

The release and uptake of greenhouse gases (GHGs), including CO₂, CH₄, and N₂O, are closely tied to land use practices, with drained peatlands representing significant emission sources. According to Iceland’s National Inventory Report to the UNFCCC, emissions from drained peatlands are the largest single contributor to the country's total GHG emissions. While international research highlights peatland restoration as an effective strategy for reducing GHG emissions, the validity of such actions in Iceland has been limited due to a lack of country-specific data.

This study seeks to fill this gap by measuring the GHG dynamics of a drained and subsequently restored peatland at the farm Lækur in W-Iceland. Drained for livestock pasture 65 years ago but never cultivated, this site represents the dominant land use category for drained peatlands in Iceland. In this research, GHG, water, and energy fluxes are measured using the eddy covariance method, complemented by additional data on climatic variables, groundwater levels, soil moisture, and soil temperature.

The eddy covariance system was installed in January 2023. Preliminary results for 2023 indicate an annual net CO₂ emission of 1734.87 g m⁻² y⁻¹, negligible net CH₄ flux, an annual evapotranspiration of 420,416.10 g m⁻² y⁻¹, and equivalent rainfall of 420.42 mm y⁻¹.

The project uses a two-phase research approach: (1) baseline assessment of GHG fluxes under drained conditions and (2) ongoing monitoring post-rewetting (2025 onward). The study provides a comprehensive analysis of diurnal, seasonal, and annual GHG flux dynamics in drained peatlands and evaluates the initial impacts of rewetting. By generating high-quality, site-specific data, this research aims to inform the development of effective peatland restoration strategies as a GHG mitigation measure in Iceland and beyond.