Understanding Carbon Emissions in a Drained Peatland Undergoing Restoration: Insights from Chamber-Based Measurements

Peatlands are the largest terrestrial carbon stores on earth and play a significant role in the global carbon cycle. They become major sources of carbon when drained and degraded through unsustainable management like peat extraction, drainage, and conversion to agriculture and forestry. Restoration through rewetting—such as ditch blocking and bund construction—has been identified as one of the most efficient methods to accelerate biodiversity recovery while lowering carbon emissions and increasing carbon uptake. Since 2021, restoration efforts constructing contoured peat embankments (bunds) have been underway at a raised bog previously drained for horticulture extraction in Ireland. We investigated the net ecosystem exchange (NEE) and methane (CH₄) emissions using an Eddy Covariance (EC) system to assess the impacts of restoration on carbon dynamics, with results over a four-year period  indicating the site is still emitting carbon after restoration efforts. However, the restored bog comprises a mosaic of land cover types including bare and vegetated peat, open water and bunds and the spatial variation in soil respiration (Rs) across the site remained unknown. To address this, a chamber-based spatial Rs measurement campaign was carried out over a 10-month period. Unmanned Aerial Vehicle (UAV) surveys were also carried out to quantify land cover at the site. Initial findings revealed that the mean CO₂ efflux from bare peat and bund were 33.45 ± 2.73 (±SEM), and 60.43 ± 5.61 µmol CO₂ m² h⁻¹, respectively, 1-2 years post-restoration work. The study investigated the relationship of Rs with the explanatory factors such as soil temperature (Ts), soil moisture (Ms), and water-table height (Wt). The correlation analysis showed that in the bund areas, Ts exhibited a positive moderate influence on the Rs, while Wt significantly influence Rs in the bare peat areas. This chamber measurements approach spatially will help us to gain the deeper understanding of carbon dynamics in the restored peatland. It will allow us to capture the variations in carbon flux across the site’s various microtopographic features, which provide valuable insights for refining peatland restoration strategies and design methods to mitigate climate change mitigation effectively.