Immediate Impact of Rewetting on Carbon Dynamics in a Degraded Irish Raised Bog

Peatlands are the most efficient terrestrial ecosystems for long-term carbon (C) storage. In Ireland, approximately 84% of raised bogs are degraded, contributing an estimated emission of 1.9 Mt C year−1, nearly one-third of which originates from domestic peat extraction sites. Rewetting aims to reduce C emissions and restore sequestration capacity; however, immediate post-restoration effects remain poorly quantified. We investigated the short-term impact of rewetting on C fluxes over a 3-year period at a former domestic peat extraction site. CO2 and CH4 fluxes were measured across rewetted and adjacent unrestored areas with matched ecotopes (vegetation communities). Results show that rewetting led to substantial reductions in C emissions across all ecotopes. Compared to unrestored areas, the Sub-marginal and Facebank ecotopes had lower average annual C emissions by 0.88 and 0.74 t C ha−1, respectively. In the cutover bog, rewetting reduced emissions in Eriophorum and Molinia ecotopes by 2.17 and 0.59 t C ha−1 year−1, respectively. This study demonstrates that rewetting led to immediate carbon reduction, and can deliver immediate climate mitigation benefits. Expanding restoration to include undesignated domestic extraction bogs offers a cost-effective strategy to reduce emissions from degraded peatlands in the near term.