Evaluating Restoration Effects on Net Ecosystem Exchange (NEE) of CO2 in an Irish Peatland

In Ireland, peatlands cover around 20% of the land area, holding more than 50% of the country's soil carbon. Unfortunately, over 85% of Ireland's peatlands have already been drained due to a long history of peat extraction, drainage, and conversion to agriculture and forestry. Degraded peatlands have become sources of carbon emissions, raising awareness of the need for peatland restoration as a critical strategy for climate change mitigation. Though there has been extensive and ongoing research on peatland ecohydrology, restoration, and Net Ecosystem Exchange (NEE) of CO₂ in Ireland, holistic ecosystem research is limited and has largely been carried out on a short-term basis as part of discipline-specific or restricted multidisciplinary research projects. There remains significant gaps in our understanding in the specific causal relationships between ecohydrological conditions and carbon sequestration. The study was conducted at a degraded, peat-extracted raised bog previously used as a horticultural site with significant drainage. In order for the expansive national peatland restoration schemes to deliver the optimal climate, ecological, hydrological, and environmental benefits, a clear understanding of the trajectory of NEE of a degraded raised bog undergoing restoration is required, and of equal importance are the causal ecohydrological processes influencing this trajectory.  A large-scale engineering restoration has been carried out at the site by constructing contour bunds and water level control stations. To address the restoration effectiveness, the Net Ecosystem CO₂ Exchange (NEE) and environmental data were collected from 2021 to 2024 using the Eddy Covariance (EC) technique, which is a direct, ecosystem-based measurement method. The analysis revealed that yearly cumulative NEE exhibited variable trends, rising from 114 g C m⁻² in 2021, 207 g C m⁻² in 2022, 221 g C m⁻² in 2023, and 237 g C m⁻² in 2024. The findings indicated that the site is still emitting carbon even after restoration efforts. Further analysis aims to explore the seasonal and temporal trends in emissions, considering the key biotic and abiotic factors. This study will provide insights into restoration effectiveness to support the national peatland restoration and conservation strategies for the degraded peatland scheduled for restoration.