Impacts of Fire Disturbance on Carbon Dynamic and Ecosystem Recovery in a Blanket Bog Ecosystem

Fire is an increasingly important disturbance in Atlantic blanket bogs, yet empirical evidence of its effects on carbon dynamics remains limited. This study quantified the immediate and short-term impacts of a burning event on ecosystem atmosphere carbon dioxide (CO₂) exchange, vegetation loss, and post-fire recovery from a blanket bog in the North-West of Ireland in 2023. Continuous eddy-covariance (EC) measurements collected over three years (2023-2025) were analysed together with biomass sampling and burn severity mapping (dNBR) conducted in 2023.

Field scale measurements of  CO₂ by EC quantified an emission event of 42.7 g C m^-2 d^-1during the burning window. Footprint-weighted biomass assessments indicated an above-ground vegetation carbon loss of 28.3 g C m^-2, dominated by heather and graminoids, demonstrating that surface vegetation combustion was the primary contributor to the observed emission spike. Burn severity and field observations confirmed that combustion was surface limited, with no evidence of deep peat burning. Despite this disturbance, the bog remained a net annual carbon sink in all years analysed, indicating rapid functional recovery but reduced net carbon uptake in the later post-fire year. Annual net ecosystem exchange (NEE) remained within the range reported for blanket bogs under prevailing land management conditions.

Generalized additive models (GAMs) showed that post-fire CO₂ exchange was primarily controlled by solar radiation and air temperature, with moisture related controls more pronounced in 2023 when the peat surface was exposed. Rapid graminoid regrowth and persistently high-water tables supported recovery of photosynthetic function and reduced moisture sensitivity by 2024.

Overall, the fire disturbance caused a distinct temporary carbon loss, with emissions during the burn substantially exceeding pre-fire emissions. Despite this disturbance, the ecosystem remained a net annual carbon sink, and post fire carbon recovered quickly due to intact hydrology and shallow burn severity. These findings demonstrate that Atlantic blanket bogs can exhibit high resilience to low-moderate severity surface fires and highlight the importance of maintaining high water tables and peatland condition to minimize fire related carbon losses under future climate change.  

Keywords: Atlantic blanket bog, fire disturbance, eddy covariance, CO₂ exchange, burn severity, post-fire recovery