Modelling the northern peatland methane fluxes with a process-based model

Northern peatlands are significant carbon reservoirs, serving as long-term atmospheric carbon dioxide sinks and sources of methane and nitrogen dioxide. However, methane processes interacting with environmental changes in Northern peatlands, remain unclear. Therefore, the need for better simulation of key processes of methane in peatlands is still urgent. In this study we used the process-based CoupModel combining the long-term in-situ measurements to successfully constrain the energy, water and carbon fluxes modeling in a boreal peatland (CH4, r²=0.62). We noticed that plant transportation is the most dominant pathway for methane emissions from this peatland (57.87% of total CH4 emission), followed by surface diffusion (31.06%) and ebullition (11.07%). The relationship between CH4 fluxes and water table depth is non-linear, and the dominant CH4 emission pathway varies as the water table regime changes. Our study provided new insights into the emission mechanisms of methane in boreal minerotrophic mire and contributed to a better understanding of boreal peatlands for both modelling and observation communities.