Peatland methane emissions in a changing climate: A 13-year time series of a boreal fen in Northern Finland

Boreal peatlands are a major source of global wetland methane emissions. With ongoing climate change, these emissions could rise sharply in future, further enhancing climate change. Yet, long-term studies evaluating the impact of climate change on boreal peatlands are scarce. We have monitored methane emissions at a boreal fen in Lompolojänkkä, Northern Finland (ICOS ecosystem class II site) for 13 years (2007-2019) using the eddy covariance technique, accompanied by measurements of abiotic and biotic variables, such as peat temperature, water level, and vegetation parameters. Peat temperatures strongly drove methane emissions, that is, methane emissions increased significantly with peat temperature. Year-to-year variation in CH₄ emissions was correlated to year-to-year variation in peat temperatures. Annual variation in water levels had no significant impact. Our results confirm that peat temperature explains CH₄ variation to a large extent. In this presentation, we will further evaluate the role of snow cover and melt on CH₄ emissions in spring.