Ecosystem–Atmosphere Exchange of CO ₂ in Ombrotrophic and Mesotrophic Peatlands in the Taiga Zone of European Russia and West Siberia

Abstract Northern peatlands (>50°N) account for approximately 70% of the global peatland area and play a key role in the global carbon cycle. However, their role as long‐term carbon sinks is vulnerable to modern climate warming at high latitudes. Future climate predictions require data on how peatlands respond to observed changes in global environmental parameters, particularly in the Northern Hemisphere taiga zones. Here, we compared CO 2 net ecosystem exchange (NEE), ecosystem respiration ( R eco ), gross primary production (GPP), and their responses to changes in environmental parameters using direct Eddy covariance measurements in four representative peatlands: two southern and two middle taiga sites located in European Russia and West Siberia, respectively. Three sites were ombrotrophic bogs, and one was a transitional (between bog and fen) mesotrophic peatland. All studied peatlands functioned as CO 2 sinks either annually or during the growing season. The largest net CO 2 uptake was detected in the mesotrophic peatland in the middle taiga of European Russia. In the ombrotrophic bogs, elevated air temperatures (>25°C) and vapor pressure deficits (>2 kPa) negatively impacted GPP in the summer; however, at the mesotrophic peatland, these conditions corresponded to the highest GPP observed during the measurement period. Additionally, a reduction in net CO 2 uptake was detected at the mesotrophic site during the anomalously wet summer. The study findings suggest that the differences in CO 2 exchange processes and their responses to ambient conditions in ombrotrophic bogs and transitional peatland types are important to consider in modelling studies and flux predictions.