Boreal wetlands: new evidence on who stores carbon dioxide and who emis it
Researchers of the International Laboratory of Landscape Ecology took part in a major multi-institutional study of the carbon balance of Russia’s taiga peatlands
A paper has been published in the journal Global Biogeochemical Cycles that examines the exchange of carbon dioxide in different types of peatlands in the taiga zone of European Russia and West Siberia.
Peatlands of the boreal zone are among the largest natural carbon reservoirs and an important component of the climate system. However, their role as a long-term sink of CO₂ depends on how different peatland types respond to warming, droughts, and anomalously wet seasons. To refine these assessments, comparable field data on carbon dioxide fluxes from different regions are required. The study is the result of combining observations from several research teams: the A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences (ombrotrophic bog Staroselsky Mokh, Tver Region), the Institute of Biology, Komi Science Centre, Ural Branch of the Russian Academy of Sciences (transitional bog Ust-Pojeg, Komi Republic), Yugra State University (ombrotrophic bog Mukhrino, Khanty-Mansi Autonomous Okrug), and the Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences (ombrotrophic Bakchar bog, Tomsk Region). At all sites, direct measurements of CO₂ fluxes using the eddy covariance method were carried out, which made it possible to assess the net carbon balance of the ecosystems.
The study showed that, during the observation years, all investigated peatlands acted as sinks of atmospheric CO₂. At the same time, the transitional (mesotrophic) bog exhibited a higher cumulative CO₂ uptake compared to ombrotrophic (oligotrophic) bogs. An important result concerns differences in ecosystem responses to meteorological anomalies: in ombrotrophic bogs, high air temperature and low humidity in summer led to a decrease in gross primary production and, consequently, in carbon sequestration, whereas in the transitional bog the same weather conditions corresponded to maximum CO₂ uptake. In an anomalously wet season, on the contrary, it was the mesotrophic bog that reduced its carbon sink.
Why do some bogs “give up” while others do not? One of the study’s authors, Robert Sandlersky, comments: “Apparently, the secret of resilience lies in the combination of water table level and vegetation type. In transitional bogs, the groundwater level is usually higher and more stable than in ombrotrophic bogs. But the main difference is their ‘cooling tools’. In mesotrophic ecosystems, vascular plants (sedges and grasses) dominate, with roots reaching deep into the water-saturated peat. In hot weather they function as powerful natural pumps, drawing up water and evaporating it through their leaves. This process, transpiration, effectively cools the bog surface, allowing the system to maintain order and continue photosynthesis. A completely different picture is observed in ombrotrophic bogs dominated by Sphagnum mosses. Mosses have no roots and depend on the moisture in the very top layer. As soon as the sun heats the surface above 25°C and the bog water level drops, the upper, actively functioning Sphagnum layers lose contact with moisture and ‘switch off’. At that moment the ombrotrophic bog stops functioning, converting incoming solar energy into sensible heat flux to the atmosphere and, accordingly, sharply reducing carbon uptake”.
The results indicate that when modeling the carbon balance of boreal peatlands and incorporating them into climate models, it is necessary to account not only for climatic factors, but also for peatland type, trophic status, and vegetation characteristics. Treating “peatlands” as a homogeneous ecosystem type can lead to substantial errors when forecasting the role of high-latitude regions in the global carbon cycle. It is quite possible that mesotrophic bogs may become the most reliable buffers limiting the accumulation of greenhouse gases in the atmosphere under a changing climate.
Mamkin V., Avilov V., Dmitrichenko A., Dyukarev E., Emelianova E., Gorbarenko E., Gulyaev R., Ivanov D., Kurbatov E., Kuricheva O., Lapshina E., Miglovets M., Ogurtsov S., Sandlersky R., Suvorov G., Trusova S., Zagirova S., Kurbatova J. Ecosystem–atmosphere exchange of CO₂ in ombrotrophic and mesotrophic peatlands in the taiga zone of European Russia and West Siberia // Global Biogeochemical Cycles, 2026. 40, e2025GB008592.
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