Gennady Suvorov

The results of a study of CO₂ and CH₄ fluxes at five sites of the Tarmanskoe eutrophic fen (southern Western Siberia), differentiated by the degree of anthropogenic disturbance, are presented: an undisturbed fen, a naturally rewetted site after peat mining, a meadow used as pasture and hayfield, a dry meadow under occasional agricultural use after peat extraction, and an unused meadow with undisturbed peat structure. Net ecosystem exchange, soil and ecosystem respiration, and CH₄ fluxes were measured using static chambers in August 2024. Soil and ecosystem respiration were lowest at the undisturbed fen and highest at the unused meadow with an undisturbed peat deposit, where CO₂ uptake was also greatest. During daytime measurements, most of the studied sites were characterized by negative net ecosystem exchange values, indicating the predominance of CO₂ uptake over its emission, with the exception of the dry meadow under occasional agricultural use after peat extraction, which functioned as a CO₂ source. It should be noted that the obtained net ecosystem exchange values reflect only daytime fluxes during the measurement period and cannot be interpreted as the annual carbon balance without additional measurements. CH₄ fluxes decreased systematically from the undisturbed fen toward the drained sites. Correlation analysis revealed a strong positive relationship (Spearman’s rank correlation coefficient rs > 0.90) between CH₄ fluxes and soil pH, soil inorganic carbon content, and bulk density. Ecosystem respiration was strongly positively correlated with plant biomass and biomass nitrogen content, whereas net ecosystem exchange was positively correlated with air temperature. The results confirm that drainage of a eutrophic peatland increases CO₂ emission and suppresses CH₄ release. The naturally rewetted site after peat mining occupied an intermediate position for both variables, indicating partial but incomplete restoration of fen ecosystem functions.

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.

We present E-CAHORS—a compact mid-infrared open-path diode-laser spectrometer designed for the simultaneous measurement of carbon dioxide, methane, and water vapor concentrations in the near-surface atmospheric layer. These measurements, combined with simultaneous data from a three-dimensional anemometer, can be used to determine fluxes using the eddy-covariance method. The instrument utilizes two interband cascade lasers operating at 2.78 µm and 3.24 µm within a novel four-pass M-shaped optical cell, which provides high signal power and long-term field operation without requiring active air sampling. Two detection techniques—tunable diode laser absorption spectroscopy (TDLAS) and a simplified wavelength modulation spectroscopy (sWMS)—were implemented and evaluated. Laboratory calibration demonstrated linear responses for all gases (R² ≈ 0.999) and detection precisions at 10 Hz of 311 ppb for CO₂, 8.87 ppb for CH₄, and 788 ppb for H₂O. Field tests conducted at a grassland site near Moscow showed strong correlations (R = 0.91 for CO₂ and H₂O, R = 0.74 for CH₄) with commercial LI-COR LI-7200 and LI-7700 analyzers. The TDLAS mode demonstrated lower noise and greater stability under outdoor conditions, while sWMS provided baseline-free spectra but was more sensitive to power fluctuations. E-CAHORS combines high precision, multi-species sensing capability with low power consumption (10 W) and a compact design (4.2 kg).

Rewetting is the most effective way to reduce greenhouse gas (GHG) emissions from drained peatlands and must significantly contribute to the implementation of the Paris Agreement on Climate within the land sector. In 2010–2013, more than 73 thousand hectares of fire-prone peatlands were rewetted in the Moscow Region (the hitherto largest rewetting program in the Northern Hemisphere). As the Russian Federation has no national accounting of rewetted areas yet, this paper presents an approach to detect them based on multispectral satellite data verified by ground truthing. We propose that effectively rewetted areas should minimally include areas with wet grasslands and those covered with water (cf. the IPCC categories “rewetted organic soils” and “flooded lands”). In 2020, these lands amounted in Moscow Region to more than 5.3 and 3.6 thousand hectares, respectively. Assuming that most rewetted areas were former peat extraction sites and using IPCC default GHG emission factors, an overall GHG emission reduction of over 36,000 tCO₂-eq year⁻¹ was calculated. We furthermore considered the uncertainty of calculations. With the example of a 1535 ha large rewetted peatland, we illustrate the estimation of GHG emission reductions for the period up to 2050. The approach presented can be used to estimate GHG emission reductions by peatland rewetting on the national, regional, and object level.

Haylands are the mildest option for the agricultural use of drained peatlands in terms of CO₂ emissions. However, CO₂ fluxes and their balance may depend on various conditions including the frequency of mowing and amount of phytomass removed. Based on field measurements of CO₂ fluxes using the chamber method and monitoring of environmental factors conducted in 2018–2020 on hayland and fallow on drained peatland in central European Russia, a mathematical model of CO₂ balance was built. Numerical experiments showed that mowing of hayland, irrespective of the intensity, did not lead to an increase in CO₂ emissions compared to fallow. Fallow and hayland after single mowing had closely modelled net ecosystem exchange (NEE) values: 9.9 ± 2.4 and 8.5 ± 2.7 t C ha⁻¹ season⁻¹, respectively. Furthermore, a single mowing turned out 2.8 t ha⁻¹ of hay (0.8 ± 0.1 t C ha⁻¹), and 4.4 (1.4 ± 0.1) after double mowing. The modelled NEE after double mowing increased to 9.4 ± 2.9 t C ha⁻¹ season⁻¹. A single mowing session in early summer is recommended. Compared to other uses, e.g. arable land, mowing on hayland is a compromise between reducing CO₂ emissions and gaining economic benefits from drained peatlands.

Monitoring of CO2 fluxes on Svalbard: land use alters the gas exchange in the arctic tundra Наблюдения за потоками СО2 на архипелаге Шпицберген: использование территории человеком меняет газообмен арктической тундры

For the first time were the results of studies on influence of main kinds of local anthropogenic factors on soil emission of biogenic greenhouse gases (CO2, CH4, and N2O) in permafrost ecosystems of Arctic and North-Boreal zones of the Russian Federation, and also of the Spitsbergen Archipelag summarized. Different types of land use can, depending on their manner, lead to significant enhancing or suppression of soil CO2 emission. On average, anthropogenic factors (AFs), acting in concert, favor the enhancement of local CO2 soil emission, promoting, at the same time, an increase in its dispersion. AFs directly influence the microbial-root respiration in soil, modify the soil itself, and indirectly affect important natural respiration regulators, phytomass reserves in particular, which makes them primary factors with relation to respiration pattern. AFs influence also the emission of other biogenic greenhouse gases (CH4 and N2O), though this influence can be exercised in different ways. Methane emission is mediated by degree of the territory drainage. However, in all studied cases, AFs have led to source reduction or sink intensification of this gas from the atmosphere. Unlike methane emission, N2O emission increased under the influence of AFs considered. As for the whole complex of AFs that impacts the carbon balance and fluxes of CO2 in cryogenic ecosystems, its role is expressed through the enhancement of soil respiration at the beginning of the cold season, when AFs are capable of soil emission increasing, at the level of meso-landscape, almost by 50%.