Influence of Clear Felling on СО₂ Emission from Surface of Podzolic Soil of Coniferous–Deciduous Forest (Middle Taiga, Komi Republic)

The impact of felling on the carbon cycle of boreal forests is characterized by significant uncertainties, which is largely due to the lack of information on carbon fluxes (in particular, soil respiration) at felling plots. This study is aimed to assess the effect of clear felling on CO₂ emission from the surface of a typical podzolic soil (Albic Retisol) under the coniferous–deciduous forest. Field data were obtained during the snowless periods (May–October) of 2020–2022 in the undisturbed coniferous–deciduous forest and the plot after felling in winter 2020. The carbon dioxide emission was measured by a LI-COR 8100 gas analyzer. A brief description of the weather conditions during the years of research and the dynamics of soil temperature at a depth of 10 cm is given. A positive statistically significant correlation between soil respiration and soil temperature at a depth of 10 cm (R² = 0.17–0.75; p < 0.001) was detected for the analyzed objects. The correlation with soil moisture content was both positive and negative and statistically insignificant, except for data obtained in 2022 at the undisturbed control forest plot. The high values of CO₂ flux during the snowless period were observed in July–August and reached 3.90–5.62 g C/m²/day and 2.3–2.5 g C/m²/day at the control and felled plots, respectively. In 2021, the peak of CO₂ emission shifted to June. Clear felling had a negative impact on the soil respiration from the studied Albic Retisol: it decreased by 1.2–1.9 times in the conditions of the middle taiga of the Komi Republic. A larger part most (55–66%) of the C–CO₂ emission of the snowless period occurred in summer months; the emission during the growing season (May–September) share reached 84–88% of the emission during the snowless period. The obtained data are necessary for adequate assessment of the effect of felling on the carbon cycle in taiga forests.