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

The impact of industrial logging 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) in felling sites. The aim of study is to assess the effect of clear felling on CO2 emission from the soil surface of a coniferous-deciduous forest on a typical podzolic soil (Albic Retisol). The investigation was executed during the snowless periods (May-October) of 2020–2022 in a coniferous-deciduous forest and its felling site carried out in the winter of 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 relationship 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 was both positive and negative and statistically insignificant except data obtained in 2022 in the undisturbed control forest. The high values of CO2 flux during the snowless period were observed in July–August and was 3.90–5.62 gC/ m2/ day and 2.3–2.5 gC/m2/day in undisturbed forests and felled areas, respectively. In 2021, the peak of CO2 release shifted to June. Clear felling has a negative effect on the soil respiration of Albic Retisol that decreased by 1.2–1.9 times in the conditions of the middle taiga of the Komi Republic. The most (55–66%) of the C–CO2 efflux during the snowless period was emitted during the summertime, and the vegetation period (May–September) contribution was 84–88%. The obtained data will serve to determine the role of industrial logging in the carbon cycle of taiga forests.