MONITORING OF CARBON DIOXIDE FLUXES IN DEPOSITS OF DIFFERENT AGES IN VARIOUS NATURAL AND CLIMATIC ZONES OF THE SOUTH OF WESTERN SIBERIA

The paper reflects the spatial and temporal variability of CO2 fluxes on fallow lands. The aim was to determine the soil CO2 emissions from fallow lands of different ages, taking into account the natural and climatic zones of the south of Western Siberia. The research was carried out in three natural and climatic zones of the Omsk region: steppe, forest-steppe, subtaiga; in each zone, three sites with different age fallow lands were identified: 5-10, 10-20 and older than 20 years. The soil CO2 emission was measured using exposure chambers with determination on a gas chromatograph. When comparing the intensity of CO2 emissions from fallow lands, depending on the natural and climatic zone, it can be noted that in the warm season the maximum level was in the subtaiga zone (on average for May-September 54.1 g of CO2 ∙ m-2 ∙ day-1), followed by the magnitude of flows in the forest-steppe zone (29.4), the minimum It was observed in the steppe zone (25.0). At the same time, the maximum value of the flows was observed in the subtaiga zone in July, in the forest–steppe and steppe zone in June. Younger deposits are characterized by a large amount of soil carbon dioxide emissions compared with older ones: in the subtaiga zone, the average seasonal emission of deposits 5-10 years old is 1.30 times higher than deposits older than 20 years, in the forest–steppe zone, respectively, 1.51, steppe – 1.63 times. The daily dynamics of soil CO2 fluxes has an increased level in the morning and afternoon hours, decreased in the evening and night hours, regardless of the zone.