Seasonal dynamics of carbon dioxide emissions from deposits of different ages depending on the natural zone of Western Siberia

The studies determined soil CO2 emissions from deposits of different ages in three natural and climatic zones of the south of Western Siberia. The objects of research were fallow lands of various age groups in three natural and climatic zones of the Omsk region and the size of soil CO2 emissions. The research was carried out in key areas of the Omsk region: steppe (Cherlaksky district, Preobrazhenka village), forest-steppe (Kormilovsky district, Sosnovka village), subtaiga (Tarsky district, Tara); three sites with different age fallow lands were identified in each zone: 5-10, 10-20 and 20-30 years. Carbon dioxide emissions were determined in key areas of fallow lands monthly, with an interval of 10-15 days, starting from May-October. When comparing the intensity of carbon dioxide emissions from fallow lands, depending on the conditions of the natural and climatic zone, it can be noted that its greatest value was in the subtaiga zone (on average for April-September - 39.4 CO2/m-2 * day-1), this is higher than the size of emissions in the forest-steppe (14.7) and steppe zones (16,6). The maximum intensity of flows was recorded in the subtaiga zone in August, in the forest-steppe and steppe in July. The influence of the age of fallow lands on the level of soil carbon dioxide emissions is observed. Younger deposits are characterized by a greater amount of CO2 emissions compared to the older ones. So, in the subtaiga zone, the average seasonal emission from deposits 5-10 years old is 1.51 times higher than from deposits aged 20-30 years, in the forest-steppe zone it is 1.46 times, respectively, in the steppe zone - 1.48 times.