Carbon dioxide emission estimation in different zones of the south of Western Siberia

Abstract

The research was carried out in key areas of fallow land in three natural agricultural zones of the south of Western Siberia in the Omsk Oblast: steppe (Cherlaksky district, v. Preobrazhenka), forest-steppe (Kormilovsky district, v. Sosnovka), subtaiga (Tarsky district, Tara); in each zone there are three sites with fallow land of different ages: 5-10, 10-20 and 20-30 years. When comparing the intensity of carbon dioxide emission from fallow lands depending on the conditions of natural and climatic zones, it can be noted that its highest value was in the subtaiga zone (average for April-September 39.4 CO2/m2 per day), which is higher than the emission in the forest-steppe zone (14.7) and steppe zone (16.6). The maximum intensity of fluxes was observed in the subtaiga zone in August, and in the forest-steppe and steppe zones in July. One of the main reasons for this pattern was the air and soil temperature: the higher it is, the more intensive is the release of carbon dioxide. The influence of the age of fallow land on the level of soil carbon dioxide emission is observed. Younger fallows are characterized by a higher value of CO2 emission compared to older ones, so in the subtaiga zone the average seasonal emission of fallows of 5-10 years is 1.51 times higher than fallows of 20-30 years, in the forest-steppe zone - 1.46 times, steppe zone - 1.48 times.