The influence of fire on the respiration of soil microorganisms and CO2 emission in forest biogeocenosis

Forest fires of various origins and intensities have a significant impact on the ecology of cenoses, affecting the cycle of the most important biogenic elements. Forest fires initiate a new succession of the forest canopy and, thus, regulate the accumulation of carbon determined by primary production. Fires also affect the thermal regime of the soil, which, in turn, affects the processes of soil respiration. As a result of the pyrogenic effect, primarily on vegetation, a sufficient amount of substrate gets into the soil, which is actively used by different physiological groups of microorganisms. To assess the intensity of substrate consumption by microorganisms, data on the rate of carbon dioxide emission are used. Interest in studying changes in microbiological activity in the post-fire period is caused by the rationale for the use of planned burning of vegetation and the formation of the carbon balance of plant-terrestrial ecosystems after fires. Carbon balance depends on many parameters: vegetation type, soil type, its chemical, physical and biological properties, climatic characteristics of the area, type and intensity of fires. In our work, we considered the effect of low-intensity ground fires in a forest cenosis on the background and substrate-induced respiration of soil organisms in dark-gray forest soil. Low-intensity ground fires, as well as crown fires, participate in changing the carbon balance of both the soil and the atmosphere. They increase the release of carbon dioxide due to the activity of soil microorganisms, which mineralize substrates entering the soil. An increase in CO2 release was noted a month after the fire. After 45 days of observation, it was noted that the release of carbon dioxide stabilized. Keywords: FIRES, PYROGENIC FACTOR, FOREST BIOGEOCENOSIS, MICROBIOLOGICAL ACTIVITY, BACKGROUND BREATHING