INFLUENCE OF INNOVATIVE BIOFERTILIZERS ON SOIL BIOLOGICAL ACTIVITY AND UNDERGROWTH OF SCOTCH PINE AFTER FELLING AND FIRE

Preserving the integrity of forests after logging and fires involves the development of various methods to promote natural reforestation. One of these methods is the creation of environmentally friendly and safe biofertilizers based on waste from the timber industry. The use of innovative biofertilizer in the Pogorelsky Bor (pine forest) of the Krasnoyarsk forest-steppe had a positive effect on the biopotential of soils and the amount of Scotch pine ( Pinus sylvestris L.) undergrowth after selective felling. In the first two years, in all experimental variants, an increase in the activity of hydrolytic and redox enzymes of the soil by 1.5-2 times was noted; they increased compared to the control. Immediately after the introduction of biofertilizer in the soil microbial complex, the amount of cellulolytics increases to 62 thousand CFU/g of soil in the logging areas. By the end of the growing season, both in the first and in the second year of application of biofertilizer in the experimental variant of the logging, sprouts of Scots pine were recorded 2-3 times more than in the control variant of this site. The fire that took place in May 2022 led to an increase in the total number of microorganisms up to 38 million CFU/g of soil and an increase in the activity of a number of hydrolytic enzymes during the growing season in experimental plots using biofertilizer. At the end of the growing season in 2022, there was no response of microorganisms to the application of biofertilizer, and actinomycetes dominated in the soil microbial complex. Also, by September of this year, the cellulose-decomposing potential, humification, and the activity of hydrolytic and redox enzymes decreased by more than 2 times. Biofertilizer significantly stimulated the formation of shoots and undergrowth of pine in the post-fire areas of the technological areas of felling (logging sites and portage) by 2 times.