Krasnoyarsk scientists have found how fires and cutting violate the microbial communities of forests

Krasnoyarsk scientists have found how fires and cutting affect the communities of microorganisms in the soil. The results of the study were published in the journal of the Siberian Federal University “Biology”.

The Krasnoyarsk Scientific Center SB RAS noted that thanks to the study of soil microorganisms, it is possible to assess the scale of damage and predict the restoration of ecosystems. This is especially important for Siberia, where the area of ​​broken forests grow.

Microbial communities play a key role in the cycle of substances and the restoration of forests. They help to decompose organic residues, participate in the formation of humus, provide plants with nitrogen.

Scientists of the Krasnoyarsk Scientific Center of the SB RAS compared two types of ecosystems – dry lichen and wet sphagnum pine trees of the middle taiga of the Krasnoyarsk Territory. Ecosystems were violated differently in them. Scientists have investigated: forests surviving a fire; cut areas; As well as the territory where the deforestation took place. There, experts studied the forest litter and the upper soil layer up to 20 centimeters depth.

It turned out that because of fires and felling, microbial activity in the soils drops sharply. In the forest litter after fires, the carbon content of microbial biomass decreases by 2-3.5 times, and the intensity of microorganism breathing falls by 30–40 %. The number of bacteria and fungi is reduced, which are involved in the decomposition of organic residues. In some areas, the number of these microorganisms decreased by 3.5–11 times. At the same time, after a fire in soils, species that can survive with a lack of nutrients begin to prevail.

In addition, the researchers found that after fires, microorganisms are more actively decomposing organic substances, releasing carbon dioxide, but accumulate carbon in biomass less. Since many organic substances and so burned during the fire, it turns out that the soil eventually loses a significant amount of carbon. In turn, the earth becomes less fertile, and it is more difficult to recover to the forest. This can enhance the greenhouse effect in the region.

“Cutting out are extremely fire hazardous due to the presence of a large stock of combustible materials and conditions for their rapid drying. Sopagnic pines – wet – are restored faster than lichen pines – dry. In dry forests, fires damage the soil more, it takes more time to restore the functional activity of soils. Studies of the response of soil microorganisms to violations are extremely important for evaluating the consequences of fires and felling, especially under the conditions of increasing anthropogenic influence on Siberian ecosystems, ”said Anna Bogorodskaya, candidate of biological sciences, senior researcher at the Forest Institute named after V.N. Sukachev SB RAS.