Evaluation of soil microbial complexes after fires and logging in pine forests of the Lower Priangar’e

Abstract

The dynamics of ecological and microbiological parameters of the soils in fruticulose-lichen-green moss type of pine forests after fires of different intensity and logging tree stands at the initial stage (up to 10 years) of vegetation restoration in the Lower Priangar’e region are discussed in the article. It is revealed that at four to five year period after fires content of microbial biomass decreases by 2–9 times, total Cmic storages decreases by 20–40 % in the upper organo-mineral horizon of illuvial-ferrous sandy podzol, and the transformation of the structure and the number of ecological-trophic groups of microorganisms (ETGM), with more marked changes after high-intensity fires. The highest values of qCO2 (6.7–27.4 µgС–СО2/(mgСmic • h)) were observed within four years after fires with a tendency to decrease its values. The maximum changes of the functional parameters of microbial communities, decreases the number of ETGM and changes its structure, increased microbial production of CO2 by 54–40 % while reducing total Cmic storages by 20–40 %, and a high qCO2 value (5.5–14 4 µgС–СО2/(mgСmic • h)) were observed in the soil in two-five years of deforestation with significant mechanical disturbance of litter, whereas in the soil of ten logging at the young stage the considered parameters of microbial communities approximated the control. The restored successions of microbiocenoses of the of illuvial-ferrous sandy podzol of pine forests in five to eight years after high-intensity fires and after logging of pine forests with disturbance of soil and vegetation cover had similar trend and focus, reflecting the transformation of hydrothermal and trophic soil conditions.

Keywords

• fires of different intensity
• logging areas
• ecological-trophic groups of microorganisms
• microbial bio-mass
• basal respiration
• microbial metabolic coefficient