Impact of Forest Fires on the Microbiological Properties of Oligotrophic Peat Soils and Gleyed Peat Podzols of Bogs in the Northern Part of the Sym-Dubches Interfluve, Krasnoyarsk Region

Key plots of hydromorphic and semihydromorphic peat soils of oligotrophic bogs were studied in the area of the Middle Yenisei Station of the Institute of Forest, Siberian Branch of the Russian Academy of Sciences. Hydromorphic soils were classified as Fibric Histosols (FHS1 and FHS2), and semihydromorphic soils were classified as Histic Albic Podzols (PZ1 and PZ2). It was found that fires had a significant impact on the initial waterlogging of the studied territory. The pyrogenic horizons of peat soils were generally enriched in ash elements and differed from one another in the contents of carbon and nitrogen. The functional activity of microbial communities in the studied soils was low, and this affected the content of microbial biomass and respiration rate. The restoration of microbial activity in pyrogenic horizons proceeded slowly because of the deficit of available organic matter. The qualitative and quantitative compositions of bacterial biomes and mycobiomes of peat soils differed in the studied plot and soil horizons. The number and species diversity of prokaryotes in all areas was quite high. Representatives of Proteobacteria and Archaea played the leading role in the development of pyrogenic horizons; the number of their operational taxonomic units (OTUs) in these horizons was significantly higher than that in the nonpyrogenic horizons, where Acidobacteria predominated. The mycobiomes of the FHS1 and FHS2 plots were significantly less abundant and had lower species diversity as compared to the PZ1 and PZ2 plots. The number of fungi was higher in the nonpyrogenic horizons; the number and diversity of fungi decreased in the pyrogenic horizons. The mycobiomes of the upper pyrogenic horizons included groups of carbotrophic fungi that can develop on charcoal.