Assessment of forest fires influence on chemical and microbiological properties of hydromorphic soils in northern part of Sym-Dubchessk interfluve (Krasnoyarsk territory)

Abstract

The subject of the study are three raised bogs located in the vicinity of the Sredneeniseyskya monitoring station of the V. N. Sukachev Institute of Forest SB RAS (Krasnoyarsk Territory), which were affected by fires in different periods of time. It is shown that the bogs differed in thickness and age of peat, the amount of accumulated macro charcoal particles along the soil profiles. The age of the lower peat horizons showed that bog formation in the studied area started at different times: from the second half of the Boreal period of the Holocene to the Subatlantic period. The content of charcoal showed that the pyrogenic activity during the Holocene was different. The morphological structure and chemical properties of peat soils have changed in the pyrogenic horizons of all the sites, compared with non-pyrogenic ones. They are depleted of carbon and nitrogen, enriched in ash elements. The content of microbial biomass (MB) and basal respiration (BR) rate is low due to a lack of organic matter, the microbial trophy is disturbed, and the restoration of microbial activity is extremely slow. The main role in the transformation of pyrogenic horizons was assigned to bacteria, while fungal activity was significantly lower.