Home – Home – Jornals – Geography and Natural Resources 2021 number 1

This article presents an analysis of data on the transformation of the main components of ecosystems of steppizated pine forests in the Selenga Middle Mountains (Western Transbaikalia) under the influence of fires. It was established that ground fires of medium intensity prevailing in the region transform living ground cover, change the composition and properties of forest litter and morphological, physicochemical and hydrothermal properties of soils. The post-fire dynamics revealed a slight transformation of species diversity, projective cover and phytomass of herbaceous vegetation, and a more noticeable change in the parameters of moss-lichen cover, litter and soils. A fresh burn showed total death of mosses and lichens, and a small thickness and low reserves of litter consisting largely of fractions of fresh litter of the needles and branches. In the upper pyrogenic soil horizons, moisture decreased and temperature increased immediately after the fire. Very dark coloring from the products of organic matter combustion, alkalization, increasing content of calcium cations and carbon in humus-incorporated horizons and oxalate-soluble iron content in illuvial soil profile horizons were revealed. Five or more years after the passage of the ground fire there occurred positive changes associated with an increase in the thickness of litter and the formation of lichen cover as well as a gradual change in the chemical properties, a decrease in temperature indicators and some stabilization of field moisture parameters in the upper part of the soil profile. It is concluded that these transformations of the properties of litter, moss-lichen cover and soils have a negative influence on post-fire restoration of forest vegetation and pine regeneration in burnt areas formed by ground fires of medium intensity.