Changes in the Composition of Upper Soil Horizons and Lysimetric Waters in the First Years after a Surface Fire in a Lichen Pine Forest in the Komi Republic.

Changes in the chemical composition of the upper soil horizons (Albic Podzol) under lichen pine forests affected by a running surface fire in the middle taiga of the Komi Republic was studied. It was revealed that two days after the fire, the total carbon content in the pyrogenic horizon (Qpyr) increases by 1.3 times compared to the litter of the conventionally background area. During further post-pyrogenic succession, the total carbon content in the upper pyrogenic horizon decreases. Immediately after the fire, an increase in the benzene polycarboxylic acids content in the pyrogenic horizon by 14.5 times compared with the litter of the conventionally background area was revealed. The concentration of polycyclic aromatic hydrocarbons is 7 times higher than their content in the litter of the original forest. In the first 10 days after the fire, a rapid removal of carbon (4 g/m2) and PAHs (11.5 μg/m2) was shown to occur from under the pyrogenic horizon. Increased removal compared to the conventionally background area can be observed in the first three months. During the further evolution, the chemical composition of lysimetric waters approaches conventionally background values, and after two years the concentration of both carbon and PAHs is close to conventionally background values. [ABSTRACT FROM AUTHOR]