Postpyrogenic Variability of Litter in Mountain Forests of Baikal Region

Abstract

The data of experimental studies on the postpyrogenic dynamics of the litter in mountain taiga cedar (Pinus sibirica), pine (Pinus sylvestris) and subtaiga forest-steppe pine (Pinus sylvestris) forests in the Baikal region are analyzed. Ground fires prevailing in this region transform the surface organic diagnostic horizons of soils and result in the formation of new pyrogenic organic horizons (Opir, OLpir, OL/Opir, OApir). The adverse impact of ground fires on the thickness, reserves, moisture capacity and fractional composition of forest litters is shown. The data on the chemical ash composition of litters, as well as the content of mobile microelement compounds is also given. The tendency of reducing the concentration of mobile elements in the organic horizons of soils from the taiga Siberian pine (cedar) altitudinal zonal complex (AZC) to the subtaiga forest-steppe pine AZCC of forest types was revealed. Forest fires were found to cause great quantitative and qualitative changes in the chemical composition of surface organic pyrogenic horizons; they are especially manifested in the transformation of their labile properties (рН, exchangeable cations, total and mobile nitrogen, etc.).