Зональность лесных горючих материалов и их пирогенная трансформация в сосняках Средней Сибири

Abstract

Fires in the forests of Siberia occur annually and cause enormous damage to natural resources. Therefore, studies of the natural forest fire hazard, one of the components of which are forest fuels, are relevant. The research carried out on 53 sites in the pine forests growing along the Yenisei meridian transect revealed that surface fuel loads in pine stands of different zones of Central Siberia are defined by geographical latitude and increase from the forest-steppe zone to the northern taiga subzone. The largest forest fuel loads are concentrated in the pine stands of the northern and middle taiga. Their composition is dominated by loads of duff, the fraction of which in surface fuel loads increases from the forest-steppe zone (57.4 %) to the northern taiga zone (71.3 %). The obtained dynamic equations of the reserves of grass-shrub understory over the season may be applicable to grassy types of pine forests. Combustion of surface forest fuels in pine forests during surface fires of differentintensity varies from 10.8 to 31.4 t/ha, which is from 26.1 to 74.1 % of their loads before the fire. The intensity of fires determines not only the number of burned forest fuels, but also their post-pyrogenic accumulation regardless of zonal and environmental conditions. The variation of fuel loads in forest areas is related to pyrogenic effects and the recovery period after the last fire, as well as to the mosaic distribution of living ground vegetation. Equations of accumulation of surface forest fuels after fires of different intensity that can be applied to pine forests of Central Siberia are developed. A change of dominants in the ground cover and a decrease in the productivity of the grass-shrub understory occurs in a long-term absence offires in pine forests. The development of moss cover contributes to the decrease in litter reserves. The data obtained on the loads of surface forest fuels and their transformation during a fire provide the basis for understanding and simulation fire behavior, estimating emissions and impacts of fires on fuel loads, and can be used for improvement the existing global and regional models. For citation: Ivanova G.A., Ivanov V.A. Zonality of Forest Fuels and Their Pyrogenic Transformation in Pine Forests of Central Siberia. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 4, pp. 9–26. DOI: 10.37482/0536-1036-2020-4-9-26Funding: The research was supported by the Siberian Branch of the Russian Academy of Sciences and the Russian Foundation for Basic Research (grant projects No. 07-04-00562 and 19-58-80002 BRICS-t).