[M-IS01] Environmental, Socio-Economic and Climatic Changes in Northern Eurasia

[MIS01-P07] Evaluation of fuel loads and their dynamics in the forest regions of Siberia

*Ludmila Buryak^1,2,3, Elena Kukavskaya², Olga Kalenskaya³ (1.Forest pyrology center, All-Russian Research Institute for Silviculture and Mechanization of Forestry , 2.V.N. Sukachev Institute of Forest of the Siberian Branch of the Russian Academy of Sciences -separate subdivision of the FRC KSC SB RAS, 3.Reshetnev Siberian State University of Science and Technology)

Keywords:fuel loads, forest regions, Siberia

Climate change and the associated increase in fire danger and area burned are among the most significant global challenges facing the world today. There is a high interest in accurate quantitative estimates of the forest fuel loads due to increasing fire activity. In Russia, the information on forest fuel loads is rather scare while regional data on fuel loads and consumption in Siberia are almost absent.
We evaluated fuel loads in eight forest regions of the southern and central taiga of Siberia and found out that characteristics of ground cover and their dynamics depend on the zonal-geographical features, forest region, soil characteristics (granulometric composition and moisture), site category, and forest type. In the disturbed forest areas, fuel loads and their dynamics determined by the type and degree of disturbance, as well as the characteristics of fires, logging, and other anthropogenic and biotic disturbance factors. The smallest fuel loads were found in the Zabaikalsky mountainous and Altai-Sayan mountain-taiga forest regions where they did not exceed 18 t/ha in the undisturbed forests grown on dry poor soils and 30 t/ha in the forests on loamy mesic soils. At the same time, fuel loads in similar forest conditions in different forest regions of Siberia can differ by 1.5 times or more. In all forest regions, the ground fuels in the forests growing on dry sandy and sandy loamy soils are significantly lower than in the forests on wet and very wet loamy soils. Thus, in the Trans-Baikal mountain forest region, fuel loads in undisturbed forests on dry sandy soils average15.4±0.70 t/ha while in the forests on loamy mesic and wet soils - 26.5±1.93 t/ha.
Fires mainly reduce ground fuel loads. However, after the fast-moving surface fires, the fuel loads may increase due to the needles falling from damaged trees and grasses proliferation. Ground and surface fuel loads are minimal on repeatedly burnt sites and clear-cuts where they may not exceed 1 t/ha postfire. After crown and steady surface fires up to 20 years or more is required for ground fuels to return to prefire loads.
Knowledge of forest fuel loads and their temporal dynamics is necessary to predict the fire occurrence, behavior, and effects as well as to evaluate fire emissions.
The research was supported by the RFBR, Government of the Krasnoyarsk krai, and the Krasnoyarsk regional foundation of scientific and scientific-technical support (Grant #20-44-242004).