SPATIAL VARIABILITY OF FOREST FLOOR PROPERTIES IN POST-FIRE LARCH FORESTS OF THE RUSSIAN FAR EAST

The study summarizes and analyzes data on forest litter properties in the larch forests of the Russian Far East, which are subject to frequent fire disturbances. Based on a representative database, spatial variability patterns of the key litter properties were described. The research was conducted on 125 sample plots across the Amur Region, Transbaikal Territory, and Yakutia, considering the fire factor. The results revealed significant variability in litter stocks (Cv = 66.4%), whereas carbon and nitrogen contents proved to be more conservative indicators (Cv = 11.5% and 19.5%, respectively). It was established that litter carbon stocks in the studied disturbed forests are comparable to the carbon stocks in the aboveground tree biomass, averaging 8.3±0.5 t C ha-1 in the Amur Region, 10.4±1.1 t C ha-1 in Yakutia, and 4.6±0.4 t C ha-1 in Transbaikal, which exceeds the values reported in the national database. Analysis of variance (ANOVA) identified statistically significant differences in litter stocks between the regions, reflecting climatic gradients. A regression model for litter stock was developed using “elevation” and “foliage carbon stock” as predictors (R2 = 0.40). Meanwhile, fire characteristics, such as the differenced Normalized Burn Ratio (dNBR) and time since the last fire, showed no significant direct effect on litter stock. This lack of correlation may be attributed to the complexity of fire-induced processes in permafrost conditions and the inherent limitations of remote sensing assessment techniques.