Fires in the Altai-Sayan region: Landscape and ecological confinement

Resumo

Spatial and temporal patterns of vegetation fires in the Russian part of Altai-Sayan region over the period of instrumental satellite observations (1996–2014) have been studied. The distribution of fires by landscape categories, natural zones, altitudinal belts, and terrain profile forms is presented. We estimate the confinement of fire development in forests dominated by dark coniferous, light coniferous, and deciduous forest stands. The results are standardized taking into account the ratio between plant-cover areas of the selected categories, classes, and zones in the region. We have found an exponential decrease in the number of fires in the area of transition from plains and lowlands to highlands. Middle mountains are characterized by the largest burnt areas. Up to 50% of all fires are observed in the northern and adjacent slopes. The fire occurrence on concave slopes is 40% higher than that on convex slopes. The logarithmic growth in the number of burnt areas and fire frequency was found for all natural zones (forest, steppe, and forest steppe); the greatest seasonal variability in fire frequency and fire statistics is observed in the forest-steppe zone of the region. It is shown that the spatial distribution of fires is in agreement with the selected climatic facies. On the whole, the long-term dynamics of forest burning in the Altai-Sayan region and Siberia is strongly related to the variation of meteorological parameters characterizing climatic changes.