Home – Home – Jornals – Geography and natural resources 2018 number 3

An analysis of geoinformation data on the spread of steppe fires is proposed, the areas of which are identified on the basis of a series of Landsat satellite images for 1984-2015. We selected five key sites located in different geographic areas of the Trans-Volga region and South Ural, covering clusters of the Orenburgskii state nature as well as adjacent agricultural areas. By analyzing the long-term dynamics, we determined a widespread trend of an intensification of steppe fires. Since the mid-1990s till the present, it has been manifested in a significant increase in the area of occurrence and in recurrence frequency. It has been established that the cause for an intensification of fires in the steppe regions is a significant reduction in agricultural production, accompanied by restoration of vegetation cover on unused lands and accumulation of dry phytomass. It was determined that, given the favorable conditions for the occurrence of fires, the weather and climate factors increased in importance, implying a higher amplitude of fluctuations in the areas of the burnt-over areas, especially in abnormal years. Data on the current frequency of grass fires (both in protected areas and in a large part of agricultural lands) indicate that the vegetation cover and other components of steppe ecosystems are constantly in a state of post-pyrogenic succession. Using an example of one of the sites (the Burtinskaya steppe), a high restorative capacity of tree-shrub areas within the boundaries of the ecotopes occupied by them was revealed. It was noted that the absolute regime of reserve that excludes any economic activities, combined with an intensification of fire phenomena in the adjacent territories, gives rise to an acute fire-hazardous situation. It is pointed out that there is a need to establish a unified system for ecological monitoring of fires.