Reconstruction of fire activity in Kulunda steppe for the last 3500 years based on the data from the bottom sediments of lake Maloe Yarovoe

For several millennia, Kulunda has been inhabited by the peoples with different types of economy, but the paleoecological aspect of their habitation has remained understudied. The most promising source of paleoecological information is natural archives of lake sediments. This article presents the first results of studying macro-charcoals in the sediment core from Lake Maloe Yarovoe. Fire conditions for the last 3500 years and type of fuel (wood or grasses) are reconstructed for each period, based on macro-charcoal analysis. Data on the type of fuel and distribution of charcoals by depth in the core were compared with palynological data, reconstructed level of mean annual precipitation, and reconstruction of vegetation from the same core obtained by other methods. The results were also compared with another macro-charcoal column from Lake Kuchuk, which was the only researched column for the south of Western Siberia. The results were compared with archaeological data on the type of economy among the different cultures which inhabited the area in various periods. It has been established that the patterns of coal distribution do not correlate with changes in vegetation and show a weak negative correlation with the level of average annual precipitation, which means that fire activity increased with increased level of precipitation. A temporal connection of change in fire regimes and types of fuel, with change in the types of economy has been observed. From 3500 to 2700 BP, during the prevalence of cattle-breeding type of economy, fire activity was maximal, occurring mainly in the steppe. By the end of the Bronze Age, with the beginning of transition to the nomadic type of economy, intensity of fires decreased, and forest began to be burned. After 1500 BP, when the nomadic type of economy prevailed, fire activity in the area of Lake Maloe Yarovoe sharply decreased. The increase in fire activity with predominance of wood charcoals in the last 200 years coincided with exploration of the region by the Russian settlers.