Paleoecological conditions at the end of the Sarmatian period and their impact on herder and farmer communities from Eastern Europe and Western Siberia

The paper makes an attempt to consider the cultural and historical events marking the final stage of the Sarmatian epoch from the point of view of climate dynamics in Eastern Europe. It has been confirmed that the Late Sarmatian period in the Lower Volga region coincided with increasing climate humidity and was characterized by high precipitation during the cold season. This occurred in conditions of the Siberian High weakening, resulted to penetration of the Atlantic and Mediterranean cyclones into the inland regions of Eastern Europe and the western areas of Western Siberia. This led to high snow cover formation and provoked a series of other unfavorable factors that triggered migrations and population decline in nomadic or semi-nomadic societies whose economic basis was cattle herding. We suppose that this climate change scenario was not limited to the Lower Volga region. In the article we analyze paleoclimatic, cultural and historical events of the 3rd - 4th centuries AD which occured in the adjacent regions. We found that during this period the Sargat culture, whose economy was based on semi-nomadic cattle breeding, was declining in most of the forest-steppe east of the Urals. The population in the Southern Urals almost completely disappeared by the last decades 3rd century AD. The area of the Late Sarmatian culture from the Lower Volga region is reduced to the Astrakhan Right Bank of the Volga. Only the Lower Don and the Sal-Manych steppes remained inhabited, which is probably due to the regional resource base specifics. Therefore, in most part of Eastern Europe and the western regions of Western Siberia, the population was declining or disappearing long before the Huns invasion, and increase in climate humidity was among the contributing factors. At the same time, the humid climate of the 3rd - 4th centuries AD had a beneficial impact on the crop production. A high winter precipitation provided the flourish of agricultural societies.