Climate-induced changes in population dynamics of Siberian Scythians (700-250 B.C.)

Demography and population dynamics of Siberian Scythians are fundamentally underexplored topics. Scarcity of known settlements has hampered our ability to fully understand the Siberian Scythians inhabiting the Altai Mountains, known as the Pazyryk Culture. However, expanded investigation of mortuary complexes by means of dating with radiocarbon and tree rings may reveal the dynamics of Scythian pastoralists. Generally, population dynamics recorded in archaeological data trace major social and cultural changes, which relate directly to the economic sustainability of past societies. Climate has been an indirect but important factor affecting demographic trends, triggering changes in supply of important ecosystem services. This paper examines the synergy of environmental change and behavioral adaptation of Scythian horsemen in the Russian Altai.We developed well-replicated tree ring chronologies from archaeological timbers of the Pazyryk Culture (sixth to third century B.C.) to describe past temperature variability in the region. Three distinctive episodes of Altai climate change appear to be tracking three major cultural phases of the Siberian Scythians advancement: (1) 700-480 B.C., cold and highly variable climate; (2) 480-360 B.C., mild warm climate and stable environmental conditions; and (3) 360-250 B.C., turbulent cold climate with amplified decadal variability. Demographic study of mortality linked to the Siberian Scythian chronology shows population growth during the cold periods. The evidence demonstrates successful behavioral adaptation of Siberian Scythians to colder climates. The trend in population dynamics suggests an increase of mobility and possible intensification of Pazyryk interactions with the outside world during warm times and a subsequent decrease in occupancy of the Altai.