Holocene environmental history and populating of mountainous Dagestan (Eastern Caucasus, Russia)

摘要

The mountainous Dagestan region has a unique historical development, likely based in independent cereal domestication and terraced agriculture. However, there is little to no data on the nature and timing of environmental changes throughout the settlement history of this region. In contrast to the much studied neighboring Caucasus regions, Dagestan remains mostly unexplored from the standpoint of paleoecology. Here we present a detailed radiocarbon-dated 185 cm long pollen record from the Shotota swamp located in the mountainous zone of the Eastern Caucasus (Dagestan). Peat and soil deposits of the swamp span most of the Holocene from the Neolithic to the Middle Ages, and this study, for the first time, presents an analysis of Holocene vegetation history and the populating of the Eastern Caucasus.Our analysis reveals three basic stages of transformation of natural conditions: a stage of predominantly warm and dry climate, open meadow and steppe landscapes of 9200-7300 BP associated with the Neolithic period; a warm and humid climate of 7300-6000 BP which accompanied the appearance of deciduous forests in the Chalcolithic period; and cooling and several phases of humidification oscillations with the constant rise of pine forests with 5000 BP, which are associated with the Bronze Age, Early Iron Age and Middle Ages. With the data obtained on the dynamics of vegetation, we conducted a coupled analysis of climate dynamics, populating and economy in Dagestan. The results of the study show significant discrepancies in the timing and sequence of the expansion of tree species in the Holocene in comparison with Transcaucasia and the Western Caucasus. Despite the low settlement density pollen results reveal signs of agricultural development in the Khunzakh plateau in the Chalcolithic, the Late Bronze Age and the Early Iron Age that are not documented in archaeological surveys and require further investigation.