Reconstruction of Natural Conditions in the Lower Volga Region Based on Spore-Pollen Analysis Data of the Zelmen Peat Bog (Republic of Kalmykia)

The article presents the results of palynological analysis of the Zelmen peat bog in the Yergeni Upland (Republic of Kalmykia). Based on the data obtained, the dynamics of paleoecological conditions in the Lower Volga region over the past 3000 years are reconstructed. These reconstructions are compared with the results of long-term studies of buried soils under kurgans. It was found that the most humid conditions in the Lower Volga region occurred at the beginning of the 1st millennium BC. After that, a trend towards decreasing atmospheric humidity began, which continued until the early Sarmatian time with a peak of aridity in the 3rd century BC. The spore-pollen data do not confirm a short-term increase in humidity in the 1st century AD and an arid period in the 2nd century AD, which had been previously reconstructed from paleosol data. Sharply expressed humid conditions during the Great Migration Period are shown. During this period, the annual precipitation cycle changed, and the moisture supply in the cold season increased, which resulted in the formation of a peat layer in the Zelmen bog. After that, peat formation was not interrupted, either in the arid 8th century AD or in the humid 9th century AD. The pronounced humid conditions of the High Middle Ages (12th – 13th centuries) are equally well reconstructed both by soil data and in the spore-pollen spectrum of the Zelmen peat bog. It is shown that the reasons for the discrepancies between palynological and paleopollen reconstructions of natural events of the past are associated with the features of the annual precipitation cycle and its reflection in soils and peat bogs. High rates of winter precipitation, as a rule, are not reflected in the spore-pollen spectra of peat bogs, while it is winter precipitation that determines the entire spectrum of soil properties.