Reconstruction of climate, soil, and vegetation conditions of the Srubnaya cultural epoch on the basis of kurgan studies in the Cis-Ural forest-steppe of the Republic of Bashkortostan

The reconstruction of soil, vegetation, and climatic conditions for the Srubnaya cultural epoch (3660 ± 40 (date wood), 3860 ± 120 (bones date) was performed on the basis of palynological and paleosol studies with radiocarbon dating of bones and wood fragments from two kurgans in the Cis-Ural forest-steppe of the Republic of Bashkortostan. Morphological features and chemical properties of the modern background soils, the soils formed on the surface of burial mounds (kurgans), and the soils buried under them were characterized. According to palynological data, the climate of this territory in the period of construction of these kurgans was more humid than the modern climate. The paleovegetation of the Srubnaya epoch was represented by mesophilic herbaceous steppes with a lower participation of xerophytic species as compared to the modern steppe and by small forest groves composed of birch and pine trees with some admixture of lime trees. The temperature conditions were close to those at present, or somewhat cooler, which is evidenced by the lower content of pollen of the broadleaved trees. The modern background soils and the soils buried under the kurgans are classified as thin light loamy typical calcareous chernozems; they have similar morphologies and physicochemical properties. However, the reconstructed organic matter content in the upper 50 cm of the buried paleosols is higher than that in the modern soils. This attests to more favorable climatic conditions during the Srubnaya epoch and is in agreement with palynological data.