Soils of Archeological Landscape Sorokino 1 (Orel Oblast): Reconstruction of Natural Changes and Anthropogenic Transformation of the Environment

Abstract

Soil-archeological studies were performed in the area of the ancient Russian settlement Sorokino 1 dating back to the 13th century AD and located in the upper reaches of the Orlik River (Khotynets district, Orel oblast) within the natural zone of deciduous forests. Morphological, physical, and chemical properties of soils associated with the archeological monument and with the background area under the forest were analyzed. Phytolith spectra and the radiocarbon age of soil organic matter were determined in the paleosols of the archeological monument and in the background surface soils. A comparative analysis of the soil features—indicators of the environment—allowed us to determine and characterize the main stages of the formation of soils and landscapes under the influence of climate changes and anthropogenic factors. Climate-related alternation of the phases of steppe and forest development in the study area was revealed. Steppe conditions in the Boreal period of the Holocene were replaced by the spreading of deciduous forests in the Holocene Optimum (Middle Atlantic period). At the end of the Atlantic period, steppe landscapes reappeared in the area, which was reflected in the intensification of the activity of steppe burrowers (mole rats) in the soil profiles. Steppe formation in river valleys during the Medieval Climatic Optimum was replaced by the propagation of forests in the subsequent Little Ice Age. The analysis of phytolith complexes of different ages indicated that the forests growing in the studied area in the Late Holocene included both deciduous and coniferous trees and reflected cooler climatic conditions in comparison with the deciduous forests without conifers of the Atlantic Optimum. In the recent centuries of the active agricultural development, forests have been replaced by arable land and hayfields, which has led to the formation of chernozems in the areas previously occupied by dark gray forest soils (Luvic Greyzemic Phaeozems).