Soil-sedimentation archives of floodplains and ravines as a memory of the natural-anthropogenic evolution of forest-steppe landscapes (Russia) in the Holocene
Authors: Sycheva Svetlana , Ershova Ekaterina , Ponomarenko Elena , Pushkina Polina , Sedov Sergey , Simakova Alexandra , Khokhlova Olga 
Published: March 2022

&lt;p&gt;The history of the development of landscapes and land-use systems on the northern border of the forest-steppe zone of Russia (basin of the Tuskar River, Kursk region) is reconstructed. A multidisciplinary approach includes geomorphological, lithological, paleopedological, micromorphological, radiocarbon, paleobotanical (spore-pollen, carpological, pedoanthrocological) analyzes in the study of soil-sedimentation archives of floodplains (Shumskaya section), slopes (Pereverzevo section), and ravines (Senovaya gully section). The sequences of sediments and soils within accumulative and trans-accumulative archives are one of the most complete and reliable sources of information not only about climate changes, the evolution of ecosystems in the Holocene but also about the history of land use.&lt;/p&gt;&lt;p&gt;The formation of a floodplain and a new ravine-gully network in the Late Ice Age backfilled the geomorphological basis for Holocene landscapes. Alluvium, proluvium, and colluvium partially filled the Late Pleistocene floodplain and ravine. In the early Holocene, with limited sedimentation, a well-developed soil, Luvi&amp;#1089; Gleyic Phaeozem, formed on the stable surface of the newly formed landforms. Its &lt;sup&gt;14&lt;/sup&gt;C-age is 8.1-8.7 ka yrs cal BP. This paleosol is widespread not only in the forest-steppe area of the Russian Plain but throughout the world. At the beginning of the middle Holocene, during droughts, as a result of strong fires and increased erosion, this paleosol in the floodplains and bottoms of ravines was buried by alluvium and colluvium. An episode of afforestation of the area is also noted. The slopes were covered with deciduous forests with oak and linden. This led to the formation of Gleyic Cutanic Luvisol (Humic, Siltic), as evidenced by the humus-clay cutans in the Ah horizon and degradation of Phaeozem. Strong fires during droughts periodically resumed and were accompanied by a subsequent catastrophic increase in runoff and accumulation of colluvium in the bottoms of ravines. They happened around 8.1, 7.4, and 5.2 ka yrs cal BP, as evidenced by the finds of oak coals, and ferruginous-manganese nodules with a carbonaceous core in colluvial loams. The oak was preserved on the slopes, while other parts of the catchment were essentially treeless. In the late Holocene, the afforestation process intensified. However, about 2.8-2.5 ka years ago, arable farming began to spread in the studied area. In the immediate vicinity of the study site, there were settlements and numerous villages of the Scythian culture population. Deforestation and plowing of land with wooden ralo (ancient Slavic plow) caused slight soil erosion and accumulation of agro-colluvium in the bottoms of the ravines and on the floodplain. With the appearance of iron parts on wooden ralo, the plowing depth increased. Due to the increase of population since the beginning of the new era (4-5 centuries AD), the catchments were cleared for arable land. The onset of continuous erosion and intensive redeposition of the soil mass containing pollen of weeds and cultivated cereals correlates chronologically with the expansion of the population of the Chernyakhov culture into this region. Since that time, the agricultural use of the catchment area and anthropogenic deforestation has continued. The study was supported by the RFBR, project N19-29-05024mk.&lt;/p&gt;