Holocene erosion and pedogenesis on watersheds of the Central Russian Plain

Watershed landscapes of the Borisoglebsk Upland and Suzdal Opolie are characterized by absence of the well-developed early Holocene paleosols suggesting dominantly negative sediment budget. Detailed study of Retisols revealed polycyclic type of pedogenesis during the Early Holocene. Discontinuous deposition with certain interruptions (but without distinct buried soil formation) occurred only within closed depressions and gully fans. The second part of the Holocene prior to the widespread human settlement left more substantial traces in soil and sediment record. It is identified both at locations dominated by denudation (evidences of multiple topsoil truncation in Atlantic and Subatlantic) and at zones of alternating incision and infill of small linear erosion features. Such extremes were most likely associated with combination of several triggers including natural forest fires and high-magnitude rainfall or snowmelt runoff events. The last phases of increased hillslope and fluvial activity within the study area can be related to increased human interference, starting about 1600-900 years ago. Latest period of intensive gully growth can most likely be attributed to the XIXth Century land tenure reform and peak tillage cultivation after the World War II when most of the study area gullies experienced significant linear growth, bottom incisions and appearance of several new gully branches. Rates of the most recent soil redistribution on slopes decreased significantly over the last several decades due to combination of natural and anthropogenic impacts.