Tracing land use history using a combination of soil charcoal and soil pollen analysis: An example from colluvial deposits of the Middle Volga region

Abstract

Gully deposits were studied in the vicinity of Early Medieval archaeological sites in the Volga River Bend region, Russia. Anthropogenic and natural causes of erosion were distinguished by a novel combination of sedimentological, palynological, and pedoanthracological methods. Within the 10 ka-old colluvial fan sequence deposited in the forest-steppe zone, sedimentation rates are reconstructed as negligible in the first half of the Holocene, increasing drastically in the first centuries AD. Seven episodes of erosion and stabilization were distinguished, each beginning with the deposition of coarser sediments enriched in charcoal and gravel. Erosional events were followed by local deforestation; tree taxa found in charcoal assemblages of each cycle generally mirrored the taxa of the previous cycle in the pollen spectra. The cycles chronologically matched known archaeological occupations in the area. First portions of colluvia in the sequence (1st to 3rd cent. AD) contained seeds of zoochores indicative of livestock husbandry; from the 3rd century AD to 16th cent. AD, colluvia contained micro-artifacts (1–20 mm), pollen of cultivated plants and their weeds, and pollen of taxa typical for trails and drove ways. We reconstruct a change in the type of cultivation techniques from pollen spectra in the gully deposits. Cerealia and Onagraceae pollen indicative of swidden agriculture is present in the 3rd-6th cent. AD, while Cerealia, Fagopyrum, Centaurea cyanus pollen and Riccia spores in the 8th- 14th cent. AD are evidence of permanent fields within the catchment.