Landscape evolution around the oppidum of Bibracte (Northern Massif Central, France) from the Late Iron Age to the Post-Mediaeval period

The considerable intensification of human activity in the second and first centuries BC in Central Europe was related to the sudden appearance of a network of large fortified towns, which are known as oppida. Bibracte was one of the most important oppida in France, but knowledge about the evolution of its hinterland is still incomplete. This article addresses the evolution of the landscape surrounding this oppidum. Our research was based on a study of sedimentary profiles sampled around the archaeological site and examined by physical, geochemical and palaeoecological analyses. Sediment sequences indicate that the earliest human-induced erosion associated with geomorphological change occurred in the 4th–1st century BC. Geochemical results indicate ancient mining and metallurgy in the catchment during the same time. Palaeoecological proxies from the same period point to a mosaic of an open cultural landscape with locally suppressed forest vegetation and prevailing pastoralism. Anthropogenic impact resurged in the 11th–13th centuries AD and was associated with livestock grazing and rye (Secale cereale) cultivation. Thereafter, the reconstructed human impact from the 15th century AD onwards was probably related to forest management focused on timber floating as well as to the cultivation of chestnut (Castanea sativa) and hemp (Cannabis sativa).