Logn�, a peat bog of European ecological interest in the Massif Armorican, Western France: Bog development, vegetation and land-use history

Abstract

Logne, one of three raised bogs (Hochmoor) in the Massif Armorican, was officially designated as a nature reserve in 1987 and is of considerable ecological interest from botanical, ornithological and herpetological aspects. Palynological investigations reveal the history of local and regional vegetation during the last ca. 4000 years. From the end of the Neolithic Age to the present day, changes in the bog appear to have been considerably influenced by variations in local watertable level that may be of natural origin or caused by human activity. Alder carr withOsmunda regalis, which was the dominant vegetation around the periphery of the bog at ca. 4200 B.P., underwent many changes. Its final demise occurred in Gallo-Roman times when the local landscape took on a distinctly open appearance. The first clear evidence for cereal cultivation relates to the Bronze Age. After a decline in farming at the beginning of the Iron Age, there was a strong renewal of farming in the La Tene period, which included a distinct arable component and also records forJuglans andCastanea pollen. The timing of the introduction of walnut and chestnut to the Massif Armorican is discussed.