Late Holocene vegetation change and increasing of anthropogenic pressure in the volcanic mountains of Cantal (Massif Central, France): the example of Le Vallon du Frau
L’évolution de la végétation à l’holocène récent et l’augmentation de la pression humaine dans le massif volcanique du Cantal (Massif Central, France): l’exemple du vallon du Frau (commune de Chavagnac, Cantal)
Abstract
This paper discusses the results of a palaeobotanical and archaeological analyses carried out in the North-Eastern part of the massif of Cantal in the valley of the Frau. This area is not as well studied as other regions of the Massif Central to which this mountain belongs. The archaeological research conducted in this valley was completed by palaeobotanical analyses performed on a core extracted from the peatbog of the Frau. The results clearly reveal how human populations gradually extended their agro-pastoral activities and in turn modified the environment. Active clearings, especially through fire, were used since the end of the Neolithic period in order to extend agro-pastoral activities. The second transformation in the environment caused by the people who inhabited this region dates to the 13th century. This period marks the maximal extension of human activities including the setup of hamlets and agro-pastoral settlements and the extension of pastured and cultivated areas. These activities are associated with the almost complete disappearance of the forest. The extension of agro-pastoral activities through time appears to modify the functioning of the hydro-sedimentary basin notably through the inception of peatland, an increase of morphogenic activities and a degradation of vegetation and soils.