Landscape human shaping and spatial mobility of agropastoral practices in the Chaîne des Puys during historical times (Massif Central, France)

The Chaîne des Puys is a great collection of extinct volcanoes that cover the Hercynian basement and belongs to the Auvergne Volcanoes Natural Regional Park. Both the sedimentary record and the historical archives of this area are numerous. However, the cores studied hitherto do not offer a good knowledge of the historical dynamics because most of the wetlands have dried out during historical times, causing gaps in the sedimentary record and pollen oxidization. Moreover, all the studied cores are located on the crystalline basement or on an old volcanic one predating the Chaîne des Puys. Thus they do not directly provide information about the volcanoes. This article presents the only core obtained from a site, a small maar, located on a volcano. The sequence is short but does not have the same sedimentary gaps as the others. Owing to physical (grain size), chemical (C, N, P, K, Ca, Mg, N–NO₃, N–NH₄), palaeoecological (pollen and non-pollen palynomorphs) and historical analyses, this study gives a more precise recording of the landscape changes during the last 500 years in the volcanic area and contributes to the knowledge of the Chaîne des Puys landscape. It illustrates the mobility of the historical landscape, in particular the progression and regression of the forest and the erosive crises related to more intensive grazing activity. The observations are linked with the social and economical changes, especially with the consequences of the French Revolution and the rural depopulation. This landscape history gives data about the direction of changes to the landscape preservationists. They demonstrate that even if the Chaîne des Puys landscape looks natural, it has been shaped by a very specific socio-economical system inherited from the Middle Ages. These aspects could be integrated in a management plan.