The origins of a Nardus stricta grassland through soil charcoal analyses: Reconstructing the history of a mountain cultural landscape (Mont Lozere, France) since the Neolithic

摘要

This paper presents the use of soil charcoal analyses in order to identify the origin of a Nardus stricta grassland in a mountain system (Mont Lozere, France), and the use of environmental resources and the construction of a cultural landscape. Two opposing theories have been proposed to explain the origin of this open landscape (1450-1700 m altitude): natural or anthropogenic. The identification and radiocarbon dates of charcoal fragments of Fagus sylvatica, which were found in all of the pits located in the current grassland area and dated to 3695-3633 cal BC, demonstrate that this species has been present on the upper part of Mont Lozere since the Middle Neolithic. In addition, the presence of pioneer species (Betula, Salix, Corylus avellana), as well as mid- (Prunus cf avium) and late-successional species (F. sylvatica) supports the hypothesis that the grassland contained both pioneer and mature phases of forest landscapes. The C-14 dates, ranging from c. 4200 cal BC to 1200 cal AD, show that fire events occurred with different climatic influences. Fire events may correspond to one or several fires in a short period at the scale of the slope. Moreover, the dates coincide with the early and extensive human impact detected in the Massif Central and Mont Lozere. To explain the regular occurrences of fire events from the Middle Neolithic to the Central Middle Ages, agro-pastoral clearings have been postulated, as have been identified in other areas in the Pyrenees and in the Alps. Such human impact may have been magnified, or least facilitated, by climatic conditions. Comparison with additional data (pollen, archaeology, ecology) demonstrates that this grassland area is not natural and corresponds to an ancient forested system that has been used and transformed by societies since the Neolithic, although climate change may have certainly affected this transformation. The aim of this research is to promote this cultural heritage in collaboration with the National Park of the Cevennes in order to protect its future. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.