Plant exploitation and diet in altitude during Mesolithic and Neolithic : Archaeobotanical analysis from a hunting camp in the Chartreuse massif (l'Aulp-du-Seuil, Isère, France)

International audienceThis paper presents the state of knowledge on plant economy in the Northern French Alps from Middle Mesolithic to Middle Neolithic (about 10,500 to 6200 cal. BP). The recent analysis of charcoal and seeds/fruits of a hunting camp of the Chartreuse massif provides new information on the way people managed their environment in a subalpine context. We focus here on a block shelter (l'Aulp du Seuil), located in an isolated valley, at 1720 m a.s.l. Excavations carried out between 1993 and 2005 permitted the discovery of an archaeological sequence stretching from Middle Mesolithic to Historic times. Charcoal and seeds/fruits analyses were performed on layers dated from Mesolithic to Middle Neolithic. Botanical assemblages mainly recorded the local vegetation, dominated by Pinus (charcoal and needles). The charcoal and macroremain assemblages reflect the exploitation of a large territory, especially during the Middle Neolithic: inhabitants of the shelter gathered plants in a large zone, from the collinean level to the immediate surroundings of the site, the subalpine level. Finally, the results inform us about fuel management and diet. The high amount of pine used for fuel has most probably two causes: its abundance in the vegetation but also its easiness of use in a temporary occupation (important amounts of dead wood). Seasonal inhabitants of the shelter brought hazelnuts and cereals. The presence of these last clearly shows, during Neolithic, a connection between the shelter and a permanent village located at lower altitude. L'Aulp du Seuil could be used as a seasonal residential station during that period. This study shows the importance to integrate the analyses of ecofacts in such archaeological programs in order to better understand the socio-economic systems of prehistoric alpine communities