Crossing taxonomic and isotopic approaches in charcoal analyses to reveal past climates. New perspectives in Paleobotany from the Paleolithic Neanderthal dwelling-site of La Combette (Vaucluse, France)

Robust methodology in charcoal analyses has strong potential in the reconstruction of past environments. However, charcoal assemblages from Pleistocene contexts, particularly those that formed under varying climatic conditions during glaciation and mostly composed of the genus Pinus, can neither express changes in forest density, nor can they reveal climatic conditions. Here, we explore the potential of a combined approach using taxonomic and δ13C isotopic study of archeological charcoal from middle Paleolithic sequence of La Combette. In order to investigate past climate and/or environmental conditions, we focus on charcoal of Pinus spp. from infra stratigraphic units at the site that showed a high potential for isotope analysis. Those isotopic results are consistent with other paleoenvironnemental data (anthracology, micromorphology, palynology, etc.) that are manifested at different time scales. In some cases, isotopic data provide, more accurate information than that derived from taxonomic identifications. This is due to the quicker physiological response of the plants compared to the long-term changes in forest biodiversity under climatic pressure. Subsequently, this first application of cross taxonomic and isotopic approach offers promising and original results and must be applied to different context (low to high taphonomic process). Lastly, the degree of asynchrony or synchrony between taxonomic and isotopic findings allows us to rethink Neanderthal fuel management and mobility patterns and to explain the correlation between Neanderthal occupations of the rock shelter in view of climatic conditions.