Environnement ligneux et gestion du bois de feu au cours du Mésolithique au Clos de Poujol (Campagnac, Aveyron)

Abstract

This paper presents the results of the study of the charcoal remains from the rock shelter of Clos de Poujol (Campagnac, Aveyron), located at an altitude of 850 m on the Séverac karstic plateau (causse). The site has yielded well-individualised occupations dating from the Early Mesolithic, with two main occupation phases dated respectively between 8286 – 7579 and 7584 – 7198 cal. BC. The archaeological deposits covering these occupations are less well preserved, and are indiscriminately attributed to the late Mesolithic/ early Neolithic. Charcoal from all the levels was sampled in order to perform a palaeo-ecological study. Some of the charcoal samples, generally very well-preserved, showed microscopic alterations of the wood’s cellular structure. Cell wall perforations and deformations were very frequently observed, whereas intensely vitrified charcoal fragments were sporadically noted. These stigmata, also referred to as anatomical signatures, potentially convey information on the state of the wood before its combustion and, consequently, may be interpretable in terms of firewood acquisition practices (wood felling vs. wood gathering), or even highlight specific orientations in the choice of the wood, which could have been made with regard to different criteria such as the species, but also the state of the wood (e. g., healthy, dead, decayed). Moreover, the strongest deformations that were observed raised the question of the use of lignite, previously identified within the Epipalaeolithic levels of a neighbouring site. At Clos de Poujol, the existence of well-defined burning features and pits adds to the general coherence of the occupations of the Early Mesolithic and their potential suitability for palaeo-ethnographic reconstructions. Hence, it was decided to evaluate the feasibility of performing a palaeo-ethnographic charcoal approach on these structuring features. In order to do so, literature on the interpretation of the various stigmata on charcoal was examined and completed by the integration of specific experimental data. Different kinds of results were obtained. First, on a palaeo-ecological level, the charcoal study allowed part of the Holocene vegetation history to be retraced in a region that is still poorly known in this respect. The floristic results are extremely homogeneous ; the charcoal spectra are strongly dominated by pine, probably Scots pine (P. sylvestris type). Deciduous oak and the companion species of pine and/ or oak woodlands are poorly represented. As regards queries on the fuel management practices of the Mesolithic occupants, this study revealed the dominant use of dead wood, a fuel well adapted to immediate consumption which seems to have been abundant enough to meet the needs of the shelter’s occupants. More generally, our results prompt us to remain cautious when it comes to interpreting charcoal remains in terms of human practices and, concomitantly, to multiply data references allowing a better understanding of Mesolithic fire-related behaviour.