Anthracological analyses of charcoal production sites at a high spatial resolution: the role of topography in the historical distribution of tree taxa in the northern Vosges mountains, France

The rising demand for charcoal from industrialization during the eighteenth century led to the establishment of a large number of charcoal production sites (CPSs) within the woodland ecosystems of Europe. The CPSs still present today can be investigated to assess the past woodland composition in terms of taxa present and timber size, at a high spatial resolution. The present study was done in the northern Vosges region in France, an area of low mountains covered by woods with some important past industrial sites in several of its valleys. We aimed to investigate the possible role of topographical variables such as altitude and aspect in the distribution of CPSs and in the past distribution of tree taxa. Charcoal production sites were found, identified and sampled in four valley catchment areas, and a numerical model of elevation was used to compute the topography of the landscape. A total of 233 sites were recorded and anthracological (charcoal) samples from 121 of these were analysed. The radiocarbon dates of 20 CPSs range between the late 17th and the early twentieth century AD, which corresponds to the peak of industrial activity in this region. The spatial distribution of CPSs appears to increase in density close to streams, and 14 tree taxa were identified in the charcoal records, with Fagus and Quercus being dominant by far. Our results revealed the strong influence of the direction in which the slope faced on the taxon composition of the anthracological spectra. These results suggest that the local woodland stands which were used to supply the charcoal kilns depended on the local environmental conditions. Furthermore, the composition of the woodland has changed significantly over time, with more Pinus sylvestris at present.