Impact of genera-specific traits on wood-to-charcoal conversion rates: Implications for palaeoenvironmental reconstruction in European Palaeolithic contexts

Abstract

Palaeoenvironmental reconstruction, especially in prehistoric contexts, is frequently dependent on anthracology, the identification of charcoal to at least the genus level. However, in order to understand past arboreal compositions, and by proxy wider environments and hominin-environment interactions, the charcoal found must accurately represent the original hearth assemblages, to enable further interpretations of local palaeoenvironments. Several filters affect this, including anthropogenic fuel choice, differential charcoal fragmentation, and varying archaeological recovery and identification techniques between sites. A further potentially confusing factor is genera-specific wood-to-charcoal conversion rates, whereby different genera of woods, through specific morphological or chemical characteristics, commonly create different quantities of charcoal on burning. It is debated whether this is an issue at all; to address this, this paper tests the wood-to-charcoal conversion rates of 42 arboreal and shrubby genera identified in Palaeolithic European contexts, burning them at 350 °C and 700 °C. Whilst those at 700 °C created somewhat random quantities of charcoal, genera-specific differences were identified at 350 °C, correlating with deciduous, evergreen and coniferous tree types, with conifers creating far more charcoal than other trees. These findings have wide applications for all palaeoenvironmental reconstruction relying on anthracology, especially where conifers are common.