A 'long-burning issue': comparing woody resource use for ironworking in three major iron smelting centres od sub-Saharan Africa

Abstract

Ancient sub-Saharan iron metallurgy has often been blamed for triggering ecological deterioration, above all by a presumed over-exploitation of wood for operating the fuel-thirsty smelting furnaces. This assessment is largely negative, regardless of the different natural environments where iron smelting took place, and thus in spite of the variability of provided ecosystem services and differing resilience to wood exploitation. We argue for a more differentiated view of the impacts of traditional African iron smelting, respecting the fact that wood is a renewable resource and bearing the dissimilarity of exploitable resources in mind. Summarizing our previous research, we compare the anthracological results which we obtained at three major iron smelting centres (Fiko Tradition, Mali; Bassar, Togo; the Meroe area, Sudan). Regardless of the prevailing environmental conditions, the predominant use of high density wood is striking. However, only in the Meroe area is extreme selectiveness of a single species evident, whereas in the West African iron smelting centres a wide array of woody taxa has been used. In addition to fuel quality, cultural preferences probably controlled the choice of species. Fuel provision in Fiko and Bassar was mainly based on the exploitation of zonal vegetation, particularly the agroforestry systems surrounding the sites. In contrast, the extrazonal Acacia nilotica woodlands of the Nile River valley seem to have provided a stable and reliable fuel supply in the arid Meroe area. At the West African sites, the anthracological records point to vegetation changes over the course of time. However, we consider fuel exploitation for iron smelting as only one among multiple causal factors affecting the regional woody vegetation during the Late Iron Age. The expansion of arable land and changing agricultural practices due to the general availability of iron agricultural tools intensified the effects of wood exploitation, for iron production and various other purposes, on the tree cover.