Fuelwood harvesting rates from the perspective of early hunter-gatherers on the Cape south coast, South Africa

Abstract

Understanding fuelwood harvesting and burn characteristics of different plant species can contribute to understanding early hunter-gatherer mobility patterns and heat-requiring practices such was used to produce advanced heat-treated silcrete stone tools (lithics) and cooking food. With the help of modern female foragers, who still collect fuelwood for their own use, we harvested fuelwood within the Cape south coast, South Africa. Experimental fires were then staged to examine the heat-generating properties of 24 different plant species chosen as fuelwood. Burnt and unburnt Limestone fynbos yielded the highest fuelwood return rates and Sand Fynbos and Subtropical Thicket yielded the lowest. There is a range of plant species sufficient to carry fire temperatures (both beneath the sand and within the embers) for the heat-treatment of silcrete (350 °C). For cooking food in an open fire, few species retained an ember temperature above 500 °C for more than an hour – the temperature deemed necessary to cook shellfish and tubers. The size of hunter-gatherer groups would have impacted fuelwood depletion around a central foraging point and combining the heat-treatment of silcrete with cooking food would have maximised foraging expenditure of fuelwood procurement.