Wood or Wood Charcoal? Questioning Sustainability
One of the big questions regarding the consumption of wood, is whether raw wood, or wood charcoal was being consumed in different cultural situations (and if both were in use, in what proportions). Some processes, e.g. iron working, require charcoal as fuel, while most processes do not, but charcoal is a superior fuel to wood: burning hotter, producing a more consistent heat, and producing far less smoke. However, it may take from a few, to perhaps as many as ten, or more, kilograms of wood to make one kilogram of charcoal. To date we have not been able to tell whether an excavated charcoal fragment arises from raw wood burnt for the first time, or has originated from raw wood, converted into charcoal, and 'reburnt'. A new process called 'reflectance' is being trialled to measure absolute burn temperature of charcoal, and this shows real promise. The photos show (L to R), raw wood faggots; raw wood branches heaped ready for charcoalification: a process whereby the heap is covered with mud, leaves and ash, and then partially ignited in order to 'char' but not burn, the heap; newly made charcoal being swept and bagged up (Borgo Pace, Italy). New investigations of excavated charcoals using a range of laboratory techniques will help answer questions about charcoal quality. Much has been written about Roman 'deforestation', but little evidence exists in the pollen record for large scale deforestation in the Mediterranean until the Mediaeval period. Anecdotally, however, some local areas (especially in the Roman provinces) did suffer. Ultimately we wish to shed light on questions of ancient forest sustainability across the Mediterranean. Early indications, contrary to a number of recent studies, demonstrate that the Romans practised sustainable forest management.