Stable isotope analysis of archaeological oak charcoal from eastern Anatolia as a marker of mid-Holocene climate change

Comparison between modern trees and archaeological charred wood is an underexplored method to study climate change, which may help to infer past environmental changes. The stable carbon content of deciduous oak charcoals was analysed for five periods covering more than a 1000 years (3350–2000 BC) at the site of Arslantepe, Turkey, together with modern deciduous oak specimens from five rare arboreal patches still present in the area (17–64 km from the site). In studies of past climate change it is difficult to distinguish human-induced changes from independent variations, such as the impact of past populations on the landscape and their relationship with climate changes in the mid-Holocene. Archaeology can evaluate climate signals preserved in fossil plants in light of past human life. This paper will contribute to understanding environmental changes that can be attributed to climate variation and those linked to human activities. We compared 13C⁄ 12C of modern and fossil oaks in order to correlate the 13C-content to environmental features of Arslantepe, both today and between 3350 and 2000 BC. At present, this area is semi-arid. The results show important similarities to palaeoenvironmental records for the rest of the Near East. The climate trend can be divided in three main phases: instability phase from ca. 3200 to 2900 BC; a phase of relative stability (until 2350 BC); and a final increase in aridity. The comparison of D13C values between fossil and modern plants shows that present climate is more arid than that between the end of the fourth and the whole third millennium BC.