Environmental changes based on multi-proxy analysis of core sediments in Lake Aktas, Turkey: Preliminary results

Abstract

A sediment core covering the last millennium from Lake Aktas, a shallow alkaline soda lake in the northeast Anatolian highland of Turkey, was studied for pollen and physical and chemical proxies to reconstruct past climate change. The sediments were dated by AMS radiocarbon dating of bulk organic carbon. Among arboreal pollen (AP) from around 930 years ago, dominant trees were Pinus sylvestris, Picea orientalis, Abies, Betula, Fagus, and Quercus. AP exceeded NAP (non-arboreal pollen) in this time, whereas the opposite is the case in a pollen trap in the same region collecting the pollen for one year in 2015-2016. The comparison of modern and fossil pollen influx indicates that in that period trees were more widely distributed around the lake than today, where steppe vegetation now prevails. Inferred causes for the disappearance of trees are anthropogenic impacts and climatic change towards more continental conditions. The results also identify the onset of the Little Ice Age in the NE Anatolian highland of Turkey. (C) 2018 Elsevier Ltd and INQUA. All rights reserved.