Holocene vegetation change, climate variability, and human impacts on the Seki Basin (southwestern Türkiye): Evidence from a multiproxy approach

This study presents a multiproxy palaeoenvironmental analysis of a 4.7 m sediment core from the Seki-Eceler Höyük (mound) archaeological site in southwestern Türkiye, providing a detailed reconstruction of vegetation and climate from 12000 yr BP to the present. Based on the first pollen record and geochemical proxies (μXRF-measured elements and total organic and inorganic carbon), our findings reveal a clear transition from a cold and dry steppe environment during the Younger Dryas period to warmer and wetter conditions in the early Holocene. A major shift occurred during the early Holocene, characterised by a significant increase in arboreal pollen (Quercus and Juniperus) with Pinus and aquatic herbs, indicating a transition to wooded and wetter environments. This is supported by high Sr/Ca ratios and elevated μ-XRF concentrations of Ti, K and Fe, which suggest increased precipitation and hydrological activity. A sharp decline in arboreal pollen, which coincided with the 8.2 ka event, indicated a return to cold and arid conditions. This was followed by the Mid-Holocene Climatic Optimum (around 6000 yr BP), characterised by a significant increase in forest cover and biodiversity due to favourable, warmer and wetter conditions. During the late Holocene (4200 yr BP to present), the record shows a complex interplay of climatic shifts and increasing human impact. Although evidence of human presence in the region dates back to the Palaeolithic era, archaeological findings relating to grazing and pastoral activities are confined to the Neolithic era and later periods. This is consistent with the regional archaeological framework. While the 8.2 ka drought event may have influenced early subsistence strategies, clear signals of agro-pastoral practices only emerge after the onset of the Neolithic.