How have Mediterranean peatlands changed in response to human influence during the Late Holocene? A case study from the Gölbaşı peatlands, Türkiye

Abstract

The eastern Mediterranean is a landscape that has been shaped by thousands of years of climatic shifts, cultural change and extensive human land use. However, late Holocene landscape change in the peatlands of southeastern Anatolia is currently not well understood. This environment is important to protect as a valuable carbon sink with many endemic plant species and a rich biodiversity. This study, which was carried out in the Gölbaşı depression in southeastern Anatolia, aimed to investigate vegetation changes during the Late Holocene and to evaluate human impact on the landscape. Late Holocene studies conducted in Anatolia have demonstrated an increase in aridity especially in continental regions and that this was a warmer period in general. Palaeovegetation studies indicate that the effects of human activities on vegetation in Anatolia have been considerably more pronounced during the last two millennia of the Late Holocene. In this study we have investigated how human activities have influenced vegetation change during the Late Holocene in the Gölbaşı basin, which is one of the eighteen largest peatlands in Anatolia, and located in a transition area between Mediterranean and continental climate regions. A sediment core (GLBS21) was taken from the Gölbaşı peatlands region and analysed for fossil pollen as a proxy for vegetation change. The arboreal pollen (AP) to non-arboreal (NAP) pollen ratio in the study area is 56 % AP and 44 % NAP indicating a semi-open landscape. According to the fossil pollen record, Pinus, Cedrus, Juniperus, Quercus cerris types are the most common tree species, and Artemisia, Asteraceae, Amaranthaceae, Poaceae and Plantago are common herbaceous pollen types. The high representation of non-arboreal pollen known to be associated with human impacts, such as Artemisia, Plantago, and Cerealia type, and the presence of arboreal pollen associated with cultivation, such as Castanea, Juglans, and Pistacia, indicate that human land use has played an important role in shaping this landscape. The record from Gölbaşı highlights the sensitivity of this region to changing human activity, for example, reforestation is evident following abandonment associated with plague that affected Anatolia in the 14th-15th century. The record also reveals continued agricultural activity during periods of conflict. The fossil pollen record emphasizes the resilience and changing character of this landscape.