Vegetation history and paleoclimate at Lake Dojran (FYROM/Greece) during the late glacial and holocene

A new high-resolution pollen and NPP (non- pollen palynomorph) analysis has been performed on the sediments of Lake Dojran, a transboundary lake located at the border between Greece and the former Yugoslav Re- public of Macedonia (FYROM). The sequence covers the last 12500 years and provides information on the vegeta- tional dynamics of the Late Glacial and Holocene for the southern Balkans. Robust age model, sedimentological di- atom, and biomarker analyses published previously have been the base for a multi-perspective interpretation of the new palynological data. Pollen analysis revealed that the Late Glacial is characterized by steppic taxa with prevailing Ama- ranthaceae, Artemisia and Poaceae. The arboreal vegetation starts to rise after 11500yrBP, taking a couple of millen- nia to be definitively attested. Holocene vegetation is charac- terized by the dominance of mesophilous plants. The Quer- cus robur type and Pinus are the most abundant taxa, fol- lowed by the Quercus cerris type, the Quercus ilex type and Ostrya–Carpinus orientalis. The first attestation of human presence can be presumed at 5000 yr BP from the contempo- rary presence of cereals, Juglans and Rumex. A drop in both pollen concentration and influx together with a δ18Ocarb shift indicates increasing aridity and precedes clear and contin- uous human signs since 4000 yr BP. Also, a correlation be- tween Pediastrum boryanum and fecal stanol suggests that the increase in nutrients in the water is related to human presence and pasture. An undoubted expansion of human- related plants occurs since 2600yrBP when cereals, arbo- real cultivated and other synanthropic non-cultivated taxa are found. A strong reduction in arboreal vegetation occurred at 2000 yr BP, when the Roman Empire impacted a landscape undergoing climate dryness in the whole Mediterranean area. In recent centuries the human impact still remains high but spots of natural vegetation are preserved. The Lake Dojran multi-proxy analysis including pollen data provides clear evidence of the importance of this approach in paleoenvironmental reconstruction. Cross-interpretation of several proxies allows us to comprehend past vegetation dynamics and human impact in the southern Balkans.