CLIMATIC CONTROLS ON HUMAN DEVELOPMENT DURING THE NEOLITHIC: NEW PALAEOECOLOGICAL DATA FROM THE CARROWKEEL/KESHCORRAN AREA, WESTERN IRELAND

The relationship between climatic variation, vegetation dynamics, and early human activity during the Neolithic was reconstructed from a high-resolution multi-proxy record obtained from a small lake located southwest of the Carrowkeel/Keshcorran passage tomb complex, Co. Sligo, Ireland. With several impressive megalithic tombs and a cluster of upland hut sites, this complex represents one of the most important megalithic sites in Ireland. Due to its sheltered position between surrounding upland areas, Templevanny Lough is optimally located to record vegetation change and in-wash events linked to climatic fluctuations and human impact in an area that was of great importance during the Neolithic. A decline in the elm population and the onset of warmer and drier climatic conditions coincided with the first evidence for increased anthropogenic activity in the landscape at ca. 3800 years BC (calibrated radiocarbon years). Palynological evidence suggests that pastoral farming occurred at Templevanny Lough during this period of climatic amelioration, whereas cereal growing was part of the early Neolithic farming economy to the north of the Carrowkeel/Keshcorran megalithic complex. An interval of increasingly wetter climate accompanied by further woodland clearance followed. Abandonment of the area by the early settlers due to deteriorating climatic conditions permitted an initial woodland recovery within about 100 years. At ca. 3200 years BC, when the forest canopy was fully closed, increasing amounts of allogenic material were deposited in the lake. In-wash from the upland slopes likely resulted from increased precipitation. During the late Neolithic, drier conditions prevailed and trees that up to now were of minor importance expanded and contributed substantially to the woodland. The investigations suggest that Neolithic activity in this part of Ireland may have been more strongly influenced by mid-Holocene climatic variations than hitherto assumed.