Tephra-dated climate-and human-impact studies during the last 1500 years from a raised bog in central Ireland

Abstract

Historic Icelandic tephrochronology constrains the time frame of a plant macrofossil and palynological study of ombrotrophic peat to evaluate the effects of climatic and human impact over the last 1500 years on the landscape at a large monastic site in the Irish Midlands. The plant macrofossil climate proxy record indicates maximum wetness during the sixth century AD. Decreasing wetness occurred from the late ninth century to the late thirteenth century. From c. AD 1290 to 1830, the plant macrofossils record a reduction in mire surface wetness and there is no evidence for ‘Little Ice Age’ climatic deteriorations. The pollen analytical evidence indicates an agricultural system dominated by pastoralism throughout the first millennium AD with arable agriculture increasing in the closing years of the first millennium and throughout the second millennium AD. From the eighteenth century onward, agricultural land use expands with a concomitant reduction in scrub.