Holocene Vegetation Dynamics, Landscape Change and Human Impact in Western Ireland as Revealed by Multidisciplinary, Palaeoecological Investigations of Peat Deposits and Bog-Pine in Lowland Connemara

Abstract

Palaeoecological investigations, involving pollen analysis, dendrochronology, and radiocarbon dating of bog-pine, provide the basis for reconstruction of vegetation dynamics, landscape development, and human impact in two contrasting parts of lowland northern Connemara, western Ireland, namely Ballydoo and Derryeighter in the east, and Renvyle/Letterfrack/Cleggan at the Atlantic coast some 40 km to the west. The history of Scots pine (Pinus sylvestris) is traced in detail. Standout features include the dominant role the tree played from the early Holocene onwards and especially at Ballydoo, its ability to grow on peat surfaces (so-called pine flush) over the course of several millennia during the mid-Holocene (centred on c. 5 ka), and its demise in a three-step fashion to become regionally extinct at c. 2.3 ka. The factors influencing these developments, including climate change, are discussed. Another natural phenomenon, namely the spread of blanket bog, is shown to be an on-going process since the early mid-Holocene, with accelerated spread taking place during the Neolithic and Bronze Age. The course of human impact, as reflected in pollen records and in archaeological field monuments, including megaliths and prehistoric stone walls, is reconstructed in detail.