Holocene vegetation and land-use dynamics in the karstic environment of Inis Oı́rr, Aran Islands, western Ireland: pollen analytical evidence evaluated in light of the archaeological record

Abstract

A detailed Holocene pollen record, elaborated in the project TIMECHS, is presented from An Loch Mór, a deep lake at the north-eastern end of Inis Oı́rr, Aran Islands, western Ireland. Woodland development in the early Holocene is broadly comparable, as regards the general sequence of tree spread and overall woodland composition, to that known from mainland sites in the nearby Burren and Connemara. The main trees in the early Holocene woodlands were Quercus, Pinus and Ulmus. Corylus and a variety of tall shrubs including Betula, Juniperus, Rhamnus catharticus, Ilex, Viburnum opulus and Sorbus had an important role. Taxus expanded and attained dominance for a short period in the later Neolithic and then persisted in small numbers until at least the beginning of the early Medieval period (late 6th century AD). Other notable features included substantial opening-up of woodland cover prior to the Elm Decline, a well-defined Landnam in the early Neolithic (after the Elm Decline), considerable though varying human impact throughout the Bronze Age and continuing into the Iron Age, a distinct regeneration phase that involved regeneration of woody plants—mainly Juniperus, Corylus and Taxus—in the late Iron Age, i.e. the so-called Late Iron Age Lull, and renewed farming activity in the early Medieval period with Secale being introduced in the early 8th century AD. The final demise of woodlands took place between the 13th and the beginning of the 16th centuries though minor amounts of woody vegetation probably persisted on Inis Oı́rr until at least the late 18th century. The palynological record is discussed in the light of the available archaeological and historical information, and with particular reference to the recently completed archaeological excavations at Dún Aonghasa, the largest stone fort on the Aran Islands.