History of vegetation and land use from 3200 B.P. to the present in the north-west Burren, a karstic region of western Ireland

A radiocarbon-dated pollen profile provides the first evidence for the vegetation history of the north-west Burren, a karstic region in Co. Clare, western Ireland. The profile, which spans the period ca. 3200-0 B.P., shows that Corylus was the main woody species and that, apart from the later eighteenth and nineteenth centuries, when woody species were almost totally cleared, it constituted a more important element in the landscape than at present. The data indicate that small populations of Quercus, Fraxinus, Betula, Alnus and possibly Ulmus were also present until at least the mid seventeenth century. Exceptionally high values of Plantago lanceolata (mostly in excess of 20% total terrestrial pollen) suggest intensive pastoral farming over most of the period. Between A.D. 200-580, a lull in activity is recorded during which woody species and, in particular, hazel scrub regenerated. The separation of pollen of cereal origin from large cereal-type pollen produced by non-cultivated grasses proved particularly problematic. Reliance has therefore been placed on the weed pollen flora as a guide to arable activity. This flora indicates that arable farming was of some importance in the Burren from A.D. 1000 onwards. The implications of the various findings for the longer term history of the rarer elements of the Burren flora and the relationship between the pollen record and the archaeological and historical evidence for settlement and land use are discussed.