Holocene landscape development and human impact in the Connemara Uplands, Western Ireland.

Aim Aim Investigate: (1) the role of human impact in shaping the landscape and particularly the initiation of blanket bog; (2) the short-lived abrupt changes and their causation; (3) the phenomenon of large-scale upland peat erosion to answer the question of when and why erosion of upland blanket peat commenced in the Connemara uplands. Location Lough Maumeen in the Maumeen Gap, Connemara, Western Ireland. Methods Pollen, sedimentary analysis and ¹⁴ C dating on the lake sediment cores. Results Pollen diagrams, charcoal fragments, bulk and dry densities, mineral content (or loss-on-ignition), whole core magnetic susceptibility, specific magnetic susceptibility for the core profile. Main conclusions Pine-dominated woodland developed from 9250 BP. Human activities effected the deforestation between 5050–4000 BP. Peat bog initiated on the wet hollow ground in the gap during the elm decline. The major expansion of blanket bog landscape in the upland commenced at 4000 BP following immediately the Taxus decline. Human impact was the dynamic force responsible for the destruction of the woodland and the formation of blanket bog in the upland. Three episodes of short-lived erosion events were identified between 8650–8400 BP, 5450–5250 BP, and 600–200 cal. BP, respectively. They are very different from each other in their causation. Large-scale peat erosion is a recent phenomenon. It has been caused by intensive sheep grazing, which has been extended to the upland blanket bogs since the late eighteen century. [ABSTRACT FROM AUTHOR]