The Neolithic landnam event during the mid-Holocene

High-resolution temporal and spatial reconstruction of the vegetation history and environmental changes in western Ireland

The study of proxy records from lake and bog sediments provides a powerful tool to reconstruct past vegetational changes, which can often be linked to patterns of human activity in the landscape. In Ireland, the first significant human impact occurred during the Neolithic landnam period, which broadly coincides with the ‘elm decline’ at c. 5800 cal. BP. The more or less complete clearance of the postglacial woodland by these first settlers resulted in long-term changes in the Irish vegetation. Previous palaeoecological investigations in the vicinity of archaeological sites suggests that the Neolithic populations and the impact of their largely pastoral-based farming economies on the environment were substantial, but ceased quite abruptly at c. 5100 cal. BP.

Hitherto, regional reconstruction of vegetational changes coinciding with the period of Neolithic settlement has been hampered by the uneven distribution of proxy records with well-defined chronological controls. In this respect, the most glaring gap relates to those parts of Ireland where passage tombs are concentrated. This research project attempts to address this lack of information by examining palaeoecological evidence for vegetational and environmental changes during the Neolithic period at a high temporal and spatial resolution in the Carrowkeel area in Co. Sligo.

Based on the analysis of biological (pollen, fungal spores, and microcharcoal) and geochemical proxies, it will be tested to which extent vegetational and palaeoenvironmental changes can be used to trace human activities in this part of Co. Sligo. Proxy records were recovered from two small lakes and one bog site located at various elevations ranging from the fertile lowlands to the east of Carrowkeel to the uncultivable highlands of the Bricklieve Mountains, where a cluster of passage tombs is located. Radiocarbon dating will be used to test the hypothesis that Neolithic settlement commenced in the lowlands and that woodland clearing only proceeded over time into the less accessible mountainous regions. It is a key objective of the project to constrain the farming history of the area and to test whether cereals were cultivated or if Neolithic farming was limited to pastoral activities. In addition, it will be tested for whether an extreme climatic event occurred at the end of the Neolithic, which may have been responsible for the decrease of human activity in the study area.

The research project is financed by the German Research Foundation (research grant to Oliver Nelle and Walter Dörfler, NE 970/2-1, 2-2) and carried out in close collaboration with the Palaeoenvironmental Research Unit at the National University of Ireland.