Long-term human impact and environmental change in mid-western Ireland, with particular reference to Céide Fields – an overview

Abstract

How to cite:O'Connell, M., Molloy, K., and Jennings, E.: Long-term human impact and environmental change in mid-western Ireland, with particular reference to Céide Fields -an overview, E&G Quaternary Sci. J., 69, 1-32, https://doi.org/10.5194/egqsj-69-1-2020, 2020. Abstract:This paper presents new palaeoecological data from north County Mayo (Co. Mayo), western Ireland, and reviews published data with a view to achieving a better understanding of the timing and nature of early farming in the region, its impact on the natural environment, and the factors, including climate change, that influenced mid-and late-Holocene vegetation dynamics and farming in the region. A long pollen profile from Glenulra, a deep basin situated within Céide Fields, and short profiles from blanket peat that overlies the prehistoric stone-wall field system provide unambiguous evidence for substantial farming, including widespread woodland clearance, in the early British and Irish Neolithic (beginning ca. 3800 BCE). This was followed by a distinct lull that lasted several centuries until farming activity resumed again, at first modestly (at ca. 2700 BCE) and then more markedly from 2350 BCE, i.e. at the Neolithic-Chalcolithic transition. It is argued on the basis of this and other palaeoecological evidence, including pollen analytical investigations at nearby Garrynagran, that, contrary to recent suggestions, there is no reason to doubt the widely held view that the stone-wall field system -unique in a western European Neolithic context -is correctly ascribable to the earlier part of the British and Irish Neolithic. The history of pine growing in bog contexts (mainly blanket bog) in the region is considered in the light of 14 C dates derived from pine timbers, and the results of dendrochronological investigations at Garrynagran that have enabled two floating pine chronologies to be constructed, are presented. The climatic implications of these data are discussed within local and wider regional contexts. Kurzfassung: Diese Studie präsentiert neue paläoökologische Daten aus dem nördlichen Co. Mayo (Grafschaft Mayo), Westirland, und überprüft bereits veröffentlichte Daten in Hinblick auf ein besseres Verständnis der Zeitstellung und des Typus früher Landwirtschaft in der Region, deren Auswirkungen auf die natürliche Umwelt, und auf Faktoren, einschließlich des Klimawandels, die die mittelbis spätholozäne Vegetationsdynamik und Landwirtschaft der Region beeinflusst haben. Ein langes Pollenprofil aus Glenulra, einem tiefen Becken im Bereich der Céide Fields, und kurze Profile aus Torfen, die das prähistorische System aus Steinmauern flächenhaft überlagern, liefern eindeutige Published by Copernicus Publications on behalf of the Deutsche Quartärvereinigung (DEUQUA) e.V. 2 M. O'Connell et al.: Holocene environmental change in western Ireland Beweise für umfangreiche Landwirtschaft, einschließlich ausgedehnter Rodung von Waldgebieten, im frühen Britischen und Irischen Neolithikum (beginnend ca. 3800 BC). Daran schloss eine ausgeprägte Flaute der l...

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

“…The absence of evidence for a Neolithic landnam is somewhat surprising, especially given that early Neolithic impact is strongly expressed in many Irish pollen records. Landnam may have gone unrecorded in the present instance (~140 y between samples in this part of the profile; each sample integrates ~70 y of pollen deposition) but this seems unlikely given that Landnam events in Ireland are invariably of much longer duration than a century and often result in high P. lanceolata values (can be up to 10% TTP [59,62]; see also profile DYR V below). It is concluded that there was no major early Neolithic farming impact at Ballydoo, which fits in with the lack of archaeological evidence for a local Neolithic presence.…”

“…The pastoral farming phase is followed by a period during which human impact is minimal (DYR V-5b; 5-4.17 ka). This presumably corresponds with the lull in farming that is a feature of the late Neolithic in Ireland generally, particularly in western Ireland [59,62]. As regards chronology, the changes recorded in DYR V-5a and 5b are dated to somewhat later (5.65-5 ka and 5-4.17 ka, respectively) than expected on the basis of the generally accepted chronological framework for the Neolithic in Ireland [59,77,78].…”

“…In addition to the 14 C dates, the following indicators of age were used for constructing the age/depth model for BDB I: Lateglacial/Holocene transition (11.65 ka; [57]); Juniperus in the early Holocene has expanded (11.5 ka); early Holocene Alnus rise (7.7 ka); elm decline (5.8 ka); and pine flush (4.95 ka) (see [58][59][60]), and an estimated age for the top of the pollen profile, i.e., c. 1700 CE (12 cm depth; secondary rise of Pinus-indicative of afforestation; it has not registered in the profile). The age/depth curve, i.e., a smooth spline curve (smoothing factor = 0.3) generated by Clam, was regarded as giving the best age/depth relationship and is used to assign ages to the profile.…”

“…Elevated Pinus values at the end of PAZ 8 probably reflect the regional establishment of pine woodland on bog, i.e., the pine flush that was widespread in western Ireland at c. 5 ka ( [59,60]). There are no local pine timber records that can be assigned with certainty to this time but given that pine timbers are frequent in the basin and persisted until at least 3.6 ka ( 14 C dates from pine timbers in Figure 5, inset), it is reasonable to assume that bog-pine was locally present at this time.…”

A Pleistocene deposit preserved in deep karst at Coolough, County Galway, western Ireland

“…Pollen counts were recorded and calculations were carried out using CountPol version 3.2 (Feeser & O'Connell, 2009). Results were plotted as a series of histograms in a percentage pollen diagram following the format produced at the PRU (O'Connell, Molloy, & Jennings, 2020).…”