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Although the use of sub-fossil testate amoebae as a proxy for raised bog hydrology in Holocene paleoecological studies is well-established, some detailed aspects of species-environment relationships remain under-researched. One such issue is the effect of bog surface microtopography on the climatic sensitivity of testate amoeba communities. Although it has been suggested that some microforms—especially hummocks—may be less sensitive to climatic forcing than others, this has rarely been objectively tested. To investigate this, subfossil testate amoebae assemblages have been examined in a series of shallow cores collected along a hummock-lawn-hollow transect from a bog in central Ireland and the resulting reconstructed water table records, dated using 210Pb, have been compared with instrumental weather data. Testate amoebae communities in the hollow microform were found to be significantly less diverse than those in the hummock and lawn, and both the hummock and lawn showed statistically significant correlations with instrumental temperature and precipitation data. Therefore, whilst the suggestion that paleoecological investigations should target intermediate bog microforms remains sound, the notion that hummock-based testate amoebae hydrological data are climatically-insensitive is challenged. [ABSTRACT FROM AUTHOR]

Abstract: A database comprising some ∼5200 individual striation measurements on bedrock surfaces across the island of Ireland was used to produce maps of flowsets corresponding to individual ice flow events during the last (late Devensian) glacial cycle. These flowsets were identified on the basis of regional-scale correspondence between striae orientations which, when linked together spatially, are able to identify consistent ice flow vectors. Four main chronological stages are identified on the basis of this evidence: (i) incursion of Scottish ice into Ireland; (ii) glacial maximum conditions; (iii) ice retreat and dissolution; and (iv) development of localised ice domes. Striae-based reconstructions of the glaciology of the last Irish ice sheet are qualitatively different from those based on bedform (mainly drumlin and ribbed moraine) evidence. Significant differences are apparent in upland areas which have fewer preserved bedforms and a higher concentration of striae. Combining bedform and striae datasets will enable a better understanding of the temporal evolution of the ice sheet. It is likely that both datasets record a snapshot of ice flow direction and subglacial conditions and environments immediately prior to preservation of this directional evidence. [Copyright &y& Elsevier]

We present an analysis of the Northern Irish bog oak record presented in Turney et al. (2005) for the last 4500 years. The record is compared with a compiled peatland water table record from the same region and palaeohydrological data from northern England and mid-latitude Europe. It is apparent that there is no consistent relationship between the population frequency of Irish bog oaks and the palaeohydrological reconstructions, illustrating that the record is not reflecting wetness changes in peatlands. We suggest that the bog oaks should be scrutinised on a within-site and a site-by-site basis to assess the spatial coherency of the shifts in tree populations and the synchronicity of phases of germination and dying off (GDO). Further work is needed to critically examine the controls on the establishment and demise of bog oaks on Irish peatlands before these data can be used as a palaeoclimate proxy. Only then can they be used to test solar forcing of Holocene climate change. [ABSTRACT FROM AUTHOR]

Abstract: The Early Medieval period in Ireland (c. A.D. 400–1150) has been the subject of much archaeological and historical study. The recent application of various forms of archaeological sciences, as well as palaeoenvironmental studies, to the archaeological record have, however, added fresh impetus to this study area. It seems increasingly evident that significant changes to economy and society occurred during this period and were not recorded in detail in the contemporary documentary sources. This paper will attempt to outline those changes and to assess whether, or to what extent, they were influenced by climate change. [Copyright &y& Elsevier]

Abstract: Digital elevation models of the area around the Solway Lowlands reveal complex subglacial bedform imprints relating the central sector of the LGM British and Irish Ice Sheet. Drumlin and lineation mapping in four case studies show that glacier flow directions switched significantly through time. These are summarised in four major flow phases in the region: Phase I flow was from a dominant Scottish dispersal centre, which transported Criffel granite erratics to the Eden Valley and forced Lake District ice eastwards over the Pennines at Stainmore; Phase II involved easterly flow of Lake District and Scottish ice through the Tyne Gap and Stainmore Gap with an ice divide located over the Solway Firth; Phase III was a dominant westerly flow from upland dispersal centres into the Solway lowlands and along the Solway Firth due to draw down of ice into the Irish Sea basin; Phase IV was characterised by unconstrained advance of Scottish ice across the Solway Firth. Forcing of a numerical model of ice sheet inception and decay by the Greenland ice core record facilitates an assessment of the potential for rapid ice flow directional switching during one glacial cycle. The model indicates that, after fluctuations of smaller radially flowing ice caps prior to 30kaBP, the ice sheet grows to produce an elongate, triangular-shaped dome over NW England and SW Scotland at the LGM at 19.5kaBP. Recession after 18.5kaBP displays a complex pattern of significant ice flow directional switches over relatively short timescales, complementing the geomorphologically-based assessments of palaeo-ice dynamics. The palaeoglaciological implications of this combined geomorphic and modelling approach are that: (a) the central sector of the BIIS was as a major dispersal centre for only ca 2.5ka after the LGM; (b) the ice sheet had no real steady state and comprised constantly migrating dispersal centres and ice divides; (c) subglacial streamlining of flow sets was completed over short ... [Copyright &y& Elsevier]

1. The European Union (EU) Water Framework Directive (WFD) requires that member states establish type-specific reference conditions for all waterbodies, including freshwater lakes. This presents a problem in those locations where human activity has resulted in significant changes to the biological, chemical and physical characteristics of waterbodies. 2. Seventy-six oligotrophic and meso-oligotrophic [0–19 µg total phosphorus (TP) L−1] lakes thought to be relatively unimpacted by human activity have been nominated as candidate reference lakes (CRL) by the Irish Environmental Protection Agency. This research has used palaeolimnological (lake sediment-based) techniques to test the actual and historical ecological site-specific status of a representative selection of these CRL. Where the temporal record of sedimentation was sufficiently long, the study adopted c. 1850ad as the primary baseline date for reference conditions. 3. Short sediment cores were obtained from the deepest parts of 35 CRL, and chronologies were established from profiles of spheroidal carbonaceous particles (SCP). Twenty-two cores of sediment appeared to date back to c. 1850 on the basis of SCP concentrations. Unless the SCP chronologies suggested otherwise, diatom assemblages present in top and bottom samples from the cores were used as proxies of, respectively, present-day and reference conditions. Past lake water pH (DI-pH) and TP concentration (DI-TP) were inferred from the diatom data. Higher resolution sampling (up to five sediment samples per core) was adopted at seven sites where the SCP-based chronology was more robust and for at least one core from each of the most common types of CRL. Sediment chemistry data were determined to identify possible anthropogenic drivers of the observed changes in the diatom assemblages. 4. Ordination and dissimilarity measures identified the main patterns of variation in the diatom data. Eleven of 34 CRL for which diatom data were available showed little or no change in biological status between core top and bottom samples. Core bottom samples in six of these dated back to pre- or c. 1850 and reference (and high ecological) status could therefore be confirmed in these cases. The estimated age of core bottom samples in the remaining five cores was in the period just after c. 1850 to c. 1950ad (four cores) or was impossible to determine (one core). Twenty-three (68%) of the CRL sampled showed biologically important deviation from the reference condition, with acidification and nutrient enrichment seemingly the main causes of change. Catchment disturbance, notably peat erosion possibly linked to recent afforestation, also appeared to have been a factor in some cases. 5. Synthesis and applications. This study provides the first systematic examination of changes to water quality in (perceived) pristine lakes over the last c. 150 years for Ireland, and demonstrates the potential of palaeolimnology to support the implementation of the WFD. The results indicate that diatom communities in low alkalinity lakes have been particularly altered, and acidification and nutrient enrichment appear to have been important drivers for some lakes. Furthermore, higher resolution results call into question the validity of applying c. 1850 as the date for reference conditions across Ireland. [ABSTRACT FROM AUTHOR]

Long-term river flow data are instrumental in understanding the risks posed by fluvial flooding and drought events. They assist in providing greater understanding of the drivers of hydrological variability and are fundamental to contextualising extreme events and detecting emerging climate change signals. In many parts of the world, these insights are limited given the lack of long-term river flow records, which in turn limits the opportunity for robust planning decisions in the water sector. Here we link datasets that take advantage of data rescue efforts and paleoclimate reconstructions with rainfall-runoff modelling techniques, to develop river flow reconstructions at a monthly timestep. Using Ireland as an exemplar, gridded European temperature and precipitation datasets are used to reconstruct monthly flows from 1766 to present for 30 river catchments. Uncertainties in reconstructions from hydrological model structure and parameters are integrated using the Generalised Likelihood Uncertainty Estimation (GLUE) method. Reconstructions are validated through use of quality assured long-term precipitation series for selected catchments and an assessment of historical drought undertaken. We find that the methodology produces robust reconstructions of monthly flows that allow for detailed assessment of catchment responses to varying climatic conditions on monthly, seasonal and annual timescales. Despite the uncertainty associated with reconstructions, we find that the low flows signatures associated with notable historic drought events are identifiable in our reconstructions. Finally, we highlight that the datasets and methods used can be readily employed to reconstruct river flows in other European contexts. [ABSTRACT FROM AUTHOR]