The nature and cause of the so-called 2.8 kyr BP event have been a subject of much debate. Peat sequences have provided much of the evidence for this event, but the process link between climate and peatland response is not well understood. Multiproxy, high-resolution analysis of a core from Bargerveen in the eastern Netherlands based on pollen, non-pollen palynomorphs, testate amoebae and geochemistry identified an abrupt shift from relatively dry to extremely wet conditions. Radiocarbon-based wiggle-match dating (WMD) and biostratigraphy based on the pollen record show that this shift in local hydrology occurred around 2800 cal. yr BP. We interpret an erosional hiatus lasting up to 950 years immediately prior to this, as the effect of a bog burst after excessive rainfall. This phenomenon was not limited to our sampling location but occurred over a large part of the former Bargerveen. Peat at the hiatus contains microfossils that reflect temporary eutrophication as a consequence of local fires and secondary decomposition because of increased drainage after the erosion event. Our data show how detailed multiproxy analyses can elucidate the past response of peatlands to changing climate and suggest that the climatic change in northwest Europe at this time caused major non-linear disruption to these ecosystems.

A range of detailed palaeoenvironmental analyses carried out on a series of three peat profiles from Achill Island, Co. Mayo, western Ireland, reveal evidence for an extreme climatic event, probably a storm or series of storms, around 5200-5100 cal.yr BP that caused the deposition of an extensive layer of silt across blanket peat. This event followed a period of relatively dry climate during which Neolithic communities expanded in the region. There was a subsequent period of continuing dry conditions allowing extensive colonisation of the peat by Pinus before a shift to wetter conditions characteristic of the later Holocene. The extreme climatic event is possibly linked to human abandonment of the area comparable to that observed from the work on the internationally significant Céide Fields in the same region.

No abstract

No abstract

No abstract