Testing the presence of cereal-type pollen grains in coastal pre-Elm Decline peat deposits:Fine-resolution palynology at Roudsea Wood, Cumbria, UK

By the time of the Mid-Holocene Ulmus pollen decline (UD) ca. 5100 14C bp (ca. 5900 cal. BP), the Neolithic was becoming well established in Britain and Ireland. The importance of cereal cultivation as part of the initial neolithization process in the British Isles is uncertain, as archaeological sites of the first Neolithic remain elusive. Palaeoecologists have recorded cereal-type pollen grains in peat deposits that pre-date the UD significantly, but as some wild grasses can produce pollen that closely resembles cereal pollen grains, these early pollen records are not trusted as evidence of cereal cultivation. Some of these wild grass taxa grow in coastal wetland environments, making cereal-type pollen from such locations particularly open to question. This study uses fine-resolution palynology through a sequence of coastal hydroseral deposits that contain no evidence of human activity, to look for the presence of wild grass pollen of cereal size and morphology. Our results show that while such grains are not recorded at 1 cm resolution, at contiguous 2 mm resolution sampling sporadic occurrences of large grass pollen of possible cereal-type, resembling Hordeum, were detected. Morphology suggests that these cereal-type grains are of wild grass origin, almost certainly Glyceria, but their presence suggests that high-resolution analyses of coastal zone sediments will often discover cereal-type grains. Great care must be taken in identifying cereal-type pollen in coastal palaeo-wetland sediments, and rigorous identification protocols should be applied. Where grains could still be of cultivated cereal-type, the presence of other disturbance indicators is an important factor in inferring their origin.</p

A Detailed Record of Deglacial and Early Post-Glacial Fluvial Evolution: The River Ure in North Yorkshire, UK

The lower reaches of the River Ure, on the flanks of the Pennine Hills in northern England, contain sedimentary and erosional landforms that are a record of fluvial activity during deglaciation and valley-glacier retreat at the end of the last (Devensian) glacial period, and in the subsequent post-glacial Holocene. Terraces and channels, most of which are now relict features well above the altitude of the present river, attest to the impacts of massive meltwater discharge and deposition of sand and gravel outwash, and dynamic river regimes with rapid incision. Through field survey, we have created a detailed geomorphological map of these landforms and glacial and fluvioglacial surface deposits, as well as the terraces and palaeochannels that were abandoned by the river due to avulsion and incision-driven course changes. We have recorded the nature of the outwash gravels, now effectively terrace features, from exposed sections in working quarries, one of which we discuss here. The palaeochannels have accumulated sediment fills and we have examined several which lie within the range of 100 and 16 m above present sea level. The results of lithostratigraphic, palynological, and radiocarbon analyses at two main and three subsidiary sites indicate that palaeochannel ages range from almost 14,000 to approximately 4000 calibrated years ago in a clear altitudinal sequence. The oldest are probably caused by rapid incision due to deglaciation-driven isostatic uplift. The similarity in date of the three downstream sites suggests that a late Holocene combination of climatic deterioration and increased human activity in the catchment caused instability and entrenchment. Pollen data from the channel fills provide relative dating, and agree well with pollen records from other regional Lateglacial and Holocene sites. Non-pollen palynomorph (NPP) analysis at one of the sites allows reconstruction of the hydrological history of channel infill. This research shows that the application of an integrated suite of research techniques can yield a highly detailed understanding of fluvial evolution and landscape history

sj-doc-1-hol-10.1177_09596836231219461 – Supplemental material for Testing the presence of cereal-type pollen grains in coastal pre-Elm Decline peat deposits: Fine-resolution palynology at Roudsea Wood, Cumbria, UK

Supplemental material, sj-doc-1-hol-10.1177_09596836231219461 for Testing the presence of cereal-type pollen grains in coastal pre-Elm Decline peat deposits: Fine-resolution palynology at Roudsea Wood, Cumbria, UK by James Innes, Mairead Rutherford, Peter Ryan, Peter Rowley-Conwy and Jeff Blackford in The Holocene</p

Early to Mid-Holocene Tree Immigration and Spread in the Isle of Man: The Roles of Climate and Other Factors

The Isle of Man is a large island which lies in the middle of the northern Irish Sea between Britain and Ireland and, because of its insularity and size, has an impoverished flora compared with the two main islands. This has been the case throughout the postglacial and warrants the island’s description as a separate phytogeographic province. We have considered Holocene tree pollen data from seventeen sites on the island which together preserve a vegetation history that spans the six thousand years of the early and mid-postglacial from the end of the Lateglacial at 11,700 cal. BP to the mid-Holocene Ulmus decline at ca. 5800 cal. BP. Radiocarbon dating of the rational limits of the pollen curves for the main tree taxa has allowed an appraisal of the timing of each one’s expansion to become a significant component of the island’s woodland, and comparison with the dates of their expansion on the adjacent regions of Britain and Ireland. The radiocarbon dates show that, although some variability exists probably due to local factors, there is considerable concordance between the timings of major pollen zone boundaries in Britain and Ireland around the northern Irish Sea. On the Isle of Man the expansions of both Juniperus and Betula were delayed by several centuries compared to the British/Irish data, however the timing of the expansions of Corylus, Ulmus, Quercus, Pinus and Alnus on the Isle of Man all appear closely comparable to the ages for these pollen stratigraphic events in north Wales, northwest England, southwest Scotland and eastern Ireland, as are those for the Ulmus decline. It is likely that local pedological and edaphic factors on the island account for the differences in the first Holocene millennium, while regional climatic factors governed the timings for the rest of the expansions of tree taxa across the wider region, including the Isle of Man. Disturbance, including by human agency, was important at the site scale and perhaps triggered early tree expansion in some places, including Quercus, Ulmus and Alnus. Insularity seems not to have been a significant factor in the expansion of the major forest trees