Pollen analysis of peat deposits in eastern Sutherland and Caithness

SUMMARYA series of radiocarbon dates from critical levels in a pollen diagram from a site near Scourie, Sutherlandshire, proves the recorded events to be much younger than the trend of the pollen curves would suggest. Evidence of pine forest growing in the area during the late Atlantic and Sub-boreal confirms earlier observations that these forests persisted in north-west Scotland later than in many other parts of the British Isles. The extremely slow rate of accumulation between about 420 cm and 455 cm, 1320 years, implies a break in deposition, but there is no biostratigraphic or lithostratigraphic evidence of this.

Section: T-ujmentioning

confidence: 66%

“…There are a number of pollen diagrams from eastern Sutherland and Caithness (Durno, 1958), but they do not necessarily reflect conditions in the more oceanic west. Besides these there are the early observations of Lewis (1907) and Samuelsson (1910) who drew attention to two wood layers in Scottish peats, the Lower and Upper Forest beds.…”

Section: Introductionmentioning

confidence: 99%

A Radiocarbon‐dated Pollen Diagram From North‐west Scotland

Moar¹

1969

“…The Boreal spread of Corylus was not the dramatic event in Scotland that it was in other regions of the British Islands. C. avellana occurs throughout Scotland and it cannot be doubted that it has been widespread since Boreal time, but available evidence suggests that it was rather locally distributed (Durno, 1956(Durno, , 1958(Durno, , 1959Durno and McVean, 1959;Donner, 1957Donner, , 1962, a factor associated perhaps with the base status of the soil. In any event the greatest development of Corylits occurs in areas of calcareous till, as at Little Lochans, Culhorn Mains, and in Orkney (Moar, 1969), or in the southern Grampians in areas of calcareous rock of the Dalradian Series (Donner, 1962), Jessen (1949) notes that in Ireland the lowest frequencies of Corylus pollen occur in regions of lime-deficient soil.…”

Section: History Of the Flora And Vegetationmentioning

confidence: 99%

“…The only detailed regional investigations into the history of the flora and vegetation of Scotland have been restricted to the Highlands (Donner, 1957(Donner, , 1958(Donner, , 1962 although Late Weichselian and Flandrian sites have been studied throughout Scotland (Durno, 1957(Durno, , 1958(Durno, , 1959Kirk and Godwin, 1963;Mitchell, 1948;Nichols, 1967;Steven and Carlisle, 1959). These results show, as was evident from the earlier work of Erdtman (1928), that the development of Flandrian vegetation in Scotland varies from that in England, and that there were affinities between Scottish and Irish Late Weichselian vegetation.…”

Section: Introductionmentioning

confidence: 99%

Late Weichselian and Flandrian Pollen Diagrams From South‐west Scotland

Moar¹

1969

SUMMARYThe history of Late Weichselian and Flandrian vegetation in south-west Scotland has been studied by examining sites ranging from near sea-level up to about 1500 ft O.D. (c. 500 m). Pollen was scarce or absent in Lower Dryas sediments, but the relatively high counts in Allerod sediments implied that an open herbaceous vegetation was established before this time. Throughout the Late Weichselian the vegetation was an herbaceous one which became more stable and denser during the Allerod, but was much reduced during Upper Dryas time. Early Flandrian vegetation remained open and the spread of birch woodland was delayed for some time. Once established the birch forests remained dominant or co-dominant for a long period and were never completely replaced by mixed-oak forest. Because of the differences in vegetation development it was difficult to correlate significant changes in the pollen curves with the standard British system of pollen zones. For this reason an attempt has been made to devise a system of zones appropriate for Scotland which bears comparison with the presently accepted scheme. Apparent breaks in sedimentation at Bigholm Burn and Culhorn Mains, only revealed by pollen analysis, are treated as local phenomena, the causes of which had no effect upon the character of the regional vegetation. Radiocarbon assay of samples from Bigholm Burn show that the ages of Allerod sediments are consistent with those from other parts of Britain, but early and mid-Flandrian dates are considerably younger than their biostratigraphical equivalents elsewhere. Until more dates are available from the region this apparent anomaly is regarded as being an effect of local factors influencing forest development and sedimentation. Although the distribution of sites about the Southern Uplands implies that glaciers were restricted to higher altitudes the present study does not add significantly to our knowledge of the extent of glaciation in this region during the Late Weichselian.

“…Data concerning the Late-glacial and Holocene periods on the centra] northern coast have also been published (Birks, 1984;1993). The only pollen data available for the central Flow Country region are those of Durno (1958), but there are no radiocarbon dates, counts are low and expressed in terms of arboreal pollen, and temporal resolution is poor. Peglar (1979) suggests that the landscape in eastern Caithness has been largely treeless for the whole of the Late-glacial and Holocene, while there was widespread pine forest present in south west Sutherland until c 4000 BP (Pennington, 1975).…”

mentioning

confidence: 99%

Late‐glacial and Holocene vegetation history of the Flow Country, northern Scotland

Charman

1994

SUMMARYThe vegetation history of an important conservation area, the Flow Country in northern Scotland, is descrihed using the results of pollen analysis from two closely spaced cores from the Cross Lochs, eastern Sutherland. Buried lake sediments and shallower surface peats yieid a continuous record covering the Devensian Late-glacial and the Holocene. The earliest Late-glacial pollen spectra recovered suggest a transition from open habitat to more stable communities, dominated by *Empetrum heath. This Windermere Interstadial vegetation shows some variability, with a phase of increased growth of juniper and birch, followed by deteriorating climate and less stable soil conditions in the transition to the Stadial, with Huperzia selago and Salix. There are poorly defined Loch Lomond Stadial and Stadial-Holocene transition periods, characterized by Rumex/Oxyria, after which much warmer, Holocene conditions occur, with a succession of birch-jumper and birch-hazel woodland. Birch persists in small amounts locally, but the presence of other arboreal pollen is thought to be mostly due to long distance pollen transport. From c. 5500 BP, the landscape is largely treeless, apart from a brief phase of local pine forest c. 4500-4000 BP. These changes are compared with other pollen records for northern Scotland. The trends in the Late-glacial vegetation are hroadly similar to those displayed by other sites, although many of the changes appear to be less extreme than for areas to the south and west. The lack oi Artemisia during tbe Loch Lomond Stadial in the east Sutherland and Caithness area is particuiarly noteworthy. This may imply more extensive snow cover. The early Holocene is similar to the rest of northern Scotland, but invasion of Betula was more rapid and the later growth of this genus and hazel was not so dense. The lack of pine in the early Holocene allies the site with eastern Caithness and the Northern Isles, rather than north-west Scotland and the Grampians, It is suggested that the effects of early human populations on such margina] forest areas may have been underestimated in the past. The paradoxical existence of pine macrofossiis with no pollen evidence in several areas of Scotland is explained, at least in part, by the lack of temporal precision of pollen diagrams rather than by low pollen productivity, extremely localized occurrences of the species or strong prevailing winds.