THE IDENTIFICATION OF <i>BETULA NANA</i> POLLEN

Birks, H. J. B.

doi:10.1111/j.1469-8137.1968.tb06386.x

Cited by 117 publications

(66 citation statements)

References 9 publications

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“…When the history is reconstructed using sub-fossil pollen from sediments as a main source, emphasis is usually made on differentiating the tree-birch pollen of B. pubescens from the pollen of dwarf-shrub birch B. nana (e.g. Birks, 1968;Mäkelä, 1999;Caseldine, 2001). The results of the present study suggest that the hybridisation of the two species, which has presumably led to the establishment of mountain birch (B. pubescens ssp.…”

Section: Discussionmentioning

confidence: 67%

“…This finding may provide a means to detect the presence of hybrid pollen in a mixed sample, by its unique morphology, and to calculate proportions of hybrid pollen according to distribution curves, especially those with low D/P ratios. Birks (1968) emphasized the usefulness of D/P ratio in distinguishing pollen of the tree birch B. pubescens from that of the dwarf birch B. nana (lower D/P ratio in B. pubescens), but the problem seemed to be with the pollen of mountain birch (B. pubescens ssp. tortuosa).…”

Section: Discussionmentioning

confidence: 99%

“…As different birch species represent different ecosystems, several attempts have been made to differentiate sub-fossil pollen of Betula, especially between B. pubescens and B. nana (see Caseldine, 2001). Pollen of B. pubescens is on average larger than pollen of B. nana, has more protruding apertures and a larger vestibulum (Birks, 1968). However, size frequency curves overlap significantly and interpretation of sub-fossil data has to rely on mean sizes rather than individual grains.…”

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confidence: 99%

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Characteristics of pollen from natural triploidBetulahybrids

Karlsdóttir¹,

Hallsdóttir²,

Thórsson³

et al. 2008

Grana

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Section: Discussionmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Characteristics of pollen from natural triploidBetulahybrids

Karlsdóttir¹,

Hallsdóttir²,

Thórsson³

et al. 2008

Grana

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“…Other tree pollen was assumed to be reworked. A division between pollen of B. nana Birks, 1968;Usinger, 1977;Kolstrup, 1982;Ma «kela «, 1996;Blackmore et al, 2003); since they overlap in size and shape the identi¢cation remains tentative. Furthermore, pollen of Poaceae with pollen grains s 35 and 9 35 Wm were separated.…”

Section: Botanical Analysismentioning

confidence: 99%

Flora, fauna and climate of Scotland during the Weichselian Middle Pleniglacial – palynological, macrofossil and coleopteran investigations

Bos

Dickson

Coope

et al. 2004

Palaeogeography, Palaeoclimatology, Palaeoecology

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Thin lenses of organic-rich material, on the upper surface of a layer of glacio-fluvial deposits have been studied in an open cast coal-mine near Sourlie, western Scotland. Radiocarbon dates on antler fragments, plant debris and bulk organic matter from silt, showed that the sediments accumulated between ca. 33 500 and 29 000 14 C yr BP, during a period when this part of western Scotland was free of glaciers. The organic-rich sediments yielded a very rich flora and fauna and in total about 160 plant taxa and 61 coleopteran taxa were recorded together with other invertebrates. The Sourlie flora is one of the richest late Middle Weichselian floras yet studied within the British Isles. Leg bones of Coelodonta antiquitatis (woolly rhinoceros) and Rangifer tarandus (reindeer) were also found at the site. During this period, the landscape was treeless and the vegetation could be characterised as an intermediate between a low shrub tundra and sedge^grass^moss tundra. Both the flora and arthropod fauna suggest that during formation of the organic-rich layers at Sourlie, mean July temperatures were 9^10 ‡C. The flora suggests also that at the beginning of formation of these layers, minimum mean July temperatures increased from 7 to 9^10 ‡C, but later dropped again to 7^8 ‡C. A possible time correlation with one of the warmer periods of the Dansgaard^Oeschger cycles in the stable oxygen isotope record of the Greenland ice cores during this period is proposed. The arthropod fauna suggests that mean January temperatures were somewhere between 334 and 311 ‡C. Mean annual temperatures lay probably between 31 and 310 ‡C, which implies the possible presence of discontinuous or continuous permafrost in the area. During winter, a protective snow cover of varying thickness probably enabled perennial plants, especially shrubs, to survive. ß

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“…Betula pubescens (tree birch) was the dominant tree taxon during the Lateglacial period in Denmark but the separation of tree birch pollen from that of B. nana (dwarf birch) is problematic (Birks 1968;Usinger 1977;Andersen 1980). In addition, local pollen production is limited in Arctic environments, and the contribution of pollen transported a long distance can be disproportionately high, which can lead to misleading results (see Birks and Birks 2000).…”

Section: Introductionmentioning

confidence: 99%

Living on the good soil: relationships between soils, vegetation and human settlement during the late Allerød period in Denmark

Mortensen

Henriksen

Bennike

2014

Veget Hist Archaeobot

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The immigration of woody plants, especially Betula (tree birch), is examined in relation to geomorphological regions in a compilation of Late-glacial plant macrofossil records from Denmark. The immigration of trees led to a large ecological transformation of the landscape and had a major effect on the flora and fauna available to Palaeolithic people. We show that soil type was a controlling factor in the development of vegetation during the Allerød and Younger Dryas periods. Following the first immigration of trees during the Allerød period, woods became established in the eastern part of Denmark, where ice advances from the Baltic had deposited calcareous and clayey sediments. The western and northern parts of Denmark that are characterised by more sandy and noncalcareous sediments remained treeless throughout the whole Late-glacial period. Finds from the Bromme Culture are concentrated in the region which was wooded, suggesting that the regional variable environment allowed local adaptations using the diverse resources available.

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THE IDENTIFICATION OF BETULA NANA POLLEN

Cited by 117 publications

References 9 publications

Characteristics of pollen from natural triploidBetulahybrids

Characteristics of pollen from natural triploidBetulahybrids

Flora, fauna and climate of Scotland during the Weichselian Middle Pleniglacial – palynological, macrofossil and coleopteran investigations

Living on the good soil: relationships between soils, vegetation and human settlement during the late Allerød period in Denmark

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