Studies in the Vegetational History of the Northern Pennines: II. An Atypical Pollen Diagram from Pow Hill, Co. Durham

1981 ◽  
Vol 69 (1) ◽  
pp. 171 ◽  
Author(s):  
Judith Turner ◽  
Joyce Hodgson
Keyword(s):  
Pollen Diagram ◽  
History Of

Late Glacial and Holocene history of Plešné Lake and its surrounding landscape based on pollen and palaeoalgological analyses

Biologia ◽  
2006 ◽  
Vol 61 (20) ◽  
Author(s):  
Vlasta Jankovská
Keyword(s):  
Late Glacial ◽  
Forest Steppe ◽  
Southern Europe ◽  
Pollen Diagram ◽  
History Of ◽  
The Bohemian Forest ◽  
Surrounding Landscape ◽  
Late Glacial And Holocene ◽  
High Degree ◽  
Biostratigraphic Units

AbstractPollen analysis has been carried out on a 549 cm thick sediment profile from lake Plešné jezero (Plešné Lake) in the Bohemian Forest (Šumava, Czech Republic; 1090 m a.s.l.; 48°47′ N; 13°52′ E). Analyses of 67 samples characterise the development of the lake biotope and the surrounding landscape during the last ca. 14,000 years. The pollen diagram shows a very distinct transition between the Late Glacial and the Holocene biostratigraphic units at a depth of ca. 312 cm. In the surroundings of Plešné Lake the vegetation was treeless during the entire Late Glacial. The alpine tree limit, formed by Betula and Pinus with undergrowth of shrubs, might have been at ca. 500 m a.s.l. Pollen transported from long distances was significant due to the openness of the landscape, coming from southern Europe and even Africa, and including high numbers of Artemisia, Poaceae, Chenopodiaceae, and some other herbs and shrubs from steppe and forest-steppe areas in southern Europe or Africa (likely Ephedra, certainly Lygeum spartum). The expansion of shrubs, particularly Juniperus, preceded the expansion of trees near the end of the Late Glacial. Afforestation of the region by thin stands of Betula and Pinus occurred during the Preboreal. Significant warming in the Boreal resulted in the expansion of Corylus, Quercetum mixtum (QM) trees, and probably also Picea and Alnus. Picea as well as QM trees were further expanding during the Early Atlantic. Picea was the dominant tree during the Late Atlantic and Fagus started to spread towards its end. Abrupt expansion of Abies marks the Subboreal. A high degree of afforestation (Abies, Fagus, Picea) was characteristic for the Early Subatlantic. During Late Subatlantic, pollen of synanthropic plants appears. Phases of the lake biotope development were defined on the basis of coccal green algae and Isoëtes.

Modern Pollen Assemblages and Vegetational History of the Moraines of the Klutlan Glacier and Its Surroundings, Yukon Territory, Canada

1980 ◽  
Vol 14 (1) ◽  
pp. 101-129 ◽  
Author(s):  
H. J. B. Birks
Keyword(s):  
Picea Glauca ◽  
Yukon Territory ◽  
Canonical Variate ◽  
Pollen Diagram ◽  
Modern Pollen ◽  
Canonical Variates ◽  
Shrub Tundra ◽  
History Of ◽  
Shepherdia Canadensis ◽  
Modern Pollen Assemblages

AbstractModern pollen assemblages have been studied from surficial lake muds and moss polsters collected from five vegetated ice-cored moraines of the Klutlan Glacier. The youngest vegetated moraine (K-II) is characterized by high pollen values for Salix and Hedysarum, K-III by high Salix and Shepherdia canadensis and low Hedysarum and Picea, K-IV by high Betula, Salix, and Shepherdia, and K-V and the Harris Creek moraine (HCM) by high Picea. Variations are summarized by canonical variates analysis. A percentage pollen diagram from Gull Lake on the upland east of the glacier records vegetational development since the deposition of the White River volcanic ash 1220 14C yr ago. An initial species-rich treeless vegetation was replaced by birch-alder-willow shrub-tundra, and this by open Picea glauca forest similar to present vegetation around the lake. Sites on HCM show two basic stratigraphies. Triangle Lake reflects vegetational succession from Salix-Shepherdia canadensis scrub similar to that on K-III today, through open Picea woodland of K-IV type, to closed Picea forests of K-V and HCM. Heart Lake and Cotton Pond reflect vegetational development following melting of ice underlying the spruce forests of HCM. These two types are summarized by positioning the fossil spectra on the first two canonical variate axes of the modern surface spectra.

A palynological study of postglacial vegetation changes in the University Research Forest, southwestern British Columbia

1973 ◽  
Vol 51 (11) ◽  
pp. 2085-2103 ◽  
Author(s):  
Rolf W. Mathewes
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Vegetation Change ◽  
Vegetation History ◽  
Sediment Cores ◽  
Silty Clay ◽  
Pollen Diagram ◽  
History Of ◽  
Palynological Study ◽  
The University

The postglacial vegetation history of the University of British Columbia Research Forest was investigated using percentage and absolute pollen analysis, macrofossil analysis, and radiocarbon dating. A marine silty clay deposit records the oldest (12 690 ± 190 years before present (B.P.)) assemblage of terrestrial plant remains so far recovered from the postglacial of south-coastal British Columbia. Lodge-pole pine (Pinus contorta) dominated this early vegetation, although some Abies, Picea, Alnus, and herbs were also present. Sediment cores from two lakes were also studied. The older is Marion Lake, where five pollen assemblage zones are recognized, beginning with a previously undescribed assemblage of Pinus contorta, Salix, and Shepherdia in clay older than 12 350 ± 190 B.P. The pollen diagram from Surprise Lake (11 230 ± 230 B.P.) is divided into three pollen zones which show the same major trends of vegetation change as the Marion Lake diagram.The first report of the postglacial vegetation history of cedar (Thuja and perhaps Chamaecyparis) in southwestern British Columbia is presented from pollen and macrofossil analyses.At about 10 500 B.P. in both lakes, pollen of Douglas fir (Pseudotsuga menziesii) began a rapid increase, probably in response to climatic amelioration. The palynological evidence, supported by well-preserved bryophyte subfossils, suggests that humid coastal conditions have prevailed in the study area since about 10 500 B.P., with virtually no evidence for a classical Hypsithermal interval between 8500 B.P. and 3000 B.P.

Late Quaternary vegetation history of Kettlehole Pond, southwestern Yukon

1988 ◽  
Vol 18 (10) ◽  
pp. 1270-1279 ◽  
Author(s):  
Les C. Cwynar
Keyword(s):  
Vegetation History ◽  
Late Quaternary ◽  
Initial Period ◽  
Forest Tree ◽  
Published Data ◽  
Vegetation Changes ◽  
Pollen Diagram ◽  
Mesic Forest ◽  
Effective Moisture ◽  
History Of

A pollen diagram with a detailed chronology reveals Late-Pleistocene and Holocene vegetation changes which, in combination with previously published data, provide information on regional vegetation changes in the western boreal forest of the southwestern Yukon. A Populus woodland with an understory of Shepherdiacanadensis and extensive open areas dominated by Artemisia occurred from 11 030 to 9250 BP. Juniperus populations expanded at 9700 BP and then more-mesic forest communities developed when Piceaglauca populations increased at 9250 BP and Populus declined. At 6100 BP there is a remarkable shift from Piceaglauca woodland with Juniperus to a mixed spruce forest in which P. mariana was the dominant species. At 4100 BP conditions altered to favour P. glauca which expanded at the expense of P. mariana, and Juniperus again became important in the vegetation. By 1900 BP Pinuscontorta had become a dominant tree as P. mariana declined, the latter eventually disappearing from the local vegetation. There is no evidence that grasslands were more extensive in the early Holocene, as has been hypothesized for the southwestern Yukon. The vegetation sequence implies an initial period of aridity from 11 030 to 9250 BP, when summer warmth was probably greater than that of the modern climate, a period of increased effective moisture between 9250 and 6100 BP, when Piceaglauca was abundant, even greater effective moisture between 6100 and 4100 BP, when Piceamariana was the dominant forest tree, and then a prolonged period of increasing aridity beginning at 4100 BP and culminating in the development of the modern semi-arid climate.

Origin of a postglacial kettle-fill sequence near Georgetown, Ontario

1991 ◽  
Vol 28 (12) ◽  
pp. 1965-1974 ◽  
Author(s):  
Barry G. Warner ◽  
Helen J. Kubiw ◽  
Paul F. Karrow
Keyword(s):  
Plant Communities ◽  
Fossil Record ◽  
Radiocarbon Dating ◽  
Developmental History ◽  
Wetland Plant ◽  
Pollen Diagram ◽  
Wetland Plant Communities ◽  
Kettle Hole ◽  
History Of ◽  
Fossil Records

Stratigraphic relationships, radiocarbon dating, and pollen and plant macrofossil analyses establish the origin and developmental history of a kettle near Georgetown, Ontario. The early inorganic sediments contain redeposited fossils, particularly from local vegetation. Fossils in peat younger than 10 000 BP largely represent past wetland plant communities in the basin. Although the fossil record probably began about 1300 years after deglaciation of the site, an additional 1700 years passed before the dead ice block melted; only then did sedimentation and biological activity stabilize in the basin and produce an accurate fossil record of past vegetation. Truncated fossil records, illustrated further here by a pollen diagram from nearby Heart Lake, should be expected from kettle-hole deposits, and the radiocarbon ages and fossils from the earliest parts of such sequences should be interpreted with caution.

Holocene Vegetation and Environments Near Goulburn, New South Wales

1986 ◽  
Vol 34 (3) ◽  
pp. 231 ◽  
Author(s):  
JR Dodson
Keyword(s):  
New South ◽  
Sediment Accumulation ◽  
Lake Levels ◽  
Pollen Diagram ◽  
South Wales ◽  
History Of Vegetation ◽  
History Of ◽  
Western Side ◽  
Eucalypt Woodland ◽  
Collection Sites

Three sites from Breadalbane Basin and one from Wet Lagoon near Goulburn were studied to provide a history of vegetation, fire and lake levels in the region. Stratigraphy, a percentage pollen diagram from each site, an influx diagram from two sites and 29 radiocarbon analyses provided the basic data and chronology of the study. The sedimentary history shows that Breadalbane Basin has undergone several cycles of lake phases with sediment accumulation and dry phases with deflation of the lake sediments. The present lake clays and silts of Breadalbane Basin and Wet Lagoon are all Holocene in age. A lake began forming in Breadalbane Basin before 9300 B.P. and probably reached its greatest extent between 7400 and 2700 B.P. At Wet Lagoon water stands were in evidence from 5000 B.P. Over the last 2000 years the sites have dried out and are ephemeral swamps but their water level histories are not necessarily synchronous. A comparison of the records shows that the vegetation of the region has been open eucalypt woodland with understorey dominated by grasses and herbaceous taxa. The most dramatic change was woodland clearance after the arrival of European settlers. The spread of pollen and charcoal collection sites, however, emphasizes a number of local differences in the vegetation of the region. Casuarina, for example, expanded during the mid Holocene along the escarpment on the western side of Breadalbane Basin. The charcoal input curves show fire was a frequent occurrence in the region but the vegetation was apparently resilient to its effects until European settlers used it as a tool in woodland clearance.

Recent history of fire and vegetation from laminated sediment of Greenleaf Lake, Algonquin Park, Ontario

1978 ◽  
Vol 56 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Les C. Cwynar
Keyword(s):  
Forest Fires ◽  
Drainage Basin ◽  
Forest Composition ◽  
Natural Phenomenon ◽  
Pollen Diagram ◽  
Sediment Samples ◽  
The Past ◽  
Lake Algonquin ◽  
Laminated Sediment ◽  
History Of

Laminated sediment (presumed varved) from Greenleaf Lake was examined for evidence of forest fires. A 500-year section dating approximately 770–1270 A.D. was analysed for influx of pollen, charcoal, aluminum, and vanadium using decadal samples. Intervals showing concurrent peaks in charcoal, aluminum, and vanadium influx, varve thickness, and charcoal:pollen ratio were interpreted as representing major fires within the drainage basin of Greenleaf Lake. By these criteria, six fires occurred within 500 years, or one fire approximately every 80 years. The pollen diagram indicates a stable forest composition for the past 1200 years. This, coupled with abundant charcoal fragments in all sediment samples, suggests that fire has been a frequent, natural phenomenon affecting the landscape during this period. There is a significant positive correspondence between peak charcoal influxes and peak influxes of aluminum and vanadium, indicating that increased soil erosion is responsible for their deposition.

The Ancient Cultivation of Hemp

Antiquity ◽  
1967 ◽  
Vol 41 (161) ◽  
pp. 42-49 ◽  
Author(s):  
H. Godwin
Keyword(s):  
Western Europe ◽  
Cannabis Sativa ◽  
Pollen Grain ◽  
Economic Plant ◽  
Historical Account ◽  
East Anglia ◽  
Pollen Diagram ◽  
Indian Hemp ◽  
History Of ◽  
Archaeological Knowledge

The discovery in a long pollen diagram from East Anglia of a substantial curve for a pollen-grain referable to Cannabis sativa, L., the Indian hemp, raised the hope that we might, through palynology, have the means of tracing the history of cultivation of this important and sinister economic plant in England and in Western Europe. It was clearly essential that pollen-analytic evidence should be related fully to existing historical and archaeological knowledge, and aided by a notice in this journal (ANTIQUITY, 1964, 287), and by the notable kindness of a great many academic colleagues, I have put together a condensed historical account of the plant in antiquity as preface to a description of the pollen-analytic data.

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