Late-Quaternary vegetational history of the Inner Hebrides

1983 ◽  
Vol 83 ◽  
pp. 269-292 ◽  
Author(s):  
H. J. B. Birks ◽  
W. Williams
Keyword(s):  
Pollen Analysis ◽  
Late Quaternary ◽  
Late Glacial ◽  
Last Glaciation ◽  
Wide Range ◽  
Native Woodland ◽  
Outer Hebrides ◽  
Glacial Stage ◽  
History Of ◽  
Vegetational Diversity

SynopsisThe Inner Hebrides support a diverse flora and a wide range of vegetation types today. Native woodland is rare, even on the larger islands of Skye and Mull. The present-day floristic and vegetational diversity and the scarcity of native woodland raise important ecological questions, answers to which can be provided by pollen analysis of loch or bog sediments.Pollen analysis of sediments deposited during the last glacial stage on Skye and on Lewis suggest that some plants may have survived the last glaciation within the Hebrides. Pollen analysis of late-glacial (13500–10000 years ago) sediments on Skye indicate that even at the close of the last glaciation there was considerable floristic and vegetational diversity related to geology, altitude, and climate.Post-glacial (10000–0 year ago) vegetational histories are available from Skye, Soay, Canna, Tiree, and Jura. Forest was rare or absent on Canna and Tiree as well as on the Outer Hebrides throughout the postglacial. In contrast Soay and southern and eastern Skye were well forested, with birch, alder, hazel, and small amounts of elm and oak. Pine was confined to eastern Skye. Since 5,000 years ago there has been extensive forest destruction by man, especially on the better soils, and the spread of bog and heath on the poorer soils. Northern Skye supported birch, hazel, and willow scrub during the post-glacial. This has largely been removed by man since about 5,000 years ago. The present-day vegetation of the Inner Hebrides is predominantly anthropogenic.

Late Quaternary Vegetation of Southern Isla Grande De Chiloé, Chile

1988 ◽  
Vol 29 (3) ◽  
pp. 294-306 ◽  
Author(s):  
Carolina Villagran
Keyword(s):  
Climatic Change ◽  
Pollen Analysis ◽  
Tree Species ◽  
Late Quaternary ◽  
Late Glacial ◽  
Pollen Diagrams ◽  
History Of ◽  
Valdivian Forest ◽  
Nothofagus Dombeyi ◽  
Pollen Records

Late-glacial-Holocene forest history of southern Isla Chiloé (latitude 43°10′ S) was reconstructed on the basis of pollen analysis in three profiles (Laguna Soledad, Laguna Chaiguata, Puerto Carmen). Prior to 12,500 yr B.P. pollen records are dominated by plant taxa characteristic of open habitats (Zone I). From 12,500 yr B.P. to the present, tree species predominate in the pollen records (Zones II–V). Between 12,500 and 9500 yr B.P. ombrophyllous taxa (Nothofagus, Podocarpus nubigena. Myrtaceae, Fitzroya/Pilgerodendron, and Drimys) are frequent in all pollen diagrams, suggesting a wetter and colder climate than the present. Between 9000 and 5500 yr B.P. Valdivian forest elements, such as Nothofagus dombeyi type, Weinmannia, and Eucryphia/Caldcluvia, dominate, indicating a period of drier and warmer climate. From 5500 yr B.P. onward, the expansion of mixed North Patagonian-Subantarctic forest elements and the increased frequence of Tepualia suggest increased rainfall and temperatures oscillating around the modern values.The change from open to forest vegetation (ca. 12,500 yr B.P.) probably represents the most pronounced climatic change in the record and can be interpreted as the glacial-postglacial transition in the study area.

Late Quaternary glacial and interglacial environments of the Nechako River - Cheslatta Lake area, central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A Plouffe ◽  
V M Levson
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Late Glacial ◽  
Lake Area ◽  
Glacial Lakes ◽  
Ice Flow ◽  
Coast Mountains ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Quaternary History

The Quaternary stratigraphy of the Nechako River – Cheslatta Lake area of central British Columbia is described and interpreted to reconstruct the late Quaternary history of the region. Exposures of glacial and nonglacial sediments deposited prior to the last glaciation (Fraser) are limited to three sites. Pollen assemblages from pre-Fraser nonglacial sediments at two of these sites reveal forested conditions around 39 000 BP. During the advance phase of the Fraser Glaciation, glacial lakes were ponded when trunk glaciers blocked some tributary valleys. Early in the glaciation, the drainage was free in easterly draining valleys. Subsequently, the easterly drainage was blocked either locally by sediments and ice or as a result of impoundment of the Fraser River and its tributaries east of the study area. Ice generally moved east and northeast from accumulation zones in the Coast Mountains. Ice flow was influenced by topography. Major late-glacial lakes developed in the Nechako River valley and the Knewstubb Lake region because potential drainage routes were blocked by ice.

Late Quaternary vegetation, climate, and fire history of the Southeast Atlantic Coastal Plain based on a 30,000-yr multi-proxy record from White Pond, South Carolina, USA

2019 ◽  
Vol 91 (2) ◽  
pp. 861-880 ◽  
Author(s):  
Teresa R. Krause ◽  
James M. Russell ◽  
Rui Zhang ◽  
John W. Williams ◽  
Stephen T. Jackson
Keyword(s):  
South Carolina ◽  
Vegetation Change ◽  
Fire History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Atlantic Coastal Plain ◽  
Proxy Records ◽  
Dry Conditions ◽  
History Of ◽  
Mississippian Culture

AbstractThe patterns and drivers of late Quaternary vegetation dynamics in the southeastern United States are poorly understood due to low site density, problematic chronologies, and a paucity of independent paleoclimate proxy records. We present a well-dated (15 accelerator mass spectrometry14C dates) 30,000-yr record from White Pond, South Carolina that consists of high-resolution analyses of fossil pollen, macroscopic charcoal, andSporormiellaspores, and an independent paleotemperature reconstruction based on branched glycerol dialkyl tetraethers. Between 30,000 and 20,000 cal yr BP, openPinus-Piceaforest grew under cold and dry conditions; elevatedQuercusbefore 26,000 cal yr BP, however, suggest warmer conditions in the Southeast before the last glacial maximum, possibly corresponding to regionally warmer conditions associated with Heinrich event H2. Warming between 19,700 and 10,400 cal yr BP was accompanied by a transition from conifer-dominated to mesic hardwood forest.Sporormiellaspores were not detected and charcoal was low during the late glacial period, suggesting megaherbivore grazers and fire were not locally important agents of vegetation change.Pinusreturned to dominance during the Holocene, with step-like increases inPinusat 10,400 and 6400 cal yr BP, while charcoal abundance increased tenfold, likely due to increased biomass burning associated with warmer conditions. Low-intensity surface fires increased after 1200 cal yr BP, possibly related to the establishment of the Mississippian culture in the Southeast.

scholarly journals Some aspects of the last glaciation in the Mazury Lake District (north-eastern Poland)

2013 ◽  
Vol 53 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Katarzyna Pochocka-Szwarc
Keyword(s):  
Ice Sheet ◽  
Late Glacial ◽  
Climatic Changes ◽  
Lake District ◽  
Last Glaciation ◽  
North Eastern ◽  
Melt Water ◽  
History Of ◽  
Organic Sediments ◽  
Late Glacial And Holocene

ABSTRACT The morphology of the Mazury Lake District (north-eastern Poland) dates from 24-19 ka (main stadial of the youngest Vistulian glaciation). During this last glacial maximum (MIS 2) a belt with lacustrine basins was formed when the ice sheet retreated at the end of the Pomeranian phase. The ice-sheet retreat is morphologically also expressed by the occurrence of end moraines. The study area is situated in the Skaliska Basin, in the northern part of the Lake District (near the Polish/ Russian border), at the periphery of zone with end moraines. Originally the basin was an ice-dammed depression filled with melt water; the water flowed out into the developing Pregoła valley when the ice retreated and did no longer dam off the depression. The basin, which is surrounded by hill-shaped moraines, is filled now with Late Glacial and Holocene glaciolacustrine sediments. The organic sediments of the basin record the history of the Late Glacial and Holocene climatic changes in this region.

Holocene to Middle Last Glaciation vegetation history at Tullabardine Dam, western Tasmania

1986 ◽  
Vol 229 (1255) ◽  
pp. 177-207 ◽  
Keyword(s):  
New Zealand ◽  
Lake Sediments ◽  
Pollen Analysis ◽  
Temperate Forest ◽  
Vegetation History ◽  
Late Glacial ◽  
Pollen Assemblage ◽  
Temperate Rainforest ◽  
Last Glaciation ◽  
Peat Swamp

Pollen analysis of 4 m of peat, swamp-soil and lake sediments dated from 0 to > 43800 years b.p. indicates the occurrence of three major pollen assemblage zones. During Zone 1 (11000-0 years b.p.) the area had temperate rainforest and the climate was warm, moist and interglacial. During Zone 2 ( ?25000-l 1000 years b.p.), correlated approximately with the last period of glaciation, the vegetation was mainly grassland and the climate was considerably colder than present. In late glacial times (14000-11000 years b.p.) pollen of shrub and tree taxa increased, especially during the later part of the period as the climate became warmer and moister. During Zone 3 (more than 4 3 0 0 0 -?25000 years b.p.) the vegetation was predominantly sub-alpine and alpine. This vegetation represents an interstadial assemblage for a lowland site. The climate was cool and moist. The results are compared with sites of similar age in Tasmania, and with sites from temperate forest environments in Chile and New Zealand.

Late Pleistocene and early Holocene environmental history of southwestern Washington State, U.S.A.

1984 ◽  
Vol 21 (6) ◽  
pp. 619-629 ◽  
Author(s):  
Cathy W. Barnosky
Keyword(s):  
Environmental History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Cascade Range ◽  
Early Holocene ◽  
Olympic Mountains ◽  
Tundra Vegetation ◽  
Plant Remains ◽  
History Of ◽  
Glacial Time

A comparison of pollen records and associated plant remains from sites along a major precipitation gradient in southwestern Washington enables reconstruction of the late Quaternary environment during glacial and early Holocene time. During the Evans Creek Stade (25 000 – 17 000 years BP) little moisture reached lowlands east of the Olympic Mountains and as a result both the Puget Trough and the Columbia Basin featured a cold dry climate and parkland–tundra vegetation In glacial time, greatest aridity seems to have occurred between 19 000 and 17 000 years BP. After 17 000 years BP the development of mesophytic subalpine parkland suggests that maritime conditions extended farther east into the Puget Trough, and the Cascade Range became an important precipitation divide. Conditions warmer and (or) drier than today developed throughout western Washington between 10 000 and 8000–6000 years BP. Vegetation on opposite sides of the Cascade Range became dissimilar as early as 17 000 years BP, but this trend was accentuated in late glacial and early Holocene time.

scholarly journals Late-Glacial and Postglacial Vegetation and Climate of Jackson Hole and the Pinyon Peak Highlands, Wyoming

1985 ◽  
Vol 9 ◽  
pp. 44-49
Author(s):  
Cathy Barnosky
Keyword(s):  
Rocky Mountains ◽  
National Park ◽  
Vegetation History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Glacial Refugia ◽  
Northern Rocky Mountains ◽  
Jackson Hole ◽  
History Of ◽  
Vegetation And Climate

The late-Quaternary vegetation history of the northern Rocky Mountains has thus far been inferred largely from isolated records. These data suggest that conifer forests were established early in postglacial time and were little modified thereafter. The similarity of early postglacial vegetation to modern communities over broad areas gives rise to two hypotheses: (1) that glacial refugia were close to the ice margin, and (2) that vegetation soon colonized the deglaciated areas and has been only subtly affected by climatic perturbations since that time. It is the goal of this project to test these two hypotheses in the region of Grand Teton National Park.

On the extent of the Last Glaciation in eastern England

1959 ◽  
Vol 150 (939) ◽  
pp. 263-282 ◽  
Keyword(s):  
Pollen Analysis ◽  
Age Determination ◽  
Carbonaceous Material ◽  
Late Glacial ◽  
Glacial Deposit ◽  
Southern Limit ◽  
Radiocarbon Age ◽  
Last Glaciation ◽  
Boulder Clay

From pollen analysis of a Late-glacial deposit in east Lincolnshire, it is inferred that the earliest sedimentation in a depression in boulder clay immediately followed melting of the ice. Radiocarbon age determination confirms the Late-glacial age. The boulder clay is the Hessle Boulder Clay of Lincolnshire, and the correlation of this with the Hessle Boulder Clay of Holderness and with the Hunstanton Brown Boulder Clay of north Norfolk is accepted. The evidence from the Late-glacial site, from the stratigraphical position of the boulder clay, and from the topographical form of the boulder clay, all point to the Last Glaciation ice having extended south of the Humber as far as north Norfolk, with a lobe pushing into the Wash. This conclusion reasserts the traditional southern limit of Last Glaciation ice in eastern England, on which doubt had recently been cast by various authors on topo­graphical inference alone. The pollen analysis has been made more accurate by the introduction of a method of correcting for derived pollen, using derived Carboniferous and Mesozoic spores as a control. Significant errors in the radiocarbon age determination are shown to be caused even in peat by derived carbonaceous material from the boulder clay.

Late Quaternary vegetational history of the Howard Pass Area, northwestern Alaska

1999 ◽  
Vol 77 (4) ◽  
pp. 570-581 ◽  
Author(s):  
W Wyatt Oswald ◽  
Linda B Brubaker ◽  
Patricia M Anderson
Keyword(s):  
Late Quaternary ◽  
Local Variation ◽  
Late Glacial ◽  
Early Holocene ◽  
Pollen Accumulation Rates ◽  
Rubus Chamaemorus ◽  
History Of Vegetation ◽  
History Of ◽  
Western Arctic ◽  
Northern Alaska

Palynological records from Tukuto and Etivlik Lakes contribute to an improved understanding of the late Quaternary history of vegetation in the Howard Pass area of northern Alaska. During the Itkillik II glaciation (24-14 ka BP), the vegetation of the western Arctic Foothills was sparse, xeric tundra, as evidenced by taxa indicative of dry, rocky substrates (e.g., Selaginella rupestris (L.) Spring, Chenopodiaceae, and Encalypta cf. rhaptocarpa) and very low pollen accumulation rates in this interval of the 30-ka-old Tukuto Lake record. Mesic tundra dominated by non-Sphagnum (Bryidae) mosses, Cyperaceae, and Salix species expanded near Tukuto Lake during the late-glacial period, followed by the establishment of Sphagnum moss and increased shrub cover at ca. 10 ka BP. Landscapes around both lakes supported stands of Populus cf. balsamifera during the early Holocene, and Alnus crispa expanded in the Howard Pass area during the middle Holocene. Local variation in plant communities is illustrated by the comparison of the Tukuto and Etivlik pollen records. During the early Holocene, Populus cf. balsamifera was more common near Etivlik Lake than Tukuto Lake, and Juniperus cf. communis was present only in the vicinity of Etivlik Lake. Throughout the middle to late Holocene, Sphagnum, mesic tundra shrubs (Betula nana L., Salix, and Ericaceae species), and minor herbaceous taxa (e.g., Rubus chamaemorus L., Thalictrum, and Caryophyllaceae) were more prevalent at Tukuto Lake than at Etivlik Lake. These differences are likely related to the influence of local landform and soil characteristics near the two sites.Key words: Alaska, Arctic Foothills, Brooks Range, pollen analysis, Quaternary.

scholarly journals Late Quaternary Pollen Records and Vegetation History of the Southwest Yukon Territory: A Review

2007 ◽  
Vol 45 (2) ◽  
pp. 175-193 ◽  
Author(s):  
Xia-Cheng Wang ◽  
Marie-Anne Geurts
Keyword(s):  
Vegetation History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Yukon Territory ◽  
Circulation System ◽  
Spruce Forest ◽  
Migration Routes ◽  
Shrub Tundra ◽  
History Of ◽  
Pollen Records

ABSTRACTThis paper is a summary of all known late Quaternary palynostratigraphic records from the southwest Yukon Territory. Thirty two pollen sites available by the end of 1988 are reviewed. Most pollen records in the region are of Holocene age. During the late-glacial to early Holocene, the southwest Yukon supported a herb-dominated tundra vegetation which was replaced by a birch-dominated shrub-tundra at about 10,000 yr BP. Spruce invaded the area between 9000 and 8600 yr BP at different localities, and a southward time transgression is visible in the Aishihik Basin. The current regional vegetation has been stable since 7600-8000 yr BP when dense spruce forest and/or spruce forest-tundra was established in most localities. In the Snag area, however, dense spruce forest developed only around 5700 yr BP, which is about 2000 years later than in the Aishihik Basin. The exotic pine pollen records in the region exhibit an interesting pattern, suggesting a frequent shift of the atmospheric circulation system. Anomalous records of alder pollen from the Aishihik Basin and adjacent regions suggest that alder has never been widespread in these areas due to aridity, and alder pollen is greatly overrepresented in pollen spectra. Spruce arrival dates suggest that further investigations in the Tintina Valley, Yukon River Valley, and Car-macks region might provide useful information concerning the spruce migration routes.

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