Late Holocene Glacier Fluctuations and Vegetation Changes at Maktak Fiord, Baffin Island, N.W.T., Canada

1976 ◽  
Vol 8 (4) ◽  
pp. 343 ◽  
Author(s):  
G. S. Boulton ◽  
J. H. Dickson ◽  
H. Nichols ◽  
M. Nichols ◽  
S. K. Short
Keyword(s):  
Late Holocene ◽  
Vegetation Changes ◽  
Baffin Island ◽  
Glacier Fluctuations

A Good Place to Live: Plants and People at the Santa Elina Rock Shelter (Central Brazil) from Late Pleistocene to the Holocene

2020 ◽  
Vol 31 (2) ◽  
pp. 273-291
Author(s):  
Rita Scheel-Ybert ◽  
Caroline Bachelet
Keyword(s):  
Late Pleistocene ◽  
Late Holocene ◽  
Vegetation Changes ◽  
Vegetation Types ◽  
Rock Shelter ◽  
Good Place ◽  
Central Brazil ◽  
Cultural Preference ◽  
Vegetation And Climate ◽  
Over Time

The Santa Elina rock shelter (Central Brazil) was recurrently occupied from the Late Pleistocene to the Late Holocene. We compare sets of previously published anthracological analyses with new data to reconstruct the landscape, vegetation, and climate over the several thousand years of occupation, providing information on firewood management from about 27,000 to about 1500 cal BP. Laboratory analyses followed standard anthracological procedures. We identified 34 botanical families and 84 genera in a sample of almost 5,000 charcoal pieces. The Leguminosae family dominates the assemblage, followed by Anacardiaceae, Bignoniaceae, Rubiaceae, Euphorbiaceae, and Sapotaceae. The area surrounding the shelter was forested throughout the studied period. The local landscape was formed, as it is today, by a mosaic of vegetation types that include forest formations and open cerrado. Some regional vegetation changes may have occurred over time. Our data corroborate the practice of opportunistic firewood gathering in all periods of site occupation, despite a possible cultural preference for some taxa. The very long occupation of Santa Elina may be due not only to its attractiveness as a rock shelter but also to the continuously forested vegetation around it. It was a good place to live.

Late Holocene Vegetation Changes in Greenwater Valley, Mojave Desert, California

1985 ◽  
Vol 23 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Kenneth L. Cole ◽  
Robert H. Webb
Keyword(s):  
Lower Limit ◽  
Principal Components ◽  
Mojave Desert ◽  
Late Holocene ◽  
Small Scale ◽  
Vegetation Changes ◽  
Factor Analyses ◽  
Downward Shift ◽  
A Site ◽  
Coleogyne Ramosissima

Small-scale late Holocene vegetation changes were determined from a series of 13 modern and fossil packrat middens collected from a site in the Greenwater Valley, northern Mojave Desert, California. Although the site is above the modern lower limit ofColeogyne ramosissima(black-brush), macrofossils of this shrub are only present in samples younger than 270 yr B.P. In order to measure changes more subtle than presence vs absence, macrofossil concentrations were quantified, and principal components and factor analyses were used to distinguish midden plant assemblages. Both the presence/absence data and the statistical analyses suggest a downward shift of 50 to 100 m forColeogyne(blackbrush) communities between 1435 and 1795 A.D.

Late Quaternary Glacial and Vegetation Changes, Little Cottonwood Canyon Area, Wasatch Mountains, Utah

1979 ◽  
Vol 12 (2) ◽  
pp. 254-270 ◽  
Author(s):  
David B. Madsen ◽  
Donald R. Currey
Keyword(s):  
Rocky Mountains ◽  
Late Holocene ◽  
Late Quaternary ◽  
Summer Temperature ◽  
Vegetation Changes ◽  
Glacial Geology ◽  
The Holocene ◽  
Wasatch Mountains ◽  
Relative Moisture

Glacial geology and 14C dating in the central Wasatch Mountains indicate: an early canyon-mouth glaciation (Dry Creek till), probably during isotope stage 6; on that till, a paleosol (Majestic Canyon soil) dated at about 26,000 yr B.P.; overriding that soil, a later canyon-mouth glaciation (Bells Canyon till) probably beginning prior to about 19,000 yr B.P.; a midcanyon deglacial pause (Hogum Fork till) prior to 12,300 yr B.P.; an upper-canyon deglacial pause (Devils Castle till) prior to 7500 yr B.P.; and late Holocene periglaciation. Pollen ratios from bog profiles in the mid to upper reaches of the canyon suggest that temperatures cooler than the Holocene average occurred until after about 8000 yr B.P. Warmer and dryer than average conditions were initiated about 8000 to 7500 yr B.P. During the later portion of this Altithermal period conditions became relatively warm and wet. Two subsequent episodes of cooler than average temperatures correspond chronologically to the initial stades of Neoglaciation elsewhere in the Rocky Mountains. However, there is no geomorphic evidence of corresponding glacial activity in the canyon area. Relative moisture during these two periods differs significantly, suggesting that Neoglacial conditions were controlled primarily by changes in summer temperature.

Holocene and Last Interglacial cloudiness in eastern Baffin Island, Arctic CanadaThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.GEOTOP Publication 2008-0027.

2008 ◽  
Vol 45 (11) ◽  
pp. 1221-1234 ◽  
Author(s):  
Bianca Fréchette ◽  
Anne de Vernal ◽  
Pierre J.H. Richard
Keyword(s):  
Air Temperature ◽  
Growing Season ◽  
Dwarf Shrub ◽  
Interglacial Period ◽  
Vegetation Changes ◽  
Baffin Island ◽  
Last Interglacial ◽  
The Holocene ◽  
Growing Season Length ◽  
Shrub Tundra

This study presents Last Interglacial and Holocene vegetation and climate changes at Fog Lake (67°11′N, 63°15′W) on eastern Baffin Island, Arctic Canada. The vegetation cover is reported as vegetation structural types (or biomes). July air temperature and sunshine during the growing season (June–July–August–September) were reconstructed from pollen assemblages using the modern analogue technique. The vegetation of the Last Interglacial period evolved from a prostrate dwarf-shrub tundra to a low- and high-shrub tundra vegetation. The succession of four Arctic biomes was distinguished from the Last Interglacial sediments, whereas only one Arctic biome was recorded in the Holocene sediments. From ca. 8300 cal. years BP to present, hemiprostrate dwarf-shrub tundra occupied the soils around Fog Lake. During the Last Interglacial, growing season sunshine was higher than during the Holocene and July air temperature was 4 to 5 °C warmer than present. A principal component analysis helped in assessing relationship between floristic gradients and climate. The major vegetation changes through the Last Interglacial and Holocene were driven by July air temperature variations, whereas the minor, or subtle, vegetation changes seem rather correlated to September sunshine. This study demonstrates that growing season sunshine conditions can be reconstructed from Arctic pollen assemblages, thus providing information on feedbacks associated with cloud cover and summer temperatures, and therefore growing season length.

Spatial patterns of modern diatom distribution and multiple paleolimnological records from a small arctic lake on Baffin Island, Arctic Canada

1996 ◽  
Vol 74 (3) ◽  
pp. 435-449 ◽  
Author(s):  
Alexander P. Wolfe
Keyword(s):  
Late Holocene ◽  
Baffin Island ◽  
Diatom Assemblages ◽  
Arctic Canada ◽  
Habitat Specificity ◽  
Radiocarbon Dates ◽  
Numerous Species ◽  
Sediment Reworking ◽  
Clear Differentiation ◽  
Lake Ontogeny

The assumption that within-lake, deep-water sedimentary diatom assemblages are relatively uniform and that a single core is sufficient to depict lake ontogeny was tested for a small tarn on the southwestern Cumberland Peninsula of Baffin Island, Northwest Territories. Diatom transport and deposition were evaluated through analyses of periphytic, planktonic, and epipelic habitats. Diatom stratigraphies of four cores were used to test whether or not trends are comparable in different regions of the lake and throughout the Holocene. Among 12 surface-sediment stations, diatom distributions were alternately highly equitable or variable. Valves of evenly distributed genera (Aulacoseira and Achnanthes) are mixed in the water column prior to deposition. This is supported by plankton tow and periphyton samples, which were respectively dominated by Aulacoseira distans (and varieties) and Achnanthes altaica. Conversely, frequencies of several benthic taxa (e.g., Pinnularia biceps, species of Eunotia) varied up to 30% between stations, in patterns unrelated to water depth, and reflecting habitat specificity and minimal transport prior to burial. Of the four cores (38.0–95.5 cm), analysis of the two longest revealed three distinct zones: (i) a zone dominated by species of Fragilaria (> 9000 BP); (ii) a zone containing benthic acidophilic diatoms indicating natural acidification (9000–7000 BP); and (iii) a zone characterized by numerous species of Aulacoseira ranging from the mid to late Holocene. Clear differentiation of the lower two zones was impossible in the shorter cores, and radiocarbon dates suggest that sediment reworking truncated the earliest records of organic sedimentation at these sites. Correspondence analysis facilitated comparisons of the diatom stratigraphies and enabled the evaluation of core reproducibility. Central cores preserve the most useful paleolimnological records in this environment. Keywords: diatoms, paleolimnology, Arctic Canada, Baffin Island.

scholarly journals Late holocene climate and vegetation changes around lake Malye Chany

2016 ◽  
Vol 7 (1) ◽  
pp. 68-75 ◽  
Author(s):  
S V Zhilich ◽  
N A Rudaya ◽  
S K Krivonogov
Keyword(s):  
Late Holocene ◽  
Vegetation Changes ◽  
Holocene Climate

В статье представлены результаты палинологического и седиментологического анализов колонки донных отложений озера Малые Чаны (Новосибирская область). По палинологическим данным проведена количественная реконструкция доминирующих типов растительности с помощью метода биомизации. Реконструированы основные этапы развития озера Малые Чаны и изменения климата и растительности вокруг озера за последние 4.3 тыс. лет. В начале своего существования озеро было мелководным и соленым. Климат в это время был очень сухой и теплый, вокруг озера была распространена полынная степь. После 3 тыс. л. н. распространяются злаково-полынные степи, климат становится более влажным, а озеро более глубоким, по его берегам начинают расти водные растения. После 2 тыс. л. н. в районе озера распространяется лесостепь, климат остается достаточно влажным, но становится более холодным. Глубина Малых Чанов увеличивается и происходит эвтрофикация озера, прибрежная зона озер зарастает макрофитами.

scholarly journals Holocene Environmental Change in the Frobisher Bay Area, Baffin Island, N.W.T.: Deglaciation, Emergence, and the Sequence of Vegetation and Climate

2007 ◽  
Vol 39 (2) ◽  
pp. 151-162 ◽  
Author(s):  
J. D. Jacobs ◽  
W. N. Mode ◽  
C. A. Squires ◽  
G. H. Miller
Keyword(s):  
Late Holocene ◽  
Late Glacial ◽  
Pollen Record ◽  
Baffin Island ◽  
Bay Area ◽  
Modern Pollen ◽  
Moist Environment ◽  
Organic Fractions ◽  
Late Glacial And Holocene ◽  
Inland Ice

ABSTRACT The late-glacial and Holocene paleoenvironmental sequence for the Frobisher Bay area is outlined using glacial, sea level, and palynological evidence. A rapid retreat of ice from the late Foxe glacial maximum in the lower part of the bay after 11,000 BP was followed by a series of stillstands or minor readvances between ca. 8500 and 7000 BP and possibly later, before the final disappearance of the inland ice centred near Amadjuak Lake. Lithostratigraphy of three buried organic sections which together represent deposition occurring over the period from 5500 to 400 BP indicates a change from a relatively warm, moist environment before 5500 BP to neoglacial conditions, with the coldest phases centred around 5000, 2700, 1200 BP and probably sometime after 400 radiocarbon years BP. As evidenced by peat growth and pollen data, milder, wetter conditions prevailed from 4500 to 3000 BP and again from ca. 2600 to 1800 BP. Peat growth and soil organic fractions point to lesser mild intervals ca. 900 BP and 400 BP, but these are not apparent in the pollen assemblage. The pollen record does not extend to the last four centuries; however, lichenometric studies of neoglacial moraines by DOWDESWELL (1984) show that the maximum late Holocene advance of glaciers in the area occurred within the last century. Modern pollen samples indicate that the present vegetation of the inner Frobisher Bay area is comparable to that of the milder intervals of the late Holocene.

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