Late Glacial fossil leaves of Thuja occidentalis from Manitoulin Island, Ontario

1982 ◽  
Vol 60 (8) ◽  
pp. 1352-1356 ◽  
Author(s):  
Barry G. Warner
Keyword(s):  
North America ◽  
Late Glacial ◽  
Pine Forests ◽  
Eastern North America ◽  
Before Present ◽  
Thuja Occidentalis ◽  
Spruce Forests ◽  
Fossil Leaves

A leafy twig fragment of Thuja occidentalis L. was isolated from sediments dating about 10 000 years before present (B.P.) from Manitoulin Island, Ont. This is the earliest known record of Thuja leaves in postglacial deposits in eastern North America. Thuja may have arrived in Ontario in association with boreal spruce forests, but was a component of early pine forests.

Postglacial dispersal of freshwater fishes into Ontario

1992 ◽  
Vol 70 (11) ◽  
pp. 2247-2259 ◽  
Author(s):  
Nicholas E. Mandrak ◽  
E. J. Crossman
Keyword(s):  
North America ◽  
Freshwater Fishes ◽  
Eastern North America ◽  
Glacial Period ◽  
Before Present ◽  
Last Glacial Period ◽  
Historical Processes ◽  
Dispersal Routes ◽  
Atlantic Coastal ◽  
The Last Glacial

The present-day distributions of 117 native freshwater fishes in Ontario have been shaped by processes active following the Wisconsinan glacial period, 80 000–10 000 years before present. During this glacial period, these species survived in unglaciated réfugia. To understand the processes that resulted in the recolonization of Ontario by fishes following the last glacial period, the refugial areas occupied by each species were determined using a refugial index, and glacial water bodies used as dispersal routes were identified. The refugial origins of the Ontario populations of 91 species were resolved. Seventy-two species resided in the Mississippian refugium, 13 species in the Atlantic Coastal refugium, 4 species in dual Atlantic Coastal – Mississippian refugia, 1 species in a Missourian refugium, and 1 species in Atlantic Coastal, Mississippian, and Missourian refugia. These conclusions differed significantly from those of other studies. Five general patterns were identified from the distributions of 104 species. In addition, there are 13 species that do not fit any of the general patterns. Most species with similar distributions in Ontario shared the same refugia and dispersal routes in eastern North America, therefore it is hypothesized that historical processes were important in shaping the present-day distributions of Ontario freshwater fishes.

scholarly journals Erratum: A previously unrecognized late-glacial cold event in eastern North America

Nature ◽  
1993 ◽  
Vol 363 (6425) ◽  
pp. 188-188 ◽  
Author(s):  
André J. Levesque ◽  
Francis E. Mayle ◽  
Ian R. Walker ◽  
Les C. Cwynar
Keyword(s):  
North America ◽  
Late Glacial ◽  
Eastern North America ◽  
Cold Event

Quaternary Vegetation History of the Mississippi Embayment,

1980 ◽  
Vol 13 (1) ◽  
pp. 111-132 ◽  
Author(s):  
Paul A. Delcourt ◽  
Hazel R. Delcourt ◽  
Ronald C. Brister ◽  
Laurence E. Lackey
Keyword(s):  
North America ◽  
Vegetation History ◽  
Deciduous Forest ◽  
Late Glacial ◽  
Eastern North America ◽  
Mississippi Valley ◽  
Yellow Poplar ◽  
Mississippi Embayment ◽  
Creek Watershed ◽  
History Of

AbstractNonconnah Creek, located in the loess-mantled Blufflands along the eastern wall of the Lower Mississippi Alluvial Valley in Tennessee displays a sedimentary sequence representing the Altonian Substage through the Woodfordian Substage of the Wisconsinan Stage. The site has a biostratigraphic record for the Altonian and Farmdalian Substages that documents warm-temperate upland oak-pine forest, prairie, and bottomland forest. At 23,000 yr B.P., white spruce and larch migrated into the Nonconnah Creek watershed and along braided-stream surfaces in the Mississippi Valley as far as southeastern Louisiana. The pollen and plant-macrofossil record from Nonconnah Creek provides the first documentation of a full-glacial locality in eastern North America for beech, yellow poplar, oak, history, black walnut, and other mesic deciduous forest taxa. During the full and late glacial, the Mississippi Valley was a barrier to the migration of pine species, while the adjacent Blufflands provided a refuge for mesic deciduous forest taxa. Regional climatic amelioration, beginning about 16,500 yr B.P., is reflected by increases in pollen percentages of cooltemperate deciduous trees at Nonconnah Creek. The demise of spruce and jack pine occurred 12,500 yr B.P. between 34° and 37° N in eastern North America in response to postglacial warming.

A late-glacial transition from Picea glauca to Picea mariana in southern New England

2007 ◽  
Vol 67 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Matts Lindbladh ◽  
W. Wyatt Oswald ◽  
David R. Foster ◽  
Edward K. Faison ◽  
Juzhi Hou ◽  
...  
Keyword(s):  
North America ◽  
New England ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Single Species ◽  
Late Glacial ◽  
Eastern North America ◽  
Southern New England ◽  
Edaphic Conditions ◽  
Ecological Changes

AbstractPicea is an important taxon in late-glacial pollen records from eastern North America, but little is known about which species of Picea were present. We apply a recently developed palynological method for discriminating the three Picea species in eastern North America to three records from New England. Picea glauca was dominant at ∼ 14,500–14,000 cal yr BP, followed by a transition to Picea mariana between ∼ 14,000 and 13,500 cal yr BP. Comparison of the pollen data with hydrogen isotope data shows clearly that this transition began before the beginning of the Younger Dryas Chronozone. The ecological changes of the late-glacial interval were not a simple oscillation in the position of a single species' range, but rather major changes in vegetation structure and composition occurring during an interval of variations in several environmental factors, including climate, edaphic conditions, and atmospheric CO2 levels.

Ochotona (Lagomorpha) from Late Quaternary Cave Deposits in Eastern North America

1996 ◽  
Vol 45 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Jim I. Mead ◽  
Frederick Grady
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Ice Sheets ◽  
Late Glacial ◽  
Eastern North America ◽  
Large Species ◽  
The West ◽  
Northeastern North America ◽  
Large Form

AbstractPikas (Ochtona)—small gnawing mammals, related to rabbits—range today throughout parts of the Northern Hemisphere, but had a wider distribution during the Pleistocene. Nine caves from northeastern North America (a region not occupied by pikas today) have Pleistocene deposits containing remains of Ochotona. We examine 526 fossil specimens (ranging in age from approximately 850,000 to 8670 yr B.P.) from five of these caves. Two morphological forms of Ochotona lived in northeastern North America during the late Pleistocene—a large species (probably O. whartoni) and a small species (probably O. princeps).Ochotona of glacial age are not necessarily indicative of talus slopes and mesic communities. O. princeps-like of the Irvingtonian of West Virginia were living with an amphibian-reptilian assemblage found in the area today, implying winters not much, if at all, colder than at present. Late glacial and postglacial change in climate south of the ice sheets in effect would have isolated Ochotona in eastern North America, where they were unable to retreat to the west or north. Whereas western pika had the option of moving up in elevation, into boreal islands, eastern forms became restricted to ever-diminishing habitats, culminating in extinction and extirpation. Radiocarbon ages imply that Ochotona lived in eastern North America during the late Pleistocene (late Rancholabrean) and into the earliest Holocene. We describe the youngest remains of Ochotona in eastern North America and the youngest for the extinct large form, O. whartoni.

On the Inferred Age and Origin of Lithic Bi-Points from the Eastern Seaboard and their Relevance to the Pleistocene Peopling of North America

2015 ◽  
Vol 80 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Matthew T. Boulanger ◽  
Metin I. Eren
Keyword(s):  
North America ◽  
Late Glacial ◽  
Glacial Maximum ◽  
Eastern North America ◽  
Archaeological Record ◽  
Late Archaic ◽  
Early Woodland ◽  
Definitive Evidence ◽  
Middle Atlantic ◽  
Eastern Seaboard

AbstractRecently, advocates of an “older -than- Clovis” occupation of eastern North America have suggested that bi-pointed leaf-shaped lanceolate stone bifaces provide definitive evidence of human culture on the eastern seaboard prior to the Late Glacial Maximum. This argument hinges on two suppositions : first, that points of this form are exceedingly rare in the East and second, that all known occurrences of these point forms are from landforms or depositionaI environments dating to some time before the late Pleistocene. Neither of these suppositions is supported by the archaeological record. Bi-pointed leaf shaped blades have been recoveredfrom throughout the Middle Atlantic and Northeast, where they have been repeatedly dated, either radiometrically or by association with diagnostic artifacts, to between the Late Archaic and the Early Woodland. Statistical analysis of supposed “older-than-Clovis” leaf-shaped blades demonstrates that there are no significant differences in morphology between them and unequivocally Middle Holocene leaf-shaped blades. Until such time as evidence demonstrates otherwise, there is no reason to accept that these leaf-shaped bifaces are diagnostic of a Pleistocene, much less pre-Late Glacial Maximum, occupation in eastern North America.

scholarly journals Ipsenol, Ipsdienol, Ethanol, and α-Pinene: Trap Lure Blend for Cerambycidae and Buprestidae (Coleoptera) in Pine Forests of Eastern North America

2015 ◽  
Vol 108 (4) ◽  
pp. 1837-1851 ◽  
Author(s):  
D. R. Miller ◽  
C. M. Crowe ◽  
K. J. Dodds ◽  
L. D. Galligan ◽  
P. de Groot ◽  
...  
Keyword(s):  
North America ◽  
Pine Forests ◽  
Eastern North America

Environmental Potential and the Postglacial Readaptation in Eastern North America

1968 ◽  
Vol 33 (4) ◽  
pp. 441-445 ◽  
Author(s):  
James E. Fitting
Keyword(s):  
North America ◽  
Population Density ◽  
Carrying Capacity ◽  
Late Glacial ◽  
Cold Climate ◽  
Gradual Transition ◽  
Eastern North America ◽  
Entire Area ◽  
Periglacial Zone ◽  
Single Standard

AbstractIn definitions of the postglacial readaptation in eastern North America, attempts have been made to apply a single standard to the entire area. Such definitions are inadequate since a number of environmental zones existed in the region during late glacial and early postglacial times. These consisted of a periglacial zone with a fairly high carrying capacity supporting a cold-climate hunting adaptation; a zone of closed boreal forest with a relatively low carrying capacity; and a region of broadleaf and southern forests with a relatively high carrying capacity for a mixed gathering-and-hunting base. In the southeast there is a gradual transition from formally defined Paleo-Indian to Archaic culture, although both groups, if separation is possible, had potentially the same subsistence base. In the northeast there is a low population density hiatus between two periods of higher population density.

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