The Use of Pedological Studies in Interpreting the Quaternary History of Central Yukon Territory

1977 ◽  
Author(s):  
A E Foscolos ◽  
N W Rutter ◽  
O L Hughes
Keyword(s):  
Yukon Territory ◽  
History Of ◽  
Quaternary History

Late Quaternary history of black spruce and grasslands in southwest Yukon Territory

1992 ◽  
Vol 70 (7) ◽  
pp. 1336-1345 ◽  
Author(s):  
T. J. Keenan ◽  
L. C. Cwynar
Keyword(s):  
Dominant Species ◽  
Black Spruce ◽  
Late Quaternary ◽  
Minor Component ◽  
White Spruce ◽  
Yukon Territory ◽  
The Past ◽  
History Of ◽  
Quaternary History ◽  
A Minor

Pollen records from Long Last Lake and Two Horsemen Pond, near the centre of the arid region of southwest Yukon Territory, do not support the hypotheses that (i) black spruce was a dominant species in the region and (ii) the southwest Yukon supported widespread grasslands during most of the past 10 000 years. Black spruce became established between 8500 and 8000 BP, shortly after the arrival of white spruce, but its low pollen percentages (< 5%) indicate that it was a minor component of forests. Between 6000 and 5000 BP, white spruce populations decreased as black spruce and green alder increased, but black spruce remained a minor constituent of the forest, never becoming a dominant species as at Kettlehole Pond near the southeast margin of the arid southwest Yukon. The initial vegetation was a poplar woodland, dating from 9200 to 8500 BP at Long Last Lake. At both Long Last Lake and Two Horsemen Pond, the high percentages of herb pollen indicate that the forest was open, but the low values of grass pollen suggest that grasslands were not extensive. Coincident with the establishment of spruce woodland at 8500 BP, pollen of herbs declines and remains comparatively low until 1300 BP when herbs, including grasses, increase to maximum values for the period of record, indicating the grassland communities were probably never more abundant during the Holocene than they are now. Key words: southwest Yukon, black spruce, pollen analysis, paleoecology, climate change.

Late Quaternary history of colluvial deposition and erosion in hollows, central California Coast Ranges

1990 ◽  
Vol 102 (7) ◽  
pp. 969-982 ◽  
Author(s):  
STEVEN L. RENEAU ◽  
WILLIAM E. DIETRICH ◽  
DOUGLAS J. DONAHUE ◽  
A. J. TIMOTHY JULL ◽  
MEYER RUBIN
Keyword(s):  
Late Quaternary ◽  
California Coast ◽  
Central California ◽  
History Of ◽  
Quaternary History ◽  
Coast Ranges ◽  
California Coast Ranges

Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada

2012 ◽  
Vol 90 (6) ◽  
pp. 714-721 ◽  
Author(s):  
J.J. Bowden ◽  
C.M. Buddle
Keyword(s):  
Reproductive Effort ◽  
Abiotic Factors ◽  
Wolf Spider ◽  
Local Variation ◽  
Yukon Territory ◽  
The Arctic ◽  
Wolf Spiders ◽  
Female Body Size ◽  
Trade Offs ◽  
History Of

We studied populations of three tundra-dwelling wolf spider (Lycosidae) species to determine reproductive trait relationships and developmental timing in the Arctic. We collected 451 Pardosa lapponica (Thorell, 1872), 176 Pardosa sodalis Holm, 1970, and 117 Pardosa moesta Banks, 1892 during summer 2008. We used log-likelihood ratio tests and multiple linear regressions to determine the best predictors of fecundity and relative reproductive effort. Female body size best explained the variation in fecundity and body condition was the best predictor for relative reproductive effort. We tested for a trade-off between the allocation of resources to individual eggs and the number of eggs produced (fecundity) within each species using linear regression. There was variation in detectable egg size and number trade-offs among sites and these may be related to local variation in resource allocation linked to density-related biotic or abiotic factors. These findings contribute to knowledge about the fitness of arctic wolf spiders in the region of study and are particularly relevant in light of the effects that climate changes are predicted to have on the arctic fauna.

scholarly journals Plio-Quaternary history of the Turkish coastal zone of the Enez-Evros Delta: NE Aegean Sea

2001 ◽  
Vol 2 (2) ◽  
pp. 95 ◽  
Author(s):  
B. ALPAR
Keyword(s):  
Late Pleistocene ◽  
Sand Dunes ◽  
Aegean Sea ◽  
Interglacial Period ◽  
Shelf Area ◽  
Sea Level Changes ◽  
Seismic Profiles ◽  
Alluvial Deposits ◽  
History Of ◽  
Quaternary History

The Enez-Evros Delta, NE Aegean Sea, is located in one the most important wetlands in the world with its sandy offshore islands, abandoned channel mouths, sand-dunes, shoals, marshlands, saline lagoons and saltpans. It comprises very well developed sedimentary units and a prodelta lying on an older submarine delta. The present day elevations of the middle-late Pleistocene marine terraces indicate a regional tectonic uplift in the area. Due to lack of geophysical and bore hole data and partly due to its strategic position, the structural and stratigraphic features of the submarine extension of the delta are not known in detail. In this paper, Plio-Quaternary history of this delta and its submarine part on the Turkish shelf was explored by using high-resolution shallow reflection seismic profiles. The delta is formed by the alluvial deposits of the Enez-Evros River and shaped by their interaction with the sea. It takes place in front of a large and protected ancient bay which was filled rapidly over millennia. The sediments in the plateau off the river are principally pro-deltaic with muddy areas near the river mouths changing to muddy sand further out. The sea-level changes in Plio-Quaternary were characterised by three different seismic stratigraphic units on the folded Miocene limestone basement. In the late Pleistocene, the shelf area over an Upper Miocene basement was flooded during the Riss-Würm interglacial period, exposed in the Würm glacial stage, and flooded once again during the Holocene transgression.

Sign in / Sign up

Export Citation Format

Share Document