scholarly journals Characteristics of the Okanagan Highlands Intrusive Complex As a Source For Basal-type Uranium Deposits, South-central British Columbia

1982 ◽  
Author(s):  
D R Boyle
Keyword(s):  
British Columbia ◽  
Intrusive Complex ◽  
Uranium Deposits ◽  
South Central ◽  
Okanagan Highlands ◽  
Basal Type

Uranium series disequilibrium in young surficial uranium deposits in southern British Columbia

1984 ◽  
Vol 21 (5) ◽  
pp. 559-566 ◽  
Author(s):  
A. A. Levinson ◽  
C. J. Bland ◽  
J. R. Dean
Keyword(s):  
British Columbia ◽  
Uranium Content ◽  
Igneous Rocks ◽  
Uranium Deposits ◽  
Secular Equilibrium ◽  
Uranium Series ◽  
South Central ◽  
Activity Ratios ◽  
Different Sources

Disequilibrium studies involving the determination of total U and the activity ratios of 234U/238U and 234U/230Th or activities of 230Th, 226Ra, and 210Pb were carried out on samples from three surficial (generally within 5 m of the surface) uranium deposits in south-central British Columbia that give apparent 234U/230Th ages of 1000–20 000 years. As a result of the young ages, the deposits have not yet reached radioactive secular equilibrium and, therefore, yield very little gamma activity.The deposits formed from groundwaters that leached labile uranium from intermediate to felsic igneous rocks. Two accumulation mechanisms concentrate the uranium: evaporation, and adsorption onto organic matter.The uranium content and the activities of the various daughter nuclides are highly variable within and between the various deposits studied. Some of the variations can be explained in terms of the accumulation processes. In the evaporative process the highest value of uranium and daughter nuclides will be found at the surface, whereas in those deposits in which adsorption is the dominant mechanism these nuclides are found in association with buried organic matter. Under these circumstances, accumulations will be influenced by the flow of groundwater from different sources and also depend on whether daughter nuclides remain immobile or are leached after formation.

Systematics and phytogeography of selected Eocene Okanagan Highlands plants

2005 ◽  
Vol 42 (2) ◽  
pp. 205-214 ◽  
Author(s):  
Melanie L DeVore ◽  
Kathleen B Pigg ◽  
Wesley C Wehr
Keyword(s):  
British Columbia ◽  
North America ◽  
North American ◽  
Middle Eocene ◽  
Rapid Evolution ◽  
Witch Hazel ◽  
South Central ◽  
The Republic ◽  
Okanagan Highlands ◽  
Early Radiation

The diverse Early to Middle Eocene Okanagan Highlands floras of south central British Columbia and northeastern Washington reflect a time of rapid evolution and the early radiation of many dicot families that are currently significant elements of temperate floras. Recent studies of the Republic, Washington flora (Klondike Mountain Formation) and related Okanagan floras in British Columbia have documented both the earliest, and sometimes the only, known fossil occurrences of genera. Today many once more widespread taxa are restricted, particularly to Asian and (or) eastern North American refugia. Examples include members of the families Betulaceae (birch, hazelnut), Rosaceae (rose), Hamamelidaceae (witch hazel), and the endemic Asian family Trochodendraceae. Earliest occurrences are noted for Neviusia (Rosaceae), Trochodendron (Trochodendraceae), Corylus and Carpinus (both Betulaceae). The first unequivocal leaf records of Corylopsis and Fothergilla (both Hamamelidaceae), and two new Eocene species of the extinct fruit Palaeocarpinus (Betulaceae) are also recognized. Today, Trochodendron and Corylopsis are restricted to Asia, whereas Neviusia and Fothergilla, genera with close Asian relatives, occur only in North America. Corylus johnsonii from Republic is most similar to the extant Asian species C. heterophylla, C. wangii, and C. ferox. Neviusia leaves from One Mile Creek near Princeton, British Columbia are more similar to N. cliftonii, an endemic from Mount Shasta, California, than to N. alabamensis of southeastern North America. A better documentation of the Okanagan Highlands floras is essential to our understanding of the evolution of North American temperate floras and the nature of Asian – North American disjunct taxa.

scholarly journals Monitoring ecological representation in currently non-harvestable areas: Four British Columbia case studies

2006 ◽  
Vol 82 (3) ◽  
pp. 383-394 ◽  
Author(s):  
David J Huggard ◽  
Glen B Dunsworth ◽  
Jim R Herbers ◽  
Walt Klenner ◽  
Laurie L Kremsater ◽  
...  
Keyword(s):  
British Columbia ◽  
Case Studies ◽  
Landscape Planning ◽  
Biodiversity Monitoring ◽  
Managed Forests ◽  
South Central ◽  
Coarse Filter ◽  
Clayoquot Sound ◽  
Okanagan Highlands ◽  
Regional Analyses

We evaluated representation of ecosystem types in non-harvestable areas within managed forests, as a coarse-filter indicator for biodiversity monitoring, with four case studies in British Columbia: Weyerhaeuser's coastal tenure, Clayoquot Sound on western Vancouver Island, Arrow Lakes in southwestern B.C. and Okanagan highlands of south-central B.C. Representation of some coarser- and finer-level ecosystem units was poor in the two studies with lower amounts of non-harvestable area, and more equitable in the two studies with more diverse harvesting constraints. Under-representation of highly productive sites and high proportions of edge area were concerns for most ecosystems. Representation would be improved with the addition of proposed new reserves in two of three study areas. We discuss specific management implications and broader recommendations for monitoring representation, including the need for regional analyses, tests with habitat structures and organisms, effects of other disturbances and updating monitoring results. Key words: biodiversity monitoring, ecological indicators, ecosystem representation, landscape planning, unmanaged areas

scholarly journals Conservation Evaluation of Lemmon's Holly Fern, Polystichum lemmonii, a Threatened Fern in Canada

2004 ◽  
Vol 118 (2) ◽  
pp. 164
Author(s):  
George W. Douglas
Keyword(s):  
British Columbia ◽  
Road Construction ◽  
Montane Forest ◽  
Mountain Area ◽  
Forest Road ◽  
South Central ◽  
Northern Idaho ◽  
Mining Exploration ◽  
Conservation Evaluation ◽  
Forest Road Construction

In Canada, Lemmon's Holly Fern, Polystichum lemmonii, is restricted to the Baldy Mountain area on the eastern side of the Okanagan River valley in south-central British Columbia. This population represents the northern limits of the species which ranges south through northern Idaho, Washington and Oregon to northern California. In British Columbia, P. lemmonii is associated with ultramafic rocky ridges within a montane forest at an elevation of 1900 m. The population in the Baldy Mountain area is relatively small, unprotected and potentially imperilled by mining exploration, forest road construction or wildfires.

scholarly journals Conservation Evaluation of the Pacific Population of Dwarf Woollyheads, Psilocarphus brevissimus var. brevissimus, in Canada

2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton
Keyword(s):  
British Columbia ◽  
Coalbed Methane ◽  
Groundwater Levels ◽  
Gas Drilling ◽  
Pacific Population ◽  
South Central ◽  
The Pacific ◽  
Recreational Vehicles ◽  
Forest Openings ◽  
Conservation Evaluation

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.

Trap response of cutworm moths (Abagrotis orbis) to a sex-attractant lure in grape vineyards

2010 ◽  
Vol 142 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Peter J. Landolt ◽  
D. Thomas Lowery ◽  
Lawrence C. Wright ◽  
Constance Smithhisler ◽  
Christelle Gúedot ◽  
...  
Keyword(s):  
British Columbia ◽  
Vitis Vinifera ◽  
Field Experiments ◽  
Sex Attractant ◽  
Early Spring ◽  
South Central ◽  
Tetradecenyl Acetate ◽  
Feltia Jaculifera ◽  
Multiple Field ◽  
Lepidoptera Noctuidae

AbstractLarvae of Abagrotis orbis (Grote) (Lepidoptera: Noctuidae) are climbing cutworms and can damage grapevines, Vitis vinifera L. (Vitaceae), in early spring by consuming expanding buds. A sex attractant would be useful for monitoring this insect in commercial vineyards. (Z)-7-Tetradecenyl acetate and (Z)-11-hexadecenyl acetate were found in extracts of female abdominal tips. In multiple field experiments, male A. orbis were captured in traps baited with a combination of these two chemicals but not in traps baited with either chemical alone. Males were trapped from mid-September to early October in south-central Washington and south-central British Columbia. Other noctuid moths (Mamestra configurata Walker, Xestia c-nigrum (L.), and Feltia jaculifera (Guenée)) were also captured in traps baited with the A. orbis pheromone and may complicate the use of this lure to monitor A. orbis. Abagrotis discoidalis (Grote) was captured in traps baited with (Z)-7-tetradecenyl acetate but not in traps baited with the two chemicals together.

scholarly journals Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Teresa A. Newsome ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Geographic Range ◽  
Regression Analyses ◽  
Relative Height ◽  
Trembling Aspen ◽  
Ecosystem Productivity ◽  
Height Ratio ◽  
Critical Height ◽  
South Central

Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximizedR2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. MaximumR2values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

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