• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 158
  • 19
  • 19
  • 19
  • 19
  • 19
  • 18
  • 11
  • 6
  • 5
  • 1
  • Tagged with
  • 212
  • 65
  • 33
  • 19
  • 19
  • 18
  • 18
  • 16
  • 15
  • 15
  • 14
  • 14
  • 13
  • 13
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

ACES : connecting youth to the environment through outdoor education

Perrin, Alison 11 July 2011 (has links)
ACES is an integrated curriculum program that has been a part of the Yukon public education system since 1989. This study explores the impacts of this place-based outdoor education program on the participants‟ relationships with the environment. Interview and observation data were collected from 15 participants during a 13 day canoe trip on the Yukon River, which was the culmination of their semester long course. There were nine significant themes that emerged from the data that provide insight into the successes of the program and the impact it has on the students. The findings support the importance of outdoor education as a means for connecting young people with nature and as a catalyst for change and growth. They demonstrate the central role the teacher has in the success of the program and how the Yukon-centric focus promotes a connection with the local landscape resulting in concern for local environmental issues.
162

APPLICATIONS OF SHRUB DENDROCHRONOLOGY IN TRACKING DECADAL CHANGES IN POND MARGIN DYNAMICS

Lowcock, ASHLEY 28 September 2012 (has links)
Decadal changes in the surface area of small ponds in the Kluane region, Yukon were quantified from remote sensing and dendrochronological techniques. Both dead and live shrubs from the genus Salix were sampled and cross-dated from a total of 28 pond ecotones in two different study areas. The rate of ecotone shrub colonization was calculated for each pond by determining the minimum age of Salix spp. in ten zones extending from forest edge to shoreline. Changes in the surface area of 20 ponds in each study area, for a total of 40 ponds, since 1948 were measured using multi-temporal remote sensing analysis. Measured changes were then validated using colonization rates derived from the dendrochronological analysis. Results were compared with meteorological records to elucidate the connection between climate change and shoreline dynamics. Ponds experiencing similar rates of ecotone colonization exhibited similar changes in shoreline position over the last 60 years. Ponds measured with remote sensing showed an overall decline in surface area since 1948; however, direction and extent of change varied within and between the two study areas. Colonization rates also varied within and between study areas. This corresponded to differences in pond ecotone population structure as well as relative extent and direction of changes in surface area, and supported the changes observed in the low-resolution remote sensing time series data. Changes in ponds tended to correspond to increases in annual temperatures which, when combined with a longer growing season and stable precipitation, may have accelerated evaporation potential causing ponds to decrease. The negative consequences of surface area decline are exacerbated by the potential increases in evapotranspiration and the much less extensive wetland system in southwest Yukon relative to other regions in the North. The successful implementation of remote sensing and dendrochronological techniques has value for remote areas that are sensitive to climate change, yet lack direct measurement of changing environmental conditions. / Thesis (Master, Geography) -- Queen's University, 2012-09-28 13:03:05.43
163

Fort Selkirk: Early Contact Period Interaction Between the Northern Tutchone and the Hudson's Bay Company in Yukon

Castillo, Victoria E. Unknown Date
No description available.
164

Caribou hunting at ice patches: seasonal mobility and long-term land-use in the southwest Yukon

Bowyer, Vandy Unknown Date
No description available.
165

Shrub encroachment in arctic and alpine tundra: Patterns of expansion and ecosystem impacts.

Myers-Smith, Isla H. Unknown Date
No description available.
166

Place identity, guides, and sustainable tourism in Canada's Yukon Territory

de la Barre, Suzanne Unknown Date
No description available.
167

The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge

Ryan, Michael J. 29 March 2007 (has links)
Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigma-CHB), sigma-PCB and chlorinated benzenes (sigma-CBz) in sentinel fish (species of consistent annual observation and collection) from two Yukon lakes (Kusawa, Quiet), and from the aquatic food web of a focus lake (Lake Laberge) across several temporal points between 1993 and 2003. OC analysis and phytoplankton counts from dated sediment cores as well as climate data were also collected. Population, morphological (length, weight, age), biochemical (lipid content, delta-13C, delta-15N) and OC contaminant data for fish and invertebrates (zooplankton, snails, clams) were reviewed to elucidate the primary causes for these OC declines. Although some spatial differences in contaminant levels exist between the Yukon lakes, OC concentrations were declining for lake trout in all three lakes, with declines also noted for burbot from Lake Laberge. Several other fish species as well as zooplankton from Lake Laberge exhibited decreases in contaminant levels except northern pike, which registered consistently higher levels from 1993 to 2001. There was no evidence to support the hypotheses of changes in fish trophic levels or food sources with the exception of burbot, which marginally decreased, and northern pike, which climbed a half trophic level. Through OC flux analysis in dated sediments, the hypothesis that declines in abiotic deposition affected the contaminant levels in the food web was also negated. The closure of the Lake Laberge commercial fishery resulted in faster fish growth and larger fish populations, which are contributing to biomass dilution of OC concentrations, higher OC biomagnification factors for some species and likely changes in predator-prey interactions as resource competition increases. The large ratio of OC decreases in the lower vs. higher trophic levels of Lake Laberge have increased food web magnification factors (FWMF) for all six OC groups. It is also suspected that above-average temperatures and below-average precipitation in the lower Yukon region over the 1990s may have contributed towards an increase in lake primary production resulting in biomass dilution of contaminants in zooplankton for all three study lakes. Concurrently, shifts in the Lake Laberge zooplankton community, from climate fluctuations or increased fish predation, have gone from an abundance of Cyclops scutifer in 1993 to dominance by Diaptomus pribilofensis in 2001, although sample sites were limited. Characteristics specific to each species (e.g. body size, composition and metabolism) likely play a role in the significant OC declines measured in zooplankton. Fluctuations in population dynamics, species characteristics and OC contaminant concentrations in the Lake Laberge ecosystem may continue for several years to come. Sentinel species such as lake trout, burbot, whitefish, cisco and plankton should continue to be monitored in all three Yukon lakes for future temporal correlations with contaminants or climate change.
168

A Geochemical Characterization of a Cold-Water Acid Rock Drainage Stream Emanating From the Zn-Pb XY-deposit, Howard's Pass, Yukon Territory, Canada

Feige, Kristen B. 08 February 2011 (has links)
An acid rock drainage (ARD) stream emanating from the Zn-Pb XY-deposit in the Yukon Territory was examined in order to evaluate the physico-chemical and geochemical processes governing the distribution of dissolved elements from the creek. The creek showed very high concentrations of metals (300 mg/L Fe, 500 mg/L Zn, 15 000 µg/L Ni, 1300 µg/L Cu and 4500 µg/L Cd), low water temperatures (1 – 12°C) and was acidic to moderately acidic (pH 3.1 – 5.0). It was found that this stream experienced a strong seasonal evolution, with increased sulphate and metal concentrations and decreased pH over the course of the summer. The mineral precipitates that formed under low pH conditions were a mixture of schwertmannite, goethite, jarosite and barite, while those that formed under moderately acidic conditions were a mixture of jurbanite, hydrobasaluminite, gibbsite and an X-ray amorphous Al-sulphate phase. Most of the mineral precipitates were of inorganic origin, although microbes may have played a role in mineral formation and trace metal sequestration in some of the precipitates. All of the mineral precipitates contained anomalous concentrations of trace elements (up to 1.5 % wt Zn) and showed a seasonal evolution in their mineralogy, both of which were determined to be a function of the pH and prevailing geochemical conditions. The geochemistry of the ARD creek draining the XY-deposit was compared to another ARD creek in the area that was likely draining shales. The two creeks were compared in order to determine if ARD geochemical characteristics can be used as a tool for the mineral exploration industry.
169

Solitudes in Shared Spaces: Aboriginal and EuroCanadian Anglicans in the Yukon and the Northwest Territories in the Post-Residential School Era

Cheryl, Gaver 16 May 2011 (has links)
This thesis examines the current relationship between Aboriginal and EuroCanadian Anglicans in the Northwest Territories and the Yukon as they seek to move beyond past hurts into a more positive future. After three field trips to Canada's North, visiting seven communities and interviewing seventy-nine individuals, complemented by archival research, I realized the dominant narrative based on a colonialism process linking residential schools, Christian Churches and federal government in a concerted effort to deliberately destroy Aboriginal peoples, cultures, and nations was not adequate to explain what happened in the North or the relationship that exists today. Two other narratives finally emerged from my research. The dominant narrative on its own represents a simplistic, one-dimensional caricature of Northern history and relationships. The second narrative reveals a more complex and nuanced history of relationships in Canada's North with missionaries and residential school officials sometimes operating out of their ethnocentric and colonialistic worldview to assimilate Aboriginal peoples to the dominant society and sometimes acting to preserve Aboriginal ways, including Aboriginal languages and cultures, and sometimes protesting and challenging colonialist policies geared to destroying Aboriginal self-sufficiency and seizing Aboriginal lands. The third narrative is more subtle but also reflects the most devastating process. It builds on what has already been acknowledged by so many: loss of culture. Instead of seeing culture as only tangible components and traditional ways of living, however, the third narrative focuses on a more deep-seated understanding of culture as the process informing how one organizes and understands the world in which one lives. Even when physical and sexual abuse did not occur, and even when traditional skills were affirmed, the cultural collisions that occurred in Anglican residential schools in Canada's North shattered children's understanding of reality itself. While the Anglican Church is moving beyond colonialism in many ways - affirming Aboriginal values and empowering Aboriginal people within the Anglican community, it nevertheless has yet to deal with the cultural divide that continues to be found in their congregations and continues to affect their relationship in Northern communities where Aboriginal and EuroCanadian people worship together yet remain separate.
170

Permafrost Changes Along the Alaska Highway Corridor, Southern Yukon, from Ground Temperature Measurements and DC Electrical Resistivity Tomography

Maxime Arsène, Duguay 09 July 2013 (has links)
Permafrost temperatures were measured by the Geological Survey of Canada (GSC) in 1977-1981 at boreholes along a proposed pipeline route in the southern Yukon. Analysis of climate station records indicate that mean annual air temperatures in the region have since increased by 0.5-1.0˚C. Renewed interest in the pipeline and the need to develop adaptation strategies for existing highway infrastructure have meant that information on permafrost and geotechnical conditions must be updated. To accomplish this goal, a total of eight GSC boreholes ranging in depth from 5-9 m were located, unblocked of ice and instrumented with thermistor cables and data-loggers to permit renewed ground temperature monitoring. Manual temperature measurements were also taken at four other shallow boreholes. Electrical resistivity tomography (ERT) surveys were conducted at each site. MAGTs below 1 m at permafrost sites in the study area range from -0.2˚C to -1.5˚C with permafrost depths greater than 25 m. The permafrost at the study sites can be classified as sporadic discontinuous and extensive discontinuous. Ground temperatures indicate that permafrost can persist under warmer climatic conditions as long as it remains protected by its ecosystem properties. Thermal monitoring for 2011-2012 shows an average increase of 0.5-1.0˚C when compared to the original 1978-1981 ground temperatures. This slow rate of ground warming is mainly attributed to a combination of limited climate change, especially in the south of the study area, ground temperatures close to 0˚C, and the possible disturbance of sites from the removal of vegetation prior to the original measurements being made. ERT surveys conducted at most borehole sites show deeper thaw or taliks where the cleared cut-line used for geophysical work in the 1970s is crossed. These results indicate the impacts of climate change and environmental change in the study area over the past three decades. They appear to match the relatively slow rates of ground warming observed elsewhere in northern Canada where permafrost temperatures are close to 0˚C and where warming also requires changes in latent heat due to internal thaw. TTOP equilibrium modelling suggests that if climate change is responsible for the ground warming, most of the change can be attributed to the step-like MAAT increase that occurred between 1975-1976.

Page generated in 0.0323 seconds