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  • 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.
1

Rethinking Urban Connectivity - a Case of Skellefteå, Sweden

Kai, Boyang January 2021 (has links)
This project aims to explore alternative ways of promoting urban connectivity in Skellefteå, a northern Swedish city in the sub-arctic region. Skellefteå was initially known for its mining history, rich natural resources including wood, wind, and hydropower. An economic transition began in the 1990s when digital and electronic industries started to grow. In 2019, Northvolt decided to build its battery plant in Skellefteå, which is going to impact the city dramatically.Skellefteå is on its way to become an innovative and technology-oriented economy, but there are underlying challenges due to its location, climate, and population. This project argues that one prominent factor is the lack of connectivity both within the city itself and to the outside world, and that the traditional ways of promoting physical connectivity may not be viable in the sub-arctic context. As a resolution three non-physical layers are proposed as alternative means to strengthen social, economic, and ecological connectivity:FOOD: a number of food hubs and connecting networks provide spaces for co-presence and participative food production, activating public life.KNOWLEDGE: existing schools and offices are opened up and reprogramed for the public, encourage the exchange of information and opinions.WASTE & ENERGY: ecological assets will be tightly integrated through the circulation of waste and energy.
2

Indian Trappers and the Hudson's Bay Company: Early Means of Negotiation in the Canadian Fur Trade

Honeyman, Derek January 2003 (has links)
The fur trade and arrival of the Hudson's Bay Company had numerous effects on northern North American indigenous populations. One such group is the Gwich'in Indians in the northwestern portion of the Northwest Territories. Aside from disease and continued reliance on goods imported from the south, the fur trade disrupted previous economic relationships between indigenous groups. In some examples, the presence of the Hudson's Bay Company furthered tension between indigenous groups as each vied for the control of fur-rich regions and sole access to specific Company posts. However, due to the frontier nature of the Canadian north, the relations between fur trade companies and indigenous peoples was one of mutual accommodation. This was in stark contrast to other European-Indian relations. This paper examines how credit relations between the Hudson's Bay Company and the Gwich'in reveals a model of resistance.
3

Organohalogen contaminants in Greenland shark (Somniosus microcephalus)

Strid, Anna January 2010 (has links)
The remote sub-Arctic/Arctic environment has due to human activities become a sink for organohalogen contaminants (OHCs). These OHC include traditional contaminants such as polychlorinated biphenyls (PCBs), DDTs and technical mixtures of polybrominated diphenyl ethers (PBDEs), all included in the Stockholm Convention list of persistent organic pollutants (POPs). Other OHCs, currently under evaluation to be included among the POPs i.e. short chain chlorinated paraffins (SCCPs) and hexabromocyclododecane (HBCDD) are also found in these environments as well as a whole range of other OHCs. The main objective of this thesis is to increase the knowledge about the presence of OHCs in a high trophic Arctic shark species, the Greenland shark (Somniosus microcephalus). The Greenland shark is an opportunistic feeder, occasionally feeding at the top of the Arctic marine food chain. Furthermore may this species have a life span in excess of 100 years and is probably among the oldest of any fish species. These traits make the shark prone to accumulate elevated concentrations of OHCs. This has shown to be true for the Greenland sharks studied and most of the targeted OHCs were determined in the species. The highest concentrations were observed for the DDTs, ranging up to 26 μg/g fat. Other OHCs reported that are of special interest are SCCPs and brominated flame retardants used as replacement products to PBDEs; pentabromoethylbenzene (PBEB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Also a range of OHCs whose origin is assumed to be natural, were shown to be present in Greenland sharks. This thesis is stressing the fact that even though the use of certain OHCs has been banned for decades they are still present at high concentrations in the deep waters of the Arctic. Therefore it is of major importance to continue to monitor the fate of traditional and emerging OHCs in the environment, and for this purpose the Greenland shark is an excellent species. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
4

Waterborne Carbon in Northern Streams : Controls on dissolved carbon transport across sub-arctic Scandinavia

Jantze, Elin January 2015 (has links)
Waterborne carbon (C) forms an active and significant part of the global C cycle, which is important in theArctic where greater temperature increases and variability are anticipated relative to the rest of the globe withpotential implications for the C cycle. Understanding and quantification of the current processes governing themovement of C by connecting terrestrial and marine systems is necessary to better estimate future changes ofwaterborne C. This thesis investigates how the sub-arctic landscape influences the waterborne carbon exportby combining data-driven and modeling methods across spatial and temporal scales. First, a study of the stateof total organic carbon monitoring in northern Scandinavia was carried out using national-scale monitoringdata and detailed data from scientific literature. This study, which highlights the consistency in land cover andhydroclimatic controls on waterborne C across northern Scandinavia, was combined with three more detailedstudies leveraging field measurements and modeling. These focused on the Abisko region to provide insightto processes and mechanisms across scales. The thesis highlights that the governing transport mechanismsof dissolved organic and inorganic carbon (DOC and DIC respectively) are fundamentally different due todifferences in release rates associated with the nature of their terrestrial sources (geogenic and organic matterrespectively). As such, the DIC mass flux exhibits a high flow-dependence whereas DOC is relatively flowindependent.Furthermore, these investigations identified significant relationships between waterborne C andbiogeophysical as well as hydroclimatic variables across large to small spatial scales. This thesis demonstratesthat both surface and sub-surface hydrological processes (such as flow pathway distributions) in combinationwith distributions of C sources and associated release rates are prerequisite for understanding waterborne Cdynamics in northern streams. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Submitted. Paper 4: Accepted.</p>
5

Environmental Controls on Snow Cover Thickness and Water Equivalent in Two Sub-Arctic Mountain Catchments / Miljöns påverkan på snötäckets tjocklek och vattenvärde i två subarktiska höglänta avrinningsområden

Cosgrove, Christopher January 2015 (has links)
The spatial variability of snow cover characteristics (depth, density, and snow water equivalent [SWE]) has paramount importance for the management of water resources in mountain environments. Passive microwave (PM) inference of SWE from space-borne instrumentation is increasingly used but the reliability of this technique remains limited in mountainous areas. Complex topography and the transition between forest and alpine tundra vegetation zones create large spatial heterogeneities in the snowpack in such environments. A better understanding of the factors that control these heterogeneities is therefore needed to improve and extend the use of PM-derived SWE estimation to mountain settings. In this study, two seasonally snow-covered sub-Arctic mountain catchments at comparable latitudes, one in Hemavan, northern Sweden and the other in Wolf Creek, Yukon, Canada, were investigated to evaluate the relative influence of climate vs. landscape factors on the variability of snow cover characteristics. Field measurements of snowpack stratigraphy and SWE were performed at the approximate time of late winter snow depth maximum using various in situ methodologies. Regression analysis was then employed to identify possible relationships between snow depth, density and SWE, and landscape properties (altitude, slope angle and aspect) at both sites, both within and between different vegetation zones. Snow depth, density and SWE were found to be greatest in the alpine tundra zone of both catchments, and were largest in Hemavan, probably on account of the relatively warmer and wetter winter climate of northern Sweden compared to that of the Yukon. Elevation was the only quantifiable landscape property found to show a positive and significant relationship with SWE in both catchments. Notable differences in the spatial variability of snowpack properties were also found between the two study sites. The local variability of snow depth was greatest in the forest-alpine transition zone at Hemavan, but greatest in the alpine zone at Wolf Creek. Differences in the vegetation cover type between the two catchments (coniferous vs. deciduous in the forest zone) is suspected to exert an important influence on spatial patterns of snow depth, density and SWE, likely because of differences in the efficiency of snow interception. Further investigations of how different vegetation characteristics (e.g. leaf area index) influence snowpack properties over the course of the winter are recommended in order to improve and extend the use of PM-based SWE retrievals in high-latitude mountain environments.
6

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. / May 2006
7

Fostering Adaptive Capacity and Resilience to Environmental Change in Sub-Arctic First Nations: The Use of Collaborative Geomatics, an Interactive, Web-based Informatics Tool

Barbeau, Christine January 2011 (has links)
The Western James Bay region of northern Ontario (the Mushkegowuk Territory) is home to some of Canada’s largest wetlands and most pristine ecosystems. This region is also home to approximately 10,000 Omushekgo Cree who inhabit four First Nation communities. Environmental change due to climate change and major resource development are a reality to the people of this sub-arctic region. Furthermore, it is predicted that climate change will have amplified impacts in northern climates. Climate change has and will continue to have impacts on the distribution of species in arctic and sub-arctic ecosystems. To date, it is not clear to what extent these distributional changes in species due to climate change will have on First Nations’ place-based relationship with the land and what measures the Cree will take to adapt to these changes. The University of Waterloo’s Computer Systems Group has developed an approach and toolkit for the development of web-based, spatial data and information management systems referred to as collaborative geomatics. This system allows for place-based information, environmental and traditional environmental knowledge (TEK) storage and sharing between First Nation communities. And allows for the development of adaptive strategies and plans for future land use activities in the face of further resource development. This collaborative geomatic system has been designed with First Nation input and has been demonstrated to Chiefs and Councils of the Mushkegowuk Territory. Collaborative geomatics is an interactive, web-based, informatics tool that has been designed to store data, in a secure and culturally-appropriate framework on high-resolution satellite imagery. High-resolution imagery will become the backdrop to placed-based and TEK data. Community members will have the ability to input locations (e.g., significant sites, such as, seasonal camps and hunting locations) on the map in addition to uploading tabular and media data. This allows for the generation of dynamic and robust spatially-relevant information and knowledge-base. Beginning in August of 2009, formal and informal meetings were held with personnel from the Lands and Resources unit of Mushkegowuk Council, First Nations Chiefs and Councils (the elected local government), and other community members of MooseCree First Nation, Fort Albany First Nation, Kashechewan First Nation, Attawapiskat First Nation, and Weenusk First Nation to gather their assessment (i.e., viability) of the Mushkegowuk collaborative geomatics tool. Together with this formative assessment process, 16 semi-directive interviews (from October 2010 to February 2011) were conducted with community members of Fort Albany First Nations. Interview participants were purposively sampled and included: Chief & Council members, First Nation office personnel, education personnel, health services personnel, elders (≥60 years of age), and young adults. Each interview was audio recorded and transcribed verbatim. Following an adapted grounded theory methodological approach, the transcripts of each interview were coded and categorized according to themes. Throughout the assessment process, the research team received constructive feedback on the system. Each participant noted the utility of the tool to be used in the education of younger generations. Furthermore, participants felt that they would be able to use the tool to store TEK and help monitor environmental change. The greatest strength of the system was seen to be the visualization of information in numerous media forms (pictures and videos), while the greatest perceived weakness of the system was the security of the information. However, once user accessibility (usernames and passwords) was explained the concern over security of information was greatly reduced. This collaborative geomatic system has the potential to enhance the Mushkegowuk First Nations’ adaptive capacity to address environmental change by allowing them to make informed decisions, utilizing the knowledge stored in the collaborative geomatics tool.
8

Influence of fish competitors on Lake Trout trophic ecology in sub-arctic lakes

Hulsman, Mark F. Unknown Date
No description available.
9

Soil organic carbon pools of the Torneträsk catchment area : The importance of soil depth and stone and boulder content for carbon inventories in formerly glaciated subarctic soils

Holmgren, Bror January 2013 (has links)
High latitude soils are estimated to store a considerable part of the global pool of soil organic carbon (SOC). Studies of global and regional SOC pools have estimated total inventories in northern Sweden’s subarctic region to fall within 10-50 kg m-2. However, correction factors for stone and boulder content of soils are often overlooked in SOC-studies and soil profiles are commonly normalized to a depth of 1 m, which can result in substantial overestimates of the SOC pool if a large part of the soil volume is occupied by stones/boulders or if the soil depth is shallower than 1 m. This study was performed to quantify SOC in soils of the Torneträsk catchment area using detailed measures of soil depth and stone/boulder contents. Two non-destructive sampling methods, ground penetrating radar (GPR) and rod penetration, were used to measure soil depth and stone and boulder content in the catchment area. Results show that average soil depth (n = 52344) varied between 0.95 – 2.14 m depending on elevation and the average mire depth was 0.63 m. Stone and boulder content of the soil was estimated to 49 – 68 % depending on elevation. The results were added to existing carbon and soil density data from the Torneträsk catchment area and total SOC inventories were calculated to 6.8 – 13.1 kg m-2. The results of this study indicate that previous studies on regional and global scale may have overestimated the SOC pools in the subarctic regions of northern Sweden.
10

Spatial distribution of soil nematodes in the sub-arctic environment of Churchill, Manitoba

Lumactud, Rhea Amor 07 April 2010 (has links)
The tundra ecosystem, with its frost-molded landscape and large peat reserves, is vulnerable to climate change. Thus, any increase in temperature due to global warming will cause changes in above-and belowground biota. Understanding the linkage between these biotas will help make prediction of the biodiversity and ecosystem functioning when global change phenomena occur, and consequently aid in making management strategies. The role of nematodes in nutrient cycling and decomposition, among many other attributes, make them useful organisms to study soil processes. Associations between plant and nematode communities, from six sites (Berm Face, Berm Crest, Tundra Heath, Polygon, Hummock and Forest) and from within a young, visually homogeneous tundra heath field site, were examined in the subarctic environment of Churchill, Manitoba. The study also provided nematofaunal information, which is very limited in this region. Multivariate analyses of nematode taxa abundance revealed four distinct groupings: Berm Face, Berm Crest, heaths (Tundra Heath, Polygon and Hummock) and Forest. The result showed a parallel relationship between nematode and vegetation assemblages, and thus, a seeming interdependency between above-ground and below-ground biota. Conversely, association between nematode and plant assemblages within a visually homogeneous tundra site was not as obvious. At this fine scale, the heterogeneous nature of edaphic factors and not plant assemblages is hypothesized to influence within-site nematode communities. The thesis also provided results to improve nematofaunal analysis to enhance their utility as bioindicators of soil food webs.

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