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This research focuses on contemporary and historical relationships between landscape change and human impacts in southwest Yukon, Canada, in order to bring to light the nature of cumulative social effects, and culturally appropriate methodologies that may be used for their evaluation. Results were acquired through twenty eight semi-structured interviews with natural resource managers, health and social workers, First Nations, and non-First Nations residents, in which resource development, and other important local markers of change were topics of discussion. Social thresholds are also developed from these results for their use in supporting resource management decisions. Resilience theory plays a center role in...
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Pilfering is thought to play a role in the evolution of scatter-hoarding strategies; but is not well understood in larder-hoarding animals. I studied intraspecific pilfering in red squirrels in Kluane, YT, Canada. The purpose of this project was to estimate the natural rate of cache pilferage, and to examine variation in pilfering behaviour. Results from experimental removal of territory owners, suggested that younger squirrels with smaller food caches were more likely to pilfer when given the opportunity. Survival over-winter was dependent on the number of cones cached and pilfering squirrels were less likely to survive. Using a mark-recapture study of marked cones I found that few individuals (14%) did any pilfering...
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This paper examines changes in climate with respect to permafrost and engineering design in Arctic regions. Current understanding of climate changes, predictive modeling, and climate data were studied. Inconsistencies and differences were noted, discussed, and evaluated using comparisons of the resulting climate data and graphs. A graphical analysis was done to compare different methods of data analysis and different visual interpretations of historical climate trends. The graphical analyses in this paper should be used as a guide for determining the accuracy of thermal design parameters applied to current project designs. The methodology used to evaluate raw data can greatly affect the output values used in design....
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Neotyphodium are fungal endosymbionts of grasses that reproduce asexually by infecting the host's seed. This relationship has traditionally been considered mutualistic, with the fungus improving host fitness by alleviating important stresses. To determine the importance of biotic and abiotic stresses in mediating the endophyte-grass interaction, I investigated the relationship between grazing pressure by collared pikas and Neotyphodium sp. infection frequency in the grass Festuca altaica in an alpine meadow. I conducted a factorial design experiment combining endophyte infection, grazing history, fungicide and fertilizer. Leaf demography and herbivory damage were monitored every two weeks. In areas with chronic...
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This dissertation is an exploration of forests as understood and encountered from numerous perspectives in the Yukon Territory. Dealing primarily with non-indigenous Yukon residents who hunt, trap, work, recreate within, and aim to protect Yukon forests, it addresses the origins and implications of diverse forest perspectives in Canada's north. This work is based primarily off of anthropological fieldwork that took place in the Yukon Territory in 2009. Methods included archival research, interviews and participant observation. As a means of exploring the origin of forest perspectives, the author focuses on four key areas: Yukon forest history and contemporary forest views that invoke forest history, different experiences...
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The transition from forest to tundra, commonly called treeline, is expected to advance, particularly in northern latitudes. Treeline in two subarctic locales: the western Mackenzie Mountains, Northwest Territories, and the western Hudson Bay Lowlands southeast of Churchill, Manitoba were studied, with the objectives of determining: (i) the historical and current characteristics of the trees at altitudinal and latitudinal treelines, and; (ii) what factors contributed most to the configuration of treeline at its altitudinal and latitudinal limits. Five investigations were undertaken, each employing different methods in order to assess several variables, theorized to be key drivers of pattern and process at treeline....
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Plant interactions can range from competition to facilitation. While competition is the most common outcome in most systems, facilitation may be important but hidden by competitive interactions. This study determined the mechanisms and overall effects of plant interactions on plant aboveground biomass, within-season growth, and abundance for two species, Artemisia norvegica and Carex consimilis, in a subarctic-alpine meadow in the Yukon. Additionally, the effects of local-scale abiotic and biotic factors on interaction outcomes were investigated. While the overall outcome of plant interactions in this system was weakly competitive, simultaneously both competition and facilitation were present. The balance between...
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To quantify its wind energy potential the wind climate of the mountainous Yukon has been examined through data analysis and numerical modelling. Using many surface climate stations and radiosondes it was determined that the region's atmosphere is generally stably stratified, causing air to flow horizontally around mountain obstacles. The mesoscale model MC2, a non-hydrostatic and compressible model, has been used to simulate the mean wind climate of the steep mountainous Yukon with the intent to produce a reliable wind energy map. Early results of full scale simulations initialized with the standard NCEP/NCAR Reanalysis provided erroneous results for wind speeds and directions when compared to measurements. A detailed...
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Stratigraphic observations from sites in eastern Beringia - Ch'ijee's Bluff and nearby exposures in northern Yukon, the Palisades on the Yukon River in Alaska, and placer mining exposures at Thistle Creek in west-central Yukon - provide insight into the chronostratigraphic significance of Old Crow tephra (124 ± 10 ka) and permafrost response to warming during the last interglaciation. Pollen and insect, bryophyte, and vascular plant macrofossils from a vegetated surface buried by Old Crow tephra suggest the local presence of mesic tundra, wet meadow, and aquatic habitat when the tephra was deposited. A revised glass fission-track age for Old Crow tephra places its deposition closer to the time of the last interglaciation...
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The Yellowstone to Yukon Conservation Initiative (Y2Y) is developing a reserve design to maintain avian biodiversity throughout the Rocky and Mackenzie Mountains. My study identified core areas of high quality bird breeding habitat in the region that represented broad habitat types important to mountain bird communities. I prioritized habitat using existing bird survey data to develop statistical models for a group of focal birds. The models predicted the probability of each bird's occurrence throughout Y2Y based on biophysical factors and anthropogenic stressors. I used the probability of species' occurrence as an index of relative habitat quality, and combined all model predictions to identify conservation priority...
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The boundary between forest and tundra in mountainous areas, alpine treeline, is expected to advance as climate warming continues and change is likely to be pronounced in northern latitudes. I studied the white spruce ( Picea glauca (Moench) Voss) treeline in the Kluane region of southwest Yukon, Canada, with the objectives of: (i) characterizing its responses to past climate change, and (ii) assessing the influence of different environmental variables on spruce growth and treeline dynamics. Four investigations were conducted, each employing fundamentally different methodologies and occupying distinct levels within a hierarchical, scale-based, analytical framework. At the landscape scale, I mapped spruce distribution...
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I conducted the first demographic analysis of collared pikas in the southwest Yukon. Individual growth rates were best described using a Gompertz model, and these rates were higher than those reported from southern latitudes. Parturition dates were asynchronous and weakly related to snow accumulation. Over-winter survival was low (34% adults; 25% juveniles), and juvenile survival was not related to dispersal, patch density, or parturition date. Survival was not sex-biased but varied depending on year of birth, aspect and other habitat variables, the latter showing considerable variation among years. A minimum of 34% of juveniles made inter-patch movements (mean of 332m); and both sexes dispersed with equal frequency....
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Recently documented ice patch sites in the southwest Yukon are ideal for evaluating precontact hunter-gatherer land-use patterns in the western subarctic. Located in the alpine of the mountainous regions of the boreal forest, ice patches are associated with well preserved hunting equipment, caribou ( Rangifer tarandus ) dung and an abundance of faunal remains dating to over 8000 years ago. However, current models are inadequate for explaining caribou hunting at ice patches as they tend to emphasize large-scale communal hunts associated with latitudinal movements of caribou. Much less is known about the alititudinal movment of caribou and the associated hunting forays to ice patches in the alpine. Based on literature...
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In the last century the frequency and severity of outbreaks of tree-killing Dendroctonus beetles (Coleoptera: Curculionidae) have increased. Small-scale drivers within trees likely drive outbreak dynamics across landscapes. At a small scale, variation in carbohydrate availability within the stems of lodgepole pines (Pinus contorta var. latifolia ) impacts the fungal symbionts of the mountain pine beetle (D. ponderosae Hopkins). I found that, during the growing season, carbohydrates were less available in the lower stems of pines than in their upper stems. After inoculation with a fungal symbiont of the mountain pine beetle however, trees mobilized carbohydrates to lesion fronts regardless of inoculation height along...
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The boreal region in Canada contains a quarter of the world's remaining frontier forest, of which the majority is unprotected and publicly owned. This offers Canada an unprecedented conservation opportunity. The establishment of new reserves, designed to function as ecological benchmarks, could contribute to conservation of the boreal forest, and support more sustainable economic development by enabling adaptive resource management. I developed quantitative methods for identifying ecological benchmarks in the Canadian boreal forest that met ecologically-based size and connectivity requirements, as well as minimum intactness criteria. This involved (1) approximating the size required for ecological benchmarks to...
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Several new species of the ischnacanthiform acanthodian Ischnacanthus are described from a Lower Devonian (Lochkovian) fossil locality in the Mackenzie Mountains, Northwest Territories, Canada. These new species are distinguished based on features of the jaws, teeth, and tooth bearing bones. Ischnacanthus gracilis , a similar species from the Old Red Sandstone of Scotland, is not found at the Canadian fossil site. The presence of a range of sizes of specimens of Ischnacanthus suggests a growth series (juvenile to adult). The genus is found to develop in a largely isometric manner, with a few body proportions exhibiting slight allometry. Inability to diagnose species based on body fossils of Ischnacanthus implies...
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Habitat quality is largely heterogeneous over space and time, although common simplifying assumptions in ecological research include homogeneity of areas occupied by a population and equal resource availability among individuals. These assumptions are made due to difficulties in quantifying the food available to individuals and following the effects of food on individual performance under natural conditions. My objectives were to document temporal and spatial variability in food availability, and its effects on seed predator individual performance and population dynamics in a white spruce-red squirrel system near Kluane Lake, Yukon. This system was ideal for my study because white spruce is the only conifer present,...
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This research increases the understanding of how Southeast Yukon residents want to see their community develop. The analysis provides information on attribute trade-offs and implicit rates of time preference. The research utilized focus groups and expert consultation to design a choice experiment survey The participants were asked to vote between two development scenarios that were described by four attributes that vary over 100 years: the regional population, the percentage of local residents who have jobs, the number of moose (an indicator of wildlife populations), and the fish catch rates (an indicator of aquatic ecosystem health). A conditional logit model provides estimates of preferences and their variability...
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The Eagle River meltwater channel and braid delta record overflow from the Bonnet Plume Basin caused by the achievement of the maximum position of the northwest Laurentide Ice Sheet in the late Pleistocene. This thesis examines landforms and deposits associated with spillway drainage along the Eagle River and subsequent fine-grained deposition in the Bell Basin. A process-depositional model for flood channel evolution was applied successfully to predict and characterize erosional and depositional features related to sudden, short-lived, high-energy flooding along the Eagle River. Braid delta sedimentation within the meltwater channel is crudely-coarsening upward and contains no evidence for a significant hiatus...
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Dramatic climate changes and expansion of new biomes characterize the late Pleistocene - early Holocene of eastern Beringia. Analysis of plant macrofossils and pollen from three different sites in the Yukon Flats, central Alaska, record the past vegetation during the late Pleistocene - early Holocene (ca. 11,500-6,900 14 C yrs BP) transition. The first paper deals with plant macrofossils associated with one of the earliest post glacial beaver dams (ca. 9,300 14 C yrs BP) found in central Alaska. Vegetation reconstruction suggests a warmer than modern climate during the early Holocene. The second paper examines eight paleosols and their associated plant macrofossils and pollen within eolian deposits at two sites...
map background search result map search result map A process to identify high quality avian habitat for the Yellowstone to Yukon reserve design Modelling inter-temporal development preferences: A case study in the Southeast Yukon Quantitative methods for identifying ecological benchmarks in Canada's boreal forest Stratigraphy, sedimentology and chronology of the Eagle River meltwater channel and braid delta, northern Yukon Stratigraphy, chronology and paleoenvironmental significance of perennially frozen interglacial sediments in eastern Beringia Caribou Hunting at Ice Patches: Seasonal Mobility and Long-term Land-Use in the Southwest Yukon Taxonomy and ontogeny of Ischnacanthus (Pisces: Acanthodii: Ischnacanthiformes) from the Lower Devonian (Lochkovian), Northwest Territories, Canada Fungal endophyte infection in an alpine meadow: Testing the mutualism theory Perceptions of change in southwest Yukon land and socialscapes: Implications for the study of cumulative effects and social thresholds Intraspecific cache pilferage by larder-hoarding red squirrels (Tamiasciurus hudsonicus) in Kluane, Yukon Spatial and temporal variability in white spruce (Picea glauca) cone production: individual and population responses of North American red squirrels (Tamiasciurus hudsonicus) Late Pleistocene - early Holocene plant macrofossils and pollen from the Yukon Flats, central Alaska Wind climate in Yukon mountainous terrain Alpine treeline and climate warming: A multiscale study of pattern and process in southwest Yukon Dendrochronology and treeline dynamics within arctic and alpine localities in western and central Canada Shades of Green: The social nature of Yukon forests Competition and facilitation in a subarctic-alpine plant community Demography and metapopulation dynamics of collared pikas ( Ochotona collaris) in the southwest Yukon Physiological, ecological and environmental factors that predispose trees, stands and landscapes to infestation by tree-killing Dendroctonus beetles Intraspecific cache pilferage by larder-hoarding red squirrels (Tamiasciurus hudsonicus) in Kluane, Yukon Fungal endophyte infection in an alpine meadow: Testing the mutualism theory Spatial and temporal variability in white spruce (Picea glauca) cone production: individual and population responses of North American red squirrels (Tamiasciurus hudsonicus) Alpine treeline and climate warming: A multiscale study of pattern and process in southwest Yukon Competition and facilitation in a subarctic-alpine plant community Demography and metapopulation dynamics of collared pikas ( Ochotona collaris) in the southwest Yukon Perceptions of change in southwest Yukon land and socialscapes: Implications for the study of cumulative effects and social thresholds Dendrochronology and treeline dynamics within arctic and alpine localities in western and central Canada Stratigraphy, sedimentology and chronology of the Eagle River meltwater channel and braid delta, northern Yukon Caribou Hunting at Ice Patches: Seasonal Mobility and Long-term Land-Use in the Southwest Yukon Late Pleistocene - early Holocene plant macrofossils and pollen from the Yukon Flats, central Alaska Modelling inter-temporal development preferences: A case study in the Southeast Yukon Shades of Green: The social nature of Yukon forests Quantitative methods for identifying ecological benchmarks in Canada's boreal forest Wind climate in Yukon mountainous terrain Taxonomy and ontogeny of Ischnacanthus (Pisces: Acanthodii: Ischnacanthiformes) from the Lower Devonian (Lochkovian), Northwest Territories, Canada A process to identify high quality avian habitat for the Yellowstone to Yukon reserve design Physiological, ecological and environmental factors that predispose trees, stands and landscapes to infestation by tree-killing Dendroctonus beetles Stratigraphy, chronology and paleoenvironmental significance of perennially frozen interglacial sediments in eastern Beringia