Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Arctic tundra"”.
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Higher fungi in soils of coastal Arctic tundra plant communities
… was determined in North American coastal Arctic tundra soils near Barrow, Alaska. Soils were examined at one centimeter intervals from the surface to the depth of thaw, 0-24 cm, over a three year period during the International Biological Programme Tundra Biome study. Examined were 1217 …
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In situ carbon dioxide flux from Arctic tundra during freeze- up
… soil cores was examined during freeze-up of arctic tundra. Three habitats which dominate tundra topography, polygon trough, ridge and basin, produced significantly different amounts of CO₂ when soil temperatures were above 0 C. A significant positive correlation between soil temperatures …
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Runoff from hummock-covered Arctic tundra hillslopes in the continuous permafrost zone
… within a 95 ha catchment (Siksik Creek) in the tundra region of the Canadian western Arctic were studied for three years (1992-1994). Measurements over the study included all hydrological inputs, monitoring of active layer and water table depths, chemical tracer-based measurements of subsurface …
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The role of acid phosphatases in the phosphorus nutrition of arctic tundra plants
… associated with two major rooting strategies in arctic tundra plants was examined: that of Eriophorum vagina tum, a dominant plant in tussock tundra ecosystems, with its predominantly non-mycorrhizal root system; and that of ectomycorrhizal roots. Eriophorum has phosphatase activity which is …
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Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra
Arctic tundra vegetation communities are rapidly responding to climate warming with increases in aboveground biomass, particularly in deciduous shrubs. This increased shrub density has the potential to dramatically alter the functioning of tundra ecosystems through its effects on permafrost …
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Spatiotemporal dynamics of carbon cycling and thermokarst in response to climate and fire-regime changes in the Arctic tundra biome
… threat to key properties and functions of tundra ecosystems, including soil carbon stock, permafrost stability and vegetation types. However, it remains poorly understood how tundra ecosystems will feedback to the combined forces of changing climate and fire disturbance. In this study, I …
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Ground-based hyperspectral and spectro-directional reflectance characterization of Arctic tundra vegetation communities : field spectroscopy and field spectro-goniometry of Siberian and Alaskan tundra in preparation of the EnMAP satellite mission
The Arctic tundra, covering approx. 5.5 % of the Earth’s land surface, is one of the last ecosystems remaining closest to its untouched condition. Remote sensing is able to provide information at regular time intervals and large spatial scales on the structure and function of Arctic ecosystems. But …
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Monitoring Regional Vegetation Changes in Seward Peninsula, Alaska, Using Remote Sensing Technique
Arctic vegetation has been undergoing various transitions depending on its regional characteristics and numerous contributors to these changes include direct human impact and natural changes in the earth’s climate system. The commonest causes of the vegetation change over a large arctic area are …
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Modelling the Thermal Dynamics of Polygonal Soil Structures in the Permafrost of the Lena Delta, Northern Siberia
… a common feature of permafrost landscapes in the Arctic. In this thesis, an existing permafrost model including conductive heat transfer and the phase change of water is extended to simulate the thermal dynamics of polygonal soil structures in an Arctic tundra wetland in Northern Siberia. A …
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Determinants of gemmae output in the liverwort Lophozia ventricosa
… affecting gemmae output of a boreal and arctic liverwort species, Lophozia ventricosa, were studied in Trnndelag, a boreal region of central Norway and in the arctic tundra on Svalbard. The population parameters investigated included colony size, colony shoot density, number of gemmae per …
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Investigation into the mechanisms of size-resolved particle dry deposition across three environments
… particle and black carbon deposition from a low Arctic tundra during snow-cover that are elevated compared to predictions of dry deposition in that region. Incorporating interception into the model parameterizations improved model measurement agreement and provides evidence to suggest that …
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ECOHYDROLOGICAL MODELING OF BEAVER DAMS
… their range into urban environments and the Arctic tundra. Outside their natural range, they are also in Southern Patagonia because of historic releases in the fur industry. Given the broad geographical span of this expansion, it is critical to understand and predict the hydrology of …
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Satellite Microwave Remote Sensing of Boreal-Arctic Land Surface State and Meteorology from AMSR-E
… the Aqua satellite for eight Boreal forest and Arctic tundra biophysical monitoring sites across Alaska and northern Canada. Daily vapor pressure deficit is determined by employing AMSR-E daily maximum/minimum air temperature retrievals. The seasonal pattern of microwave emission and relative …
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Satellite Microwave Remote Sensing of Boreal-Arctic Land Surface State and Meteorology from AMSR-E
… the Aqua satellite for eight Boreal forest and Arctic tundra biophysical monitoring sites across Alaska and northern Canada. Daily vapor pressure deficit is determined by employing AMSR-E daily maximum/minimum air temperature retrievals. The seasonal pattern of microwave emission and relative …
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Remote sensing characterisation of the forest-tundra ecotone
The transition zone between the boreal forest and Arctic tundra, the Forest-tundra ecotone (FTE), is an area of high ecological and climatological significance. Satellite remote sensing has the potential to enable accurate circumarctic mapping and characterisation of both latitudinal and …
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Environmental Controls on Foliar Respiration in Arctic Plants
The Arctic is warming at rapid, unprecedented rates, causing cascading ecological and environmental changes that threaten to destabilize the vast amounts of carbon stored in the vegetation and soils of the tundra. Foliar gas exchange, which is responsible for the initial fixation of carbon, is …
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Terrestrial Si dynamics in the Arctic: a study on biotic and abiotic controls
… and perenially frozen soil conditions, Arctic terrestrial ecosystems is hypothesized to store a significant fraction of the global soil ASi stock. The Arctic environment is highly sensitive to climate change, with unknown effects for terrestrial Si cycling. Hence, in this thesis we …
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Arctic shrub growth responses to environmental drivers and implications for tundra community decomposition
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-05-01
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