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 25 for “"Treeline"”.
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Landscape-Scale Variability in the Composition, Growth and Pattern of Alpine Treeline Vegetation
… to climate warming, particularly across the treeline ecotone. However, responses to warming in the past century have been highly variable, especially in regions with complex topography. In order to improve predictions of future change, I used field surveys, dendrochronology, and remote …
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Treeline of mountain birch (Betula pubescens Ehrh.) in Iceland and its relationship to temperature
Die Waldfläche der Moorbirke (Betula pubescens Ehrh.) in Island wurde zwischen der Besiedlung des Landes durch die Wikinger ab 874 n. Chr. und heute dramatisch reduziert. Ursachen des Rückgangs waren v. a. grossflächige Nutzung des Waldes für die Produktion von Holzkohle, Verbiss durch frei …
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Geospatial Variation of an Invasive Forest Disease and the Effects on Treeline Dynamics in the Rocky Mountains
… tree island development in Rocky Mountain treelines. The manifestation of white pine blister rust in the cold and dry treelines of the Rockies, and the subsequent infection and mortality of whitebark pines raises questions as to how these extreme environments harbor the invasive disease, …
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Landscape pattern and blister rust infection in whitebark pine (Pinus albicaulis) at alpine treeline, Northern Rocky Mountains, U.S.A.
… is a foundation and keystone species at alpine treelines of the northern Rocky Mountains and is threatened by the fungus white pine blister rust (Cronartium ribicola). This disease affects all five-needled white pines, but has caused particularly widespread mortality in whitebark pine. …
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VEGETATIVE REPRODUCTION BY LAYERING VERSUS SEXUAL REPRODUCTION IN A SPRUCE-FIR FOREST AT ALPINE TREELINE, MEDICINE BOW MOUNTAINS, USA
… and tree islands found across the alpine treeline ecotone. Observational data on vertical stem origin, size, and cone production were collected for fifty krummholz mats and forty tree islands within the Libby Flats area. Vertical woody stems originated mainly from layering in both the …
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Variación geográfica de la distribución altitudinal de Kageneckia angustifolia (D.Don): Uso de Google Earth como herramienta de muestreo
The treeline corresponds to the altitude that marks the separation between two vegetational formations: Native forest and alpine vegetation, with the temperature the main factor that explains this transition zone. Because de latitudinal variation of temperature, the altitude that define the …
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Fine-Scale Mechanisms Influencing Germination Success, Seedling Growth and Survival in an Alpine Forest-Tundra Ecotone
Despite the expectation that treeline will advance as climate continues to warm, it has only done so in approximately half of all sites studied. One of the explanations for the nonresponse of treelines is based on reproductive limitations including seed production, germination, establishment and …
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Neoglacial climate in the Southern Coast Mountains, British Columbia
… allowed partial quantification of shifts in treeline. Treeline at the site was at least 85 m above the present level from 4800-3800 BP, suggesting that summer temperatures were at least 0.6°C above the present. High treeline until 3800 BP indicates a relatively late date for the …
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Modeling Blister Rust Incidence in Whitebark Pine at Northern Rocky Mountain Alpine Treelines: A Geospatial Approach
… species and a pioneer establisher at alpine treeline, is threatened by the invasive and exotic fungal pathogen (Cronartium ribicola) that causes white pine blister rust in five-needled pines. Originally thought to be limited to moderate environments, the disease is now found extensively …
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Population Structure and Biophysical Density Correlates of Whitebark Pine (Pinus albicaulis) at Two Treelines in the Northern Rocky Mountains
… a keystone species and an important component of treeline ecosystem dynamics; however, subalpine populations have declined nearly rangewide in recent decades. Though declines in subalpine forests have been well documented in the literature, few studies have assessed population structure and …
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SPATIAL VARIABILITY IN SPECIES COMPOSITION IN NEOTROPICAL MONTANE TREE COMMUNITIES
… and 121 in the landscape sample near Andean treeline. At mid elevation plots (1600 — 2900 m) Cyatheaceae and Melastomataceae were the most abundant families. The plots near treeline (above 3200 m) were similar in their composition at family and genus level but distinct at the species …
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Spruce bark beetle disturbance in the forest-tundra ecotones of southwest Yukon: impacts and predisposing factors
… stressed by abiotic factors, arctic and alpine treeline environments will therefore become increasingly vulnerable to insect disturbances. Using vegetation surveys and dendrochronological techniques, we examined factors that may have predisposed the forest-tundra ecotones of southwest Yukon to …
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Remote Sensing Methods for Environmental Monitoring of Human Impact on sub-Arctic Ecosystems in Europe
… and of the forest/tundra interface (the treeline), is the most representative indicator of environmental changes in the sub-Arctic. For some time now, monitoring land cover and vegetation changes using remote sensing techniques have been a powerful method for studying human impact on …
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Rethinking Update-in-Place Key-Value Stores for Modern Storage
… prototype update-in-place key-value store called TreeLine. On YCSB, we find that TreeLine outperforms RocksDB and LeanStore by 2.18× and 2.05× respectively on average across the point workloads, and by up to 10.87× and 7.78× overall.
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Role of the thermodynamic regime in ecosystem self-organization and its response to human perturbations
… -- in particular, the region beyond the treeline in alpine and Arctic ecosystems. We therefore ask the question: Since the existence of multiple vegetation groups provides a thermodynamic advantage, is the existence of only a single functional group a result of a thermodynamic limitation? …
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Patterns and Disturbance-Induced Drivers of Plant Diversity and Endemism on High Elevation Islands
… from coastal to alpine systems. The alpine treeline, as the borderline between forest and treeless alpine systems, is therefore fundamental in describing HEIs. Interestingly, I demonstrate that globally treeline elevation on HEIs, which is generally lower on HEIs than on the mainland, is …
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Conserving temperate montane birds under climate change: an assessment of potential management options
… birds that are restricted to habitats above the treeline – conservation practitioners will be more limited in their choice of management approach. Assisted colonisation (AC) has been proposed as a strategy for mountaintop species with nowhere left to go. However, this strategy is reliant on the …
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An investigation of two periglacial landforms on ignimbrite blockslopes in Kluane National Park and Reserve, Yukon Territory
… on low- to mid-slopes of Campsite Peak above the treeline, mantling a blocky open matrix of ignimbrite cobble-to-boulder material. BSTs differ from expected solifluction characteristics by showing apparent periodicity, large sample sizes, oblique orientations relative to their slope, and material …
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