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 19 of 19 for “"Vegetation and climate"”.
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Reconstruction of late Holocene vegetation and climate of Hluhluwe Mfolozi area using phytoliths
… of C₄ grasses throughout (Chloridoideae and Panicoideae; adapted to higher temperatures and greater insolation), and slightly more C₃ grasses (Pooideae; adapted to cooler temperatures and/or winter rainfall) towards the base. The tree cover density index (D/P) does not reflect increased …
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Interactions of Vegetation and Climate: Remote Observations, Earth System Models, and the Amazon Forest
… of terrestrial ecosystems can be shaped by climate to take advantage of local environmental conditions. Ecosystem functioning, e.g. interaction between photosynthesis and temperature, can also acclimate to different climatological states. The combination of these two factors thus determines …
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High-Resolution Record of Vegetation and Climate Change During the Holocene in Southwestern Québec
… pollen record documents the post-glacial vegetation history of the region over the course of the Holocene. The record shows an initial open spruce woodland, the establishment of the boreal and mixed conifer-hardwood forest into the area, as well as the expansion and contractions of tree …
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The Ground thermal regime with special reference to the occurrence of permafrost
This thesis deals with the ground thermal regime and specific reference is made to the occurrence of Permafrost.Consideration is given to the thermal characteristics of soils in that various methods for determining the specific heat and the thermal conductivity of soils are reviewed. The methods …
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The role of historical land-cover changes as a mechanism for global and regional climate change
… the results from several modeling studies and an observational analysis as to the effect of historical land-cover change on regional and global climates. We discuss methods for determining historical vegetation change and present results from model simulations at the global and regional …
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Miocene paleoenvironments and paleosol pH proxies.
… on sedimentology, stratigraphy, geochemistry, and geostatistics. This dissertation includes two paleoenvironmental case studies and the development of a new suite of proxies for soil pH. The first case study was performed at Coffee Ranch, the site of a late Miocene (6.6 Ma) bonebed in the Texas …
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Landscapes of the apes: modelling landscape use of chimpanzees and early hominins across an environmental gradient.
… flexibility of primates to adapt to changing landscapes is important. Landscape-scale studies of primate habitat use are, however, scant. Predictive models can provide important tools in investigating primate landscape use. Chimpanzees (Pan troglodytes) face habitat loss throughout their range, …
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Stomatal sensitivity to photosynthetic and environmental signals in glycine max grown at elevated atmospheric concentrations of CO2 and O3
… concentrations of carbon dioxide (CO2) and ozone (O3) will stimulate and impair, respectively, yield and productivity of both managed and natural ecosystems in the 21st century. The ease of diffusion of these gases, as well as water vapor, between the atmosphere and interior of leaves is …
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A taphonomic investigation of the agency of microfaunal accumulation at Elands Bay Cave
… used to make extrapolations of past changes in vegetation and climate. It was assumed that the agent of accumulation, the Barn owl, remained constant. This thesis used taphonomy to analyse the micromammal bones from Elands Bay Cave in order to question the traditional assumption of the Barn owl …
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Vegetation feedback on the boundary layer climate of South Africa
Upward feedbacks from the land surface and vegetation to the atmospheric boundary layer over southern Africa are investigated. Satellite derived rainfall and vegetation data and model evaporative fluxes for the period 1981-2000 are used to reveal spatial and temporal inter-relationships via …
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Relationships of piñon juniper woodland expansion and climate trends in the Walker Basin, Nevada
Landscapes are in constant flux. Vegetation distributions have changed inconjunction with climate, driven by factors such as Milankovitch cycles and atmosphericcomposition. Until recently, these changes have occurred gradually. Human populationsare altering Earth's systems, including atmospheric …
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Novel disturbance regimes in the Arctic: paleoecological perspectives on fire and thermo-erosion from Alaskan tundra
… is amplified in the northern high latitudes, and disturbance processes such as wildfire and thermo-erosion (i.e., ground subsidence transport of ice-rich sediments) have increased in frequency and magnitude in tundra ecoregions in recent decades. These novel disturbance regimes could increase …
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The Use of Biomarker and Stable Isotope Analyses in Palaeopedology / Reconstruction of Middle and Late Quaternary Environmental and Climate History, with examples from Mt. Kilimanjaro, NE Siberia and NE Argentina
… for the reconstruction of the Quaternary landscape and climate history. In order to derive reliable information from these archives about sedimentation, vegetation and climate history, various methods and proxies are traditionally applied, e.g. texture analysis, numeric dating methods and …
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Reconstructing climate variability on the Tibetan Plateau : comparing aquatic and terrestrial signals
Spatial and temporal temperature and moisture patterns across the Tibetan Plateau are very complex. The onset and magnitude of the Holocene climate optimum in the Asian monsoon realm, in particular, is a subject of considerable debate as this time period is often used as an analogue for recent …
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The winds of change: A study of post-glacial dispersal in pacific-northwest conifers
"Anthropogenic climate change has caused shifts in the abundances and geographic distributions of many organisms. Given the estimated rates of climate change in the coming decades, many plant species may be unable to migrate or adapt in time, thereby increasing their risk of extinction. The history …
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Late glacial to Holocene climate and vegetation changes on the Tibetan Plateau inferred from fossil pollen records in lacustrine sediments
The past climate in central Asia, and especially on the Tibetan Plateau (TP), is of great importance for an understanding of global climate processes and for predicting the future climate. As a major influence on the climate in this region, the Asian Summer Monsoon (ASM) and its evolutionary …
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Effects of environmental factors on wood decay micromorphology of Pinus radiata and Fagus sylvatica, and its significance for in-ground wood preservative performance
… use of wood in situations where fungal decay and damage from wood boring insects such as termites, would otherwise occur. Significant risks to health and the environment arising from their correct use are unproven but new legislation and consumer trends continue to cause a decline in the use …