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 38 for “"range shifts"”.
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Impacts of climate warming on range shifts with emphasis on tropical mountains
Climate warming induced range shifts are evident globally for a wide range of taxonomic groups. However, whether such responses have taken place in tropical insect species is unclear. I provided the first such evidence that tropical insects have moved uphill over four decades of climate warming. I …
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CLIMATE DRIVEN RANGE SHIFTS OF NORTH AMERICAN SMALL MAMMALS: SPECIES’ TRAITS AND PHYLOGENETIC INFLUENCES
… at an unprecedented rate. In response, species’ ranges may shift, tracking optimal climatic conditions. Species-specific differences may produce predictable differences in the extent of range shifts. I evaluated if patterns of predicted responses to climate change were strongly related to …
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THE INFLUENCE OF RANGE SHIFTS AND WIND ENERGY ON THE ATLANTIC SURFCLAM (SPISULA SOLIDISSIMA) AND OCEAN QUAHOG (ARCTICA ISLANDICA) FISHERIES ON THE U.S. OUTER CONTINENTAL SHELF
… Northwestern Atlantic. The surfclam’s historic range extended from Cape Hatteras to Georges Bank, but recent decades of warming bottom water temperatures have caused the surfclam to shift its range to cooler waters north and offshore within the range of the ocean quahog, <em>Arctica …
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Potential impacts of climate change on myosorex as a model for extinction risk of montane small mammals in South Africa
… were counted to get the present and future range including percentage decrease or increase in range. The current distributions and the future distributions for all the species were compared to determine the range shifts. The model results for range shifts revealed that the more temperate …
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A unified population model of Calanus finmarchicus and C. helgolandicus in the North Atlantic
… ecology is to understand climate change induced range shifts. At the level of individual ecosystems, the impacts of these range shifts will result from the complex changes in community composition. This forces us to consider not simply individual species, but the species that may replace them and …
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Factors influencing the timing of breeding in a range expanding raptor at two spatial scales
Range shifts and expansions have been recorded in a number of species and it is expected that as climate change proceeds it will result in more species joining this trend. A major concern with these shifts is the suitability of the receiving novel environments, for example, if these areas …
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The Past, Present, and Future of Large Reptiles: Rewilding, Climate Change, and Conservation Palaeobiology
… change is likely to cause local extinctions and range shifts of reptile species, disrupting the ecosystem functions they provide. Despite this, rewilding projects and related research have largely overlooked reptile species. In this thesis I took an interdisciplinary approach, drawing on …
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Local impacts of global change: shifting range limits, advancing phenology, and communicating research
… (if any) do pollinators play in establishing the range limits of one subalpine flowering plant (published in American Journal of Botany, 2016). I find that in some years, fruit and seed set is limited by pollinators at the high-elevation range limit, suggesting that pollinators may contribute to …
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Fish Ladders Designed for Drop Culverts and Central Stoneroller Ecology Across a Latitudinal Gradient
… important worldwide as climate change may force range shifts to stay within thermal requirements. Understanding how populations and metapopulations respond to climate is important as fisheries managers can use this information to make informed management decisions in regards to climate change and …
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Evolutionary responses to global change: an experimental test of the effect of altered precipitation on hybridization rates in sunflower (Helianthus)
… and adaptive responses to climate change (i.e., range shifts and phenology) have been widely noted across taxa. However, the effects of climate change on evolutionary processes such as interspecific gene flow (hybridization) are less well known. In this study, we quantified hybridization rates in …
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Physiological tolerances of high temperatures in Fynbos birds: implications for climate change
… already responded to changes in climate, with range shifts towards higher latitudes and altitudes being one of the most common responses to climate warming. Bioclimatic envelope modelling provides a useful method for predicting a species, future distribution under a given climate change …
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The eco-evolutionary consequences of multiple introductions for colonizing individuals
… control, climate change-induced species range shifts, and reintroductions of rare species. Propagule pressure, which comprises the number of introduction events (propagule number) and the number of individuals per introduction event (propagule size), consistently correlates with a greater …
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Environmental driver effects on population growth rates vary by rarity type and variation in demographic rate sensitivity
… effects could vary by population or rarity type (range size, habitat specificity, and population density). I examined how the effects of drivers on vital rates could impact population growth due to variation of population growth sensitivity to demographic rates. I found significant variation in …
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The direct implications of warming on the phenotype and underlying functional traits of marine phytoplankton
… on the effects of warming SST on biogeographical range shifts is advancing, it remains unknown how phytoplankton mediated biogeochemical transformations may be altered. Focusing on patterns in species functional traits (FTs), this thesis applied trait-based approaches in laboratory and field …
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Ecological consequences of genetically-based thermal traits in fishes
… traits can predict population persistence, range shifts, and evolution in the face of contemporary climate change, but the mechanisms underlying these relationships are unknown. In this thesis, I characterize the impact of abiotic environmental factors on population distributions, assess the …
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Adapting Protected Area Networks to the Impacts of Climate Change: Potential Options for the Sub-Saharan Africa Important Bird Area (IBA) Network
… species, species which have restricted ranges or species of global conservation concern found on the continent. Here I explore ways in which the IBA network can be adapted to the impacts of climate change. Data of present species ranges and simulations of future range shifts for 1608 …
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The Evolutionary Causes and Consequences of Mammalian Hybridization
… unexpected habitats consistent with contemporary range shifts. Collectively, I demonstrate the power of diverse mammalian hybrid systems in revealing the evolutionary processes underlying speciation.</p>
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Topography as a determinant of range extent and overlap : a species level phylogenetic reconstruction and geographical range analysis of Syncarpha (Asteraceae)
Understanding what determines species' geographic range extents has several implications for questions in ecology, evolution and conservation biology. The Cape Floristic Region of South Africa is noted for its remarkably high geographic species turnover, often attributed to the exceptional …
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Palaeoclimatic impacts on the phylogeography of an Afro-montane liverwort: Jamesoniella colorata (Lophoziaceae )
… explain the impact of past climates on species ranges. This paper combines these two approaches by analysing the distribution of genetic diversity of the Afro-montane liverwort Jamesoniella colorata and associating its inferred evolutionary history with major palaeoclimatic trends in South …
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Exploring the potential impacts of global change on the woody component of of South African savannas
… change is predicted to directly drive species range shifts in savannas, however several important gaps exist in the literature which prevent the development of a clear predictive framework to describe these changes. Whilst climate is often assumed to be the primary factor underlying savanna …
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