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 “"Loss of species"”.
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Geographic distribution of tree species diversity of the United States reveals positive association between biodiversity and site productivity
With the loss of species worldwide due to anthropogenic factors, especially in forested ecosystems, it has become more urgent than ever to understand the biodiversity-ecosystem functioning relationship (BEFR). BEFR research in forested ecosystems is very limited and thus studies that incorporate …
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Ecological Responses to Climate Change: Using the Common Ragworm (Hediste diversicolor) as an Indicator for Benthic Ecosystems
… over the next century. Similar drivers of change have been observed in the geological past and were also associated with loss of species, particularly in the marine environment. This research uses the common ragworm Hediste diversicolor as a model organism to investigate the …
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Physiological tolerances of high temperatures in Fynbos birds: implications for climate change
… 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 scenario. However, these models require verification with empirical …
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Out with the Anthropocene: Art for an Animate Earth
Ensnared in but fed up with the inanity of late capitalism and environmental ruin, this thesis examines the ways in which contemporary artists are working against the grain of the dominant anthropocentric Western culture to seek new pathways out of the so-called Anthropocene. The artists under …
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Habitat use and diet preference of extralimital giraffes in the Kgalagadi Transfrontier Park
… introductions in the south-western region of Kgalagadi Transfrontier Park, South Africa, may result in changes to the vegetation structure for the region through overutilization of two keystone tree species in the area. In the areas where giraffe density was highest, I determine the …
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Applications of Imaging Spectroscopy in Forest Ecosystems at Multiple Scales
Forests provide a number of ecosystem services which sustain and enrich the wildlife, human societies, and the environment. However, many disturbances threaten forest ecosystems, making it necessary to monitor their health for optimal management and conservation. Although there are many indicators …
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Impacts of degradation on critically endangered Oudtshoorn Gannaveld
In the Succulent Karoo biome of South Africa vegetation degradation by overgrazing is a recognized threat to biodiversity. In the eastern Little Karoo region of the Western Cape Province, ostrich farming has degraded large areas of natural vegetation, particularly in the Gannaveld habitat of the …
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Reconstructing animal-vectored nutrient fluxes in paleoenvironments: A case-study of Aotearoa New Zealand’s burrowing procellariiforms
The cross-ecosystem flux of nutrients resulting from animal activity (animal-vectored subsidies) can significantly impact the communities receiving them. However, these functions are threatened by the ongoing decline and loss of species driving them. To understand ecosystem response to the loss of …
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The Impact of Global Climate Change on Tropical Forest Biodiversity in Amazonia
Species’ ranges are configured according to their tolerance of environmental conditions, especially climate, and their history of dispersal since speciation. Previous studies of the potential impact of climate change on biodiversity have been biased towards species of high latitudes. This situation …
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Spatial ecology informs reintroduction tactics for warabin (Burhinus grallarius;bush stone-curlew)
… conservation intervention used to restore species and their ecological functions within their former range. Reintroduction success relies on the appropriate selection of tactics and strategies tailored to the species and recipient ecosystem; however, sufficient ecological knowledge is not …
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Spatial ecology informs reintroduction tactics for warabin (Burhinus grallarius;bush stone-curlew)
… conservation intervention used to restore species and their ecological functions within their former range. Reintroduction success relies on the appropriate selection of tactics and strategies tailored to the species and recipient ecosystem; however, sufficient ecological knowledge is not …
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The Investigation of the Soil Seedbank in a Long-term Mowing and Fertilization Experiment
Seedbanks, the assemblage of dormant seeds found in soils, play a vital role in plant community dynamics and can aid in environmental restoration efforts. Studies have shown that fire suppression, anthropogenic nutrient addition, and human-altered hydrology can all have negative effects on …
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Plant Species and Functional Diversity along Altitudinal Gradients, Southwest Ethiopian Highlands
… space and time has long been a central focus of ecologists and biogeographers. Altitudinal patterns of richness gradients are one of such striking patterns in the landscape. Despite its historical and ecological importance as a heuristic natural experimental site for development of ecological …
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Plant community assembly and biodiversity: a spatio-temporal perspective
Biodiversity, the variety of life at all organisational levels from genes to ecosystems, affects ecosystem processes and therefore the goods and services ecosystems provide. More research is needed to provide new insights into biodiversity changes and the processes that drive these changes, in …
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CHROMOSOME-LEVEL DE NOVO GENOME ASSEMBLIES OF AVIAN SPECIES AND THEIR RELEVANCE FOR COMPARATIVE GENOMICS, PANGENOMICS, POPULATION GENOMICS AND SPECIES CONSERVATION.
… experiencing the sixth mass extinction. A major loss of species is being caused by anthropogenic habitat destruction, illegal wildlife trade, overfishing, massive fossil fuel consumption and the consequent climate changes, leading to a progressive collapse of biodiversity. The establishment of …
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Enhancement of diversity via disturbance and seed addition in two sand prairies dominated by different grasses
… can be reduced by native and non-native dominant species, through heightened competition for resources and low colonization by non-dominant species. Traits of the dominant species may influence these interactions and also the extent to which the dominant is affected by disturbance. Disturbances …
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The benefits and burdens of living beside the Cederberg Wilderness Area
A great deal is riding on conservation efforts of the twenty-first century. In an era of extinction rates one thousand times faster than ever before, protected areas have emerged as the most widely used tool available to conservationists to curb the loss of species (Child, 2004; Jepson & Ladle, …
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Macrobenthic community and ecotoxicological status of the Nhlabane Estuary
… Northern KwaZulu-Natal coastline, 40 km north of Richards Bay. Historically, the Nhlabane Estuary formed the tidally influenced lower reaches of the Nhlabane coastal lake system, but in 1978, its connection with the coastal lake was permanently severed by the construction of a weir across the …
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Effects of fragmentation and invasion on ant communities
Human alteration of natural environments has triggered a sixth major extinction event. Activities such as land-use change, habitat loss and fragmentation, the transport and establishment of invasive species, overhunting, pollution and climate change have threatened tens of thousands of species …