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 141 for “"species distributions"”.
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ECOLOGICAL AND EVOLUTIONARY DRIVERS OF SPECIES DISTRIBUTIONS IN THE GRASSY BIOME
… change is anticipated to further modify biome distributions and contribute further to biogeochemical cycling. However, with increased theoretical attention and availability of global datasets (e.g., remote sensing, trait consortiums) there is a growing awareness of climate disequilibrium in …
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Modeling Point Patterns, Measurement Error and Abundance for Exploring Species Distributions
… 6, we proceed to joint modeling of multiple-species datasets. The challenge is to infer about inter-species competition with a large number of populations, possibly running into several hundreds. Our contribution involves applying hierarchical Dirichlet process to cluster the presence …
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Statistical and process-based models for understanding species distributions in changing environments
Understanding the distribution of species is fundamental for biodiversity conservation, ecosystem management, and increasingly also for climate impact assessment. The presence of a species in a given site depends on physiological limitations (abiotic factors), interactions with other species …
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Can hydrological niche segregation explain species distributions in an aquifer-dependent wetland?
… wetland plant communities, test whether these species segregate along fine-scale hydrological gradients and to identify species potentially most sensitive to groundwater abstraction. Intro: Hydrological gradients, which form between permanently inundated wetlands and adjacent dry habitats, are …
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Foraminiferal species distributions and sedimentological dynamics of the Knysna Estuary, South Africa
Although the status of the Knysna Estuary is considered to be in an acceptable environmental condition, pressures of development and tourism in the area are likely to cause substantial deterioration. Investigating the microfossil assemblages in the Knysna Estuary is imperative, since foraminifera …
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Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands
… to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a …
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Impacts of climate and land use change on fish species distributions in the central United States
Species distribution models are useful tools that can be used to evaluate tradeoffs of management and conservation strategies under scenarios of environmental change. Modeling efforts for fish species have largely focused on cold-water, commercial, and recreationally-valued species, even though …
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Plant communities in field margins of agricultural landscapes: species distributions, functional traits, and contributions to landscape function
… includes alpha, beta and gamma diversities and species level characteristics such as rareness, growth forms, and dispersal types in hundred field margins in Haean-myun catchment, South Korea. We found that abandonment of local management in field margins positively influenced alpha diversity and …
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Soil factors and competition as determinants of fynbos plant species distributions in the South-western Cape, South Africa
The Cape Floristic Region is one of the most species-rich regions of the world. Fynbos, the Mediterranean climate shrubland which comprises the largest part of this region, is characterized by high beta diversity and high edaphic endemism. However, very few quantitative studies of the factors …
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Foraging efficiencies and species' distributions : an explanation of the Hadeda ibis (Bostrychia hagedash) in relation to soil moisture
The influence of soil moisture on the foraging time needed to meet BMR (foraging efficiency) in hadedas was explored in Cape Town, South Africa. This was done by monitoring hadedas foraging and recording the prey items eaten successfully per minute on soils of different moisture. BMR was calculated …
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EFFECTS OF GROUND-WATER FLOW ON SOIL CHEMISTRY, NUTRIENT AVAILABILITY AND PLANT SPECIES DISTRIBUTIONS IN FOUR NEW YORK STATE FENS
… P-limitation of plant growth and differences in species composition along the GWF. I compared vegetation and hydrochemical gradients among four fens during 2002 with nested piezometers set parallel to GWFs. I found that local ground water influenced soil and water chemistry of the wetland edge, …
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Regional Rarity: Consequences of Dispersal Limitation and Strategies for Reintroduction
<p>Understanding factors that limit species distributions within restored habitats has been a longstanding goal of restoration ecology, particularly with respect to differences between rare and widespread species. Numerous mechanisms have been proposed to contribute to rarity, including species …
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Environmental granularity, rivers and climate history as shaping factors for species' distribution and diversity patterns
Species distributions are composed by those places in which the environmental conditions are suitable for the species to survive and maintain populations; where the interactions with other species are adequate; that have been accessible given species' dispersal capabilities. Biodiversity patterns …
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Spatial structure and dynamics of the plant communities in a pro-grading river delta : Wax Lake Delta, Atchafalaya Bay, Louisiana
… plant community development, productivity, and species distributions in the Wax Lake delta, a young, actively pro-grading river delta in coastal Louisiana, USA. A species distribution map created using high-resolution 8-band WorldView-2 imagery was found to have an overall accuracy of 75 …
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High-Resolution Mapping of Fish Conservation Priorities within the Mobile River Basin
… of streams, potentially threatening aquatic species. The goal is to assess the capacity for protected areas to maintain diverse stream fish communities within the Mobile River Basin, including the upper Coosa River basin, by overlaying projections of fish species distributions and footprints …
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Vegetation patterns and plant reproductive processes in the succulent Karoo
… and competition in explaining variation in species distributions. The aim was to investigate changes in soil properties associated with species turnover (replacement series). Patterns of species abundances have been attributed to cyclic succession driven by disturbance and inter-specific …
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Carabid Beetle Ecology as a Function of Disturbance in Temperate and Tropical Forests
… knowledge of the changes and patterns of forest species in relation to disturbance events are important to our understanding of ecosystem change. The focus of this research is to examine the effects of forest disturbance on species distributions and species assemblages, with carabid beetles …
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Determining the Influence of Abiotic and Biotic Predictors on Ecological Niche Models
… assumed to have negligible effects on broadscale species distributions and are typically excluded from ecological niche models (ENMs). However, the role such interactions play in shaping species distributions is increasingly recognized, sparking the development of methods for their integration …
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