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 “"species dispersal"”.
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Effects of morphology, habitat and weather on the movement behaviour of range-expanding butterfly species
Dispersal capacity is an important trait enabling species to respond to climate change, particularly in fragmented landscapes, where individuals often need to move longer distances to colonise new areas. It is therefore crucial to understand species’ movement behaviour and how it is affected by …
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Spatial and temporal dynamics of plants colonizing species-poor hedgerows
… ancient hedgerows due to distinct differences in species-richness and historical significance. However, other potential ecological functions of species-poor hedgerows may have been overlooked, especially their potential role as corridors and habitats that help overcome the effects of habitat …
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UNDERSTANDING THE INFLUENCE OF ANTHROPOGENIC HABITAT MODIFICATION ON URBAN ANIMALS: CASE STUDIES OF CARRIBEAN LIZARDS AND NORTH AMERICAN MAMMALS
… accompanied by the introduction of non-native species, which alter community and habitat structures. These changes may disrupt ecosystem functions upon which animals and humans rely. Therefore, it is essential to understand the impact of anthropogenic habitat modifications on urban animals. In …
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Spatial models of plant diversity and plant functional traits : towards a better understanding of plant community dynamics in fragmented landscapes
… understanding of ecological processes, such as species dispersal and persistence. Therefore, this thesis seeks an improved understanding of community dynamics in fragmented landscapes. In order to approach this overall aim, I identified key questions on the response of plant diversity and plant …
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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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Responses of fruit-feeding butterflies to selective logging in Sabah, Borneo
… of 3996 adult butterflies was recorded from 63 species over a period of one year (October 1999 - September 2000). Most of the butterfly species that were present in unlogged forest were also present in logged forest. There was little difference between habitats in numbers of individuals or …
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Conserving Moving Species under Changing Landscapes and Climates
… dynamic landscapes and climates through which species move and how the environment influences movement choices. In particular, I am interested in how species respond to human modifications to landscapes and climates. Chapter 1 uses datasets on the spatial and temporal coverage of remotely …
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The relationships between forest and mountain fynbos communities in the southwestern Cape Province of South Africa
… and competitive abilities of forest and fynbos species were determined in controlled growth experiments. Established forest stands in Swartboskloof were stable in response to fire. Studies on the relationship between plant size and ability to survive fire showed fire intensity to be the …
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Ecological implications of introducing Leucaspius delineatus (Heckel, 1843) and Pseudorasbora parva (Temminck and Schlegel, 1842) into inland waters in England
Non-native species invasions threaten the structure, function and biodiversity of ecosystems worldwide, and those of non-native fishes pose amongst the greatest threats to inland waters of the U.K. This PhD investigated the establishment, dispersal and ecological implications of introducing the two …
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Larval dispersal between hydrothermal vent habitats
… communities establish themselves and maintain species identity despite their isolation and impermanence is a significant question in vent ecology. Planktonic larval forms provide a dispersive life stage for many species, but the exact mechanism and controls of dispersal are unknown. A …
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The Corticolous Crustose and Microfoliose Lichens of Northeastern Brazil – Diversity, Ecology, and Conservation
… in northeastern Brazil yielded a total of 450 species, distributed in 110 genera, in 32 families, 12 orders, and 4 classes of Ascomycota and one of Basidiomycota. A total of 14 taxa are described here as new to science in the genera Aciculopsora, Bacidina, Calopadia, Cryptothecia, Enterographa, …
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The genetic structure of New Zealand's coastal benthos: using the estuarine clam Austrovenus stutchburyi, to determine rates of gene flow and population connectivity
For many benthic marine taxa, dispersal over large distances is dependent on a pelagic larval phase. It is through the dispersal process that benthic taxa can found new populations, colonise disturbed or degraded habitats and achieve genetic exchange between geographically separated subpopulations. …
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Process oriented infrastructure for climate-driven forest migration through cities
… to shift the geographical distribution of tree species worldwide. Increasing empirical evidence has emerged showing that many tree species are already moving toward higher latitudes to track suitable climatic conditions. Yet, such movement cannot guarantee their survival, especially if the …
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Confirming the status of Lancashire’s endemic freshwater Nemertean – Prostoma jenningsi
… with losses occurring among many native UK species. P. jenningsi (known locally as the ‘Croston Worm’), is considered to be Lancashire’s only endemic species, thought to exist solely in the Clay ‘Ole, Bretherton; however, its existence at the site has not been confirmed since 1999. Endemic …
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Drivers of plant and arthropod diversity and community structure in a grassland ecosystem
… different spatial scales are known to influence species coexistence and community organization, although the relative importance of these forces is debated. While niche-based models emphasize the effect of local processes on community structure, regional species pools and dispersal abilities of …
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Biodiversity and Biogeography of Amphipod Crustaceans
… context. This thesis first assessed trends in species descriptions across all, benthic, pelagic, marine, freshwater, and subterranean amphipods. The prediction of the number of amphipod species remaining to be described, the taxonomic effort indicators, the number of single and multiple …
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Examining the Cover and Composition of the Successional Vegetation Mosaic of Pre-SMCRA Mined Landscapes in Southeast Ohio
… and electrical conductivity. In clear contrast, species richness and the composition of the vegetative community were influenced primarily by physical landform features and the size and shape of mine extents. While some features of surface mines may act as barriers to the dispersal of native …
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Effects of interspecific competition, salinity, and hurricanes on the success of an invasive fish, the Rio Grande cichlid (Herichthys cyanoguttatus)
… least 20 years. It is often the most common fish species in urban canals and has also been found in natural waterways outside of the GNOMA. The effects and potential for further spread of H. cyanoguttatus is uncertain. My research addressed how extensive the cichlids spread in the GNOMA, how H. …
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Linking mechanism to pattern in community assembly: Ant-mediated seed dispersal in neotropical pioneer tree species
Dispersal is a fundamental process that affects all aspects of an organism’s biology including its distribution, genetic structure, demography, and reproduction. Ant-mediated seed dispersal has evolved multiple times in many biogeographical locations. Most research in this area has focused on …