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Dissertations / Theses on the topic 'Theory of island biogeography'

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Published: 4 June 2021
Last updated: 26 January 2023

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1

Turegård, Björn. "Traditional forest reserves and their contribution to conservation biology in Babati District, Tanzania." Thesis, Södertörn University College, School of Life Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-2644.

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Traditional forest reserves are protected natural forests established by ancestors to perform many socio-cultural functions and are protected in accordance to customary laws, not based on government legislation. These reserves generally have a long history with well preserved forests that could demonstrate what the surrounding environment could have looked liked, if humans had not altered it. Therefore, the traditional forest reserves might have significant ecological value and a potential high biodiversity. During February and March of 2009 a field study with semi-structured interviews and field observations was carried out in Babati District in Manyara Region in Tanzania, to study the possible contribution TFRs might have to conservation. The information collected were then analysed using Metapopulation Theory, Island Biogeography Theory and local knowledge concepts. The analysis indicates that there is a higher biodiversity in TFRs compared to surrounding areas and unprotected forests as a result of a rigid traditional protection that local people respect. Further on the MPT and IBT show how TFRs could benefit conservation as islands of refuge for threatened species or as migration corridors between nearby forest reserves and national parks. The future for TFRs and possible conversion into CBFM must include respect and support for the local beliefs as a basis for protection and thereby conservation.

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2

Velasquez, Eleanor. "Unique island habitats: A comparison of community assembly in marine and terrestrial contexts." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/124649/2/Eleanor%20Velasquez%20Thesis.pdf.

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This project investigated the fundamental principles of the Theory of Island Biogeography. How biodiversity is influenced by habitat age, size, isolation and quality was studied in two little-known ecosystems; pumice-rafted marine communities that travel through the Pacific Ocean and strand on shorelines, and Queensland's critically endangered Melaleuca irbyana forests. This research found that while habitat age, size and isolation were important for species richness; habitat quality, defined by resource availability and climate, was more influential for predicting biodiversity levels. Small pumice stones and small remnant forests can provide the conditions species need to prosper. Therefore, small and isolated habitats are also important to conserve.
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3

Wood, Melissa. "A study of fragmented calcareous grasslands to determine optimal management intensity and reserve design, using the application of MacArthur and Wilson's Equilibrium Theory of Island Biogeography, to maintain biodiversity /." Leeds : University of Leeds, 2006. http://0-www.leeds.ac.uk.wam.leeds.ac.uk/library/secure/counter/geogbsc/200506/wood.pdf.

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4

Shirley, David. "The phytogeography of the Summer Isles, Wester Ross, Scotland : a test of island biogeographic theory and its implications for conservation strategy." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239989.

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5

Cazelles, Kévin. "Influence des interactions biotiques sur la répartition gégographique des espèces." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT122.

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Parmi les problèmes les plus fréquemment soulevés en biogéographie, figure celui de l’intégration des interactions écologiques dans les modèles de distribution d’espèces. Bien que la littérature scientifique apporte un ensemble de preuves soulignant le rôle prépondérant des interactions dans la structuration des communautés locales, on trouve relativement peu d’études révélant les empreintes laissées par les interactions dans les données de distribution d’espèces. Proposer une explication simple et claire à ce problème demeure un défi important que la biogéographie doit mener. Le problème majeur que pose l’absence de réponse claire sur le rôle des interactions aux larges échelles spatiales est que la plupart des scénarios de changements de biodiversité partent de l’hypothèse que les interactions sont négligeables. Si cette hypothèse est régulièrement rejetée, alors il faut réviser ces scénarios et soutenir le développement de méthodologies incluant les relations entre les espèces. Je commence cette thèse par un travail théorique sur le sujet car les théories classiques en biogéographie relèguent souvent au second plan les interactions écologiques. Au premier chapitre, je traite de l'intégration des interactions écologiques dans un modèle théorique de distribution d'espèces issue d'une des théories les plus importantes en biogéographie: la théorie de la biogéographie des îles. Ce travail montre comment les effets conjoints des facteurs biotiques et abiotiques changent les attendus de la théorie classique. En m'appuyant sur ce premier chapitre, je montre au second chapitre comment les interactions peuvent se répercuter dans les données de co-occurrence d’espèces. Ces données indiquent la présence ou l’absence de plusieurs espèces sur un même ensemble de sites dispersés sur de larges étendues spatiales. À l’aide d’un modèle probabiliste, j'obtiens des résultats théoriques liant les données de co-occurrence et l’information contenue dans les réseaux écologiques.Je démontre clairement que les interactions affectent les données de co-occurrence. Je montre également que plus le nombre d’interactions séparant deux espèces est grand, moins leur interactions indirect est détectable. De même si une espèce entretient de nombreuses interactions, il sera difficile de trouver une quelconque trace des interactions dans les données de co-occurrence pour cette espèce. Au troisième chapitre, je présente l’analyse de cinq jeux de données de co-occurrence pour lesquels la description des interactions était disponible. Avec ces donnés, j'ai été capable de confirmer les hypothèses du second chapitre en montrant que les espèces qui interagissent co-occurrent différemment de celles n’interagissant pas. Mes résultats indiquent aussi que l’abondance d'interactions est un frein à leur détection dans les données de co-occurrence. Cependant, en intégrant la similarité des facteurs abiotiques pour les différents sites, je montre que les signaux de co-occurrence s’affaiblissent pour parfois disparaitre. Mes résultats suggèrent donc qu’en utilisant des facteurs abiotiques pour inférer les probabilités de co-occurrence,une partie du lien entre les espèces est capturée, mais cette part est entachée d’une grande incertitude. Ceci vient questionner la qualité des prédictions données par les modèles classiques de distribution d'espèces actuellement utilisés. Les résultats de ma recherche apportent des éléments théoriques nouveaux sur le rôle des interactions écologiques dans le tracé des aires de répartition des espèces en plus de proposer une méthode originale pour étudier les données de co-occurrence d’espèces : les regarder à la lumière des réseaux écologiques. Avant de conclure ma thèse, je propose au chapitre 4 une démarche prometteuse pour aller encore améliorer l’intégration des interactions en biogéographie : les introduire par le biais des contraintes énergétiques, ce qui offre une base solide pour une théorie métabolique de la biogéographie
One of the most pressing challenges currently in the field of biogeography is the successful integration of ecological interactions in species distribution models. Although the scientific literature points out the evidence of the controlling role interactions play on local community structure, relatively few studies have demonstrated its importance over large geographical gradients. Developing a concise, clear explanation for this issue remains a significant challenge that biogeographers need to answer. The main issue associated to the lack of a clear answer concerning the role of interactions at broad spatial scales is that most of scenarios of biodiversity changes assume that interactions can be ignored. When tested, if this hypothesis is proven false, then a re-consideration of species distribution models and their development must be undertaken to include relationships among species. I begin this thesis with a theoretical investigation on this topic, where classical theories have typically ignored ecological interactions. In the first chapter of the thesis I present the integration of interaction networks into a theoretical model of species distribution coming from one of the most important theory in biogeography: the theory of island biogeography. This work shows how together the biotic and abiotic factors can affect the expectations derived from the classical theory. Building upon the findings in the first chapter, in the second chapter, I show how interactions can affect co-occurrence (between species) data. Such data contains the presence or absence of several species for a similar set of sites dispersed along large latitudinal gradients. Using a probabilistic model, I obtain theoretical results linking co-occurrence data and the information included in ecological networks. I clearly demonstrate that interactions shape co-occurrence data. Furthermore, I show that the higher the number of links between two species, the more difficult it is to detect their indirect interaction. Similarly, if a species experiences many interactions, it is then challenging to detect any sign of interactions in co-occurrence data for this species.In the third chapter of the thesis, I assess five sets of co-occurrence data, which had descriptions of their interactions available. Using this data, I was able to confirm my hypotheses put forth in my second chapter, by showing that species co-occur differently from non-interacting one. These results also point out that the abundance of interaction must preclude their detection in co-occurrence data. However, when accounting for abiotic similarities among sites, signals of interactions are weakened. Therefore, my results suggest that using abiotic factors to infer co-occurrence probabilities capture a part of the link between species and further pinpoint the uncertainty associated to this part. As a result of these findings, the predictive power of classical species distribution models used to date is brought into question. My research findings bring new theoretical elements to the forefront when considering the influence of ecological interactions and how they shape species geographical distributions, while also introducing an original methodology for studying species co-occurrence: examining them in the light of ecological networks. Before concluding, my fourth and final chapter, I propose a promising new avenue to further investigate integrating species interactions in biogeography. Here, I introduce interactions in terms of energetic constraints, which will provide a sound basis for a metabolic theory of biogeography
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6

Walker, Kevin R. "Climatic Dependence of Terrestrial Species Assemblage Structure." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23697.

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An important goal of ecological studies is to identify and explain patterns or variation in species assemblages. Ecologists have discovered that global variation in the number of species in an assemblage relates strongly to climate, area, and topographic variability in terrestrial environments. Is the same true for other characteristics of species assemblages? The focus of this thesis is to determine whether species assemblage structure, defined primarily as the body mass frequency distributions and species abundance distributions relate in convergent ways to a set of a few environmental variables across broad spatial scales. First, I found that for mammals and trees most of their geographic variation across North and South America in assemblage structure is statistically related to temperature, precipitation, and habitat heterogeneity (e.g. different vegetation types) in convergent ways. I then examined bird assemblages across islands and continents. Despite the evolutionary and ecological differences between island and continental assemblages, I found that much of the variation in bird assemblage structure depends on temperature, precipitation, land area, and island isolation in congruent patterns in continent and island bird assemblages. Frank Preston modeled species richness based on the total number of individuals and the number of individuals of the rarest species. Building on Preston’s model, Chapter 2 hypothesized that gradients of diversity correlate with gradients in the number of individuals of the rarest species, which in turn are driven by gradients in temperature and precipitation. This hypothesis assumes that species abundance distributions relate to temperature and precipitation in similar ways anywhere in the world. I found that both the number of individuals of the rarest species (m) and the proportion of species represented by a single individual in samples of species assemblages (Φ) were strongly related to climate. Moreover, global variation in species richness was more strongly related to these measures of rarity than to climate. I propose that variation in the shape of the log-normal species abundance distribution is responsible for global gradients of species richness: rare species (reflected in m and Φ) persist better in benign climates. Even though body mass frequency distributions of assemblages show convergent patterns in relation to a set of a few environmental variables, the question remains as to what processes are responsible for creating the geographical variation in the body-size distribution of species. Several mechanisms (e.g. heat conservation and resource availability hypotheses) have been proposed to explain this variation. Chapter 5 tested and found no empirical support for the predictions derived from each of these mechanisms; I showed that species of all sizes occur across the entire temperature gradient. In conclusion, assemblage structure among various taxonomic groups across broad spatial scales relate in similar ways to a set of a few environmental variables, primarily mean annual temperature and mean annual precipitation. While the exact mechanisms are still unknown, I hypothesize several to explain the patterns of convergent assembly. Résumé Un but important de l'écologie est d'identifier et d'expliquer la variation de premier ordre dans les caractéristiques des assemblages d'espèces. Un des patrons ayant déjà été identifié par les écologistes, c'est que la variation mondiale de la richesse en espèces est liée à la variation du climat, de l'aire et de la topographie. Est-ce que d'autres caractéristiques des assemblages d'espèces peuvent être reliées à ces mêmes variables? Le but de cette thèse est de déterminer si la structure des assemblages d'espèces, ici définie comme la distribution des fréquences de masse corporelle ainsi que la distribution d'abondances des espèces, est reliée de manière convergente à un petit ensemble de variables environnementales, et ce, partout dans le monde. D'abord, j'ai déterminé que, pour les mammifères et les arbres, la majorité de la variation géographique dans la structure des assemblages d'espèces est reliée statistiquement à température, précipitation, et l’hétérogénéité du couvert végétal , et ce, de manière convergente pour l'Amérique du Nord et du Sud. Je me suis ensuite penché sur l'assemblage des oiseaux sur les îles et les continents. Malgré les larges différences évolutives et écologiques qui distinguent les îles des continents, je démontre que la majorité de la variation dans la structure des assemblages d'oiseaux dépend de la température, la précipitation, la superficie et l’isolation de façon congruente sur les îles et les continents. Frank Preston a modélisé la richesse en espèces d'une localité, basée sur le nombre total d'individus ainsi que le nombre d'individus de l’espèce la plus rare. En s'appuyant sur les modèles de Preston, Chapître 3 propose une nouvelle hypothèse voulant que les gradients de diversité dépendent des gradients du nombre d'individus de l’espèce la plus rare. Celle-ci dépend des gradients de température et de précipitation. Cette hypothèse repose sur le postulat que la distribution d’abondances des espèces dépend de la température et la précipitation, et ce, de la même manière n’importe où au monde. J’ai mis en évidence que le nombre d’individus de l’espèce la plus rare (m), ainsi que la proportion d’espèces représentées par un individu unique () dans des échantillons locaux étaient fortement reliés au climat. D’ailleurs, la variation globale de la richesse en espèces était plus fortement reliée à ces indices de rareté qu’au climat. Je propose que la variation dans la forme de la distribution log-normale d’abondances d’individus soit responsable des gradients mondiaux de richesse en espèces. En d’autres mots, les espèces rares (indiquées par m et ) persistent mieux dans des climats bénins. Malgré que la distribution des fréquences de masse corporelle des assemblages d'espèces soit liée de manière convergente à seulement quelques variables environnementales, la question demeure à savoir quels processus sont responsables des gradients géographiques de variation en masse corporelle des espèces. Plusieurs mécanismes ont été proposés pour expliquer cette variation. Dans Chapitre 5, j'ai testé les prédictions dérivées de chacun de ces mécanismes sans trouver de support empirique pour aucun. Je démontre aussi que des espèces de toutes tailles se retrouvent sur le gradient de température en entier. En conclusion, la structure des assemblages d'espèces, pour différents groupes taxonomiques et à travers le monde, est liée de façon similaire à un petit nombre de variables environnementales. Bien que les mécanismes soient encore inconnus, j'en propose plusieurs pouvant expliquer ces patrons d'assemblages convergents.
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7

Santos, Ana Margarida Coelho dos. "Ecology and biogeography of island parasitoid faunas." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5759.

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Islands constitute natural laboratories for the study of evolutionary and ecological processes due to their discrete and isolated nature. Island biotas tend to be species–poor and disharmonic compared to the mainland; typically, interspecific competition is low, and entire groups of predators, parasitoids or pathogens are absent from their biotas, so the ecological space is often not fully saturated. Consequently, species from island assemblages often use a wider range of resources than their counterparts from the source mainland. Here, I investigate whether island parasitoid communities have proportionally more generalist species than their source mainland, and which factors determine island community structure. These questions were approached using data on the distribution of Ichneumonoidea (Hymenoptera) species worldwide and with data from a survey conducted in the Macaronesian region. Prior to the global analyses, I assessed whether islands and archipelagos follow the same species–area relationship, and identified which islands have comparable inventories. Globally, islands have proportionally more idiobionts (i.e. generalists) than continental areas. However, there is a latitudinal gradient in the level of generalism of island parasitoid faunas that correlates with some environmental factors and island characteristics; the species pool is the most important determinant of island community structure, together with temperature (for braconids) or biogeographical region (for ichneumonids). Host and parasitoid larvae collected in different islands of the Macaronesian region and adjacent mainland were assigned to Molecular Operational Taxonomic Units using a protocol based on host dissection and DNA barcoding. At this scale, mainland faunas have proportionally more koinobiont species and island communities have a greater proportion of idiobionts. Although overall parasitism rates were similar between islands and mainland, islands had higher idiobiont parasitism rates than expected by chance. In summary, results from this thesis indicate that indeed island parasitoid faunas are biased towards generalist species.
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Diver, Kimberly Christine Bendix Jacob. "Biogeography of island flora in the Georgian Bay, Lake Huron, Ontario." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2004. http://wwwlib.umi.com/cr/syr/main.

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9

Jones, Stephen Howard. "The landscape ecology of hedgerows with particular reference to island biogeography." Thesis, University of York, 1992. http://etheses.whiterose.ac.uk/2487/.

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10

Du, Dawei. "Biogeography-Based Optimization: Synergies with Evolutionary Strategies, Immigration Refusal, and Kalman Filters." Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1251218712.

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Thesis (M.S.)--Cleveland State University, 2009.
Abstract. Title from PDF t.p. (viewed on Sept. 8, 2009). Includes bibliographical references (p. 70-73). Available online via the OhioLINK ETD Center and also available in print.
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11

Wragg, Graham M. "The fossil birds of Henderson Island, Pitcairn Group, South Pacific : a chronology of human-caused extinctions." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339060.

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12

Bollmer, Jennifer L. "Population genetics of island endemics neutral and major histocompatibility loci /." Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2008. http://etd.umsl.edu/r2941.

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13

Meyer, Kirstin. "Community assembly of benthic invertebrates on island-like marine hard substrata." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20686.

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Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats. Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities. In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf. Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities. On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same.
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Gaudioso, Jacqueline M. "Quantification of plumage coloration of a Hawaiian honeycreeper (Hemignathus virens virens) along gradients of biogeography: Does variation exist between sub-populations on the island of Hawai'i? /." University of Hawai'i at Hilo, 2009. http://proquest.umi.com/pqdweb?did=1937737681&sid=1&Fmt=2&clientId=23658&RQT=309&VName=PQD.

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Murray, Kevin Lager. "The Genetic Structure and Mating System of the Buffy Flower Bat (Erophylla sezekorni)." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/138.

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The buffy flower bat (Erophylla sezekorni) is a neotropical leaf-nosed bat (Phyllostomidae) that is endemic to the Greater Antilles. Although this species is one of the most common and abundant species of mammals in the West Indies, very little is known about its ecology and evolution. To address this deficiency, I studied the genetic structure and mating system of the buffy flower bat on several islands throughout its range, focusing a more intensive study on the island of Exuma, Bahamas. I first studied the effects of ocean barriers on genetic diversification within Erophylla and two related endemic genera of endemic West Indian bats, Brachphylla, Phyllonycteris (Chapter II). I found evidence that ocean barriers inhibit gene flow and promote speciation within these genera. Focusing on genus Erophylla (Chapter III), I found that ocean channels usually act as barriers to gene flow among island populations within species. However, relatively shallow and narrow ocean channels formed semi-permeable barriers allowing gene flow between some island populations. Within the buffy flower bat, Erophylla sezekorni (Chapter IV), genetic diversity of mitochondrial DNA fragments was positively correlated with island size, with small islands having reduced genetic diversity. However, genetic diversity at several nuclear microsatellite loci was not correlated with island area and levels of genetic diversity were high for most island populations. In addition, island populations within the Great Bahamas Bank and Little Bahamas Bank showed high levels of gene flow between islands and showed no evidence of genetic bottlenecks. Populations of E. sezekorni on Exuma (Chapters IV and V) exhibited a polygynous mating system that included vigorous visual, acoustic, and olfactory male display behaviors. However, the social structure that I observed had a negligible effect on genetic diversity and genetic structure within these populations. Overall, the buffy flower bat exhibits very few of the genetic symptoms of island life, such as reduced genetic diversity and increased genetic isolation, and is evolutionarily adapted to persist on small oceanic islands.
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Sandberg, Rory Nimmo. "The response of biological communities to natural and anthropogenic habitat fragmentation in South Outeniqua Sandstone Fynbos, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/95460.

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Thesis (MSc)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Habitat fragmentation through the loss and modification of natural ecosystems poses a serious threat to biodiversity globally. Mechanisms and ecological implications of fragmentation have been extensively studied, yet new and meaningful insights continue to be produced. The highly diverse and ecologically complex fynbos shrubland communities that occur in the Cape Floristic Region of South Africa are amongst the most threatened by habitat fragmentation by urban, agricultural and silvicultural land uses and to the spread of invasive alien plants. Fynbos vegetation communities are fire-adapted and exploit the post-fire regeneration niche. Natural stochasticity in the fire regime means that these communities are temporally unstable; a factor that allows for the coexistence of such extreme diversity. Few studies have attempted to assess the influence of habitat fragmentation on this stochasticity, or to investigate the response of biological communities to the conditions that result. It is unknown whether this temporal instability will lead to delayed extinctions in fragmented communities, thus generating extinction debt. South Outeniqua Sandstone Fynbos occurs as a unique landscape mosaic of both insular and extensive habitats, suited to study through an island biogeography framework. Vegetation community stability was assessed through the comparison of historic and recent data sets. The responses of local vegetation and avifaunal communities to habitat fragmentation were assessed and compared on the basis of their differing motility. The unique habitat configurations also allowed for the investigation of extinction debt in the local communities and provided an opportunity to assess the influence of the surrounding matrix on species persistence and on connectivity in the artificial fragments. Data were analysed through simple regression analyses, modified Chi-squared tests and through ordination analyses. Ultimately the value of the artificial habitat fragments for the conservation of biological communities was assessed. Stability was observed in the vegetation species-area relationship for the natural islands and the mainland sites over twenty-two years. Smaller islands were found to receive fewer fires than large islands and the mainland. This consistently over-extended fire-return interval reduces the stochasticity of the local fire regime causing stable yet depauperate vegetation communities to result. Vegetation communities in the artificial fragments were found to hold area-related extinction debt, possibly due to the relatively long-term demographic turnover that typically occurs in fynbos. Avifaunal communities varied in their response to fragmentation relative to the vegetation. Birds – being motile – were found to be unaffected by isolation distance or surrounding matrix type – their response due more to changes experienced in the vegetation community than to geographic constraints. Fynbos-typical birds responded to the post-fire age of vegetation. Frugivorous birds and the matrix-habitat edge were identified as sources of alien and non-fynbos plant species that colonise the artificial fragments, potentially reducing the quality of these habitats for avifauna. Fragmented communities of South Outeniqua Sandstone Fynbos have the potential to function as biological reserves. This potential can be realised through the implementation of a fire regime that acknowledges the stochasticity required by the vegetation, the frequency required by the vegetation and the avifauna, and the practicality required by surrounding anthropogenic land-uses.
AFRIKAANSE OPSOMMING: Habitat-fragmentering, deur die verlies en verandering van natuurlike ekosisteme, hou 'n ernstige bedreiging in vir biodiversiteit wêreldwyd. Meganismes en ekologiese implikasies van die fragmentering is al breedvoerig bestudeer, maar nuwe en betekenisvolle insigte word voortaan vervaardig. Die hoogs diverse en ekologies komplekse fynbos-struikveld gemeenskappe wat in die Kaapse Floristiese Streek van Suid-Afrika voorkom, word meeste bedreig deur habitat-fragmentering deur verstedeliking, landbou en houtteeltkundige grondgebruike en die verspreiding van indringerplante. Fynbos gemeenskappe is aangepas tot vuur en die uitbuiting van post- vuur herlewing nis. Natuurlike stogastisiteit in die vuur-bedeling beteken dat hierdie gemeenskappe tydelik onstabiel word, 'n faktor wat die mede-bestaan van uiterste diversiteit moontlik maak. Min studies het al die invloed van habitat-fragmentering op hierdie stogastisiteit ondersoek, of die reaksie van biologiese-gemeenskappe tot die voortspruitende omstandighede. Dit is onbekend of die tydelike onstabiliteit sal lei tot vertraagde uitsterwing in gefragmenteerde gemeenskappe, dus genereer uitsterwings-skuld. Suid Outeniqua Sandsteen Fynbos kom as 'n unieke landskap mosaïek van beide die eilande en uitgebreide habitatte voor, geskik om deur 'n eiland biogeografie raamwerk bestudeer te word. Plant-gemeenskappe se stabiliteit is bestudeer deur die vergelyking van historiese en onlangse data stelle. Die reaksies van die plaaslike plantegroei en voëllewe gemeenskappe tot hul habitat is bestudeer en vergelyk op grond van hul verskillende beweeglikheid. Die unieke habitat konfigurasies het ook toegelaat vir die ondersoek van uitsterwings-skuld in die plaaslike gemeenskappe en 'n geleentheid gebied om die invloed van die omliggende habitat-matriks op spesies volharding en op konneksie in die kunsmatige fragmente te bepaal. Die data is ontleed deur middel van eenvoudige regressie analises, aangepasde Chi -kwadraat toetse en deur koördinerings ontledings. Ten einde die waarde van die kunsmatige habitat fragmente vir die bewaring van biologiese gemeenskappe te bepaal. Stabiliteit in die plantspesies-area verhouding vir die natuurlike eilande en die vasteland van webwerwe oor twee en twintig jaar was waargeneem. Kleiner eilande het minder brande aangeneem as groot eilande en die vasteland. Hierdie herhaalde oor-uitbrei over-extended vuur-interval het die stogastisiteit verminder van die plaaslike vuur-bedeling wat stabiele tog spesie-arme plantegroei gemeenskappe veroorsaak het. Plantegroei gemeenskappe in die kunsmatige fragmente is bevind om spesie- area -verhouding uitsterwings-skuld te bevat, moontlik as gevolg van die relatiewe lang termyn demografiese omset wat tipies voorkom in fynbos. Voëllewe gemeenskappe het gewissel in hul reaksie tot die fragmentering relatief tot die plantegroei. Voëls – weens hul beweeglikheid – blyk om nie beinvloed te word deur isolasie afstand of omliggende habitat-matriks tipe nie - hul reaksie blyk meer asgevolg van veranderinge wat ervaar word in die plantegroei gemeenskap as geografiese beperkinge. Fynbos-tipiese voëls reageer op die post- vuur ouderdom van plantegroei. Vrugte-etende voëls en die habitat-matriks rand is geïdentifiseer as bronne van uitheemse en nie-fynbos plantspesies wat die kunsmatige fragmente koloniseer, wat potensieel die kwaliteit van hierdie habitatte vir voëls verminder. Gefragmenteerde gemeenskappe van Suid Outeniqua Sandsteen Fynbos het die potensiaal om as biologiese reserwes te funksioneer. Hierdie potensiaal kan verwesenlik word deur die implementering van 'n vuur-bedeling wat erkenning verleen aan die stogastiesiteit vereis deur die plantegroei, die frekwensie wat deur die plantegroei en die voëllewe vereis word , en die praktiese vereistes van die omliggende menslike grondgebruike.
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17

Thomsen, Terry. "Biogeography of Nothofagus subgenus Fuscospora in the South Island of New Zealand inferred from chloroplast DNA." Thesis, University of Canterbury. Department of Plant and Microbial Sciences, 2002. http://hdl.handle.net/10092/4824.

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Nothofagus (‘southern beech’) is a major component in forests throughout the South Island of New Zealand. However all four species are disjunct across the central portion of the island. Hypotheses for the disjunction include the following explanations based on vicariance: (i) 'glacial refugia' hypothesis, where distributions have not recovered following elimination during the Pleistocene glacial period; (ii) 'environmental barriers' hypothesis, where edaphic, climatic and migration barriers hinder Nothofagus migration; and (iii) 'lateral plate shift' hypothesis, where populations have been rafted apart by lateral movement on the Australia-Pacific tectonic plate boundary since the early Miocene. Dispersal explanations imply nonsurvival south of the disjunction during glacial periods followed by seed dispersal during the Holocene. One dispersal hypothesis explains the presence of N fusca and N truncata in the south through long-distance pollen dispersal and hybridisation resulting in species 'reconstitution'. A phylogeographic approach using sequences and RFLPs of non-coding chloroplast DNA (cpDNA) regions in the three New Zealand Fuscospora species is used to infer historic patterns of distribution and gene flow in the South Island. Maternally inherited cpDNA is transmitted via seed, and is therefore appropriate for revealing variation at a geographically localised scale. Comparison of N fusca/N truncata and N solandri cpDNA haplotypes south of the disjunction is used to assess the validity of the long-distance pollen dispersal and hybridisation hypothesis. Evolutionary rates of cpDNA in Fuscospora was found to be very slow, in line with other studies. A single insertion in the trnL-trnF intergenic spacer was restricted to south of the disjunction. A very approximate estimate of its age was made, and it is unlikely to be more than 1-2 mya. It is unlikely to have occurred during the Holocene, indicating that Fuscospora populations have existed in isolation south of the disjunction throughout the last Pleistocene glacial period at least, and possibly much longer. Therefore a vicariance origin to the disjunction is favoured. Although no resolution can be made between the 'glacial refugia' and 'environmental barriers' hypotheses, the 'lateral plate shift' hypothesis is not supported. The southern South Island mutation is shared between all three species, suggesting that introgression of the chloroplast genome has occurred, possibly in the absence of nuclear introgression. Assuming that N solandri var. cliffortioides survived in the south during the last glacial period, this finding is compatible with scenarios of (i) N fusca/N truncata survival in the south; (ii) Holocene dispersal of N fusca/N truncata seed, and (iii) 'reconstitution' of N fusca/N truncata via long-distance pollen dispersal and hybridisation.
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18

Mahler, D. Luke, Shea M. Lambert, Anthony J. Geneva, Julienne Ng, S. Blair Hedges, Jonathan B. Losos, and Richard E. Glor. "Discovery of a Giant Chameleon-Like Lizard (Anolis) on Hispaniola and Its Significance to Understanding Replicated Adaptive Radiations." UNIV CHICAGO PRESS, 2016. http://hdl.handle.net/10150/621299.

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We report a new chameleon-like Anolis species from Hispaniola that is ecomorphologically similar to congeners found only on Cuba. Lizards from both clades possess short limbs and a short tail and utilize relatively narrow perches, leading us to recognize a novel example of ecomorphological matching among islands in the well-known Greater Antillean anole radiation. This discovery supports the hypothesis that the assembly of island faunas can be substantially deterministic and highlights the continued potential for basic discovery to reveal new insights in well-studied groups. Restricted to a threatened band of midelevation transitional forest near the border of the Dominican Republic and Haiti, this new species appears to be highly endangered.
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19

Gómez, Roberto Antonio. "On the Systematics of the North American Ground Beetle Genus Rhadine Leconte (Coleoptera: Carabidae: Platynini) with Emphasis on the Sky Island Fauna of Arizona." Thesis, The University of Arizona, 2014. http://hdl.handle.net/10150/333388.

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Rhadine is a Nearctic lineage of flightless ground beetles in the tribe Platynini notable for the slender and elongate habitus of the adults and, in the Southwest, the habitat preferences of many species, with several mountaintop endemics as well as microphthalmous species known from caves in central Texas. The genus is in need of a modern taxonomic revision as species identifications remain challenging, and a phylogenetic hypothesis for the overall structure of the group is needed in order to better understand the group's evolutionary history and test whether subterranean Rhadine are a monophyletic clade or not. To this end, a multigene phylogeny of Rhadine was inferred based on ~2.4-kb of aligned nucleotide sites from 3 molecular markers: cytochrome c oxidase subunit I (COI), 28S ribosomal DNA (28S), and carbamoylphosphate synthetase domain of the rudimentary gene (CAD). These gene fragments were obtained for 30 species or putative species of Rhadine as well as from members of their putative sister group, Tanystoma. Rhadine as currently circumscribed is reconstructed as paraphyletic with two species of subterranean beetles from caves in northern Mexico being resolved outside of Rhadine + Tanystoma. Rhadine sensu stricto (s. str.) is resolved with high support across analyses and is composed of two reciprocally monophyletic clades, clade I and II, the second of which is generally recovered in most analyses. Clade I includes those Rhadine with adult morphological characters defining the dissecta-, larvalis-, and subterranea-groups as well as a clade of macropthalmous subterranean perlevis-group species. Clade II, although not as robust as clade I, contains several surface-dwelling species from the western United States in the jejuna-, nivalis-, and perlevis-groups in addition to lineages of exclusively macropthalmous subterranean Rhadine. The troglobitic, cave-restricted, Rhadine classified in the subterranea-group are reconstructed in two different clades, and the clade contained within clade I also includes several species of large-eyed cavernicolous Rhadine. Those with a slender habitus (e.g., R. exilis, R. subterranea, R. austinica) evolved independently at least three times. Major biogeographic and evolutionary patterns based on these molecular results include: subterranea-group Rhadine north of the Colorado River in Texas (which all lack lateral pronotal setae) are found to comprise a monophyletic group, beetles in caves south of the Colorado River likely form another monophyletic group, and the "species pairs" of troglobitic Rhadine known to occur in the same caves that were sampled in our study are not resolved as each other's closest relatives suggesting that these caves were colonized independently by more than one lineage of Rhadine. The fine-scale attention given to populations of Rhadine isolated on mountain tops in the Madrean Sky Island region suggests that there is a great deal of genetic diversity among these lineages. In addition, these populations are resolved as reciprocally monophyletic with high support across all analyses. Haplotype networks constructed for these populations and compared with those of other described species for the same gene fragments reveal similar genetic distances between separate Sky Island Rhadine as compared to distances between described species from throughout the tree. Preliminary divergence time estimates of the Rhadine-Tanystoma lineage based on relaxed molecular clock analyses support a Miocene age for Rhadine and the Rhadine-Tanystoma lineage, with the crown ages of clade I and II being similar though not identical. All subterranean clade I Rhadine are dated to have begun diversifying within approximately the past 5 million years (Pliocene), an age that is compatible with the stratigraphy of the caves in the Balcones Escarpment. In addition, divergence estimates for the members of this clade support the climactic relict hypothesis, as they diversified during rapid temperature fluctuations during the Quaternary. However, the ages of the high altitude Sky Island Rhadine are estimated to be older than the most recent glacial maximum, suggesting that these distinct clades are considerably older than initially thought. We also performed character correlation tests using our phylogeny to test for patterns in form associated with cave habit and did not find statistical significance between subterranean habit and microphthalmy nor habit and development of the foveae of the mentum.Morphological characters that have been traditionally used to classify the genus into species groups were shown to be convergent in many cases. Despite these well-supported molecular clades, few morphological characters are consistent across all members, posing a challenge to the construction of identification tools. Nevertheless, a tentative update to the classification based on our findings is presented, and the future goals for reconstructing the phylogeny of Rhadine are discussed.
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20

Karlsson, Tiselius Andreas. "Island biogeography of young land uplift islands - viewed through the lens of bryophytes in a northern Swedish archipelago." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-121239.

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Increasing habitat fragmentation and rapid global warming is changing the conditions for species populations and ecological communities around the world. This presents challenges for the maintenance of biodiversity and a dominant paradigm for conservation in fragmented habitats is given by island biogeography and metapopulation (or metacommunity) ecology. In this thesis I approach key concepts (area, connectivity and community assembly) in island biogeography and metacommunity ecology within the context of a dynamic land uplift archipelago. The presented work consists of two interwoven themes: (i) A methodological theme in which statistical approaches are developed to deal with the complexities of multispecies dynamic systems, and (ii) an applied theme dealing with community assembly and island biogeography of bryophytes on young land uplift islands. To describe island connectivity for entire species assemblages, an approach using functional principal component analysis (fPCA) on patch connectivity functions (the connectivity of an island as a continuous function of a variable representing the spatial scale of species dispersal capacities) was developed. In addition, a new statistical method, functional co-inertia analysis (fCoIA), for analyzing co-variation between multivariate species data and continuous functions was developed and applied to the relation between bryophyte species incidences and the island age/area-dynamics. Primarily asexual bryophyte species are dispersal limited and presence probabilities are related to island connectivity. No such patterns were found for species, at least occasionally, producing spores. Our results suggest that bryophyte dispersal is regulated by the contribution of spores to a regional spore rain and that bryophyte species with low spore output at the landscape level may be extra vulnerable under habitat fragmentation and loss. Having specialized asexual propagules increases the presence probabilities on islands, partly compensating for the dispersal limitation in asexual species. This suggests a trade-off between dispersal and establishment capacity, but also points to the importance of local dispersal for maintaining populations under the succession driven spatial turnover of microsites on the islands. Bryophyte colonization is strongly limited by habitat availability when a given habitats is rare, but there seems to exist a threshold over which other processes (e.g. dispersal limitation) become more important. Species with more vagile life history strategies appear to be stronger affected by the area of available habitats than many perennial species
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21

Duffy, Angela. "Genetic structuring among naturally isolated dune lake populations : a microcosm of evolutionary processes on oceanic islands." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16491/1/Angela_Duffy_Thesis.pdf.

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Oceanic islands have been used as model systems for studies of evolution and speciation as the range of island sizes coupled with their known geological chronosequence make them ideal systems for the study of spatial and temporal variations in species diversity and distributions. These processes also occur on continental islands and mainland habitats but features of oceanic islands, notably their clearly delimited boundaries, natural isolation and simple geological composition make them more amenable to study. The perched dune lakes of Fraser Island, Australia share many of the properties of oceanic islands. The naturally isolated formation of the perched lakes, clearly delimited boundaries of the freshwater habitat and phase difference compared to the surrounding, terrestrial environment have significant implications for the biota these lakes support. Inhabitants of the perched dune lakes consist of the aquatic and semi-aquatic descendents of colonisers that were able to traverse a land barrier and survive in the oligotrophic, acidic waters over subsequent generations. Barriers to ongoing gene flow among lake populations, are however likely to be different for species with different life history characteristics. I therefore sought to assess the effects of three different life history characteristics on post-colonisation interpopulation gene flow. A representative species was selected to represent one of each of the following life history characteristics: * Aquatic species confined to lake for entire life cycle - freshwater shrimp Caridina indistincta. * Semi-aquatic species capable of terrestrial dispersal - freshwater turtle Emydura krefftii. * Semi-aquatic species capable of aerial dispersal - odonate Orthetrum Boumiera. 137-250 individuals were sampled per species across six lakes separated by 1-6km. Regions of the mitochondrial genome were targeted and molecular screening methods developed and employed to assess the relative levels of post-colonisation gene flow among lake populations. Parsimony analysis of the 25 unique haplotypes identified in the species with no apparent inter-lake dispersal mechanism, the freshwater shrimp Caridina indistincta, demonstrated that there was no sharing of derived haplotypes among lake populations. Star shaped genealogies were identified in four lake populations indicative of a population expansion and mismatch distribution analysis confirmed a recent population expansion estimated to have occurred no more than 200,000 years ago. This demonstrates that each of the perched dune lakes was colonised by C.indistincta soon after their inception but that no ongoing gene flow among lake populations has occurred. The population genetic structure of the species assessed which is capable of terrestrial dispersal suggests that although this species of freshwater turtle, Emydura krefftii, is capable of overland dispersal, gene flow among lake populations is limited. Even at the small spatial scale examined in this study, E.krefftii populations displayed a pattern of isolation by distance (r=0.854, p<0.03). Nested clade analysis also suggested a pattern of restricted gene flow with some long distance dispersal in recent times with long distance dispersal and a possible range expansion occurring historically. The species examined in this study that displayed the most extensive gene flow among lake populations was the dragonfly Orthetrum boumiera. No relationship was found between genetic and geographic distance (r= -0.0852, p>0.05) and nested clade analysis could not identify a geographical association among haplotypes, indicative of panmixia. While larval life stages of this species are fully aquatic, the winged adult stages of this species appear to be connecting seemingly isolated lake populations, at least at the spatial scale examined here. The results of this study have demonstrated that these perched dune lakes provide 'island like' models for recent biogeographic processes. The pattern of colonisation and subsequent diversification identified in these populations takes the form of insitu 'genetic radiations' with those populations that are isolated forming monophyletic clades endemic to a single lake. The genetic diversity and endemism identified in this study has occurred over much smaller temporal (<500,000 years) and spatial (<6.5km) scales than in studies of oceanic island fauna. However, the mode of formation of the perched dune lakes and the implications that their natural isolation and abiotic genesis have for the evolution of colonisers of these unique habitats has resulted in them being analogous to true oceanic islands.
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22

Duffy, Angela. "Genetic structuring among naturally isolated dune lake populations : a microcosm of evolutionary processes on oceanic islands." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16491/.

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Oceanic islands have been used as model systems for studies of evolution and speciation as the range of island sizes coupled with their known geological chronosequence make them ideal systems for the study of spatial and temporal variations in species diversity and distributions. These processes also occur on continental islands and mainland habitats but features of oceanic islands, notably their clearly delimited boundaries, natural isolation and simple geological composition make them more amenable to study. The perched dune lakes of Fraser Island, Australia share many of the properties of oceanic islands. The naturally isolated formation of the perched lakes, clearly delimited boundaries of the freshwater habitat and phase difference compared to the surrounding, terrestrial environment have significant implications for the biota these lakes support. Inhabitants of the perched dune lakes consist of the aquatic and semi-aquatic descendents of colonisers that were able to traverse a land barrier and survive in the oligotrophic, acidic waters over subsequent generations. Barriers to ongoing gene flow among lake populations, are however likely to be different for species with different life history characteristics. I therefore sought to assess the effects of three different life history characteristics on post-colonisation interpopulation gene flow. A representative species was selected to represent one of each of the following life history characteristics: * Aquatic species confined to lake for entire life cycle - freshwater shrimp Caridina indistincta. * Semi-aquatic species capable of terrestrial dispersal - freshwater turtle Emydura krefftii. * Semi-aquatic species capable of aerial dispersal - odonate Orthetrum Boumiera. 137-250 individuals were sampled per species across six lakes separated by 1-6km. Regions of the mitochondrial genome were targeted and molecular screening methods developed and employed to assess the relative levels of post-colonisation gene flow among lake populations. Parsimony analysis of the 25 unique haplotypes identified in the species with no apparent inter-lake dispersal mechanism, the freshwater shrimp Caridina indistincta, demonstrated that there was no sharing of derived haplotypes among lake populations. Star shaped genealogies were identified in four lake populations indicative of a population expansion and mismatch distribution analysis confirmed a recent population expansion estimated to have occurred no more than 200,000 years ago. This demonstrates that each of the perched dune lakes was colonised by C.indistincta soon after their inception but that no ongoing gene flow among lake populations has occurred. The population genetic structure of the species assessed which is capable of terrestrial dispersal suggests that although this species of freshwater turtle, Emydura krefftii, is capable of overland dispersal, gene flow among lake populations is limited. Even at the small spatial scale examined in this study, E.krefftii populations displayed a pattern of isolation by distance (r=0.854, p<0.03). Nested clade analysis also suggested a pattern of restricted gene flow with some long distance dispersal in recent times with long distance dispersal and a possible range expansion occurring historically. The species examined in this study that displayed the most extensive gene flow among lake populations was the dragonfly Orthetrum boumiera. No relationship was found between genetic and geographic distance (r= -0.0852, p>0.05) and nested clade analysis could not identify a geographical association among haplotypes, indicative of panmixia. While larval life stages of this species are fully aquatic, the winged adult stages of this species appear to be connecting seemingly isolated lake populations, at least at the spatial scale examined here. The results of this study have demonstrated that these perched dune lakes provide 'island like' models for recent biogeographic processes. The pattern of colonisation and subsequent diversification identified in these populations takes the form of insitu 'genetic radiations' with those populations that are isolated forming monophyletic clades endemic to a single lake. The genetic diversity and endemism identified in this study has occurred over much smaller temporal (<500,000 years) and spatial (<6.5km) scales than in studies of oceanic island fauna. However, the mode of formation of the perched dune lakes and the implications that their natural isolation and abiotic genesis have for the evolution of colonisers of these unique habitats has resulted in them being analogous to true oceanic islands.
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23

Pownall, Christopher David. "Simulation and theory of island growth on stepped substrates." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298745.

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24

Huntington, Brittany. "Multi-Scale Patch Dynamics of Coral Communities: A Cross-Caribbean Investigation Using a Landscape Ecology Approach." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/637.

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The overarching objective of this dissertation was to improve our knowledge of the relationship between seascape heterogeneity and diversity of stony coral assemblages across spatial scales. Coral communities on patch reefs in three regions of the Caribbean were used as a model system to investigating this relationship because patch reef heterogeneity could be readily quantified within the seascape using remote sensing and image analysis techniques. I began with a theoretical approach, exploring the origins of observed species diversity among coral communities at increasing spatial scales. Hierarchical sampling and null models revealed that coral diversity was governed by non-random processes at local- (10s of meters) and meso- (100s of m) scales. Spatial autocorrelation and reef heterogeneity were then investigated as potential mechanistic drivers of these non-random diversity patterns. I found limited support for spatial drivers. However, beta diversity was significantly correlated to metrics of reef heterogeneity (measured as reef size, spatial configuration, and complexity), indicating that differences in reef heterogeneity were making a disproportionate contribution to the overall coral community diversity. The relationship between corals and reef heterogeneity was found to be both scale-dependent and region dependent. This theoretical approach was followed by a manipulative approach using an existing artificial patch reef array to experimentally test the influence of reef spatial configuration and topographical complexity on local diversity. Corals were most sensitive to reef size and secondarily reef configuration within the seascape. Unlike reef fishes, reef complexity did not emerge as a strong predictor of the coral community composition in either the observational data or the experimental manipulation. These observational and experimental explorations of the relationship between corals and habitat reveal that intra-habitat variability (i.e. differences between patch reefs) can influence the diversity and abundance of corals. I then focused on applying this improved theoretical understanding towards improving coral management efforts. I present a new methodology to assess the efficacy of marine reserve effects by controlling for natural seascape variation within and beyond the reserve boundary, and I quantified the bias of underestimating coral diversity by using conventional reef monitoring protocols that ignore differences in reef size. In conclusion, I demonstrate empirically that seascape attributes of reef heterogeneity can contribute to coral diversity at relatively small spatial scales (<1km) and can affect corals with different life history traits in different ways. Hence, management and conservation efforts must consider the role of these meso-scale spatial metrics to influence the structure of the coral assemblage at the local scale.
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25

Svensson, Linda Maria Elenor. "Biogeographic patterns of avian malaria parasites in the Lesser Antilles prevalence, diversity, and community composition /." Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2008. http://etd.umsl.edu/r2881.

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26

Beuk, Paulus Leonardus Theodorus. "Cicadas spreading by island or by spreading the wings? historic biogeography of dundubiine cicadas of the Southeast Asian continent and archipelagos /." Amsterdam : Amsterdam : Universiteit van Amsterdam ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/61782.

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27

Dahruddin, Hadi. "Characterization of Sundaland ichthyofauna through DNA barcodes : a case study in Java island." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG033.

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L'archipel indonésien abrite 1218 espèces de poissons d'eau douce disséminées sur 14 000 îles. Englobant trois ensembles géographiques majeurs (Sundaland, Wallacea, Sahul) séparés par deux transitions faunistiques majeures (lignes de Wallace et de Lyddeker), les îles indonésiennes présentent des niveaux hétérogènes de richesse spécifique résultant de divers antécédents géologiques et paléoécologiques. Sundaland abrite 68% du nombre total d’espèces de poissons d’eau douce et constitue l’une des faunes les plus menacées au monde. Contrairement à Wallacea qui résulte d'une mise en place précoce par subduction autour de 40 Mya, Sundaland (Bornéo, Sumatra et Java) a acquis sa configuration moderne au cours des 5 derniers Mya grâce à une combinaison de fragmentation continentale et de subduction. L’état alarmant de l’ichtyodiversité de Sundaland, associé à des lacunes importantes en matière de taxonomie et de connaissances de la distribution des espèces, plaide en faveur d’une réinterprétation moderne au moyen de méthodes standardisées et basées sur l’ADN. L'ichtyodiversité de Java, en particulier, est la plus menacée et la moins connue de Sundaland. Cette thèse vise à répondre à deux questions principales: (1) Les code-barres ADN constituent-ils une approche appropriée pour caractériser l'ichtyodiversité de Java? (2) L’histoire géologique et paléoécologique de Java est-elle un bon prédicteur des profils de diversité et de la structure génétique de la population? Les principaux résultats obtenus sont les suivants: 1) d’importants écarts entre la liste de référence des poissons d’eau douce de Java fondée sur des données historiques et une réévaluation moderne au moyen de code-barres à ADN. Les raisons invoquées sont le biais taxonomique lié à l'inventaire interrompu de l'ichthyofaune de Java au cours des 3 derniers siècles et la raréfaction de plusieurs espèces ciblées par la pêche artisanale. (2) Une réévaluation basée sur l’ADN des limites et de la distribution des espèces pour les genres Nemacheilus et Rasbora a indiqué deux nouveaux taxons, plusieurs cas de diversité cryptique et plusieurs cas d’attribution erronée de populations aux niveaux de l’espèce. Les aires de distribution des espèces semblent être beaucoup plus limitées que considéré précédemment et questionne les modalités de persistance des espèces dans des paysages en mutation. (3) Une évaluation basée sur l'ADN, grace aux code-barres ADN, de la structure génétique des populations de trois espèces largement répandues à Java met en évidence des niveaux élevés de diversité cryptique et des divergences génétiques profondes entre lignées mitochondriales géographiquement restreintes et ne se chevauchant pas. Conformément à une fragmentation liée à la montée des arcs volcaniques à Java qui a entraîné un déclin à long terme de la taille effective de la population, cette tendance plaide en faveur du statut de conservation sensible de ces lignées mitochondriales. Les résultats présentés ici soulignent les avantages d'utiliser une approche standardisée et basée sur l'ADN pour la caractérisation rapide d'une faune mal connue et ouvrir de nouvelles perspectives pour la conservation de l'ichtyofaune de Java et de Bali
The Indonesian archipelago hosts 1218 freshwater fish species disseminated across 14,000 islands. Encompassing three majors geographic assemblages (Sundaland, Wallacea, Sahul) separated by two majors faunistic transitions (Wallace and Lyddeker lines), Indonesian islands display heterogeneous levels of species richness resulting from diverse geological and paleoecological histories. Sundaland itself hosts 68% of the total number of freshwater fish species and constitutes one of the world’s most endangered fauna worldwide. By contrast with Wallacea that results from an early settlement through subduction around 40 Mya, Sundaland (Borneo, Sumatra and Java) has acquired its modern configuration during the last 5 Mya through a combination of continental fragmentation and subduction. The alarming state of Sundaland ichthyodiversity, combined with major taxonomy and distribution knowedge gaps, urges for a modern reapparaisal through standardized DNA-based methods. The ichtyodiversity of Java in particular, is the most threatened and the less known of Sundaland. This dissertation aims at addressing two main questions: (1) Is DNA barcoding a suitable approach to characterize the ichthyodiversity of Java? (2) Is the geological and paeloecological history of Java a good predictor of diversity patterns and population genetic structure? The main results evidence: (1) large discrepancies between the checklist of the Java freshwater fishes based on historical records and a modern re-appraisal through DNA barcodes. Reasons invoqued are the taxonomic bias related to the interrupted inventory of Java ichthyofauna during the last 3 centuries and the rarefaction of several species targeted by artisanal fisheries. (2) A DNA-based reappraisal of species boundaries and distribution for the genera Nemacheilus and Rasbora indicated two new taxa, several cases of cryptic diversity and several cases of wrong assignement of populations to the species levels. Species range distributions appear to be much more restricted than previously thoughts and question the persistence of these species in changing landscapes. (3) A DNA-based assessment through DNA barcodes of the population genetic structure of three widespread species in Java evidences high levels of cryptic diversity and deep genetic divergences among geographically restricted and non-overlapping mitochondrial lineages. Consistent with a fragmentation related to the rise of volcanic arches in Java that prompted a long-term declines of historical effective population size, this pattern argue for the sensitive conservation status of these mitochondrial lineages. The results presented here highlights the benefits of using a standardized DNA-based approach for the fast characterization of a poorly known fauna and open new perspectives in the conservation of the ichtyofauna of Java and Bali
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Wenner, Gemma Antonine. "Marijuana-tourism| Disruptive Innovation for Small Island Developing States." Thesis, University of Maryland University College, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13428534.

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The Caribbean region consists of many small island developing states (SIDS) that are dependent on a sun, sea, and sand (3-S) tourism product. These SIDS are facing declining competitiveness vis-à-vis other tourism destinations and need to differentiate and rejuvenate their tourism product offerings. This study investigates the extent to which marijuana-tourism can lead to disruptive innovations (DI) in SIDS that are tourist dependent. A systematic review, using 53 research articles and a thematic synthesis analyzing seven different themes: (1) demographic profile of marijuana users and potential market size, (2) marijuana-tourism motivations, (3) common uses of marijuana, (4) types and structures of legal and regulatory frameworks, (5) cultivation, distribution, and marketing factors, (6) economic impacts of legalized recreational marijuana; and (7) adverse health and safety impacts were elaborated. The principal findings are that the regulatory framework for legalization acts as a mediating variable for defining the scope and structure of marijuana-related businesses and tourism niches that appear. When the recreational regulatory framework permits private competition, as evidenced in the early pioneering jurisdictions, significant economic benefits have resulted and at the same time social and health costs have been attenuated to date. In the context of SIDS, legal regimes are still largely prohibitionist, and in a few instances, partial liberalization has occurred. As liberalization progresses, structural and governance challenges exist that may moderate benefits. Further research is needed in many areas, given that the liberalization of marijuana laws is a recent phenomenon. More research is needed in areas, such as in-depth economic and social impacts analysis; the profile, composition, and expenditure patterns of marijuana tourists; the comparative advantages of different regulatory frameworks; and the public health and safety impacts for residents, marijuana tourists, and hospitality sector workers.

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D'Haijere, Tania. "Biogeography of Atlantic Central Africa - Tridactyle (Orchidaceae): a story of speciation and colonisation on São Tomé and Príncipe." Doctoral thesis, Universite Libre de Bruxelles, 2021. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/325606.

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The general objective of this work is to better understand the mechanisms of diversification of the African flora on the Gulf of Guinea islands. We focused on orchids, one of the three predominant plant families on São Tomé and Príncipe. We selected the genus Tridactyle, wich presents a high level of diversity and of endemism in the archipelago.We first redefined the taxonomical framework, as the genus belongs to a clade in which the taxonomical classification did not correspond to the phylogenetic tree obtained by previous studies. To address these classification problems (paraphyly and polyphyly of nominal genera), we firstly used Sanger sequencing to obtain more molecular markers to better estimate the phylogenetic tree of the Tridactyle-Cyrtorchis clade. We used one nuclear marker, the internal transcribed spacer (ITS), and five chloroplastic markers (matK, rps16, trnC-petN intergenic spacer, trnL-trnF intergenic spacer, ycf1). Then, we combined the phylogenetic information to a morphological survey, including as many specimens as possible for the genera concerned. We recircumscribed the previously paraphyletic genus Tridactyle, as well as three other genera within the Tridactyle-Cyrtorchis clade (Rangaeris, Ypsilopus and Podangis), and we described two genera with our collaborators, Aziza and Planetangis. We also described six species new to science, two from East Africa and four from São Tomé and Príncipe. Indeed, the morphological diversity of the Tridactyle in the Gulf of Guinea islands has been misevaluated, such that wrong names have been attributed to species new to science.Once this taxonomic work was achieved, we have focused on two other studies: a biogeographic analysis of Tridactyle, to understand the origin and mechanisms generating its diversity in São Tomé and Príncipe, and a phylogeographic study to analyse the genetic variation and geographical distribution of Tridactyle tridactylites, distributed on the archipelago as well as on the continent. These studies were based on DNA sequence variation of the chloroplast genome and ribosomal DNA genes and the data were generated through Illumina Next Generation Sequencing (NGS), which allowed us to include herbarium specimens for which the classic Sanger method did not give satisfactory results.Our study showed that all Tridactyle species currently found on São Tomé and Príncipe colonised the archipelago independently, and that the current species diversity on the islands is the result of allopatric divergence between the islands and the continent, following island colonisation.- 20 -The intraspecific study revealed a high genetic diversity for Tridactyle tridactylites individuals present on Príncipe, which is not common on oceanic islands, but could be a signal that the island was a refuge for the species during the climatic changes related to ice ages. An approximate Bayesian computation analysis (ABC) of the geographic distribution of genetic variation in Atlantic Central Africa and West Africa favoured a hypothesis of recolonisation of the continent from the island rather than a colonisation of the island from the continent. It is possible that the dust-like seeds used wind currents moving from the islands to Central and West Africa as a mean of travel.The work presented here stresses the importance of conducting such studies on more orchid genera, but also on the two other main families of São Tomé and Príncipe, Rubiaceae and Euphorbiaceae. We made a first step toward a better understanding of the mechanisms of diversifications on the Gulf of Guinea islands, but only with a larger number of studies on diverse families and genera, we could draw more general conclusions about these mechanisms for the flora of the archipelago.With regard to the limitations of our study, we were not able to include all species of the genus, especially species from the Democratic Republic of Congo or East Africa. Sampling in the African rainforests is currently not uniformly carried out, and could be improved. Another way to increase sampling is to use new NGS sequencing methods to extract DNA from herbaria preserved in European Herbarium institutions, and obtain genetic information from the chloroplast and ribosome as we have done, but potentially from low-copy nuclear genes as well.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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30

Moon, Desiree L. "A Study of the Spatial Dynamics of some Introduced Avian Species in the Southwest Region of Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/690.

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The Southwest region of Western Australia is a recognised ‘biodiversity hotspot’, as it possesses high levels of biodiversity and endemism; it also holds a number of species threatened by habitat loss. The arrival of Europeans in the region wrought major changes on the natural landscape. Extensive tracts of bushland were cleared for housing, infrastructure, forestry, farming, and mining. Another challenge to regional biodiversity was the spread of exotic plants and animals (including birds); the latter provide the focus for the present study. The research examines four bird species that colonised the Southwest region following European settlement: Australian White Ibis (Threskiornis molucca); Spotted Dove (Streptopelia chinensis); Laughing Dove (S. senegalensis) and Laughing Kookaburra (Dacelo novaeguineae). The study examines how the feeding and breeding ecology of the species influenced colonisation success and dispersal, specifically in relation to geographic i.e. climate and anthropogenic (e.g. landuse) features of the region. Each of these species has been identified as a ‘generalist’ feeder, with flexible ecological needs. The species have been able to adapt their food preferences and way of life to living in proximity to human settlements. It appears that each utilised resources made available through human endeavour and activities. It appears that the most rapid spread of invaders occurs in areas of modified habitat, in which the proportion covered by natural ecosystems has declined: i.e. in urban areas, pastoral lands and agricultural areas, although conserved natural habitats have also been invaded. The results indicate clear associations between the extent of colonisation success in the first wave of dispersal, and anthropogenic phenomena. Such is evidenced by the range expansion of Australian White Ibis into coastal urban areas, within which foraging success is assisted by access to alternative food sources and roost sites; whereas the species’ movement inland is linked to habitats associated with dairy farming and cattle production. However, the biology of each species and the extent of its ecological flexibility are also influencing factors, as attested by the wide-spread dispersal of the Laughing Kookaburra throughout the study area. This species possesses physiological features that give it an energy advantage over other species and it possesses social behaviours which offer further ecological advantages. Although it is a combination of factors: the biological attributes of the species (which define the ecological aspects of its survival), the geographical features of the adopted landscape, and the impact of human imprint upon that landscape that affect the process of biological invasion, the outcomes are specific to each species. This is shown in the development of markedly different patterns of dispersal, as between the two Streptopelia doves, despite their arriving in the study area under (approximately) the same conditions, and sharing almost identical ecological profiles. As, despite being released into rural areas, the Spotted Dove retained a localised, mainly urban, population, whilst the Laughing Dove has become spread across both urban and rural environments. This may be due to differences in the ability of each species to tolerate dryland conditions, which appear to better suit the Laughing Dove, perhaps due to similarities in climate between the adopted range and the areas from which it originates. It is felt that the study has augmented existing knowledge of biological invasion events in the study area, and contributed towards a greater understanding of biological invasion phenomena, particularly those associated with wheat production, processing, and transport. The study design incorporated Geographic Information Systems (GIS) technology as a means of processing large volumes of historical data. The methodology developed for the study could be adapted to other species, regions and eras, provided sufficient data are available. It produces temporal snapshots of changes in distributions, which can be considered in relation to changes in climate conditions and landuse practices.
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Purvis, Marie-Thérèse. "School improvement in a small island developing state : the Seychelles." Thesis, University of Warwick, 2007. http://wrap.warwick.ac.uk/2710/.

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This thesis presents an evaluative case study of school improvement initiatives in the Seychelles, in a context specific to small island developing states (SIDS). It examines the complexities of borrowing a school improvement model from a larger and more open system (the UK) and the possibilities for adapting it to the local needs. It also considers the significance of the small island and centralised contexts into which the school improvement model was imported. In so doing, the research attempts to determine the factors that may help schools in the SIDS context to develop the internal capacity to improve and to establish the basis for a possible model for school improvement in SIDS. The research is significant because it provides originality as the only study of school improvement in Seychelles secondary schools. It also contributes further insights into the development of the Seychelles School Improvement Programme (SIP); it complements the existing knowledge base on the SIP and adds to the scant literature on school improvement in small states and in centralised systems. The study attempts to capture the multi-faceted nature of the SIP and the multiple forms of people's understanding of it, by examining the most salient aspects of the Programme from the perspectives of different stakeholder groups, through the case study approach. A 40% sample of the country's state secondary schools were studied, using documentary analysis, semi-structured interviews and observation of meetings as the means of data collection. While the SIP has had far reaching implications for school development in the Seychelles system and school improvement strategies such as development planning and school-based professional development have become institutionalised, schools are yet to take ownership of them. It is hoped that the findings of this study may contribute to educators' reflections on effective teaching and learning as well as inform policy and practice.
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Lessig, Heather. "Species Distribution and Richness Patterns of Bird Communities in the High Elevation Forests of Virginia." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35899.

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Island biogeography theory predicts that the patterns and distributions of spatially isolated populations are governed by large scale processes. The high elevations forests in the Southern Appalachians represent a series of naturally fragmented islands that harbor many isolated populations of species at the southern limits of their range. Understanding the governing forces of population dynamics in this region will enhance the probability of species persistence in the face of threats such as global warming and human development. We surveyed bird populations across multiple elevations in Virginia and combined this with a multi-scale habitat analysis to determine influences of species presence and species richness. We detected 101 species across the elevation gradient, including 12 species with special conservation status and ten species whose presence increased with increasing elevation. These ten elevation sensitive species responded to habitat variables at both the microhabitat and landscape scale, with species-specific patterns of habitat variable correlation emerging. Habitat type was least effective in predicting species presence for any elevation sensitive species. Species richness declined over the elevation gradient until the highest elevations, where this trend reversed and richness began to increase. This pattern was driven by an increase in short-distance migrants beginning at mid-elevations, which ultimately overpowered a corresponding decrease in long-distance migrants beginning at similar elevations. Habitat analysis linked these patterns to a preference of short-distance migrants for smaller, more isolated non-forested patches, and a historical lack of persistence for long-distance migrants. Conservation and management decisions for the region should focus on a multi-scale approach that preserves all habitat types for continued species presence and high species richness, although the persistence of particular elevation sensitive species is compounded by unique species-habitat relationships and the perception of islands as species-specific. Continued monitoring of these fragmented populations in light of both short- and long-term threats which span multiple scales of influence will maintain high species richness and ensure the persistence of crucial breeding habitat.
Master of Science
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33

PASLARU, VIOREL. "ECOLOGICAL MECHANISMS IN PHILOSOPHICAL FOCUS." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195862599.

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34

Fethi, Sami. "Economic growth in a small island economy : the case of Cyprus, 1960-1995." Thesis, University of Leicester, 2003. http://hdl.handle.net/2381/30143.

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The determinants of economic growth have long been of interest, and have been empirically investigated in a number of recent studies. A common question in this area is: why have some countries achieved high rates of economic growth whilst the others remained at lower levels? Evidence from the literature indicates that some countries, particularly East Asian countries or small island states exploiting their own comparative advantage, achieve very rapid rate of growth and catch up with already well-off countries. Others, in particular those from Sub-Saharan Africa, have very little or no growth. This thesis empirically investigates the determinants of economic growth in Cyprus over the period 1960-1995 to evaluate whether the Cypriot economic growth during this period is better explained in an 'old' or 'new' growth modelling framework. Advanced multivariate time series techniques are applied to test the validity of models and to examine the relative importance of different variables which may have an impact on both the long-run and short-run growth of the Cypriot economy. The empirical findings show that physical capital investment, human capital and tourism investment are the major causes of growth in the Cypriot economy.
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35

Bosch, Naomi A. "Discovery Islands, Earth Islands: The Theory and Practice of Island Imagery in Environmental Thought." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/pomona_theses/127.

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Earth Island is a core metaphor of activist thought often applied in Environmental Analysis and related fields as a tool for thinking about the planet’s limited resources. It puts forth the claim that if only we thought of the earth as more like an island, we would better understand our connectivity to other living things and be drawn to develop better and more extensive practices of environmental stewardship. This thesis uses personal accounts of environmental life philosophies and political practices collected from residents of the Discovery Islands in British Columbia as a site for analytical comparison between the theory and practice of "Earth Island." First providing an overview of the history of Earth Island and exploring existing Anthropology and Island Studies scholarship on island community dynamics and environmental perspectives, this thesis examines how the environmental relationships experienced by Discovery Islanders reflect or differ from the type of activist consciousness theoretically proposed by Earth Island. This creates a context for critically reflecting on the limits and applications of the Earth Island metaphor, and suggesting shifts in current approaches to the use of island imagery in environmental political and philosophical thought, promoting a focus on more community cooperation-oriented, less fatalistic themes.
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Garcia, Rafael Antonio, and Rafael Antonio Garcia. "I'd Give My Right Kidney to Be Altruistic: The Social Biogeography of Altruism in the United States of America." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625884.

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The purpose of this dissertation is to model biosocial determinants of group-directed altruistic behavior – exploring the nomological net around it. To do this a study will be presented to determine existing associations among various biological and social predictors and test a life-history-derived causal cascade using a partially exploratory and partially confirmatory statistical technique called Sequential Canonical Analysis to ultimately predict living-donor, non-directed kidney donations (NDKD). Toward that end, some important methodological considerations first need to be discussed. The first consideration revolves around the level of analysis and how this frames the cascade model and its interpretation. Following a general discussion, an exercise in some of the general principles is provided – investigating the higher-order factor structure of the Big-5 personality constructs across two levels of analysis. The second consideration is the use of unit-weighted factor scores and their appropriateness. Following the theoretical discussion, a demonstration is provided – deriving an estimate of genetic relatedness from a set of heterogeneous data sets. Once the methodological considerations have been discussed, the primary cascade model is presented in two parts: 1) the measurement model – operationalizing the measures incorporated into 2) the structural model – testing the proposed causal cascade using Sequential Canonical Analysis. A discussion follows in which the results are summarized, limitations are articulated, and further research directions are explored.
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Rogers, Lauren Marie. "A taxonomic and biogeographic analysis of the Trifolium gracilentum species complex." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1565010559912396.

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38

Geyer, Kevin M. "Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64417.

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Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and nutrient cycling. Theory developed to explain patterns in plant and animal distributions such as the prevalent relationship between ecosystem productivity and diversity may be successfully extended to microbial systems and accelerate an emerging ecological understanding of the "unseen majority." These considerations suggest a need to define the important mechanisms which affect microbial biogeography as well as the sensitivity of community structure/function to changing climatic or environmental conditions. To this end, my dissertation covers three data chapters in which I have 1) examined patterns in bacterial biogeography using gradients of environmental severity and productivity to identify changes in community diversity (e.g. taxonomic richness) and structure (e.g. similarity); 2) detected potential bacterial ecotypes associated with distinct soil habitats such as those of high alkalinity or electrical conductivity and; 3) measured environmental controls over the function (e.g. primary production, exoenzyme activity) of soil organisms in an environment of severe environmental limitations. Sampling was performed in the polar desert of Antarctica's McMurdo Dry Valleys, a model ecosystem which hosts microbially-dominated soil foodwebs and displays heterogeneously distributed soil properties across the landscape. Results for Chapter 2 indicate differential effects of resource availability and geochemical severity on bacterial communities, with a significant productivity-diversity relationship that plateaus near the highest observed concentrations of the limiting resource organic carbon (0.30mg C/g soil). Geochemical severity (e.g. pH, electrical conductivity) primarily affected bacterial community similarity and successfully explained the divergent structure of a subset of samples. 16S rRNA amplicon pyrosequencing further revealed in Chapter 3 the identity of specific phyla that preferentially exist within certain habitats (i.e. Acidobacteria in alkaline soils, Nitrospira in mesic soils) suggesting the presence of niche specialists and spatial heterogeneity of taxa-specific functions (i.e. nitrite oxidation). Additionally, environmental parameters had different explanatory power towards predicting bacterial richness at varying taxonomic scales, from 57% of phylum-level richness with pH to 91% of order- and genus-level richness with moisture. Finally, Chapter 4 details a simultaneous sampling of soil communities and their associated ecosystem functions (primary productivity, enzymatic decomposition) and indicates that the overall organic substrate diversity may be greater in mesic soils where bacterial diversity is also highest, thus a potentially unforeseen driver of community dynamics. I also quantified annual rates of soil production which range between 0.7 - 18.1g C/m2/yr from the more arid to productive soils, respectively. In conclusion, the extension of biogeographical theory for macroorganisms has proven successful and both environmental severity and resource availability have obvious (although different) effects on the diversity and composition of soil microbial communities.
Ph. D.
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39

Barallon, Linda. "Leadership development in small island states : the case of the Seychelles." Thesis, University of Warwick, 2011. http://wrap.warwick.ac.uk/55369/.

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In common with many other countries including small island developing states (SIDS), the criteria for appointment as a head teacher in the Seychelles were not formalised but, in practice, promotion was based mainly on teaching qualifications and experience, level of commitment shown to education, and contributions made to public life. Since 2002, educational leadership training has been offered to senior school leaders through a partnership between Seychelles and UK universities but it is not clear whether these qualifications enable head teachers to lead their institutions effectively. In practice, the acquisition of such training is being considered in the selection and appointment of senior school leaders but this is not yet an official policy. This thesis reports research focused on people in headship and other senior leadership positions in Seychelles who have followed one of these programmes. The research is an evaluation of the leadership development project designed to inform senior ministry officials of its impact. It presents a critical view of leadership development and its impact in a specific context, a SIDS with a centralised education system. In a survey involving 100% of these trained leaders, the interview responses highlight issues related to the basis of their selection for training and subsequent appointment in post; their training experiences, the extent to which they have been able to put into practice what they have learnt, and how their learning has impacted on their respective school. Responses obtained from senior Ministry officials show how the trained leaders’ performance after training is perceived within the Ministry. A case study of a primary school examines in depth observable changes in leadership practices impacting on school outcomes that are attributed to leadership training and development. The research shows that the Seychelles education system was very successful in preparing its leaders through partnerships with HE education bodies; with more than 90% of senior school leaders (heads and deputy heads) achieving a master’s qualification. The findings also show a positive impact in terms of leaders’ satisfaction with the course, changes in their knowledge, disposition and skills; changes in their leadership practices and, to some extent, improved school outcomes. The findings revealed a lack of established structures and comprehensive programmes for induction and mentoring of leaders; the lack of formal criteria and procedures for the selection of leaders for training, appointment, promotion and deployment; and limited provision for on-going support and continuous professional development. Central selection prevails with female domination of leadership positions at system and institutional levels. The significance of this research is mainly in its originality as the only study of leadership development, and its impact on school outcomes, in Seychelles.
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40

Jaja, Jessica. "Beyond Climate Change Theory: What Contributes to the Adaptive Capacity of Caribbean Small Island Communities?" Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32173.

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The focus of this research is on identifying the determinants of local-level climate change adaptive capacity in Caribbean small island communities. A single case study approach was employed to assess retrospectively both internal and external factors that contributed to the adaptive capacity of Paget Farm, Saint Vincent and the Grenadines. The Caribbean region’s first solar-powered desalination plant was implemented in the community specifically as a climate change adaptation strategy and thus provides an ideal case for retrospective analysis. A series of semi-structured interviews with local residents and key stakeholders revealed a number of interacting social and institutional factors that contribute to community-based adaptive capacity. Further analysis of institutional factors was undertaken using Social Network Analysis, which enabled visualization and quantification of vertical and horizontal institutional integration of the networks formed during different phases of project implementation. The research extends scholarly understanding of the determinants that influence local-level climate change adaptive capacity and provides practical evidence that can assist small island communities to respond to a changing climate.
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Whittaker, Nicholas James. "The Island Race : geopolitics and identity in British foreign policy discourse since 1949." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/62069/.

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This thesis examines Britain's foreign policy identity by analysing the use of geopolitical tropes in discursive practices of ontological security-seeking in the British House of Commons since 1949, a period of great change for Britain as it lost its empire and joined NATO and the EC. The Empire was narrated according to a series of geopolitical tropes that I call Island Race identity: insularity from Europe and a universal aspect on world affairs, maintenance of Lines of Communication, antipathy towards Land Powers and the Greater Britain metacommunity. The aim of this thesis is to genealogically historicise and contextualise these tropes through interpretivist analysis of Commons debates concerning a series of events and issues from the establishment of NATO to the current parliament. By conceptualising parliamentary discourse as a social practice involving the fixing of ontologically secure subject positions, it presents a new reading of modern British foreign policy that addresses the traditional neglect of geopolitics and identity in approaches depicting a materially declining state engaging in the pragmatic pursuit of realist national interests. The analysis shows how Britain's foreign policy identity continues to be reliant on the geopolitical constitutions of islandness that discursively defined the empire. This is not indicative of imperial nostalgia so much as it is evidence of how discursive practices of ontological security-seeking in a political environment with a shared debating culture tend to mobilise established identity tropes that have retained relevance even without their imperial underpinnings. Narrations of the Cold War and NATO, relations with the rest of Europe and globalisation are shown to be reliant on Island Race tropes that, through contextual interactions, fix Britain in subject positions of relevance according to how British values, forged by insular geography, are of universal relevance to a world in which Britain is in a pivotal geopolitical position.
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42

Labaudiniere, Margaux Salome. "Three Mile Island, Chernobyl, and the Fukushima Daiichi Nuclear Crises: An Argument for Normal Accident Theory." Thesis, Boston College, 2012. http://hdl.handle.net/2345/2616.

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Thesis advisor: Donald Fishman
This paper will study three particular accidents in the nuclear industry: Three Mile Island, Chernobyl, and the Fukushima Daiichi plant. These crises will be evaluated through a crisis management framework, using two main accident theories: Normal Accident Theory, and High Reliability Theory. The examination of the crises and the organizations involved will show that no matter how reliable the complex systems are, accidents are inevitable in the nuclear industry. High reliability theory expresses an ideal for complex organizations. While following the theory’s suggestions can limit some problems from occurring, acting as a mindful and reliable organization cannot prevent all disasters. The three cases presented in this paper will show that Normal Accident Theory must be accepted by the nuclear industry. Thus, governments and nuclear power plant operators must be prepared with crisis management plans in order to successfully handle emergency situations and limit damages. The first part of this paper will introduce Normal Accident Theory and High Reliability Theory. Then, after a brief overview of the basics of nuclear power, Three Mile Island, Chernobyl, and Fukushima Daiichi will be examined in the theoretical framework, including a discussion of each event’s crisis management techniques
Thesis (BA) — Boston College, 2012
Submitted to: Boston College. College of Arts and Sciences
Discipline: College Honors Program
Discipline: Communication
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43

Medley, Kimberly. "Dispersal, Gene Flow, and Adaptive Evolution During Invasion: Testing Range-Limit Theory with the Asian Tiger Mosquito." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5435.

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Understanding the factors that make non-native species successful invaders is an important step towards mitigating spread. At the same time, species invasions can serve as natural experiments to test range-limit theory. Range-limit theory postulates declines in local abundance (abundant center model) and genetic diversity (central-peripheral hypothesis) towards range edges because of underlying environmental gradients. Such declines constrain adaptation to marginal habitats via gene swamping. However, broader evolutionary theory predicts intermediate rates of immigration into range-edge populations can relieve genetic drift and improve adaptive potential. I tested hypotheses generated from theory while illuminating aspects affecting of the invasion of the Asian tiger mosquito (Aedes albopictus Skuse) into the US. Using reciprocal distribution modeling, I found US populations occupied significantly different climate and habitat than in their native range (SE Asia). Most inconsistencies were found in the northern US range, where Ae. albopictus has recently crept northward, providing an opportunity to test range-limit theory as the range reaches its limit. Because of its limited natural dispersal ability, rapid spread after the 1985 US introduction pointed to human-aided dispersal. I tested the current role of human-aided versus natural dispersal using a landscape genetics framework, and found that natural dispersal dominated current patterns. Some distant localities were highly genetically similar, indicating potential human-aided transport in limited cases. Asymmetric gene flow from core to edge localities supported the abundant center model, but uniformly high genetic diversity contrasted with the central-marginal hypothesis. I detected a significant signature of local adaptation by overwintering diapause-induced eggs in multiple field sites using reciprocal transplants. Surprisingly, most genotypes from throughout the range produced large offspring when overwintered at the range edge. Relative offspring mass between home and away winters peaked at an intermediate immigration rate. These results show that rapid adaptation has occurred in US populations of Ae. albopictus and highlight the potential for further spread. Genetic admixture from multiple introductions may explain high genetic diversity throughout the US range and contribute to high offspring size for all genotypes overwintered at the range edge. Finally, my work highlights the need for a better understanding of contemporary ecological and evolutionary processes leading to range-limits (or expansion) to more accurately reflect processes occurring in a human-dominated world.
Ph.D.
Doctorate
Biology
Sciences
Conservation Biology; Ecology and Organismal Biology
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44

McNamara, David Joseph. "Applying the Theory of Constraints (TOC) to the Component Section of Naval Aviation Depot (NADEP), North Island." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23541.

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45

Al, Darmaki Ibrahim Abdul Rahman. "Globalisation and urban development : a case study of Dubai's Jumeirah Palm Island mega project." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/67552/.

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Mega projects have become an important new development strategy in globalizing cities, and a new or emerging form of development in economic, technological, social and political life, influenced by global flows of capital. Despite being acknowledged as an important factor in globalizing economies, the role of mega projects has failed to receive appropriate research attention in terms of analysis of the various advantages and disadvantages that they carry. This research seeks to achieve a better understanding of the nature of urban development, and its implications for Dubai. The research involves an assessment of whether urban mega projects actually develop as a result of globalisation processes and draws conclusions on conflicting discussions about economic growth and social change. The research aims to establish Dubai’s attitudes towards urban mega projects and globalisation, focusing on the ways the phenomenon is conceptualized, and on understanding the impacts of the new urban paradigm, with particular reference to the Jumeirah Palm Island mega project. The research sets out to examine three key issues; firstly what are the effects of global economic factors and foreign direct investment, and how have economic factors have become a catalyst for development? Secondly, the thesis considers the technological and architectural features of large-scale development. Thirdly, it focuses on new social trends and the extent of public participation, and analyses the political dimensions of globalisation. The research reveals that whilst there are some similarities with other mega projects around the world, the Jumeirah Palm Island mega project is the product of a unique development policy. There are many global elements in the Palm Island development but there is also a significant regional dimension, as in many of the underpinning capital flows. It is argued that the adoption of a mega projects policy may have had negative consequences on the indigenous population of Dubai, which has become a minority 12% of the total population.
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46

Villanueva, Zandro Vasquez. "CULTURAL ENCOUNTERS AND TRANSFORMATION OF EARLY HISTORICAL POLITIES ON LUBANG ISLAND, THE PHILIPPINES, CA. A.D. 1200-1800." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195058.

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This study explores the nature of culture contact experience of the early historical polities in the Philippines. The historical analysis and the result of the archaeological excavation at Lubang Island allows us to reexamine the entanglements of local populations against the colonial culture and how these entanglements have been perceived, mediated, and even transformed by the actions of native peoples in the past. The present study offers an alternative model for culture contact studies and how to generate questions about human behavior and interaction in the past by using critical analysis of ethnohistorical documents, archaeological data, and anthropological theory.Under the general model of culture contact study and colonialism, the archaeological study focuses on the documentation and analysis of a collection of artifacts and faunal remains excavated from a settlement-fortification site, believed to have been occupied and used from the early A.D. 1200s to the late A.D.1800s.In this dissertation, I use historical data to examine the historical trajectory of local polities on Lubang Island and situate them in a particular context where native people's interactions with other groups define their everyday actions as reflected in the archaeological record. I develop an alternative model using an agency-based approach that focuses on the relationships linking human actors and their behavior in the past. Such a model allows us to rethink the history of Lubang Island and its people according to how they acted and defined themselves. Moreover, the issues of complexity in small-scale polities in the Philipppines need to be teased out in order to elucidate the different levels and scales of complexity in the various historical contexts of early polities in Island Southeast Asia. Only then can we truly understand the variables involved in social reproduction and the ways in which early Filipinos lived and encountered cross-cultural interaction in the past.
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47

Kay, M. K. (Nod). "An experimental evaluation of resource allocation in island plants with respect to their invertebrate herbivores." Lincoln University, 2008. http://hdl.handle.net/10182/1442.

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New Zealand’s isolation and periods of marine transgression have limited its biota to an extent which can be considered depauperate, even by island standards. Endemic vertebrates are rare and prominent invertebrate families, such as the renowned forest defoliators of the Lymantriidae, are absent. The proven vulnerability of the flora to introduced vertebrates reaffirms a belief in the invasiveness of islands and fuels the contingency plans aimed at averting similar devastation from further alien invertebrate defoliators. Nothofagus is a dominant element of the climax forests of New Zealand and the larger landmasses bordering the South Pacific Ocean. Assessments of the resistance to defoliation of continental and New Zealand species of Nothofagus, and a range of other forest genera endemic to New Zealand, was undertaken using bioassays of naïve polyphagous defoliators. The bioassays were undertaken in Europe, utilising gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae) and the fall webworm, Hyphantria cunea (Lepidoptera: Arctiidae) as defoliators, fed foliage plants growing in European arboreta. In New Zealand, bioassays utilised Australian painted apple moth, Teia anartoides (Lepidoptera: Lymantriidae) and tree species from local arboreta, gardens and natural populations. Larval growth rate was the primary parameter recorded to assess plant resistance. The relevance of growth rate was investigated by comparison with other recorded parameters and resistance to a surrogate pathogen, in the form of commercially available bio-insecticide. Larval growth rate was positively correlated with survivorship, potential fecundity, mating success and resistance to disease. The growth rate of larvae fed Nothofagus was positively correlated to the species-specific leaf nitrogen content. The results of the bioassays showed that despite the accepted paradigms, New Zealand’s flora was largely resistant to exotic defoliators. As an explanation of this apparent anomaly, the Island Resource Allocation (IRA) hypothesis was developed and posits that ‘the palatability iv of a plant to invertebrate herbivores is proportional to the geographic range of the plant’. The basis for the IRA hypothesis proposes a redefinition of the fundamental ecological principle of the species: area relationship. Islands, or similarly geographically constrained ecosystems, which support lower biodiversity, have impoverished trophic levels and consequently have weaker top-down regulation of herbivores by natural enemies. The IRA hypothesis argues that island ecosystem stability is achieved through the bottom-up process of plant defence. The IRA hypothesis was tested intra-specifically using bioassays using painted apple moth in which larvae were offered foliage of specimens from naturally discontinuous populations of Nothofagus truncata. The results supported the hypothesis in that the smallest populations of N. truncata exhibited the greatest resistance to the defoliator. The IRA hypothesis and a demonstrated mechanism for a differential resistance in Nothofagus species could resolve a number of enduring debates in ecology. Habitat area appears to explain the relative strengths of top-down and bottom-up regulation of herbivores. It also predicts the strengths of reciprocal evolution within the geographic mosaic of co-evolution and highlights the influence of biodiversity in invasive ecology. It may also help to resolve the contentious and extremely relevant debate of the role of biodiversity in ecosystem function.
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48

Sabbar, Ehsan H. "Defect and Island Nucleation in Materials: Kinetic Monte Carlo, Rate Equation Theory and Temperature Accelerated Dynamics (TAD) Simulations." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1544443201322287.

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49

Martin, Camie Frandsen. "A Survey of Invasive Exotic Ants Found on Hawaiian Islands: Spatial Distributions and Patterns of Association." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3854.

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An intensive sampling of all ant species encountered on 6 Hawaiian Islands: Big Island, Maui, Oahu, Kauai, Molokai, and Lanai took place between 1988 and 1996. Species presence and absence was recorded at each site. Using remote sensing, variables were added insitu and used throughout my analysis. Species accumulation curves suggest that sampling was comprehensive. There is a significant trend between island area and species richness which validates the Theory of Island Biogeography for invasive species. Islands were found to be significantly nested by area, order, and tourism. Cluster analysis shows a link between elevation, land-use and island, and species presence. Predictive models can be built to predict spread of particular ant species as they continue toward equilibrium.
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50

Gates, Susan Wharton. "Rediscovering the Heart of Public Administration: The Normative Theory of In His Steps." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30513.

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Public administration literature lacks richness and context regarding the moral history of the founding of the field in the early 1900s. As a result, current calls for "recapturing the soul" of public administration have failed to stimulate a theory-or even a working understanding-of how to "rehydrate" the observed desiccation of public life and revivify the concept of the public interest. In correcting the historical record, this dissertation shows that the "soul" of public administration stemmed from the field's deep roots in the social gospel movement of the early 20th century. For that short period, the nascent field was not viewed as a bastardization of constitutional order, but as a noble endeavor in which beloved sons and daughters participated in their nation's governance. As a representative character of that era, Charles M. Sheldon serves as an exemplar of a citizen administrator whose sojourn into the public square was characterized by deep faith, empathy for the common person and commitment to action-regardless of the personal cost. His optimism, innovation and creativity stand in sharp relief to today's dispirited and over-regulated public work force. Sheldon's best-selling book, In His Steps (1896), stands as a pre-modern parable for moral decision-making in a dynamic and uncertain postmodern environment. In allowing for uncertainty, discourse and experimentation, the book's operative question, "What would Jesus do?" enriches our understanding of normative theory as process. It also offers back the field's lost "soul" in the way of submission, empathy, covenant, grace and hope.
Ph. D.
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