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Dissertations / Theses on the topic 'Species diversity'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Barraclough, Timothy Giles. "Biological correlates of species diversity." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320144.

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2

Senft, Amanda Ruth Peet R. K. "Species diversity patterns at ecotones." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2210.

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Thesis (M.S.)--University of North Carolina at Chapel Hill, 2009.<br>Title from electronic title page (viewed Jun. 26, 2009). "... in partial fulfillment of the requirements for the degree of Masters of Science in the Department of Biology." Discipline: Biology; Department/School: Biology.

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3

Platt, Jacqueline Berengaria. "Habitat complexity and species diversity in rivers." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/23242/.

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1. Rivers are highly structured ecosystems in which habitat complexity and heterogeneity are postulated to affect species diversity and abundance. However, the exact links between habitat structure and organisms such as macro-invertebrates remain poorly understood. 2. Field surveys at the patch and reach scale were combined with a field experiment in the Rivers Wye and Usk, Wales, to: i) quantify variations in habitat complexity and heterogeneity among habitats and river sections, ii) assess their influence on macro-invertebrates, iii) separate the ecological effects of confounding physical fa

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4

Davies, Thomas Jonathan. "Environmental energy and species diversity in flowering plants." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408927.

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5

Morath, Simon. "Effects of tree species diversity on insect herbivory." Thesis, Royal Holloway, University of London, 2013. http://repository.royalholloway.ac.uk/items/916c671f-79af-41eb-99b1-df69faa84961/1/.

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It is generally believed that tree species growing in mixed forest stands are less susceptible to insect herbivore damage than if grown in monocultures, but previous studies have been largely observational and focussed mainly on tree species richness effects. In this thesis, I examined effects of three components of forest diversity (tree species richness, intraspecific genotypic diversity and functional diversity) on insect herbivores using three long-term forest diversity experiments in Finland and Germany. I have also explored the sources of variation in and the mechanisms behind the effect

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6

Nicholson, Wendy Elizabeth. "Increasing plant species diversity in contaminated upland grassland." Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275503.

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7

Berens, Jeffrey David. "Morphological Differences and Diversity of Small Mammal Species." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/27710.

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Small mammals play important roles in ecosystems, but are often overlooked due to their small size and plentiful abundance. Two studies evaluated the morphological differences and diversity of small mammal species based on how they react to different environmental conditions. The first study analyzed the morphological differences of skulls between and within two species of Peromyscus species due to differences in shape, size, and geographic position. This study also determined if landmark-based geometric morphometrics could reliably discriminate between the two species. The second study analyz

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8

Gutiérrez, Lucía. "Genetic diversity in cultivated and wild Hordeum species." [Ames, Iowa : Iowa State University], 2008.

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9

Posthumus, Erin Elizabeth. "Do Red Squirrel Middens Promote Vertebrate Species Diversity?" Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/294022.

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The modifications animals make to their environments can be critical to species diversity. Red squirrels (Tamiasciurus hudsonicus) create large piles of conifer cone debris (middens) and are hypothesized to function as a keystone species due to positive associations between middens and other vertebrate species. We assessed vegetation and landscape structure at middens with a resident red squirrel for varying consistencies over the prior 5 years and surveyed mammals and birds at the community and population level. After accounting for vegetation and landscape characteristics, red squirrel-creat

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10

Cooper, Fiona Mary Phillips. "Geographic distribution and genetic diversity of black poplar." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246878.

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11

Corum, Aaron K. "Sixteen valence-electron species containing boron structural diversity abounds /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4303.

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Thesis (M.S.)--University of Missouri-Columbia, 2005.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 13, 2006) Includes bibliographical references.

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12

Seipel, Timothy Fridolin. "Plant Species Diversity in the Sagebrush Steppe of Montana." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/seipel/SeipelT1206.pdf.

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Sagebrush (Artemisia tridentata) is abundant in Montana and is an obvious part of an assemblage of plant species.This community of plants; the sagebrush steppe contains a mixture of grasses, early and late season forbs and shrubs. It is found in semi-arid valleys and plains of Montana and the intermountain western United States, and has received much research attention regarding increasing livestock forage, or of wildlife's dependence on the sagebrush steppe plant communities.Yet, little information on plant species diversity exists. This thesis was undertaken to describe the plant species div

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13

Noyszewski, Andrzej Krzysztof. "Mitochondrial Sequence Diversity Among Alloplasmic and Euplasmic Triticum Species." Diss., North Dakota State University, 2013. https://hdl.handle.net/10365/27020.

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Four mitochondrial genomes of Triticum species were sequenced and annotated: 1) (lo) durum mitochondrial genome, which is an alloplasmic line with Triticum longissimum(SS) cytoplasm and T. turgidum (AABB) nucleus, 2) T. longissimum, 3) T. turgidum and 4) T. tauschii (DD). Comparison showed major differences in atp6, nad9, nad6, rps19-p, cob and cox2 genes among all four species. Additionally, species-specific ORFs were also identified. A single nucleotide polymorphism search within known genes showed that the alloplasmic line differs from the two parental lines by six nucleotides in the cox3,

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14

Carvalho, Maria João Mendes de. "Diversity of Aeromonas species from different environments in Portugal." Doctoral thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/976.

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Doutoramento em Biologia<br>Espécies de Aeromonas encontram-se distribuídas por diferentes habitats, estando especialmente relacionadas com ambientes aquáticos. O seu papel em complicações na saúde humana e animal é reconhecido. De facto, não só pelo seu potencial de virulência, mas também pelos determinantes genéticos de resistência a antibióticos que possam conter, estes organismos constituem uma preocupação na medicina humana e veterinária. Assim, é essencial o estudo da diversidade de espécies de Aeromonas bem como explorar as suas características fenotípicas e genéticas que podem c

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15

Bushula, Vuyiswa Sylvia. "Genetic diversity and pathogenicity of sorghum-associated Fusarium species." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/35196.

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Doctor of Philosophy<br>Department of Plant Pathology<br>Christopher R. Little<br>Understanding the genetic structure of fungal pathogens enables the prediction of evolutionary forces that drive pathogen evolution, which assists informed decision-making regarding disease management. The genetic structure of Fusarium thapsinum and F. andiyazi, two important pathogens that cause grain mold and stalk rot of sorghum (Sorghum bicolor), are little understood. The genetic structure and pathogenicity of a F. thapsinum population from sorghum in Kansas were evaluated with amplified fragment length po

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16

Cuschieri, Katie Sarah. "Species diversity of aggregate-associated marine ammonia-oxidising bacteria." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602054.

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Two broad communities can be distinguished in marine systems, those attached to amorphous aggregate material dispersed throughout the water column and those that are freely suspended in the water column (planktonic). It has been suggested that two distinct microbial populations are associated with each habitat due to phenotypic adaptation to the different conditions in aggregates and the surrounding water. The aim of this study was to investigate the diversity of aggregate-associated and planktonic marine ammonia oxidisers (AOBs - the organisms responsible for the rate limiting step in nitrifi

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17

Santos, Ricardo. "Diversity, stress responses and ecological behaviour of Mycobacterium species." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709877.

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Mycobacterium is one of the oldest known bacterial genera and its species are commonly associated with human and animal disease, although most are free-living saprophytes which form part of a balanced microbial community in natural habitats such as water and soil Mycobacteria are highly distributed in the environment and in man-made water infrastructures mainly due to its robustness and ability to adapt Until now there are only scarce reports of their presence in extreme environments but no methodic and large-scale survey of these environments has been done in order to truly understand their d

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18

Barnes, Emma Catherine. "Chemical Diversity of Eremophila Species and Screening Library Generation." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/366931.

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This thesis explores two aspects of natural product (NP) chemistry. In part A, the use of NPs as scaffolds in the generation of screening libraries was explored as a valuable way to produce structurally diverse compounds with lead- or drug-like physicochemical parameters. Part B describes the chemical investigations of several species from the under-studied Australian endemic plant genus Eremophila, which was selected for examination as it had high potential to be a source of both new chemistry and of unique scaffolds for screening library production.<br>Thesis (PhD Doctorate)<br>Doctor of Phi

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19

Estes, Becky Lynne Gjerstad Dean H. "Impact of interacting disturbances on longleaf pine communities." Auburn, Ala., 2006. http://repo.lib.auburn.edu/Send%206-15-07/ESTES_BECKY_24.pdf.

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20

Goodwin, Zoe A. "Completing the global inventory of plants : species discovery and diversity." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:94f1a4d9-30fc-4f1b-8642-7b68760e1977.

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To complete an online world Flora by 2020 rapid progress is required towards understanding the taxonomy and distributions of the world's plants. This ambitious target set by the Global Strategy for Plant Conservation is hampered by two facts; first, many species of seed plant remain poorly known and second, the process of improving taxonomy and discovering species is not well understood. Here I investigate in detail the taxonomy and process of species discovery in a genus of tropical plants, Aframomum by examining specimens, taxonomic literature and authors of specimen determinations. I demons

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21

De, Carvalho Ximenes Arimatéa. "Mangrove species range limits and species diversity: A macroecological approach from regional to global scales." Doctoral thesis, Universite Libre de Bruxelles, 2019. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/285690.

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The mangrove forest is an ecosystem distributed worldwide along tropical andsubtropical coastlines. The environmental conditions are known to affect species distributionpatterns, and to understand them is one of the main goals of biogeography. The association ofenvironmental factors (e.g. temperature and precipitation) and species distribution patterns haschallenged scientists since long. Species are distributed in a geographical space, however, whyspecies are present in a certain location but absent in another is a fundamental question inbiogeography. This PhD thesis aims at better understand

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22

Bogardus, David C. "Comparison of tree species richness and species diversity in public landscapes of Broward County, Florida." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024623.

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23

Peh, Kelvin Seh-Hwi. "The relationship between species diversity and ecosystem function in low- and high-diversity tropical African forests." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511142.

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24

Lee, Jonathan Eric. "Partitioning β-diversity in species-area relationships: implications for biodiversity and conservation". Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1273172956.

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25

Van, der Vyver Marius Lodewyk. "Restoring the biodiversity of canopy species within degraded spekboom thicket." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1564.

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I investigated the return of plant canopy diversity to degraded spekboom thicket landscapes under restoration treatment. I attempted the reintroduction of five nursery propagated and naturally-occurring plant species in severely degraded Portulacaria afra Jacq. (spekboom) dominated thickets that have been subjected to a restoration method involving the planting of dense rows of P. afra truncheons for various time periods and also in degraded and intact thickets. I also planted nursery propagated P. afra cuttings. An average of 30 propagules of each species, were planted in each of the chosen a

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26

Kaambo, Eveline. "Investigation of South African estuarine microbial species and genome diversity." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8171_1186398717.

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<p>A study of the microbial diversity in sediments of the Great Berg River estuary is carried out using modern molecular phylogenetic methods. The aim of this study was to determine the effect of (pollution by) the effluents of the fish industry on the composition of the microbial community in the sediments. The diversity in microbial groups of sediment samples that received wastewater from the local fishing industry was investigated by a PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) approach and compared to an unaffected site.</p>

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27

Veldkornet, Dimitri Allastair. "Morphological variation and species diversity of South African Estuarine macrophytes." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1013001.

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Studies on morphological variation are important as it can depict the relationship with environmental factors clearly and convey an understanding of the manner, mechanism and factors influencing plant adaptation and evolution. Although many studies have been conducted on South African salt marsh plant physiology and phytosociology there are at present very few morphological studies on estuarine plants. The aim of this study was to compare the morphological variation of estuarine macrophytes in three different estuary types in the warm temperate biogeographic zone of South Africa and to compare

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28

Chan, Ivis Julieta. "Modelling spatial turnover patterns in tree species diversity for conservation." Thesis, Bournemouth University, 2015. http://eprints.bournemouth.ac.uk/24394/.

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The planet’s biodiversity is increasingly threatened by the effects of rapid environmental change. Biodiversity loss led by expanding anthropogenic activity, combined with the effects of changing climatic regimes, pose a threat to natural communities and the ecosystem services that they underpin. Understanding how communities of species vary across space and the factors that drive such variation is essential to predicting the impacts of human and climate-induced changes on biodiversity and ecosystem services. This knowledge can be used to plan conservation areas that effectively represent the

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29

Richard, Monique. "Fern species diversity in relation to spatial scale and structure." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0002/MQ44258.pdf.

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30

Richard, Monique 1972. "Fern species diversity in relation to spatial scale and structure." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20850.

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Species with different requirements can coexist if the environment varies in space; we therefore expect a positive relationship between species diversity and environmental heterogeneity. In this thesis I examine the influence of environmental structure on patterns of fern diversity in one hectare of old-growth forest and compare these patterns to other surveys covering a broad range of scales. The nineteen species recorded in the hectare had non-random spatial distributions and differed in their soil preferences. Diversity was positively related to soil moisture and negatively related to soil

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31

Darwell, Clive T. "Species composition and patterns of diversity in fig wasp communities." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590090.

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Here I use the wasps associated with figs (Ficus, Moraceae) to investigate a central theme of describing and understanding the composition and patterns of diversity among fig wasp communities, largely with respect to geography. Namely. in describing a community, what factors need to be considered, what methods need to be implemented, and what evolutionary and ecological processes can be identified as having shaped the observed patterns. An introductory chapter outlines a number of issues in ecology with particular focus on fig wasps. Chapter 2 investigates the efficacy and level of agreement b

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32

Green, Jennifer. "Genetic diversity in annual weed species at different spatial scales." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394431.

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33

Gillen, Susan Marie. "Links between species diversity of ammonia oxidising bacteria and pH." Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275092.

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Our ability to analyse natural microbial populations has recently been revolutionised by the application of 16S rDNA-based techniques. These techniques have proven particularly appropriate for ammonia oxidising bacteria, which carry out the initial and rate-determining step in nitrification. The strong effect of pH on ammonia oxidisers has been well documented; growth in liquid batch culture rarely occurs at pH values below 6.5 but autotrophic nitrification can occur in acidic soils. This study aims to examine the effects of pH in ammonia oxidisers in soil and laboratory culture. We employ bo

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34

Munyenyembe, Mutiyenkhu Paul. "Biological diversity of species in the leguminosae genus Dolichos L." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332062.

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35

Day, Andrew. "Environmental bacteriophages infecting Dickeya and Serratia species : receptors and diversity." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/290114.

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Phytopathogenic Dickeya species inflict large economic losses on a variety of crops. A lack of effective chemical control methods has generated interest in the use of bacteriophages (phages) as a novel tool for biocontrol. In the last decade, six phages have been isolated in Belgium and Poland using Dickeya solani as the host. Previous work in this laboratory has isolated ninety phages capable of infecting D. solani. The majority have been morphologically classified as members of the Ackermannviridae family. In agreement with findings in Salmonella and Klebsiella species, the capsule of D. sol

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36

Alsayied, Nouf Ahmad Fakieh Alsayied. "Molecular diversity and relationships of saffron and wild crocus species." Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/32189.

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Crocus sativus L., saffron Crocus, is a sterile triploid (2n=3x=24) species of unknown relationship to other diploid and polyploid species in the genus Crocus (Iridaceae). The species have large genomes (typically 3000Mbp 1C), much repetitive DNA, and show high morphological diversity within and between species, with no clear phylogenetic patterns below the level of section Crocus, series Crocus. I aimed to examine molecular diversity in C. sativus and related species by analysis of sequences and IRAPs (Inter Retroelement Amplified Polymorphisms). Repetitive DNA sequences and genomic DNA from

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37

Mól, Abel Perigolo. "How many species? Ecological drivers of cricket (Orthoptera: Grylloidea) diversity." Universidade Federal de Viçosa, 2012. http://locus.ufv.br/handle/123456789/3946.

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Made available in DSpace on 2015-03-26T13:30:40Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1259817 bytes, checksum: 312ebed75b287bd629b3efca4b0ea9ea (MD5) Previous issue date: 2012-02-24<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>No capítulo 1, este estudo investiga os determinantes da diversidade e abundância de grilos de serapilheira, e as possíveis interações com feições geomorfológicas. Ainda, nós propomos uma abordagem analítica que inclui amostragem local passiva como uma explicação necessária para a variação da diversidade e evidencia eventuais efeitos do

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38

Emrick, Verl III. "Disturbance, Functional Diversity and Ecosystem Processes: Does Species Identity Matter?" Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23211.

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The role of disturbance is widely recognized as a fundamental driver of ecological organization from individual species to entire landscapes. Anthropogenic disturbances from military training provide a unique opportunity to examine effects of disturbance on vegetation dynamics, physicochemical soil properties, and ecosystem processes. Additionally, plant functional diversity has been suggested as the key to ecosystem processes such as productivity and nutrient dynamics. I investigated how disturbance and functional composition both singly and in combination affect vegetation dynamics, soil phy

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Grobbelaar, Joha. "Taxonomy, phylogeny and species diversity in the Ophiostoma quercus complex." Diss., University of Pretoria, 2009. http://hdl.handle.net/2263/79241.

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Polymorphic sequence-characterised marker assays from a recent diversity study on the Ascomycete fungus Ophiostoma quercus from Africa showed that some isolates collected from hardwoods were genetically distinct from O. quercus. In the present study we compared these African isolates with authentic O. quercus isolates, including the neo-type of the species from oak in France, by evaluating morphological characters, growth in culture, mating compatibility, and DNA sequence data. The isolates from Africa exhibited substantial variability in culture and were morphologically similar to O. quercus.

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40

Roth, McKenzie L. "Analysis of Bacterial Abundance and Species Diversity in Various Soils." Ashland University Honors Theses / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=auhonors1355166102.

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Osburn, Andrew Wesley. "Understanding Weed Species Diversity in Railroad Crossing Rights-of-way." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574641066802878.

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Honorio, Coronado Euridice Nora. "Phylogeography and phylogenetic diversity of Amazon tree species and communities." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/4605/.

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The Amazon rain forest is the most diverse ecosystem on Earth, harbouring more than ten thousand tree species. In this project, I used ecological and molecular information to explore how ecological factors and historical events have determined the species distributions and population genetic structure of tree species and the phylogenetic diversity of tree communities in the Amazon rain forest. Chapter 2 indicates that seasonally dry vegetation in northern South America represents a barrier to migration for Ficus insipida (Moraceae) and other wet-adapted Amazonian tree species as they have diff

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Weiser, Michael Dennis. "Latitudinal Patterns of New World Species Diversity and Range Size." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195130.

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The latitudinal gradient in species diversity is one of the best-documented patterns in biogeography. Explanations for the latitudinal gradient in species diversity (LGSD) ranging from null models to evolutionary and ecological hypotheses rely on relationships between range size and species richness. I test Rapoport's rule, where mean range size of tropical organism is predicted to be smaller than for temperate and boreal organisms, using New World woody plants. Geometric constraint models (GCMs) posit that barriers to dispersal, in the absence of ecological and evolutionary gradients can

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Chowdhury, Tanmay. "Ethnobotany of Dakshin Dinajpur district with special reference to diversity and conservation of ocimum species." Thesis, University of North Bengal, 2017. http://ir.nbu.ac.in/hdl.handle.net/123456789/2571.

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45

Persson, Malin. "Changes in species diversity among echinoderms in the sill area of Gullmarsfjorden : Effects on changes in species composition among echinoderms - ecosystem functions and possible changes." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-23672.

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Increasing attention has been given marine benthic macrofauna due to its importance in marine ecosystems and for its value as bioindicator of environmental changes. One of the most abundant groups among benthic macrofauna are echinoderms which often hold keystone positions in the ecosystems and have proven to be good bioindicators. The aim of this study was to inventory echinoderms and analyze whether species diversity has change over time in Gullmarsfjorden, a fjord with limited water exchange and hence highly sensitive to environmental fluctuations. Also, what may have caused any changes and

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Verschuyl, Jacob Pieter. "Biodiversity potential in the Pacific and Inland Northwest the relative importance of forest structure and available energy in driving species diversity /." Diss., Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/verschuyl/VerschuylJ0507.pdf.

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47

Qasim, Amina. "Diversitet av mossor och lavar på åkerholmar i ett öppet och ett skogsdominerat landskap." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-121430.

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De ekologiskt betydelsefulla småbiotoperna blir allt färre i det moderna jordbruket på grund av intensifieringen av jordbrukslandskapet som resulterat i ett allt mer fragmenterat landskap. För att kunna ge småbiotoper, såsom åkerholmar, ett optimalt skydd behövs flera studier om organismerna på holmarna, deras diversitet och spridning. I denna undersökning studeras artrikedomen av mossor och lavar på busk- och trädbekädda samt öppna åkerholmar i ett öppet- och ett skogsdominerat landskap. Analysen av artrikedom i studien tyder på att de finns fler arter av mossor och lavar i det öppna landskap

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48

Yenni, Glenda Marie. "Self-limitation as an explanation for species' relative abundances and the long-term persistence of rare species." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1958.

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Much of ecological theory describes species interactions. These interactions often play an important theoretical role in facilitating coexistence. In particular, rarity in ecological communities, though often observed, provides a significant challenge to theoretical and empirical ecologists alike. I use a plant community model to simulate the effect of stronger negative frequency dependence on the long-term persistence of the rare species in a simulated community. This strong self-limitation produces long persistence times for the rare competitor, which otherwise succumb quickly to stochastic

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Sutherland, Darin Lee. "Phylogeography and Ecology of New Zealand Freshwater Amphipoda (Paracalliope, Paraleptamphopus, and Phreatogammarus)." The University of Waikato, 2006. http://hdl.handle.net/10289/2650.

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ABSTRACT This thesis examines phylogenetic patterns in three New Zealand amphipod taxa in relation to current geographic distributions and historical climatic (e.g. glaciation, marine inundation) and geological (e.g. mountain building) events using DNA sequencing and distributional data. It also examines how recognition behaviour can be used to delineate potential species boundaries and to assess the role of sexual selection. The endemic genus Phreatogammarus has been found in only a limited number of sites and is not very abundant. An analysis of the genetic variation of two species within t

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Uimaniemi, L. (Leena). "Maintenance of genetic diversity in four taiga specialists." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514274105.

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Abstract Genetic diversity in three taiga specialists – the Siberian tit (Parus cinctus), the Siberian jay (Perisoreus infaustus) and the Siberian flying squirrel (Pteromys volans) – was assessed by comparing DNA sequence variation across the mitochondrial control region and allele frequencies of microsatellites from samples collected from Fennoscandia and Siberia. Population sizes of these species have declined in association with fragmentation and loss of suitable forest habitat due to modern forestry practices in Fennoscandia. The red squirrel (Sciurus vulgaris) served as a referen

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