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Dissertations / Theses on the topic 'Diversity of nature'

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Published: 4 June 2021
Last updated: 4 February 2022

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1

Eskew, Paul. "Textural Diversity." VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd/1259.

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The sculptures I create reflect the elements of the natural world such as trees, the lumpy bush, clumps of turf. They have imperfect yet fascinating textures, picturesque in form, seemingly fractal in design, working together harmoniously to serve the aesthetic. My sculptures, like these natural shapes, are heavy or thicker toward the bottom and lighter toward the top, like a tree or stone. I strive to echo the mercurial, the animated natural surfaces, and the enticing vignettes one would experience on a woodland stroll.
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Thiele, Wiebke [Verfasser], and Michael [Akademischer Betreuer] Müller. "How nature directs diversity: investigation of selective phenol-coupling enzymes in ascomycetes." Freiburg : Universität, 2020. http://d-nb.info/1236500237/34.

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D'Arcy, N. "Exploring the nature and diversity of microorganisms in healthcare and educational settings." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1426614/.

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Many human populations spend approximately 90 % of their time indoors, yet relatively little is known about the microbial communities associated with indoor environments. This is despite knowledge that these microorganisms can contribute to adverse health effects, including the acquisition of healthcare-associated infections, which cause significant morbidity and mortality. The concept of the ‘indoor microbiome’ is relatively new and to date, few studies have been field-based, systematic and long-term. Hospitals in particular, are unique environments which have been shown to drive microbial evolutionary processes as they contain a different sub-set of the human population. The study of the hospital microbiome could have important implications for healthcare and infection control. This thesis explores a range of methods for investigating microorganisms in different indoor environments, including a classroom and outpatient’s waiting areas and wards in a hospital. Results show that the classroom is much more heavily contaminated in terms of total viable counts (TVCs) of bacteria recovered than the hospital environment. This was thought to be attributed to the absence of a strict cleaning regime in the classroom. High-touch items were less contaminated than other objects, likely due to them being obvious cleaning targets. Potential pathogens, including a number of Enterobacteriaceae were cultured from the classroom, outpatient’s waiting area and ward. Virus nucleic acid was recovered from an outpatient’s area, including norovirus and rotavirus RNA. Adenovirus DNA was frequently isolated throughout a 3 month screening protocol and there appeared to be evidence to suggest that a viral marker may be more appropriate than TVCs for identifying viral contamination. Human-associated bacteria were found to be dominant on a hospital ward over a 12 month longitudinal screening study and the presence of numerous bacterial taxa, which may be of concern in the context of paediatrics and immunodeficient patients, was also demonstrated.
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Albert, Laura. "Redefining Suburbia." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/85614.

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Suburban housing is a building type and form of development that has been neglected by many architects. Architects are responsible for designing only two percent of suburban residences. This means that the profession has largely ceded the best opportunity to be relevant and useful to ordinary people. The name itself, sub-urban, implies that the suburbs are less than or secondary to the urban typology. Suburban can also be used as an adjective to describe something which is dull and ordinary. And yet, more and more people continue to move to the suburbs each year. Since 1970, a greater percentage of the population has lived in the suburbs than in central cities or rural areas. This thesis examines why people want to live in the suburbs and the impact of suburban development on the economy, the environment and social institutions. The conclusions of this investigation are then used to redefine the current concept of suburbia as it relates to nature, community and diversity. These concepts are in turn incorporated into a prototype for a suburban housing development. The prototype is a 38 unit residential housing development on a 2-acre wooded site in a suburb 16 miles west of Washington, DC.
Master of Architecture
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Wale, Kim. "A history of the present : recognizing the complex and shifting nature of racism and resistance in the life narratives of the Khayelitsha Internal Forces." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/8114.

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This research attempts to represent and analyze the life-story narratives of a group of five former anti-apartheid combatants. Narratives were collected from a total often, in-depth, life-history interviews with five former-members of the Khayelitsha Internal Forces. The Internal Forces represent a group of ex-combatants who were operating in the Western Cape as a para-military Self Defense Unit (SOU) during the 1986-1994 period of popular township revolt. The first stage of analysis consists of five re-constructed summaries of each of the participant's narratives with a particular focus on common themes running through the experience of childhood to the experience of joining the internal forces.
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Alfaro, Lucas Joan Manel. "Influence of hydrothermal activity and substrata nature on faunal colonization processes in the deep sea." Thesis, Brest, 2019. http://www.theses.fr/2019BRES0089.

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Quatre décennies après leur découverte, nous savons maintenant que les sources hydrothermales sont répandues, diversifiées et dynamiques et qu’elles interagissent avec d’autres écosystèmes des grands fonds marins. Face aux potentiels impacts anthropiques qui pèsent sur les environnements hydrothermaux, il devient essentiel d’avoir une meilleure compréhension des processus qui façonnent la biodiversité de ces écosystèmes et de leurs interactions avec d’autres écosystèmes. Les processus structurant l'élaboration des communautés et contrôlant les interactions entre les habitats actifs, la périphérie et les communautés liées aux bois, ont été étudiés grâce à une vaste expérience de colonisation à 1700 m de profondeur sur le champ hydrothermal Lucky Strike (nord de la dorsale médio-Atlantique). Un cadre d’analyse moderne et multifacettes, basé sur la richesse spécifique, les traits fonctionnels et les isotopes stables, a été appliqué. Les résultats ont montré que les sites actifs supportent une richesse fonctionnelle plus élevée que les habitats périphériques.En outre, la diversité spécifique et fonctionnelle des habitats périphériques était très hétérogène, ce qui suggère qu’ils pourraient être particulièrement vulnérables aux impacts liés à l'exploitation minière. Les redondances fauniques et les liens énergétiques observés suggèrent que, plutôt que d'être des entités séparées, les habitats actifs et périphériques semblent être interconnectés. Les conditions environnementales et la présence de différentes ressources ont été identifiées comme étant les principaux facteurs influençant la biodiversité et la structure des communautés. Le rôle des bois en tant que potentielles « pierres de gué » pour la dispersion de la méio- et la macrofaune, non seulement pour les habitants des sources hydrothermales mais aussi pour ceux de la périphérie, est validé. Les résultats de cette thèse améliorent significativement notre compréhension des processus qui structurent les communautés associées aux sources hydrothermales et aux autres écosystèmes chimiosynthétiques dans les grands fonds marins et pourraient avoir des implications importantes dans l’élaboration de stratégies de protection dans le cadre d’éventuelles activités industrielles
Four decades after their discovery, we know now that deep-sea hydrothermal vents are widespread, diverse and dynamic, and interact with other chemosynthetic-based and background ecosystems. In the face of potential imminent anthropogenic impacts, more than ever the understanding of the processes that shape vent biodiversity, in its multiple facets, and the interactions with other systems is of paramount importance. The early processes driving community assembly and interactions between hydrothermally active habitats, vent periphery and cognate communities, namely wood falls, were investigated with an extensive colonizing experiment at 1700 m depth onthe Lucky Strike vent field (northern Mid-Atlantic Ridge). A modern multifaceted framework of community assembly based on species richness, functional traits and stable isotopes was applied. Results showed that vent ecosystems support higher functional richness that background peripheral habitats.The latter were highly heterogeneous and unique in species and functions suggesting that they may be especially vulnerable to impacts, such as deep-sea mining. The observed faunal overlap and energy links suggest that rather than being separate entities, active and peripheral habitats may be considered as interconnected. Environmental conditions and the presence of different resources at vent, periphery and wood habitats, were identified as main drivers of biodiversity patterns and community structure. The roleof woods in the deep-sea as potential stepping stones for meio- and macrofauna, not only for “vent” but for periphery inhabitants, is validated. The results of this thesis significantly improve our understanding of vent and chemosynthetic communities and may haveimplications for their protection from industrial activities
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7

Damon, Coralie. "Impact de la nature du couvert végétal sur la diversité taxonomique et fonctionnelle des champignons symbiotiques et des microorganismes eucaryotes associés." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10061.

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Au sein des sols forestiers, la richesse taxonomique et le rôle des microorganismes eucaryotes (en grande partie des champignons) restent encore largement méconnus. L’espèce d’arbre est un des facteurs qui structurent les communautés de ces microorganismes. Nous avons étudié l’impact de l’essence forestière (hêtre et épicéa) sur la diversité taxonomique et fonctionnelle de ces communautés par une approche métatranscriptomique et une approche biochimique (focalisée sur les champignons ectomycorhiziens). Nous avons montré un effet de la séquence étudiée (ADNr 18S, ADNc) sur la distribution taxonomique des communautés et développé un nouveau marqueur moléculaire mitochondrial pour l’étude des communautés de champignons métaboliquement actifs. L’identification de gènes d’intérêt écologique et industriel par séquençage systématique des banques métatranscriptomiques ainsi que l’identification fonctionnelle d’une nouvelle famille de transporteursmembranaires montrent l’intérêt de l’approche métatranscriptomique. L’approche biochimique a consisté en un dosage à haut débit, sur des extrémités racinaires ectomycorhizés, d’activités enzymatiques liées à la dégradation de la matière organique et à la mobilisation de l’azote et du phosphore du sol. L’ensemble de ces approches a permis de montrer un impact de l’essence forestière sur la nature des espèces présentes plutôt que sur la richesse taxonomique et une préférence d’hôte de certains groupes fongiques ectomycorhiziens. L’approche biochimique a montré une redondance fonctionnelle importante pour certaines activités enzymatiques tandis qu’une autre activité enzymatique était spécifique d’un groupe taxonomique fongique
In forest soils, taxonomic richness and functional diversity of eukaryotic microorganisms (mainly Fungi) remain largely unknowned. Tree species is one of the main factors that structure eukaryotic microbial communities. We have studied the impact of tree species (beech and spruce) on taxonomic and functional diversity of these communities by using a metatranscriptomic approach and a biochemical one focusing on ectomycorrhizal fungi. We showed an effet of different sequences (18S rDNA, cDNA) on taxonomic composition of eukaryotic microbial communities and we developped anew mitochondrial molecular marker for the study of metabolically active fungal communities. Identification of ecologically and industrially important genes by the shotgun sequencing of metatranscriptomic libraries and also identification of a new family of transmembrane transporter demonstrate the great potential of the metatranscriptomic approach. The biochemical approachconsisted in a multiple enzymatic test carried out on ectomycorrhizal roots, of enzyme activities linked to organic matter degradation and phosphorus and nitrogen mobilization. All these approaches revealed an impact of tree species on the microbial species composition but not on taxonomic richness and also host preference for some ectomycorrhizal taxonomic groups. The biochemical approach showed a high functional redundancy for some enzyme activities while one activity was very specific of an ectomycorrhizal taxonomic group
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Ei, Thandar Bol. "Effects of forest disturbances on edaphic factors and tree community structure of tropical evergreen forest; a case study in Kyaik Htee Yoo Nature Reserve Forest, Mon State, Myanmar." Kyoto University, 2017. http://hdl.handle.net/2433/228246.

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9

Martin, Anaëlle. "L'instrumentalisation du principe de subsidiarité, un révélateur de la nature juridique de l'Union européenne." Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAA001.

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Du fait de son ambiguïté fondatrice, de ses connotations politiques et de son caractère relativement récent, le principe de subsidiarité, expressément consacré dans l’ordre juridique de l’Union européenne par le traité de Maastricht, fait l’objet d’une instrumentalisation par de nombreux acteurs à des fins souvent contradictoires mais néanmoins cohérentes avec la nature juridique de l’Union. Si à l’évidence, sa consécration dans le droit primaire visait, à l’instar de celle du principe de proportionnalité, à rassurer les États membres et les citoyens européens de ce que l’action de l’Union se limiterait au strict nécessaire, le principe de subsidiarité était cependant porteur d’une charge quelque peu subversive en raison de sa dynamique potentiellement ascendante et de sa signification implicitement fédérale. Appliquer la subsidiarité, pour les institutions européennes qui sont les gardiennes de son respect, revient presque toujours à justifier l’intervention de l’Union au regard des objectifs de l’action envisagée et, partant, à disqualifier l’action des échelons inférieurs. Pour autant, et de façon assez paradoxale, l’instrumentalisation de la subsidiarité ne s’inscrit pas tant dans une dimension fédérale que fonctionnelle tant il est vrai que le fédéralisme cherche à promouvoir des valeurs comme l’autonomie et la diversité, ce que la subsidiarité, malgré les apparences, ne permet pas de garantir. Présentée comme un instrument de fédéralisation de l’Union européenne, la subsidiarité n’est, en réalité, qu’un instrument d’intégration puisqu’elle n’a jamais su s’extraire de la matrice fonctionnaliste qui caractérise la construction européenne depuis toujours
Due to its founding ambiguity, its political connotations and its relatively recent character, the principle of subsidiarity, expressly enshrined in the legal order of the European Union by the Treaty of Maastricht, is being instrumentalized by many actors for purposes that are often contradictory but nevertheless consistent with the legal nature of the European Union. While its consecration inprimary law, like that of the principle of proportionality, was obviously intended to reassure Member States and European citizens and ensure that the Union's action would be limited to what is necessary, the principle of subsidiarity was nevertheless some what subversive because of its potentially ascending dynamic and its implicitly federal content. Applying subsidiarity, for the European institutions which are the guardians of its observance, almost always means justifying the Union's intervention with regard to the objectives of the envisaged action and, therefore, disqualifying action by the lower levels of government. Paradoxically, however, the instrumentalization of the principle of subsidiarity is not so much « federal » as « functional », since federalism seeks to promote values such as autonomy and diversity, which subsidiarity, despite appearances, does not guarantee. Usually presented as an instrument of federalization of the European Union, the principle of subsidiarity is in reality an instrument of integration since it has never been able to extricate itself from the functionalist matrix that has always characterized the construction of Europe
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Thondhlana, Gladman, and Juliette V. Lagesse. "The effect of land-use on small mammal diversity inside and outside the Great Fish River Nature Reserve, Eastern Cape, South Africa." Elsevier B.V, 2016. http://hdl.handle.net/10962/67823.

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This study investigated small mammal species diversity at 10 paired contrast sites along a fence line inside and outside the Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. The sites outside the GFRNR are used for subsistence land-based activities including livestock production and fuelwood harvesting. From 145 live captures, a total of 114 unique individuals of five small mammal species (four rodents and one elephant shrew) were recorded over 1170 trap nights. Average small mammal species diversity and abundance were significantly higher inside the reserve than outside. Human activities such as livestock grazing seemed to explain low levels of small mammal diversity and abundance at the communal sites. Vegetation variables showed a complex interplay with small mammal diversity. In general, high vegetation diversity had a positive influence on small mammal diversity though the influence of some environmental variables was species-dependent. We conclude that the GFRNR is effective in protecting small mammals but the findings raise questions around the influence of land use practices such as livestock grazing on biodiversity, especially given that local communities in South Africa are continuously seeking greater access to reserves for livestock grazing and other provisioning services.
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Ghorbani, Dahaneh Abdolbaset [Verfasser], and Joachim [Akademischer Betreuer] Sauerborn. "Agrobiodiversity and its use in Naban River Watershed National Nature Reserve : implications for bio-cultural diversity conservation / Abdolbaset Ghorbani Dahaneh. Betreuer: Joachim Sauerborn." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2012. http://d-nb.info/1027353983/34.

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12

Plastow, Brian. "Suppressing the diversity of the ‘other’ : the nature, extent and impact of racism experienced by visible ethnic minority residents in rural southeast Scotland." Thesis, University of Leicester, 2011. http://hdl.handle.net/2381/8985.

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In recent years a growing body of academic research has identified the distinct phenomenon of rural racism. Despite this, the problem is largely unknown outside of academia and therefore those charged with a General Duty to promote effective race relations in the rural are often ‘blind’ to the problem. At the heart of the issue is the social and cultural conflation of notions of the rural as a problem free traditional ‘white landscape’ and the exercise of power and prejudice over those constructed as ‘other’. Whilst the Scottish Government has recognised the significant issue of racism in Scotland, the paucity of research means that little is known about the exact ‘nature’, ‘extent’ and ‘impact’ of the problem within specific rural localities. Accordingly, this research explores those key variables within five distinct rural areas of southeast Scotland and reveals how the process of ‘othering’ works to exclude and marginalise visible ethnic minorities by actively suppressing their diversity. The research methodology involved both qualitative and quantitative aspects and included a public attitudes survey questionnaire and focus groups with white residents, analysis of racial incidents reported to the police, a quality of life survey questionnaire and interviews with visible ethnic minorities who had been victims of racism. This analysis was conducted against an analytical framework provided by Philo’s (1992) ‘othering theory’. The research findings reveal a disturbing, complex and multi-dimensional landscape of endemic racism within rural southeast Scotland that has a profound impact on victims. In doing so, it also reveals and challenges the shifting lens of ‘agency’ and ‘state’ as the advocacy of multiculturalism so embraced after Macpherson has now apparently come to be seen as ‘yesterdays news’ through new post 7/7 state racisms which appear to reconstitute certain ethnic minority communities as a ‘problem’ that now requires to be ‘controlled’.
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Ghorbani, Dahaneh Abdolbaset Verfasser], and Joachim [Akademischer Betreuer] [Sauerborn. "Agrobiodiversity and its use in Naban River Watershed National Nature Reserve : implications for bio-cultural diversity conservation / Abdolbaset Ghorbani Dahaneh. Betreuer: Joachim Sauerborn." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-7326.

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Reimerson, Elsa. "Nature, culture, rights : exploring space for indigenous agency in protected area discourses." Doctoral thesis, Umeå universitet, Statsvetenskapliga institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110737.

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There is considerable geographical overlap between areas set aside for nature conservation or protection and Indigenous peoples’ lands, and the social, economic, and political consequences of protected areas have often been extensive for Indigenous peoples. Discourses of conservation converge with discourses of Indigenous peoples, and both carry a legacy of colonial constructs and relationships. With these overlaps as a point of departure, the purpose of this thesis is to explore how the discourses that govern nature conservation and protected areas shape the conditions for Indigenous peoples’ influence and participation in the governance and management of protected areas on their lands. I pursue this aim by analyzing, and critically examining the consequences of, the construction of Indigenous subject positions and conditions for agency in discourses of nature conservation and protected areas. The empirical focus of the thesis lies with international discourses of protected areas and Indigenous peoples and on local and national discourses articulated in relation to two cases of protected areas in Sápmi. My analytical framework builds on postcolonial theory and discourse theory. I use space for agency as a concept to describe and analyze the effects of the discursive positionings and constructions that shape the ability or capacity of individuals or group to act or to be perceived as legitimate actors. My results show twomain articulations of Indigenous subject positions in protected area discourses, which enable and restrain the space for Indigenous agency in different ways. One articulation connects Indigenous peoples to conservation through the concept of traditional knowledge, thereby positioning Indigenous subjects mainly as holders of traditional knowledge and justifying Indigenous influence by its potential contribution to conservation objectives. The other articulation focuses on the rights pertaining to Indigenous peoples as peoples, including land rights and the right to selfdetermination. These articulations are not necessarily mutually exclusive, but they have potentially different consequences and indicate discursive tensions that can affect the space for Indigenous agency in relation to protected areas. Moreover, my results demonstrate the hegemony of discourses that takes conservation through area protection for granted and subordinates Indigenous land use to conservation objectives, structure Indigenous agency as “participation” in specific types of arrangement, and articulate Indigenous rights in relation to hegemonic constructions of sovereignty, self-determination, and rights. These hegemonic formations silence articulations that would challenge the authority of colonizing societies over Indigenous territories, suppress radical critique of the fundamental nature of arrangements for protected area governance and management, and subdue alternatives to discourses of contemporary liberal democracy and individual property rights.
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Hanekom, Nicolaas Willem. "The impact of different land uses on the phytodiversity of the West Coast Strandveld in and around Rocherpan Nature Reserve." Thesis, Cape Peninsula University of Technology, 2007. http://hdl.handle.net/20.500.11838/855.

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Thesis (MTech (Applied Sciences))--Cape Peninsula University of Technology, 2007
Changes in plant specIes richness and diversity were investigated in Rocherpan Nature Reserve across a fence (or old fence line) separating 34 years of conservation management, conservation management for 11 years south and north, natural veld grazed by cattle and goats, natural veld grazed by sheep, and strip-ploughed veld grazed by sheep. Vegetation surveys were conducted in September 2001. The modified 20 m x 50 m Whittaker plot design with its attractive features of long-thin plots and the original Whittaker plot design were used. Number of species (as richness data) and the numbers of individual recordings per species per land use (as abundance data) were used in calculations in the 20 m x 50 m (1000 m2 ) plots. The species richness index showed significantly smaller numbers of species in the conservation management 11 years south land. The results also showed an increase in species numbers under the grazing land use systems. The data from the comparative study of the five different species diversity indices showed no significant differences. As a result, the Shannon-Wiener index was selected for further assessing the species diversity index and the species diversity significance of different land uses in the West Coast Strandveld. In this particular study, the species that showed an increase in vegetation cover in response to grazing land use regimes were Hemimeris racemosa (annual herb) and Ehrharta brevifolia (annual grass).
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Caballero, López Berta. "La diversitat d'artròpodes als agro-ecosistemes: efectes del paisatge, la gestió agronòmica, i la composició de la flora arvense = Arthropod diversity in agro-ecosystems: the effects of landscape, management and assembly of weed communities." Doctoral thesis, Universitat de Barcelona, 2010. http://hdl.handle.net/10803/670836.

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La agricultura ecológica se ha planteado como una posible solución paliativa a las negativas consecuencias de la intensificación agrícola. Aunque los beneficios de una agricultura más sostenible y menos intensiva son claros para la flora arvense de los campos de cereales gestionados ecológicamente, no son tan obvios para grupos de artrópodos oportunistas como son los pulgones que pueden ocasionar grandes pérdidas económicas, ni para sus enemigos naturales. Los estudios que abordan el tema de planta-artrópodo son escasos y frecuentemente se ciñen a evaluar las abundancias de ciertos grupos en vez de estudiar el impacto de la comunidad vegetal entera sobre la comunidad de artrópodos. Así que es necesario evaluar la interacción entre grupos funcionales vegetales (gramíneas, dicotiledóneas (excluyendo leguminosas) y leguminosas) y grupos funcionales de artrópodos (herbívoros succionadores y masticadores, consumidores florales, saprófagos, omnívoros, parasitoides, y predadores) para poder evaluar la efectividad real de las medidas agro-ambientales aplicadas en estas últimas décadas en la búsqueda de una gestión más sostenible.
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Broshot, Nancy Ellen. "The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon." PDXScholar, 1999. https://pdxscholar.library.pdx.edu/open_access_etds/3962.

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The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control. Many tree variables, especially those related to shade-tolerant species, were positively correlated with both the distance from downtown Portland and the number of houses in the surrounding area, and negatively correlated with the distance from the nearest forest edge; however, many shrub and herbaceous variables were negatively correlated with the distance from downtown Portland. Species diversity for herbaceous and shrub species was greater at more urban sites, but diversity of trees was lower at more urban sites. There were significantly more non-native species of plants in the city section. I found significantly fewer saplings and small trees, especially shade-tolerant species, in the section of Forest Park closest to downtown Portland, although tree mortality was positively correlated with distance from Portland. Summer bird data revealed significant increases in the abundances of urban and edge species at more urban sites, with concomitant reductions in forest species. There were significantly more ground gleaning birds and short distance migratory species. I also found a significantly greater abundance of birds in the old-growth stand during the winter. This increase was positively correlated with the depth of snow in the nearby Cascade Mountains. My results indicate that Forest Park is apparently progressing in a normal successional pattern with the exception of the city section. The reduction in shade tolerant saplings and small trees in the city section suggest that rate of succession has been slower at more urban sites. Avian data suggest that urbanization affects bird species abundance and guild composition in the more urban areas.
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Steinwall, Anders. "To do or not to do : dealing with the dilemma of intervention in Swedish nature conservation." Licentiate thesis, Umeå universitet, Statsvetenskapliga institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-128925.

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Nature conservation is often seen as being primarily about shielding parts of nature from human intervention, e.g. by protecting areas. Over the last decades, however, intervention is increasingly being seen as necessary for nature to regain or retain its values, through ecological restoration and active management. This complicates simple assumptions that ‘nature knows best’ and raises dilemmas which are hotly debated in the scholarly literature around ecological restoration, protected area management, environmental ethics and green political theory. However, how these dilemmas are dealt with in actual policy struggles among the conservation professionals who make management decisions is less studied. This thesis explores how issues regarding active intervention in nature are represented, debated and institutionalized within Swedish nature conservation, and to what effect. The empirical focus lies on policy struggles around the designation and management of protected forests and around efforts to save a nationally threatened bird species, the white-backed woodpecker. My analytical framework is informed by Argumentative Discourse Analysis and Political Discourse Theory, to which I contribute a further elaboration of the notion of discourse institutionalization. Based on documents and interviews with conservation professionals, I identify competing articulations of the ends and means of conservation and relate these to scholarly debates around ecological restoration and interventionist conservation management. The analysis further focuses on how elements of the different policy discourses are institutionalized in rules, routines or official policy documents. Two main competing policy discourses are found: one focused on leaving pristine nature to develop freely, and one focused on active, adaptive management for biodiversity. While the former has previously been said to characterize the Swedish conservation bureaucracy, my analysis shows it is now widely seen as outdated. Arguments which in the scholarly literature are associated with an ethically informed defense of nature’s autonomy are here dismissed as emotional, aesthetic and thus unscientific concerns, delegitimizing them within the rational, science-based public administration for nature conservation. In contrast, biodiversity is broadly forwarded as a self-evident goal for active intervention, in line with both science and policy requirements. Adaptive management for biodiversity is in that sense the dominant discourse. Still, the older discourse is institutionalized in the purposes and management plans of existing nature reserves, and its defenders have also succeeded in strengthening that institutionalization through new and more restrictive guidelines. The findings suggest that this has been possible not only because of the gate-keeping role of a few centrally placed actors, but also because their restrictive stance resonates with the outside threat of exploitation which organizes the common order of discourse. Naturalness, a term described as irrelevant by some proponents of adaptive management for biodiversity, is also shown to remain a shared concern in several ways. The results thus highlight the importance of both entrenched common sense and institutionalization of certain logics or arguments in authoritative documents. The main theoretical contribution of the thesis consists in clarifying the effects of such discourse institutionalization — using the terms durability, legibility and leverage — and showing how the processes of negotiation, re-interpretation and modification of institutions are more dynamic than some accounts of discourse institutionalization suggest. Rather than trying to resolve (and thus remove) the dilemma of intervention, the thesis points to the importance of keeping open discussion of the ultimately unanswerable questions about intervention in nature alive in both theory and practice.
Ecosystem restoration in policy and practice: restore, develop, adapt (RESTORE)
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19

Pagès, Escolà Marta. "New insights into the ecology and conservation of bryozoans: from global diversity patterns to the responses to anthropogenic stressors in the Mediterranean Sea = Noves aproximacions a l’ecologia i conservació dels briozous: des dels patrons globals de diversitat fins les respostes als impactes humans al Mar Mediterrani." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668538.

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Marine ecosystems are directly threatened by multiple and interactive human stressors at global and local scales. Hence, it is vital to study biodiversity and ecological patterns through a multi-disciplinary approach, from understanding global diversity patterns to evaluating the ecological responses of species to different impacts in order to protect marine ecosystems. In this thesis, we focused on bryozoans, an abundant group of sessile marine invertebrates distributed worldwide, but generally understudied. Accordingly, in this thesis we provide different approaches to understand discovery and macroecological patterns at global scales, and the response of species to different stressors at local scales, combining the use of open databases, the in situ monitoring of natural populations, experiments in aquaria and the development of restoration techniques. At global scale, in Chapter I we unraveled discovery patterns of fossil and extant bryozoans and showed the highest number of fossil species described, highlighting that the current biodiversity represents only a small proportion of Earth’s past biodiversity. Beyond these differences, both groups showed an increase in the taxonomic effort during the past century. Despite this progress, future projections of discovery patterns of both groups showed a large proportion of species remaining to be discovered by the final of this century. In Chapter II, most of the global diversity patterns of marine sessile groups, including bryozoans, showed a non-unimodal latitudinal pattern with a dip in the number of species at the equator and a higher diversity in the Southern ocean. Moreover, this region will be less affected by global warming at the final of this century. In contrast, our analyses showed that the most sampled region for both marine sessile species and bryozoans was North Temperate Atlantic, highlighting the importance to quantify environmental drivers considering sampling effort biases. For this reason, we tested the effect of using the popular method of rarefaction (ES50) vs the incorporation of a frequency index of sampling effort as co-variate in quantitative models. Despite we obtained the same best predictors for both approaches (depth, nitrate, and SST), the models using the correction of sampling biases through frequency index showed better fitting, encouraging to incorporate this methodology in future studies. Focusing on the Mediterranean Sea, in Chapter 3 we studied the responses of bryozoans to different stressors. First, we showed that two abundant and common bryozoans, Pentapora fascialis and Myriapora truncata, displayed different tolerances to warming through the combination of in situ monitoring and experiments in aquaria. Moreover, in Chapter 4 the in situ monitoring of Pentapora fascialis populations revealed its fast population dynamics, with high recruitment and growth rates, and a high capacity of recovery. Accordingly, we observed an increase in the density of its populations in the Medes Island Marine Reserve since the 1990s. However, we evidenced that diving can impact on the density, recruitment, survival, and size of the colonies, registering lower values in frequented localities. Our results highlight that the over frequentation of divers compromises the future viability of populations, highlighting the need to explore other active management strategies. For this reason, in Chapter 5, we tested and developed different restoration techniques for P. fascialis, focusing on the recruitment enhancement through the installation of recruitment surfaces and the transplantation of adult colonies. The successful results and the affordable and economic cost of tested techniques aim to encourage the managers of Marine Protected Areas to apply similar methodologies. The results presented in this thesis show the importance to combine different approaches to understand the global and local ecological patterns of understudied but abundant groups, such as bryozoans. Our findings enlarge the current ecological knowledge of bryozoans at different scales, and highlight that more effort is needed to protect vulnerable populations.
Els ecosistemes marins estan sotmesos a múltiples impactes a escales locals i globals i que a més interaccionen entre ells. Per aquesta raó, és important estudiar els patrons de biodiversitat i ecològics a través d’una aproximació multi-disciplinària, que pot anar des d’entendre els patrons de diversitat global fins a avaluar les respostes ecològiques de les espècies enfront diferents impactes, per així conservar i gestionar adequadament les comunitats marines. Fins aquest moment, la majoria d’estudis relacionat s’han centrat en grups carismàtics i populars, com ara les gorgònies, els coralls, les macroalgues o les fanerògames marines. En canvi, aquesta tesis es centra en l’estudi dels briozous, un grup abundant de invertebrats sèssils marins distribuïts per tot el món, però generalment poc estudiats. Per aquesta raó, el principal objectiu d’aquesta tesis és utilitzar diferents aproximacions per entendre els patrons de descobriment i macro-ecològics a escala global, i la resposta a diferents impactes a escala local, combinant el ús de bases de dades globals, el seguiment in situ de les poblacions, experiments en aquaris i el desenvolupament de tècniques de restauració. A més, la present tesis vol proporcionar un marc de treball per identificar, gestionar i conservar les poblacions vulnerables en el context de l’augment de les activitats humanes que afecten els ecosistemes marins. Els resultats presentats en aquesta tesis mostren la importància d’aplicar diferents aproximacions per entendre els patrons ecològics globals i locals de grups abundants però poc estudiats, com són els briozous. Els resultats obtinguts contribueixen a augmentar el coneixement dels patrons ecològics dels briozous a diferents escales, i mostren que cal més esforç per protegir les poblacions vulnerables. Així, mesures de gestió adaptativa i de restauració i són necessàries per promoure la conservació dels ecosistemes marins en un context de impactes creixents derivats de l’activitat humana tant a escales locals com globals.
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Wolf, Isabelle Diana Felicitas Gudula Biological Earth &amp Environmental Sciences Faculty of Science UNSW. "Towards sustainable tourism in outback Australia: the behaviour and impact of nature-based tourists on vegetation and selected wildlife species." Awarded by:University of New South Wales. Biological, Earth & Environmental Sciences, 2009. http://handle.unsw.edu.au/1959.4/44572.

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Nature-based tourism offers significant socio-economic incentives to successfully replace more intrusive land uses but also causes negative environmental impacts. Currently, knowledge is needed about the effectiveness of specific management actions such as the provision of different access modes and tour experiences at minimizing these impacts while maximizing visitor satisfaction. Nature-based tourism activities were studied in the species-rich gorges of the Flinders Ranges in Outback Australia. This study developed a conceptual framework of visitor-environment relationships, constructed a regional visitor profile, assessed visitor monitoring methods to quantify usage intensity in relation to the access mode (roads vs. hiking trails), examined changes in vegetation and bird communities in relation to usage intensity and access mode, tested effects of approach behaviour among driving vs. hiking tourists on kangaroo behaviour, and designed a framework for a night-time wildlife tour. The usage intensity of gorge sections was best determined from visitor numbers stratified by their behaviour, as the access mode fundamentally changed visitor behaviour in gorges. High compared to low usage recreational tracks altered species community composition, decreased total plant cover, increased non-native species cover, increased or decreased plant diversity depending on the track distance, increased soil compaction, and decreased bird numbers and species richness. Vegetation changes had secondary aversive effects on the bird community. The magnitude and spatial extent of these community impacts were greater along roads than trails. Visitor approach towards kangaroos varied with the access mode and necessitated individual recommendations for low-impact behaviour. The optimal night-time observation tour employed night-vision devices and bat detectors and coupled visitor satisfaction with low impact on wildlife. A range of factors (e.g., weather conditions) moderated the susceptibility of the wildlife to tourism disturbance. To protect wildlife and habitat along recreational tracks in arid-lands gorges, it is recommended to (1) monitor usage intensity and the identified impact indicators within their effect zone, (2) curtail gorge usage by restricting vehicle access to sections and regulating high impact activities (e.g., wild camping), (3) base environmental education upon scientifically tested low-impact visitor behaviour, and (4) engage with tourism operators in the design of low-impact, yet satisfying tours based on scientific principles.
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Sousa, Kathya Cibelle Abreu de. "A contribuição do pensamento de Rousseau na construção da antropologia como disciplina acadêmica no século XIX /." Marília : [s.n.], 2008. http://hdl.handle.net/11449/88828.

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Orientador: Christina de Rezende Rubim
Banca: Aluísio Almeida Schumacher
Banca: Ana Lúcia Pastore Schritzmeyer
Resumo: O objetivo deste trabalho é compreender a contribuição de Jean Jacques Rousseau na construção do pensamento sobre as diferenças entre os homens e que no século seguinte se constituiu enquanto disciplina acadêmica de antropologia e de que forma ela ocorreu. Suas obras mais significativas foram utilizadas, contextualizando-se as idéias dentro do momento histórico em que se desenvolveram na Europa dos séculos XVIII e XIX. Os conceitos de cultura/natureza, identidade/diversidade e singularidade/universalidade foram enfatizados numa tentativa de se entender o pensamento social europeu diante da diversidade de culturas existentes no planeta e cujo início de mapeamento teve início com o colonialismo ocidental.
Abstract: The goal of this work is comprehend Jean Jacques Rousseau's contribution on the construction of thoughts about differences between men and which on next century constituted as academic discipline of anthropology and in which way it occurs. His most significant works were used, contextualizing the ideas within historical moment at which they developed in Europe XVIII and XIX centuries. The concepts of culture/nature, identity/diversity and singularity/universality were emphasized for trying to understanding the European social thought before diversity of cultures existing in the planet and which maping had beginning with the occidental colonialism. Keywords: Nature/Culture. Identity/Diversity. Singularity/universality. Rousseau. History of classical anthropological thought. Evolution and progress.
Mestre
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22

Diallo, Hady. "Influence des gradients anthropique et géomorphologique sur la variation de la biodiversité végétale dans la réserve de biosphère de la boucle du Baoulé au Mali: cas de la réserve de Fina." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209343.

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Les travaux de recherche ont été menés dans la réserve de biosphère de la boucle du Baoulé (RBBB) au Mali. Cette réserve est constituée de 3 aires, Badinko, Kongosambougou et Fina. Cette étude a été faite dans l’aire de Fina, la plus importante pour sa richesse en faune. La péjoration des conditions climatiques et les impacts des pressions anthropiques croissantes ont entraîné une dégradation des écosystèmes en particulier la biodiversité végétale. L’objectif de notre recherche est d’étudier l’influence des gradients anthropique et géomorphologique sur la variation de la biodiversité végétale dans la RBBB. Elle contribuera à la caractérisation et à l’évaluation de l’état actuel de la végétation dans une perspective de conservation durable des ressources végétales en particulier la biodiversité. Nous sommes partis de l’idée que les aires protégées constituent des espaces témoins de conservation des milieux naturels qui, comparés aux milieux perturbés permettraient de caractériser l’état d’évolution de la biodiversité végétale. Deux approches ont été utilisées pour aborder cette étude :l’approche synchronique et l’approche diachronique. Un recensement et une classification des espèces ont été effectués en s’appuyant sur le dispositif de zonage d’une réserve de biosphère basée sur les degrés de pression (régimes de protection) et la situation géomorphologique. Puis une quantification des variations de pressions liées aux activités anthropiques a été faite.

Nos résultats ont montré que les facteurs structurants de la végétation varient suivant la géomorphologie et surtout le dispositif de zonage (gradient anthropique). C’est dans les milieux perturbés que la diversité est élevée, mais avec un niveau d’organisation peu homogène comparativement aux milieux non perturbés. L’intensification actuelle des pressions dans les milieux perturbés et la dégradation des formations végétales qui en résulte n’entraînent pas actuellement dans la réserve une baisse de diversité. Aussi, dans les conditions écologiques locales pratiquement semblables dans la réserve, le zonage caractérisant les niveaux d’anthropisation est autant important que les facteurs texture du sol qui sont liés aux conditions géomorphologiques dans la structuration floristique. Les résultats phytosociologiques ont montré l’individualisation de 10 groupements végétaux dont 6 en milieux perturbés avec une tendance à la dégradation de la végétation et sa transformation en savane arbustive et 4 en milieux non perturbés marqués par la disparition des formes de végétation originelles. La plus forte densité en espèces est observée dans les groupements végétaux des unités de plaine et de vallée pour l’ensemble des 3 zones. C’est dans ces unités également que la surface terrière pour les arbres de plus de 8 m et la valeur pastorale sont importantes. La diminution du recouvrement des espèces herbacées de bonne valeur fourragère en particulier les pérennes est corrélée aux perturbations liées aux intenses activités anthropiques (agricole et pastorale par exemple). Ces activités engendrent la dégradation du milieu, une baisse de la valeur pastorale qui est indépendante de la biodiversité. Les dynamiques temporelles de la composition du paysage forestier de la réserve ont montré une ouverture du paysage caractérisée par une extension des superficies cultivables de la zone de transition vers la zone protégée ainsi que la réduction de la superficie des savanes arborées et la transformation progressive du paysage en savane arbustive. L’étude a permis de comprendre que le dispositif législatif classique de protection ne correspond pas à la réalité de terrain. De façon générale, l’influence des gradients géomorphologique et surtout anthropique est perceptible sur la structure de la flore et de sa diversité.

Une extension de notre approche d’étude dans les réserves de Badinko et de Kongosambougou permettra d’asseoir un dispositif de suivi de l’évolution spatio-temporelle de la végétation et de poser les bases d’une politique rationnelle de conservation de la réserve de biosphère de la boucle du Baoulé.

Mots clés :Anthropisation, diversité floristique, dynamique spatiale, géomorphologie, réserve de Fina, Mali.

ABSTRACT

The research was conducted in the Fina, part of biosphere reserve of « boucle du Baoulé » (RBBB) in Mali. This reserve consists of 3 areas, Badinko, Kongosambougou and Fina. Fina area is the most important for its rich fauna, this study was done. The climatic conditions pejoration and the impacts of increasing human pressures have led to ecosystem degradation, particularly plant biodiversity of the Fina reserve. In this study we have updated data on plant diversity and its variation based on the device of biosphere reserve zoning based on the pressure degree (protects systems). The objective of this thesis was to test the main hypothesis that protected areas are witness spaces of natural settings conservation that, compared to the disturbed areas, would characterize plant biodiversity evolution. Two approaches were used to address this study: synchronic and diachronic approach. Our results showed that the vegetation structural factors vary with the environment (zones) and geomorphology. The correlations between vegetation and ecological factors showed that the disturbance gradient is a major factor in the floristic variability. Human pressure intensification in disturbed habitats and resulting vegetation degradation do not currently induce any decrease of diversity in the reserve. In local similar environmental conditions as is the Fina reserve case, zoning characterizing the human impact levels is as important as the soil texture factors that are related to geomorphological conditions in the floristic structure. The phytosociological results showed the individualization of 10 plant groups in disturbed habitats, including 6 with a tendency to shrubby savanna and 4 in undisturbed environments marked by the disappearance of the vegetation original forms. The highest density of species is observed in plant communities of the plain and valley units in all the three zones. It is also in these units that basal area for trees over 8 m and pastoral value are important. The herbaceous species of good fodder value recovery reduction in particular the perennial causes the environmental degradation, and the pastoral value reduction that is independent of biodiversity. Temporal dynamics of the forest landscape composition of the reserve showed an opening of the landscape characterized by an expansion of arable land in the transition zone to the protected area of the reserve, the decrease in savanna area and gradual transformation landscape in shrubby savanna.

An extension of our study approach in the Badinko and Kongosambougou reserves could help establishing a monitoring of the spatial and temporal vegetation evolution and putting the rational politics bases of Baoulé biosphere reserve conservation.

Key words: Anthropisation, geomorphology, floristic diversity, Fina reserve, spatial dynamics, Mali.


Doctorat en Sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished

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23

Kaya, Ozdemirel Banu. "Protected Area Site Selection Based On Abiotic Data: How Reliable Is It?" Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613060/index.pdf.

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Protected area site selection is generally carried out using biodiversity data as surrogates. However, reliable and complete biodiversity data is rarely available due to limited resources, time and equipment. Instead of drawing on inadequate biodiversity data, an alternative is to use environmental diversity (ED) as a surrogate in conservation planning. However, there are few studies that use environmental diversity for site selection or that evaluates its efficiency
unfortunately, no such example exists for Turkey, where biodiversity is high but our knowledge about it is unsatisfactory. Hence, this study was carried out to investigate the efficiency of environmental surrogates and the utility of different biological taxa in conservation planning. The objective was to find out the most efficient surrogates, either environmental or biological, for conservation planning, so that limited resources can be used more efficiently to establish an effective protected areas network. The study was carried out in northeastern Turkey, within the Lesser Caucasus ecoregion. The taxonomic groups considered include large mammals, breeding birds, globally threatened reptiles and amphibians, butterflies, highly threatened plants, and ecological communities. The distribution data was taken from a previous study, while climate and topographical data were obtained from various sources and produced through spatio-statistical techniques. Complementarity-based site selection was carried out with Marxan software, where the planning unit was the 100 sq.km. UTM grid square. Various statistical methods, including geographically weighted regression, principal components analysis, and p-median algorithm, were used to determine ED across the units. Performance of different approaches and different sets of surrogates were tested by comparing them to a random null model as well as representation success. Results indicate that endemic or non-endemic highly threatened plant species, butterfly species and ecological communities represent biodiversity better than other taxa in the study area. As such, they can be used on their own as efficient biodiversity surrogates in conservation area planning. Another finding is that highly threatened plant species are required to be used in the site selection process if they need to be represented well
in other words, they are their own surrogates. It was demonstrated that while ED alone can be used as a surrogate to represent biodiversity of an area, they are not as good as biodiversity surrogates themselves. It is also suggested that using species taxa with smaller distributional ranges or taxa that complement each other due to ecological differences as surrogates provide better results. On the other hand, ED might be a more suitable surrogate if resources are very limited or field work is impossible. In such cases, using ED in conjunction with one of the better biodiversity surrogates is probably the best solution.
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24

Sousa, Kathya Cibelle Abreu de [UNESP]. "A contribuição do pensamento de Rousseau na construção da antropologia como disciplina acadêmica no século XIX." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/88828.

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Made available in DSpace on 2014-06-11T19:23:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-22Bitstream added on 2014-06-13T20:47:56Z : No. of bitstreams: 1 sousa_kca_me_mar.pdf: 564771 bytes, checksum: 71d2abc323fd55dbe3a26dfd3eaf74a1 (MD5)
O objetivo deste trabalho é compreender a contribuição de Jean Jacques Rousseau na construção do pensamento sobre as diferenças entre os homens e que no século seguinte se constituiu enquanto disciplina acadêmica de antropologia e de que forma ela ocorreu. Suas obras mais significativas foram utilizadas, contextualizando-se as idéias dentro do momento histórico em que se desenvolveram na Europa dos séculos XVIII e XIX. Os conceitos de cultura/natureza, identidade/diversidade e singularidade/universalidade foram enfatizados numa tentativa de se entender o pensamento social europeu diante da diversidade de culturas existentes no planeta e cujo início de mapeamento teve início com o colonialismo ocidental.
The goal of this work is comprehend Jean Jacques Rousseau’s contribution on the construction of thoughts about differences between men and which on next century constituted as academic discipline of anthropology and in which way it occurs. His most significant works were used, contextualizing the ideas within historical moment at which they developed in Europe XVIII and XIX centuries. The concepts of culture/nature, identity/diversity and singularity/universality were emphasized for trying to understanding the European social thought before diversity of cultures existing in the planet and which maping had beginning with the occidental colonialism. Keywords: Nature/Culture. Identity/Diversity. Singularity/universality. Rousseau. History of classical anthropological thought. Evolution and progress.
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25

Bellacicco, Sophie. "Etude de l’impact de l’origine clonale du latex d’Hevea brasiliensis sur la composition biochimique du latex et la mésostructure du caoutchouc naturel." Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0003.

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Le caoutchouc naturel produit du latex d'Hevea brasiliensis a des propriétés remarquables qui n'ont jamais été égalées par ses homologues synthétiques. Toutefois, ce matériau d'origine naturel présente un désavantage : la variabilité non négligeable de ses propriétés. Cette dernière est partiellement attribuée aux 3 à 5 % de composés non isoprènes (lipides, protéines, sucres et minéraux) présents dans le caoutchouc naturel. Parmi les facteurs pouvant être tenus comme responsables de cette variabilité, l'origine clonale semble prépondérante. L'objectif principal de cette étude était d'évaluer l'impact de l'origine clonale sur la variabilité en composition biochimique du latex (lipides, protéines, sucres et éléments minéraux) et sur les caractéristiques mésostructurales du caoutchouc naturel; puis d'étudier les relations pouvant exister entre le génotype, la composition biochimique du latex et la mésostructure du caoutchouc. Cette étude a été conduite sur 5 clones d'Hevea brasiliensis : GT1, RRIM600, PB235, PB217 et PB260. Des études préalables à la caractérisation clonale ont permis de déterminer les conditions d'échantillonnage à mettre en œuvre pour pratiquer des prélèvements de latex clonaux les plus représentatifs possible des clones. Le latex étant un matériau instable, il été choisi de travailler sur du latex lyophilisé pour l'analyse de tous les composés biochimiques du latex (autres que les lipides) et pour l'étude de la mésostructure du caoutchouc naturel. Des protocoles d'extractions des protéines et des sucres sur lyophilisat de latex ont été développés en se basant sur les propriétés de solubilisation du caoutchouc naturel en milieu organique. L'extraction des lipides a été réalisée en suivant le protocole mis au point sur plantation sur latex frais par Liengrayoon (Liengprayoon, 2008). Les différents résultats obtenus au niveau de la composition biochimique du latex et de la mésostructure du caoutchouc ont permis de mettre en évidence l'importante de l'origine clonale des latex. L'étude des relations entre le génotype et la composition biochimique du latex (ACP) a clairement montré que l'origine clonale jouait un rôle important dans la variabilité totale des données biochimiques du latex. Les analyses des relations entre la biochimie du latex et la mésostructure du caoutchouc naturel ont permis de mettre en évidence des corrélations intéressantes des lipides et des protéines avec la mésostructure (essentiellement Mn et I). Cette analyse biochimique clonale des latex s'est révélée pertinente pour étudier la diversité clonale et ses répercutions sur la mésostructure du caoutchouc naturel. Cette approche de la diversité clonale d'Hevea brasiliensis, ainsi que les connaissances acquises lors de cette étude constituent une base de données solide à compléter par des études futures sur des plantations différentes, des clones différents et des analyses biochimiques et structurales plus poussées
Natural rubber produced from Hevea brasiliensis latex possesses remarkable properties which have not been matched by its synthetic counterparts. However, this natural origin material presents a disadvantage: the significant variability of its properties. This variability has been partly ascribed to the 3 to 5% non isoprene components (lipids, proteins, sugars and minerals) present in the natural rubber. Among the factors that could be held responsible for this variability, clonal origin seems to be decisive.The main aim of this study was to evaluate the impact of clonal origin on the biochemical latex composition and on natural rubber mésostructural characteristics and also to study relationships between genotype, latex biochemical composition and rubber mesostructure. This study was conducted with five Hevea brasiliensis clones: GT1, RRIM600, PB235, PB217 and PB260. Before clonal characterization, preliminary studies were performed to determine the suitable sampling conditions in order to get the latex samples that represented as much as possible the clones. Fresh latex is an unstable material. It was decided to work on freeze-dried latex for the biochemical components analysis (except lipids) and for the natural rubber mesostructure study. Protocols for proteins and sugars' extractions on freeze-dried latex have been developed on the natural rubber solubilizing properties in organic media. Lipids extractions was performed according to the protocol developed by Liengrayoon (Liengprayoon , 2008) on fresh latex.The different results obtained on the latex biochemical composition and the natural rubber mesostructure allowed to clearly observe the clonal origin importance. Study of relationships between genotype and latex biochemical composition (PCA) has clearly shown that the clonal origin played an important role in the total variability of latex biochemical data. Analysis of relationships between latex biochemistry and natural rubber mesostructure helped highlight interesting correlations of lipids and proteins with mesostructure (mainly Mn and I).This biochemical analysis of clonal latex has proved to be appropriate for studying the clonal diversity and its repercussions on the natural rubber mesostructure. This approach of Hevea brasiliensis clonal diversity, and the knowledge gained from this study, provides a solid basis to be completed by further studies on different plantations, different clones and further biochemical and structural analyses
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26

Rousselot, Lucie. "Des idées de nature : appréhender la diversité pour refonder l'action collective." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN026/document.

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Cette thèse cherche à explorer le rôle que les perceptions culturelles peuvent jouer pour redéfinir collectivement l’action humaine envers la nature. Dans le temps long, de manière accidentelle ou intentionnelle, l’homme a globalement modifié puis progressivement détruit de manière exponentielle la nature. Or, l’étude de l’idée de nature démontre la multiplicité et la force des attachements culturels à la nature. Cette thèse cherche donc à étudier plus précisément la diversité, la multiplicité des perceptions culturelles, et dans quelle mesure celles-ci pourraient aider à redéfinir l’activité humaine envers la nature. A cette fin, les idées de nature et leurs évolutions à travers l’histoire sont étudiées dans plusieurs pays cultures afin de déterminer si et comment la diversité peut devenir un facteur de changement de paradigme. Trois pays sont étudiés à cette fin : la France, le Japon et les États-Unis, afin de dégager les perceptions culturelles uniques et d’envisager comment cette unicité peut servir à refonder l’action collective
This thesis aims at exploring the role cultural perceptions of nature could play in redefining in depth human action towards nature. Whether on purpose or as an incidental result, humankind has since the dawn of humanity first modified then destroyed nature. Yet, when looking at cultural perceptions of nature it appears that cultures developed a strong attachment to some representations of nature. The presumption explored here is that these cultural perceptions, in their diversity, in their multiplicity, could be key to redefining our whole relation towards nature. To that effect, this thesis studies the idea of nature and its evolutions throughout history in different cultures in order to render it effective in international negotiations. Three countries are explored: France, Japan and the United States in order to isolate cultural perceptions and to understand how they can be mobilized to redefine collective action
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27

Ismail, Mohamed. "Molecular genetic diversity among natural populations of Populus." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/26273.

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Genetic diversity is a key factor in species survival, evolution, and adaptation. It also reveals species genetic structure and provides insights into how different demographic forces shape species genetic variability. Although, black cottonwood (Populus trichocarpa Torr. & Gray) is the first tree to have its genome completely sequenced; however, information regarding its natural genetic diversity and population structure is lacking. I have investigated the extent of genetic diversity within and among 38 natural populations of P. trichocarpa sampled across British Columbia using 10 nuclear (nuSSR) and 12 chloroplast microsatellite (cpSSR) markers. CpSSR represents two haplotypes, clustering as northern and southern groups; however, a Bayesian population structure analysis suggested the presence of three highly admixed groups supported by low population differentiation (low FST and RST). Monmonier’s spatial analysis suggested the presence of one genetic discontinuity dividing the studied area into northern and southern regions. These findings indicated that P. trichocarpa might have originated from two, northern and southern, glacial refugia that have experienced moderate contact through extensive gene flow. Nucleotide diversity for 10 candidate-gene loci involved in adaptive, defence, and housekeeping functions was abundant and varied across loci, with the majority showing neutral variations. Linkage disequilibrium (LD), decays rapidly to r² ≈ 0.18 within 700 base pairs (bp). Comparing the nucleotide diversity between P. trichocarpa and P. balsamifera L. to the Eurasian P. tremula L. indicated that the two North American species had lower diversity (θw range 0.002 to 0.004) than the Eurasian poplar (θw = 0.005). The estimated time of divergence between the two North American and the Eurasian species indicated that the latter was five- to six-fold older compared to the two former species. The substitution rate was lower in North American species (0.4 x 10-⁸ per year) compared to the Eurasian poplar (2 x 10-⁸). Different association genetics models produced strikingly different results after the inclusion or exclusion of population structure, highlighting the importance of proper model construction.
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28

Jeffs, Christopher. "Natural enemies and the diversity of plant communities." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:49c80db9-6590-4e06-b86f-24d225046969.

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The processes that determine the structure of plant communities are of considerable practical and theoretical interest. Natural enemies such as herbivores, seed predators and pathogens provide one potentially important influence on plant diversity. I investigated the effects of natural enemies on plant diversity in two contrasting, species-rich plant communities (tropical forests in Panama and temperate grasslands in the UK), focusing on pre-dispersal seed predation by insects, and the mortality of seeds and seedlings caused by soil fungi. In Panama I found that pre-dispersal insect seed predators generate significant levels of mortality in multiple tropical tree species, with high heterogeneity in predation rates among individuals and at different forest sites. Insect seed predators were highly host-specific, consistent with a role in enhancing plant diversity. At Upper Seeds, a calcareous grassland site in the UK, I used manipulative experiments to show that soil fungi increase the diversity of plants propagating from soil seed banks. A parallel experiment in Panama, mimicking germination under light gap conditions, revealed differential effects of fungi among sites, with fungicide treatment appearing to increase the diversity of propagated seedlings at some sites but reducing it at others. These results suggest that the influence of soil fungi on pre-emergence mortality can alter plant diversity, even when post-emergence mortality from fungal pathogens is limited. In Panama, I also tested whether enemy-mediated mortality increases with rainfall, potentially contributing to the positive regional correlations widely observed between precipitation and plant diversity. In contrast to predictions, neither pre-dispersal insect seed predation nor the influence of soil fungi on seedling recruitment were affected significantly by site humidity, or (for soil fungi) with experimentally manipulated soil moisture levels. Overall, my results provide evidence that pre-dispersal seed predators and soil fungi can affect plant recruitment and diversity at early life stages, with potential consequences for the community structure of adult plants.
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29

Mardonovich, Sandra. "The Natural Diversity of Carica papaya in Panama." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1461835428.

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30

Bois, Rémi. "Hypergraphes multimédias dirigés navigables, construction et exploitation." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S107/document.

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Cette thèse en informatique s'intéresse à la structuration et à l'exploration de collections journalistiques. Elle fait appel à plusieurs domaines de recherche : sciences sociales, à travers l'étude de la production journalistique ; ergonomie ; traitement des langues et la recherche d'information ; multimédia et notamment la recherche d'information multimédia. Une branche de la recherche d'information multimédia, appelée hyperliage, constitue la base sur laquelle cette thèse est construite. L'hyperliage consiste à construire automatiquement des liens entre documents multimédias. Nous étendons ce concept en l'appliquant à l'entièreté d'une collection afin d'obtenir un hypergraphe, et nous intéressons notamment à ses caractéristiques topologiques et à leurs conséquences sur l'explorabilité de la structure construite. Nous proposons dans cette thèse des améliorations de l'état de l'art selon trois axes principaux : une structuration de collections d'actualités à l'aide de graphes mutli-sources et multimodaux fondée sur la création de liens inter-documents, son association à une diversité importante des liens permettant de représenter la grande variété des intérêts que peuvent avoir différents utilisateurs, et enfin l'ajout d'un typage des liens créés permettant d'expliciter la relation existant entre deux documents. Ces différents apports sont renforcés par des études utilisateurs démontrant leurs intérêts respectifs
This thesis studies the structuring and exploration of news collections. While its main focus is on natural language processing and multimedia retrieval, it also deals with social studies through the study of the production of news and ergonomy through the conduct of user tests. The task of hyperlinking, which was recently put forward by the multimedia retrieval community, is at the center of this thesis. Hyperlinking consists in automatically finding relevant links between multimedia segments. We apply this concept to whole news collections, resulting in the creation of a hypergraph, and study the topological properties and their influence on the explorability of the resulting structure. In this thesis, we provide improvements beyond the state of the art along three main {axes:} a structuring of news collections by means of mutli-sources and multimodal graphs based on the creation of inter-document links, its association with a large diversity of links allowing to represent the variety of interests that different users may have, and a typing of the created links in order to make the nature of the relation between two documents explicit. Extensive user studies confirm the interest of the methods developped in this thesis
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Polaz, Carla Natacha Marcolino. "Caracterização da ictiofauna e aplicação do índice de integridade biótica no Parque Nacional do Pantanal Mato-grossense, Poconé, MT." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-26082013-091018/.

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O Pantanal é um complexo de ecossistemas que exibe grande diversidade de ambientes aquáticos. O objetivo geral deste estudo foi caracterizar a estrutura da comunidade de peixes no Parque Nacional do Pantanal Mato-grossense (PNPM), uma Unidade de Conservação federal localizada no município de Poconé, MT, a fim de apoiar a construção de um instrumento de monitoramento baseado na integridade biótica do ambiente aquático. Tal objetivo foi obtido através da adaptação do Índice de Integridade Biótica para o PNPM (IIBPNPM). Previamente ao capítulo sobre a construção do IIBPNPM, que se espera representativo para uma porção ainda intocada do Pantanal, os dois primeiros capítulos fornecem os dados necessários para subsidiar a aplicação do índice. O primeiro trata da caracterização dos diferentes ambientes que ocorrem no PNPM, agrupados em quatro estratos ambientais: rios principais (rios Cuiabá e Paraguai), corixos (canais de ligação da planície de inundação), baías permanentes (não perdem a conexão na seca) e baías temporárias (aquelas que perdem conexão com os outros elementos da planície). Essa caracterização foi realizada na primeira campanha exploratória ao PNPM, em setembro de 2009, quando foram definidos os pontos de amostragem de água e de peixes. Testes estatísticos foram realizados para verificar a existência de associação entre os diferentes estratos e os fatores abióticos (variáveis físicas e químicas da água), porém, não foram significativos, indicando que os ambientes são homogêneos. As coletas de peixes foram realizadas em 12 pontos dentro do PNPM, no período seco, no final de outubro e início de novembro de 2010 e 2011. No segundo capítulo, foram identificadas 154 espécies de peixes, totalizando 19.839 indivíduos, das quais 146 espécies (18.954 exemplares) foram consideradas para a construção do IIBPNPM, por questões de padronização dos petrechos de pesca. Testes estatísticos também não evidenciaram associação entre a estrutura das assembleias de peixes e os estratos, reforçando a hipótese da homogeneidade dos ambientes. No entanto, os índices de diversidade de Shannon (H) e equabilidade de Pielou (J) foram significativamente diferentes entre os estratos. A homogeneidade dos ambientes pode ser explicada pelo fato do PNPM estar situado num pantanal de alta inundação, que pode durar até oito meses de um único ciclo hidrológico. Analisando o que os resultados indicaram, os poucos meses de estiagem parecem não ser suficientes para gerar variablidade ambiental detectável pelos métodos utilizados. O IIBPNPM final é composto por nove métricas e três classes de integridade biótica: excelente, regular e pobre, com intervalos específicos de pontuação. A maioria das métricas se enquadrou na classe excelente, algumas na classe regular e nenhuma na classe pobre, o que era esperado pelo fato de não haver indícios de degradação ambiental no interior do PNPM. A comunidade de peixes, portanto, é bem estruturada, rica e abundante. Não houve diferença significativa nas pontuações do IIBPNPM entre os anos (2010 e 2011). Embora a localização privilegiada do PNPM amorteça o efeito dos impactos antrópicos, eles estão presentes de maneira difusa em todo o Pantanal, com intensidade e magnitude diversas. Aliado a isso, há de se levar em conta que o PNPM é uma área de berçário de muitas espécies de peixes, e exerce papel fundamental no recrutamento de recursos pesqueiros. Por isso, recomenda-se aos gestores do PNPM a implementação de um programa de monitoramento ambiental que tenha a ictiofauna como indicadora dos processos ecológicos. Nesse sentido, a aplicação sistematizada do IIBPNPM pode auxiliar na síntese das informações e na comunicação dos resultados à sociedade.
The Pantanal is a complex of ecosystems that displays high diversity of aquatic habitats. The overall objective of this thesis was to characterize the structure of the fish assemblages in the Pantanal National Park, a federal protected area located in the state of Mato Grosso, Brazil, to back up the construction of a monitoring instrument based on the biotic integrity of the aquatic environment. This objective was achieved by adapting the Index of Biotic Integrity for the Pantanal National Park habitats. Prior to the chapter on the construction of this index (IIBPNPM), expected to be representative of a quite pristine Pantanal portion, the first two chapters provide the necessary data to support the application of the index. The first one deals with the characterization of the different hábitats that occur in PNPM, grouped into four environmental strata: main rivers (Cuiabá and Paraguai rivers), corixos (channels that connect the floodplain elements), permanent bays (do not lose the river connection in the dry season) and temporary bays (lose the connection in the dry season). This characterization was performed in the first PNPM exploratory campaign, in September 2009, when the future sampling sites were defined by collecting water and fish. Statistical tests were performed aiming to detect the existence of an association between the different strata and abiotic factors (water quality variables). However, they were not significant, indicating that the hábitats are homogeneous. Fish sampling were performed at 12 points within the PNPM, during the dry season in late October and early November of 2010 and 2011. In the second chapter, we identified 154 species of fish, totaling 19,839 individuals from which 146 species (18,954 individuals) were considered for the IIBPNPM framing for reasons of standardization of the fishing gears. Statistical tests also showed no association between the structure of the fish assemblage and strata, reinforcing the hypothesis of homogeneity of environments. However, the Shannon diversity index (H\') and evenness (J) were significantly different between the strata. The homogeneity of the environments can be explained by the PNPM being located in a wetland of high flooding, which can last up to eight months of a single hydrological cycle. Analyzed results indicate that the few dry months are not sufficient to generate environmental variability detectable by the methods used. The final IIBPNPM consists of nine metrics and three classes of biotic integrity: \"excellent\", \"regular\" and \"poor\", with specific ranges of scores. Most metrics are framed in \"excellent\" class, some in \"regular\" and none in \"poor\" one, which was expected because there was no evidence of environmental degradation within the PNPM. The fish community is well structured, rich and abundant. There was no significant difference in scores between IIBPNPM years (2010 and 2011). Although the location of PNPM cushions the effect of human impacts, they are present in a diffuse manner throughout the Pantanal, with various intensities and magnitudes. Allied to this, one should take into account that the PNPM is a nursery area for many fish species, and plays an essential role in the recruitment of fishery resources. Therefore, we emphatically recommend to the PNPM managers that implement an active monitoring program considering the fish assemblage as an indicator of ecological processes. The periodic performance of IIBPNPM can assist in summarizing information and to communicate the results to society.
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32

Rieger, Jennifer Erin. "Genetic and morphological diversity of natural populations of Carica papaya." Oxford, Ohio : Miami University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1250088839.

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33

Zajc, Elizabeth. "Modelling native bird diversity in the Greater Toronto Area." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/974.

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Human-dominated landscapes often have habitat loss and fragmentation. These characteristics described at the landscape scale, called landscape elements, influence species diversity and distribution. These landscape elements include such descriptions as the amount of habitat in the landscape and the degree of fragmentation of the habitat. "Optimization of landscape pattern" studies which landscape elements will maximize species diversity and/or distribution. Some general conclusions have emerged from this research. For example, for some bird species the size of the habitat patch in which a species nests has been found to be more important than landscape variables. However, preliminary research suggested that landscape elements such as the matrix are important urban areas. My study addressed this problem by asking: which elements of the landscape are most important for predicting avian species richness and abundance in the Greater Toronto Area? A literature review revealed a number of variables that have been found to influence bird species diversity within a landscape: area of habitat in which the species nests, amount of habitat within the landscape, degree of fragmentation, vegetation characteristics of the habitat patch, and area within the landscape deemed urban in municipal land-use designations (amount of urbanization). From this literature, I formulated four hypotheses describing the most important variables for avian diversity: (1) the area of the habitat patch is most important, (2) only variables describing the habitat patch itself are important, (3) the area of the habitat patch is important, but landscape variables should also be considered and (4) urbanization is most important. These hypotheses were considered competing explanations of bird species diversity at the landscape scale.

A database of breeding bird data and landscape information, in a geographic information system platform, was used to investigate the comparative strength of the competing hypotheses for the Greater Toronto Area. A mathematical expression with a Poisson model format was created to represent each hypothesis. The model selection technique based on Kullback-Leibler information using the Akaike Information Criterion was deemed most appropriate for the comparison of the models. Four separate Poisson model competitions were completed using two habitat types and two response variables: species richness and total abundance. In three of the four competitions, the best model included the habitat area and the amount of urbanization in the landscape. In the forth competition, this model was considered as strong as another model which included habitat area, amount of habitat in the landscape and degree of fragmentation. The results from the model competition support the hypothesis that habitat area is important, but landscape variables must also be considered to explain avian richness and total abundance. It appears that maintaining native bird biodiversity in the Greater Toronto Area should focus on preserving and possibly increasing habitat area and decreasing adjacent urbanization. Exploration of the best model in the forest analysis with the richness response variable found that a 10% increase in habitat area cause approximately a 10% increase in species richness, and a 10% increase in urban area caused approximately a 20% decrease in species richness. Consequently, current natural heritage planning in Ontario should consider urban development as an important negative effect on native birds.
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34

Pichler, Peter-Paul. "Natural selection, adaptive evolution and diversity in computational ecosystems." Thesis, University of Hertfordshire, 2009. http://hdl.handle.net/2299/4006.

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The central goal of this thesis is to provide additional criteria towards implementing open-ended evolution in an artificial system. Methods inspired by biological evolution are frequently applied to generate autonomous agents too complex to design by hand. Despite substantial progress in the area of evolutionary computation, additional efforts are needed to identify a coherent set of requirements for a system capable of exhibiting open-ended evolutionary dynamics. The thesis provides an extensive discussion of existing models and of the major considerations for designing a computational model of evolution by natural selection. Thus, the work in this thesis constitutes a further step towards determining the requirements for such a system and introduces a concrete implementation of an artificial evolution system to evaluate the developed suggestions. The proposed system improves upon existing models with respect to easy interpretability of agent behaviour, high structural freedom, and a low-level sensor and effector model to allow numerous long-term evolutionary gradients. In a series of experiments, the evolutionary dynamics of the system are examined against the set objectives and, where appropriate, compared with existing systems. Typical agent behaviours are introduced to convey a general overview of the system dynamics. These behaviours are related to properties of the respective agent populations and their evolved morphologies. It is shown that an intuitive classification of observed behaviours coincides with a more formal classification based on morphology. The evolutionary dynamics of the system are evaluated and shown to be unbounded according to the classification provided by Bedau and Packard’s measures of evolutionary activity. Further, it is analysed how observed behavioural complexity relates to the complexity of the agent-side mechanisms subserving these behaviours. It is shown that for the concrete definition of complexity applied, the average complexity continually increases for extended periods of evolutionary time. In combination, these two findings show how the observed behaviours are the result of an ongoing and lasting adaptive evolutionary process as opposed to being artifacts of the seeding process. Finally, the effect of variation in the system on the diversity of evolved behaviour is investigated. It is shown that coupling individual survival and reproductive success can restrict the available evolutionary trajectories in more than the trivial sense of removing another dimension, and conversely, decoupling individual survival from reproductive success can increase the number of evolutionary trajectories. The effect of different reproductive mechanisms is contrasted with that of variation in environmental conditions. The diversity of evolved strategies turns out to be sensitive to the reproductive mechanism while being remarkably robust to the variation of environmental conditions. These findings emphasize the importance of being explicit about the abstractions and assumptions underlying an artificial evolution system, particularly if the system is intended to model aspects of biological evolution.
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35

Ramadan, Sherif Ibrahim Ahmed. "A study on genetic diversity of Egyptian native livestock." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/180640.

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36

Cordier, Christopher James. "The Diversity-oriented Synthesis of Natural Product-like Libraries." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485204.

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This thesis describes a novel approach to diversity-oriented synthesis. The approach involves the iterative assembly of building blocks onto a purification handle using temporary diisopropylsilylene tethers; this approach yields substrates for a ring-c1osing-ring-opening olefin metathesis cascade. The metathesis cascade results in a skeletal transformation and a range of scaffolds have been generated using only a few simple building blocks and a small number of common reactions. The use of a fluorous tag as a purification handle minimised labour-intensive purification steps and rendered the approach appropriate for library synthesis. The structures ofthe diverse final compounds are reminiscent ofpolyketide natural products. Chapter 1 describes alternative approaches for varying molecular scaffolds and places our generic approach in context. In Chapter 2, .the syntheses of.enant.iome~cally enriched building . blocks are described in· which an enzymatic desymmetrisation· is often used to induce asymmetry. Our investigations to conduct our methodology on solid support our described in Chapter 3. The potential of individual building blocks to participate in simple metathesis cascades is described in Chapter 4. In addition, this Chapter describes our studies to optimise the formation of unsymmetrical silaketals using diisopropylsilyl ethers as storable precursors. The thesis culminates with the preparation of36 metathesis substrates in which pairs of building blocks have been appended to the fluorous tag. The metatheses of some ofthese substrates are described and leads to natural product-like ligands.
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37

Rieger, Jennifer E. "Genetic and morphological diversity of natural populations of Carica papaya." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1250088839.

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38

Müller, Anja. "Géodiversité et diversité paysagère : évaluation de concepts spaciaux pour l'étude de la diversité des milieux et paysages : application au site Natura 2000 Madres-Coronat (Pyrénées-Orientales, France)." Phd thesis, Université Toulouse le Mirail - Toulouse II, 2011. http://tel.archives-ouvertes.fr/tel-00632247.

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La géodiversité en tant qu'interprétation géographique de la diversité spatiale de la surface terrestre, peut être définie comme la diversité morphologique des milieux dits naturels, voire comme une diversité des paysages si l'on considère ces derniers comme un ensemble d'objets matériels. Afin de combler des lacunes théoriques et l'absence d'un regard multilinguistique et pluriculturel sur la géodiversité, ce travail s'insérant dans la recherche fondamentale géographique, met en lumière et différencie les notions de géodiversité et de diversité paysagère en langue française, allemande et anglaise, tout en explorant de façon empirique une question primordiale : comment mesurer la géodiversité, interprétée comme une diversité mésologique et paysagique tenant compte des structures verticales et horizontales de la diversité spatiale ? La géodiversité dite globale ne doit pas être confondue avec une géodiversité interprétée de façon géologique: elle prend en effet en compte les éléments biotiques autant que les éléments abiotiques et intègre l'anthropisation des milieux, sans séparer le minéral et le vivant, le naturel et l'artificiel. Dans une approche systémique, on peut considérer que les structures spatiales des milieux, leur morphologie, reflètent leur fonctionnement et leur dynamique et elles permettent de différencier ces milieux pour caractériser leur géodiversité. Saisie simultanément par une approche intégrée des milieux et par des relevés pédologiques et floristiques davantage disciplinaires, les composantes et enceintes des milieux relèvent de plusieurs niveaux organisationnels de la diversité. Le volet empirique de ce travail de recherche explore, par une démarche multiscalaire, la géodiversité du Massif du Madres -Coronat situé dans la partie orientale, franco-catalane, des Pyrénées. Sur le site d'intérêt communautaire" Massif de Madres-Coronat " la diversité des milieux se trouve accentuée par une variété des roches, des formes du relief, par un étagement bioclimatique et une utilisation des sols différenciée. Les relevés de terrain permettent d'étudier la diversité mésologique (ou diversité des milieux) et de mettre en évidence les relations entre géodiversité et phytodiversité. La cartographie des unités paysagiques élémentaires, les géons, mis en évidence par photo-interprétation, illustre la mosaïque des milieux et la diversité des structures spatiales latérales qu'on peut qualifier de diversité paysagique. Les indices de diversité et l'analyse exploratoire des données multivariées appliqués aux données mésologiques et paysagiques contribuent à la caractérisation de la géodiversité du massif. Ils mettent en évidence une diversité mésologique relativement importante dans les milieux forestiers et complexes et une diversité paysagique plus importante dans les secteurs élevés du massif, modelés par les glaciations quaternaires, ainsi qu'à proximité des talwegs. Les résultats de cette analyse descriptive et exploratoire constituent le fondement d'une discussion sur les propriétés et l'utilité potentielle de la géodiversité dans le cadre de la gestion des paysages et des espaces naturels.
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Koban, Evren. "Genetic Diversity Of Native And Crossbreed Sheep Breeds In Anatolia." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605694/index.pdf.

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In this study the genetic diversity in Turkish native sheep breeds was investigated based on microsatellite DNA loci. In total, 423 samples from 11 native and crossbreed Turkish sheep breeds (Akkaraman, Morkaraman, Kivircik, ivesi, Dagliç
, Karayaka, HemSin, Norduz, Kangal, Konya Merinosu, Tü
rkgeldi) and one Iraqi breed (Hamdani) were analyzed by sampling from breeding farms and local breeders. After excluding close relatives by Kinship analysis, the genetic variation within breeds was estimated as gene diversities (HE), which ranged between 0.686 and 0.793. The mean number of observed alleles (MNA) ranged between 5.8 and 11.8. The allele frequency distribution across Turkey showed no gradient from east to west expected in accordance with the Neolithic Demic Diffusion model. The differentiation between different samples of Akkaraman, Dagliç
and Karayaka breeds was tested by FST index. Akkaraman1 sample from the breeding farm was significantly (P<
0.001) different from the other two Akkaraman samples. Deviation from HW expectations observed for Akkaraman1, ivesi, Morkaraman and HemSin breeds. AMOVA analysis revealed that most of the total genetic variation (~90%) was partitioned within the individuals. In parallel to this observation, when factorial correspondence analysis and shared alleles distances were used to analyze the relationship between the individuals of the breeds, there was no clear discrimination between breeds. Moreover, NJ tree constructed based on DA genetic distance, and PC analyses were used to analyze among breed differentiation. Delaunay Network drew 4 genetic boundaries (two of them being parallel to geographic boundaries) between breeds. All the results indicated that Kivircik was the most differentiated breed. Finally, Mantel Test and Bottleneck analysis did not reveal a significant result. Kivircik breed, among all native Turkish breeds, was found to be the genetically closest to the European breeds based on the loci analyzed. The genetic variation in Turkish breeds was not much higher than that of European breeds, which might be a consequence of the recent sharp decrease in sheep number.
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Zul, Delita. "Determinants of the Bacterial Diversity in Manipulated and Natural Soils." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-82880.

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Wint, Ashley A. "Genetic Diversity in Native and Invasive Rubus (Rosaceae)." TopSCHOLAR®, 2008. http://digitalcommons.wku.edu/theses/17.

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Invasive species are an increasing threat to biological diversity as well as a leading cause of recent species’ extinctions. Invasives spread quickly and efficiently, and the U.S spends millions of dollars annually in the control and eradication of these species. More information is necessary in order to predict which species may become invasive. Rubus (Rosaceae) was chosen for study because this genus includes various ploidy levels, reproductive modes, and species that are invasive as well as native. Three Rubus species were chosen to represent apomictic and tetraploid invasives (Rubus armeniacus), a sexual and diploid native species (R. occidentalis), and a sexual and diploid invasive species (R. phoenicolasius). Specimens were collected across the U.S. and two different genetic fingerprinting techniques were used; Amplified Fragment Length Polymorphism (AFLP) and Randomly Amplified Fingerprints (RAF). Using three AFLP primers and two RAF primers, genetic similarity was determined and phylograms were constructed. Through statistical analysis and phylogram data it was determined that there might be slightly more genetic diversity in native R. occidentalis than in invasive R. phoenicolasius. Genetic diversity between apomictic and tetraploid Rubus armeniacus and the two sexual and diploid Rubus species were so similar that no distinction could be made, although the mean pairwise distances and mean number of alleles were significantly different. It was also found that geographic distance and genetic similarity do not appear to be related in these three Rubus species. During the course of this study it was also observed that the AFLP technique produced more alleles than the RAF technique, although this difference was not significant.
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余銘儀 and Ming-yee Yu. "Enriching native floristic diversity in exotic tree plantation in HongKong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39558113.

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43

Majchrzak, Yves. "Evolution des communautés végétales de marais tourbeux soumises au pâturage de bovins et d'équins : application pour la gestion conservatoire d'une zone humide, le marais de Lavours (Ain, France)." Grenoble 1, 1992. http://www.theses.fr/1992GRE10124.

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Pour preserver l'interet ecologique de la reserve naturelle du marais de lavours (ain, france), une gestion pastorale a ete mise en place avec des bovins highland et des chevaux camargue. L'objectif de cette etude a ete de suivre l'impact des herbivores sur les communautes vegetales. Des releves selon la technique des points quadrats alignes ont ete effectues tous les ans a la meme epoque, de 1987 a 1991, sur 102 stations. Ils ont permis de suivre l'evolution de la diversite floristique, du recouvrement des especes vegetales, de la structure de la vegetation et de la dynamique du systeme. Les donnees ont ete traitees grace a l'afc et a l'acp-3 modes (cette derniere technique s'averant tres adaptee dans ce cadre). L'impact des herbivores s'est traduit par: une augmentation du recouvrement de vegetaux rares et de l'heterogeneite structurale; l'augmentation du recouvrement des especes hygrophiles et d'alnus glutinosa, la diminution du recouvrement de sanguisorba officinalis et des especes fourrageres; la diminution de la diversite des facies, de la diversite specifique et du recouvrement de juncus subnodulosus dans le parc des bovins et l'augmentation de la diversite specifique de celui des chevaux. L'evolution des prairies humides vers une fruticee a alnus glutinosa n'est pas stoppee, et il sera necessaire de modifier les modalites de la gestion
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44

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 factors and iv) determine whether habitat type and heterogeneity promote nestedness of assemblages. 3. At the patch scale, surface complexity but not habitat heterogeneity increased macro-invertebrate diversity, richness and abundance independently of surface area, but only when habitat type was ignored. Surface complexity and heterogeneity were minor determinants of variations in macro-invertebrates among habitat types. 4. A field experiment involving baskets containing cobbles, pebbles, gravel or 50:50 mixtures revealed that flow type explained significant variations in macro-invertebrate richness, abundance and composition, and appeared to filter organisms based on their body size. Surface complexity and interstitial volume had no ecological effect, implying that differences in assemblages among mineral habitats may result from flow-related effects. 5. Macro-invertebrate assemblages occurring in some mineral habitats, typically with lower macro-invertebrate diversity, richness, abundance and trait diversity, appeared to be nested sub-sets of those occurring in some organic habitats. Nested assemblages had reduced trait diversity and altered trait representation. River sections containing fewer habitats supported assemblages of lower abundance, which appeared to be weakly nested sub-sets of those in heterogeneous sections. 6. Habitat complexity and heterogeneity are concluded to have consistently weak effects on macro-invertebrates at the scales studied. In contrast, habitat type and flow type affected macro-invertebrate assemblage composition, structure, and traits, with important implications for river management and conservation.
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Wikramaratna, Paul Silva. "The evolution of viral diversity." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:1d718b15-af79-4567-84ef-f97f61f75369.

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This thesis focuses on the population dynamics of three antigenically diverse RNA viruses: dengue, influenza and HIV-1. It comprises a set of studies highlighting the roles of structural constraints on critical antigenic determinants, interactions between immune responses to different antigenic types, host lifespan, and the degree of mixing between different host populations in determining the epidemiology and within-host dynamics of these pathogen systems. Dengue exists in humans as a collection of four antigenically related serotypes. Although infection by one serotype appears to convey life-long protection to homologous infection, it is believed to be a risk factor for severe disease manifestations upon secondary, heterologous infection due to the phenomenon of Antibody-Dependent Enhancement (ADE). It is not clear if third or fourth infections are possible, and if so, how they contribute to dengue epidemiology. In this thesis, I investigate the effect of third and fourth infections on the transmission dynamics of dengue. By contrast with dengue, human influenza viruses are known to be in rapid antigenic flux, manifesting in the sequential replacement of antigenic types. This pattern of evolution does not appear to be the same in shorter-lived hosts such as swine and birds. In this thesis, I have used a simple multi-locus model to explore the relationship between host lifespan and viral evolution, as well as to elucidate the effects of transmission between hosts of different lifespan in effort to capture the cross-species element of influenza transmission. My final chapter concerns the within-host evolution of HIV-1. I propose a new model for the pathogenesis of HIV-1 where the transition to AIDS is primarily linked to the gradual loss of the ability to make new antibody responses as the CD4+ population declines. Together these studies emphasise that it is the changing profile of immune responses – either at the population level or within the host – that is the principal determinant of the dynamics of the pathogen, rather than the mode and tempo of antigenic innovation.
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Queffelec, Betty. "La diversité biologique : Outil d'une recomposition du droit international de la nature : L'exemple marin." Phd thesis, Université de Bretagne occidentale - Brest, 2006. http://tel.archives-ouvertes.fr/tel-00422643.

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La diversité biologique permet d'appréhender dans un seul tenant les différents aspects du droit applicable à la nature sous les angles génétique, spécifique et écosystémique. Forte de ce triple point de vue, la notion embrasse non seulement la protection de l'environnement mais aussi la question de l'appropriation des éléments vivants et des connaissances qui s'y rapportent, bref la multiplicité des liens de droit unissant l'homme et la nature sous ses différents aspects. Cette caractéristique est spécialement mise en lumière dans le cadre marin en raison des particularités juridiques de l'appropriation dans ce domaine. La diversité biologique non seulement rassemble mais également ordonne. Elle permet, en effet, d'envisager une gestion cohérente de la nature au moyen d'une approche écosystémique. Celle-ci permet une prise de décision holistique fondée sur une unité écologiquement et socialement cohérente et implique une responsabilité commune dans la conduite de l'action. Elle implique dès lors une démarche fondée sur l'intégration, la prise en compte du temps au moyen de la précaution et de l'adaptabilité, et de la coopération. Elle replace le citoyen au centre de la décision.
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47

Harris, Caroline. "Uncovering the effect of natural diversity on the Anopheles gambiae response to Plasmodium falciparum." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20247/document.

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Le contrôle du paludisme ne semble aujourd'hui envisageable que par stratégies combinées ciblant différents stades du parasite. Chez le vecteur, certains mécanismes de la réponse immunitaire pourraient être manipulés pour bloquer le développement sporogonique du parasite. Cette thèse examine les effets de la diversité du vecteur et du parasite dans le couple le plus important en termes d'épidémiologie, A. gambiae - P. falciparum. Des polymorphismes de gènes de l'immunité du moustique contrôlant le niveau d'infection ont été identifiés par étude d'association. Certains d'entre eux ont un effet spécifique selon les isolats de parasites, suggérant de potentielles interactions génotype X génotype. Nous avons déterminé un déséquilibre de liaison très bas dans les populations naturelles de vecteurs, validant notre approche par gènes candidats. Les caractéristiques et les forces évolutives faisant d'A. gambiae un vecteur du paludisme majeur sont discutées. Les diverses populations de vecteurs et parasites peuvent interagir de manière spécifique. Pour tester cela, des infections par des isolats de parasites sympatriques et allopatriques ont été comparées, montrant des intensités plus faibles dans les couples sympatriques. Les profils d'expression des gènes montrent cependant peu de régulations spécifiques aux populations, mais plutôt des différences extrêmes selon les isolats de parasites. Ces résultats suggèrent des effets importants de la diversité entre populations et individus. En conclusion, cette thèse souligne l'importance de la prise en compte de la diversité naturelle des vecteurs et parasites dans les recherches futures sur leurs interactions
To achieve malaria control a variety of approaches must be combined targeting different stages of the parasites life cycle. With better understanding of mosquito immunity, it is hoped that aspects of natural resistance can be manipulated to prevent parasite development. This thesis investigates the effect of both mosquito and parasite diversity on the mosquitoes response to malaria using the most important human malaria system; Anopheles gambiae-Plasmodium falciparum in natural/semi-natural conditions. Mosquito loci are identified that significantly control infection phenotype, some of which act in a parasite isolate specific manner, highlighting their potential involvement in genotype by genotype interactions. Such research is moving towards genomewide studies; however, on finding very low linkage disequilibrium in wild mosquitoes, it favors candidate gene association studies. A. gambiae characteristics that make it such a good malaria vector are discussed and the evolutionary forces driving these traits. Selection behind vector-parasite interactions can differ spatially and temporally causing specificities in sympatric couples. Sympatric and allopatric mosquito infections with malaria are compared, showing that sympatric infections develop lower infection intensities suggesting local adaptation. Mosquito gene expression profiles highlight a small number of genes differentially regulated between sympatric and allopatric infections, however extreme differences in gene regulation are observed within populations, probably driven by the variable nature of malaria parasites. This thesis highlights the importance of taking into account natural diversity in future research
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48

Yu, Ming-yee. "Enriching native floristic diversity in exotic tree plantation in Hong Kong." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39558113.

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49

Bonin, Catherine Louise. "Diversity Relationships in Native, Warm-Season Plant Communities used for Agriculture." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/26574.

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Studies suggest that diverse mixtures of plants may improve forage productivity and also be suitable as bioenergy crops. The objectives of this research were: 1) to measure the effects of native, warm-season perennial (NWSP) forage mixtures and management methods on productivity, weed biomass, nutritive value, and community composition, and 2) to identify mechanisms that generate any positive diversity-productivity relationships over a three-year establishment period. In 2008, two experiments were established to evaluate the use of native, warm-season plants in forage-livestock systems using a pool of ten native species. The first, a large-scale, three-year, experiment tested three different NWSP mixtures (switchgrass monoculture, a four-grass mixture, and a ten-species mixture) and two management methods (grazed or biomass crop). Switchgrass monocultures had the lowest forage yield and highest weed biomass in both grazed areas and biomass crop exclosures. Analysis of forage nutritive value did not show many differences among mixtures, although the monoculture tended to have higher crude protein and lower fiber concentrations than the polycultures. Management method affected community composition, with NWSP richness higher and weed species richness lower in biomass crop exclosures than in grazed areas. A second experiment examined if species richness would enhance yields through a positive biodiversity effect. It employed additive partitioning to separate the selection effect (SE) from the complementarity effect (CE) by sowing random assemblages of NWSPs at five levels of richness into small plots. Species richness was associated with increased yields in the first year only, but overyielding and positive diversity effects were present in all three years. On average, over 50% of multi-species plots overyielded and 64% exhibited a positive biodiversity effect. Both SE and CE contributed to the biodiversity effect and the importance of each effect changed over time as communities became better established. All ten species were also individually analyzed for their yield potential, nutritive value, and elemental composition. Warm-season grasses tended to be higher-yielding but of lower nutritive value. All ten NWSPs contained sufficient concentrations of eleven elements to support nonlactating cows. These experiments demonstrated that diverse NWSP mixtures may be a valuable addition to both forage and bioenergy agroecosystems.
Ph. D.
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50

Mechanda, Subbaiah M. "Molecular analysis of genetic diversity in the native populations of Echinacea." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/29235.

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Echinacea is a North American medicinal plant that was used for medicinal purposes by Native Americans. Modern uses of Echinacea preparations include the treatment of colds and influenza, wound healing, and treatment of candidiasis. While demand is increasing, the natural populations of Echinacea are dwindling due to wild crafting and the loss of habitat caused by urban development. Understanding of the genetic diversity of natural populations is crucial in the management and conservation of the natural populations of Echinacea. Genetic diversity of natural populations of Echinacea was estimated using AFLP markers. Population genetic analysis of the AFLP data put the variation at 40% among and within the populations. Canonical analysis supported the four species concept of the morphometric analyses, however phylogenetic analysis supported some of the four species, but there was very little support by all the other analyses of the eight varieties of Echinacea. No correlations were found between the genetic distances and the geographic distances at the population level. The correlations between data sets and primer pairs was high at the species level, but was lower at the variety level. AFLP markers that were species or variety specific could not be identified. The comigrating bands that are monomorphic within and among species and varieties are 90% identical in their nucleotide sequences while the polymorphic bands within and among species and varieties are only 25% identical. The assumption that comigrating AFLP fragments have identical sequences within species and varieties is not valid in Echinacea. Based on these findings, AFLP markers were treated as phenotypes rather than genotypes and as such used for phylogenetic analysis of Echinacea populations. Phylogenetic analysis supported only two species, E. purpurea and E. laevigata that separated into clear groups with all the individuals together, whereas E. atrorubens and E. pallida were separated into groups, but the individuals were scattered among the groups. The varieties could not be grouped, as the individuals were scattered among different groups. However discriminant analysis of the AFLP data revealed bands that could be used to identify the four species and only three of the eight varieties Echinacea. Tissue culture procedures for mass propagation of Echinacea purpurea (L.) Moench for producing uniform plants from leaves of mature plants were established. However, the method was not applicable for all the other species and varieties of Echinacea.
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