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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Effects of vineyard management and landscape context on taxonomic diversity and interaction networks of flower-visiting insects in the Cape Floristic Region biodiversity hotspot

Kehinde, Temitope Olatayo 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Both taxonomic diversity and diversity of species interaction networks are experiencing declines as a result of agricultural intensification at habitat and landscape scales. Reversing this trend is a key conservation issue, particularly for important functional groups such as flower-visiting insects and the networks within which they interact. This is of great concern in regions of high conservation priority such as the Cape Floristic Region (CFR), known for its high level of floral and faunal endemism and exceptional species turnover. Holistic approach to conservation in agricultural landscapes involves both preservation of natural land and wildlife friendly management of the farm land to achieve conservation targets. The value of these extensive management approaches is yet to be fully assessed, especially in perennial systems such as vineyards. I examined here the effects of vineyard management and landscape context on species richness and abundance of flower-visiting insects and their species interaction networks. Possible taxon specific effects were verified. I also investigated whether vineyards under organic and conventional management homogenized insect-flower interaction networks and whether vineyards with different management practices vary in patterns of species turnover. I sampled flower-visiting insects and their interactions in organic and conventional vineyards, and in natural reference sites. Inclusion of natural reference sites enabled me to make management recommendations for patches of natural vegetation in CFR agricultural landscape. Statistical models showed taxon-specific benefit of organic farm management, and of landscape (distance to natural habitat). There was benefit to monkey beetles (Scarabaeidae) but not to bees (Apidae). Organic vineyards had a higher number of insect-flower interactions than conventional ones, but vineyards under the two types of management were similar in terms of other important network indices. However, networks of the vineyards were more nested than the natural sites, indicating that they may be potentially more stable to perturbation and random extinctions. Multivariate dispersion tests revealed insect-flower interaction networks were not homogenized by both organic and conventional vineyards across the landscapes. I also found, through additive partitioning, that organic and conventional vineyards were similar in terms of species turnover of bees and flowering plants. The findings of this study provide heuristic value to current debates on the value of vineyard habitats for insect conservation. Both organic and conventional vineyards that promote sustainable management of the non-crop floral vegetation between vineyard rows are potential solutions for conservation of flower-visiting insects and their interactions. Also, attention has to be paid to the quality and connectivity of the natural habitat patches that are within CFR agricultural landscape. Site specific management and assessment of the value of these landscape elements is important. Management approaches such as carefully controlled burning may be beneficial, as the CFR natural vegetation is a fire-driven community. / AFRIKAANSE OPSOMMING: Taksonomiese diversiteit en diversiteit van spesies-interaksie netwerke ondervind beide afnames as gevolg van landboukundige intensifikasie op habitat en landskap skaal. Om die neiging terug te swaai, is ’n sleutel bewaringsaangeleentheid, veral vir belangrike funksionele groepe soos blom-besoekende insekte en die netwerke waarbinne hulle op mekaar inwerk. Dit is van groot kommer in streke met hoë bewaringsprioriteite soos in die Kaapse Floristiese Streek (KFS), bekend vir sy hoë vlak van plant- en dierendemisme en buitengewone spesies kentering. ’n Holistiese benadering tot bewaring van landboukundige landskappe behels beide die bewaring van natuurlike land en natuurlewe-vriendelike bestuur van die plaasgrond om bewaringsdoelwitte te bereik. Die waarde van hierdie ekstensiewe bestuursbenaderings moet nog volledig bepaal word, veral in meerjarige sisteme soos wingerde. Ek het die uitwerkings van wingerdbestuur en landskapsamehang op spesiesrykheid en volopheid van blombesoekende insekte en hulle spesies interaksie netwerke ondersoek. Moontlike takson-spesifieke uitwerkings is nagegaan. Ek het ook ondersoek ingestel of wingerde onder organiese en gebruiklike bestuur ooreenstemmende insek-blom interaksie netwerke met wingerde met verskillende bestuurspraktyke in patroon van spesies kentering gewissel het. Ek het blom-besoekende insekte en hulle interaksies in organiese en konvensionele wingerde, asook in natuurlike verwysingsgebiede gemonster. Insluiting van natuurlike verwysingsgebiede het my in staat gestel om bestuursvoorstelle vir gebiede van natuurlike plantegroei in KFS landboulandskappe voor te stel. Statistiese modelle toon takson-spesifieke voordeel van organiese plaasbestuur en van die landskap (afstand van natuurlike habitat) self. Daar was voordeel vir bobbejaankewers (Scarabaeidae), maar nie vir bye (Apidae) nie. Organiese wingerde het ’n groter getal insek-blom interaksies as konvensionele wingerde gehad, maar wingerde onder beide tipes van bestuur was soortgelyk in terme van ander belangrike netwerk aanduiders. Netwerke van wingerde was egter meer geklomp dan natuurlike gebiede wat aandui dat hulle potensieel meer stabiel betreffende versteuring en lukrake uitsterwings is. Multivariate verspreidingstoetse het aangetoon dat insek-blom interaksie netwerke by beide organiese en konvensionele wingerde oor landskappe nie eenvormig was nie. Ek het ook bevind deur aanvullende verdeling dat organiese en konvensionele wingerde gelykwaardig was in terme van spesies kentering van bye en blomplante. Die bevindings van hierdie studie verskaf heuristise waarde tot huidige debatte oor die waarde van wingerdhabitatte vir insekbewaring. Beide organies en konvensionele wingerde wat volhoubare bestuur van die nie-gewas plantegroei binne wingerdrye bevorder, is moontlike oplossings vir die bewaring van blom-besoekende insekte en hulle wisselwerkings. Bykomend moet aandag gegee word aan die kwaliteit en verbindings van en tussen natuurlike habitat gebiede binne die KFS landboulandskap. Plekspesifieke (plaaslike) bestuur en bepaling van die waarde van hierdie landskapelemente is belangrik. Bestuursbenaderings, soos noukeurig beheerde brand, mag voordelig wees aangesien die KFS natuurlike plantegroei ’n vuurgedrewe gemeenskap is.
192

The placebo effect: international patent law and the protection of traditional plant medicine

Koutouki, Konstantia 09 1900 (has links)
Une préoccupation essentielle traverse cette thèse: l'indifférence systémique de la Loi internationale sur la propriété intellectuelle a l'égard des savoirs traditionnels autochtones. De manière générale, un écart semble d'ailleurs croissant entre l'importance des accords internationaux sur les questions d'intérêt commercial et ceux de nature sociale. Les savoirs traditionnels autochtones sur les plantes médicinales sont particulièrement désavantagés dans ce système dichotomique puisqu'ils sont non seulement à l'origine d'énormes profits commerciaux mais se trouvent aussi au cœur de multiples croyances propres à ces sociétés. L'Accord sur les aspects des droits de propriété intellectuelle qui touchent au commerce (ADPIC) de l'Organisation mondiale du commerce (OMC) a cristallisé le souci de la législation internationale à l'égard d'une protection efficace des intérêts commerciaux. Deux années auparavant, la Convention sur la diversité biologique (CDB) était signée, traduisant une préoccupation à l'égard du développement durable, et elle devenait le premier accord international à tenir compte des savoirs traditionnels autochtones. On considère souvent que ces deux accords permettent l'équilibre du développement commercial et durable, requis par l'économie internationale. Après plus ample examen, on a plutôt l'impression que l'idée d'une CDB défendant, avec succès et efficacité, la nécessité du développement durable et des savoirs traditionnels autochtones contre les pressions opposées de l'ADPIC et de l'OMC est, au mieux, simpliste. La thèse explore également la fonction de la Loi sur les brevets dans la création d’industries, notamment pharmaceutique, et la manière dont ces industries influencent la législation nationale et en particulier internationale. De même, elle traite du rôle que jouent les brevets dans l'affaiblissement et la dépossession des peuples autochtones dotés de savoirs traditionnels sur les plantes médicinales, conduisant à une situation ou ces savoirs sont marginalisés ainsi que leurs détenteurs. La thèse aborde les failles institutionnelles du système juridique international qui permet une telle situation et indique l'urgente nécessité d'examiner attentivement les inégalités économiques et sociales au Nord comme au Sud, et non seulement entre eux. Finalement, la thèse suggère que la législation internationale gagnerait à s'inspirer des diverses traditions juridiques présentes à travers le monde et, dans ce cas particulier, peut être les détenteurs des connaissances traditionnelles concernant les plantes médicinales seront mieux servi par le droit des obligations. / The underlying theme of this thesis is the systemic indifference that exists within international intellectual property law towards Indigenous traditional knowledge. In general, there appears to be a widening gap between the importance international law accords to matters of commercial interest and those of a social nature. Indigenous traditional knowledge of medicinal plants is especially disadvantaged in this dichotomous system since it is not only representative of enormous commercial profits but it is also the core of many Indigenous belief and social systems. The crystallization of international law's preoccupation with the effective protection of commercial interests came in the form of the Trade Related Intellectual Property Rights (TRIPS) agreement incorporated into the World Trade Organization (WTO). Two years previously, the Convention on Biological Diversity (CBD) was signed, reflecting international law's perceived dedication to sustainable development and became the first international treaty to address Indigenous traditional knowledge. These two pieces of international law are often seen as balancing the commercial and sustainable development needs of the international economy. Upon further examination however, one is left the impression that the idea of the CBD effectively and successfully defending the needs of sustainable development and Indigenous traditional knowledge against pressure to the contrary from TRIPS and the WTO is simplistic at best. The thesis also explore the role patent law plays in the creation of modern industries, such as the pharmaceutical industry, and how these industries are able, through the power gained via patent law, to influence national and especially international legislation. Equally, it deals with the role patents play in disempowering peoples with Indigenous traditional knowledge of medicinal plants leading to a situation where such knowledge is marginalized along with its bearers. The thesis addresses the institutional shortcomings of the international legal system that allows such a situation to exist and suggests an urgent need to closely examine the social and economic inequalities within the North and South and not just between them. Finally the thesis suggests that international law needs to be guided by the many legal traditions available worldwide and in this particular case perhaps contract law is better suited to the needs of Indigenous traditional knowledge holders.
193

Diversité biologique des enfants décédés en période périnatale et traitements funéraires au Kerma classique : Les exemples de la nécropole 8B-51 (Kerma classique, Nord Soudan) et des cimetières de Blandy-les-Tours (Xe-XIIe siècle, France) et de Provins (XIIIe-XVIIIe siècle, France) / Biological Diversity of Children Deceased in Perinatal Period and Funerary Treatments in the Classic Kerma : The examples of the necropolis 8B-51 (Classic Kerma, North-Sudan) and the cemeteries of Blandy-les-Tours (XIh-XIIth centuries, France) and Provins (XIIIth-XVIIIth centuries, France)

Partiot, Caroline 28 November 2018 (has links)
En dépit des taux élevés de mortalité infantile dans les populations du passé, les sujets décédés en période périnatale ont longtemps été délaissés dans les travaux anthropologiques et paléoanthropologiques. Alors que les analyses biologiques portant sur les individus adultes intègrent l’étude de la variabilité comme une composante majeure, rares sont celles permettant de replacer un individu décédé en période périnatale dans le cadre de la variabilité individuelle ou populationnelle de cette classe d’âge. Le présent travail se propose ainsi d’investir le sujet de la diversité métrique et non-métrique des sujets décédés entre 22 et 48 semaines d’aménorrhée à partir de l’étude biologique de 116 sujets de trois collections archéologiques (une kerma et deux médiévales et modernes) et d’une collection actuelle virtuelle comportant 364 individus. Un premier axe de recherche caractérise la variabilité des corpus dans ses composantes intra-individuelles, inter-individuelles, populationnelles, ainsi que du point de vue des corrélations à l’âge au décès. Un second axe de recherche vise à identifier des caractères permettant d’estimer l’état de morbidité et de vitalité à la naissance de l’individu, donnée déterminante pour le statut du sujet dans la société. Pour le premier axe, l’étude révèle des différences de conformation selon l’âge au décès et les groupes populationnels, de même que l’existence d’asymétries directionnelles et fluctuantes. Les résultats vont ensuite dans le sens d’une forte proximité biologique pour le groupe kerma, traduisant potentiellement une certaine endogamie, au contraire du groupe médiéval et moderne dont la diversité plus importante pourrait refléter des facteurs socio-géographiques ou séculaires. Le second axe de recherche a permis de souligner que la mécano-sensibilité des régions d’insertion musculaire apparaît comme un nouveau paramètre à considérer pour discerner les sujets ayant survécu à la naissance. L’étude de la collection kerma livre également la première identification en contexte archéologique d’un critère de morbidité spécifique, la côte surnuméraire cervicale. Enfin, le croisement des analyses biologiques et des données archéologiques de la nécropole 8B-51 de l’île de Saï, permet d’appréhender et de discuter les traitements funéraires dévolus à la classe d’âge périnatale au Kerma classique. / Despite the high rates of child mortality in past populations, subjects deceased in perinatal period were often neglected in bioarchaeological and paleoanthropology studies. Unlike biological analysis on adults, investigations on newborns rarely include individual or populational variability comparisons as a major component. In the present work, we will focus on metrical and non-metrical diversity of subject deceased between 22 and 48 amenorrhea weeks, based on the biological study of 116 subjects from three archaeological collections (one kerma and two medieval and modern) and one current virtual collection with 364 individuals. The first research axis characterizes the intra-individual, inter-individual and populational variability, and differences by age at death in both samples. The second line of research aims to identify criteria making it possible to estimate individual morbidity and live birth on dry bones, informations that are needed to understand the child’s position in society. Biological studies reveal for the first research axis shape differences by age at death and populations, as well as the existence of directional and fluctuating asymmetries. Results provide evidences of strong biological proximity in the kerma group, potentially indicating of endogamy. On the contrary, the diversity of the medieval and modern group appears broader and could reflect socio-geographical factors or secular trends. The second line of research reveals the mechanical sensitivity of muscular insertions as a key parameter for tracking of live-born subjects. The study of the kerma collection provides the first archaeological identification of the supernumerary cervical rib, detected as a morbidity criterion in perinatal period. Lastly, crossing of biological and archaeological data on the 8B-51 necropolis provides an interpretative framework for funerary treatments dedicated to the perinatal age group in Classic Kerma.
194

The placebo effect: international patent law and the protection of traditional plant medicine

Koutouki, Konstantia 09 1900 (has links)
Une préoccupation essentielle traverse cette thèse: l'indifférence systémique de la Loi internationale sur la propriété intellectuelle a l'égard des savoirs traditionnels autochtones. De manière générale, un écart semble d'ailleurs croissant entre l'importance des accords internationaux sur les questions d'intérêt commercial et ceux de nature sociale. Les savoirs traditionnels autochtones sur les plantes médicinales sont particulièrement désavantagés dans ce système dichotomique puisqu'ils sont non seulement à l'origine d'énormes profits commerciaux mais se trouvent aussi au cœur de multiples croyances propres à ces sociétés. L'Accord sur les aspects des droits de propriété intellectuelle qui touchent au commerce (ADPIC) de l'Organisation mondiale du commerce (OMC) a cristallisé le souci de la législation internationale à l'égard d'une protection efficace des intérêts commerciaux. Deux années auparavant, la Convention sur la diversité biologique (CDB) était signée, traduisant une préoccupation à l'égard du développement durable, et elle devenait le premier accord international à tenir compte des savoirs traditionnels autochtones. On considère souvent que ces deux accords permettent l'équilibre du développement commercial et durable, requis par l'économie internationale. Après plus ample examen, on a plutôt l'impression que l'idée d'une CDB défendant, avec succès et efficacité, la nécessité du développement durable et des savoirs traditionnels autochtones contre les pressions opposées de l'ADPIC et de l'OMC est, au mieux, simpliste. La thèse explore également la fonction de la Loi sur les brevets dans la création d’industries, notamment pharmaceutique, et la manière dont ces industries influencent la législation nationale et en particulier internationale. De même, elle traite du rôle que jouent les brevets dans l'affaiblissement et la dépossession des peuples autochtones dotés de savoirs traditionnels sur les plantes médicinales, conduisant à une situation ou ces savoirs sont marginalisés ainsi que leurs détenteurs. La thèse aborde les failles institutionnelles du système juridique international qui permet une telle situation et indique l'urgente nécessité d'examiner attentivement les inégalités économiques et sociales au Nord comme au Sud, et non seulement entre eux. Finalement, la thèse suggère que la législation internationale gagnerait à s'inspirer des diverses traditions juridiques présentes à travers le monde et, dans ce cas particulier, peut être les détenteurs des connaissances traditionnelles concernant les plantes médicinales seront mieux servi par le droit des obligations. / The underlying theme of this thesis is the systemic indifference that exists within international intellectual property law towards Indigenous traditional knowledge. In general, there appears to be a widening gap between the importance international law accords to matters of commercial interest and those of a social nature. Indigenous traditional knowledge of medicinal plants is especially disadvantaged in this dichotomous system since it is not only representative of enormous commercial profits but it is also the core of many Indigenous belief and social systems. The crystallization of international law's preoccupation with the effective protection of commercial interests came in the form of the Trade Related Intellectual Property Rights (TRIPS) agreement incorporated into the World Trade Organization (WTO). Two years previously, the Convention on Biological Diversity (CBD) was signed, reflecting international law's perceived dedication to sustainable development and became the first international treaty to address Indigenous traditional knowledge. These two pieces of international law are often seen as balancing the commercial and sustainable development needs of the international economy. Upon further examination however, one is left the impression that the idea of the CBD effectively and successfully defending the needs of sustainable development and Indigenous traditional knowledge against pressure to the contrary from TRIPS and the WTO is simplistic at best. The thesis also explore the role patent law plays in the creation of modern industries, such as the pharmaceutical industry, and how these industries are able, through the power gained via patent law, to influence national and especially international legislation. Equally, it deals with the role patents play in disempowering peoples with Indigenous traditional knowledge of medicinal plants leading to a situation where such knowledge is marginalized along with its bearers. The thesis addresses the institutional shortcomings of the international legal system that allows such a situation to exist and suggests an urgent need to closely examine the social and economic inequalities within the North and South and not just between them. Finally the thesis suggests that international law needs to be guided by the many legal traditions available worldwide and in this particular case perhaps contract law is better suited to the needs of Indigenous traditional knowledge holders.
195

Prioridades espaciais para a conservação de mamíferos do Cerrado em um mundo em mudança / Spatial priorities for conservation of mammals from Cerrado in a change world

FALEIRO, Frederico Augusto Martins Valtuille 28 March 2012 (has links)
Made available in DSpace on 2014-07-29T16:21:19Z (GMT). No. of bitstreams: 1 Faleiro Frederico Dissertacao.pdf: 1687158 bytes, checksum: e1a8a44e89beea38d1a839934c890e56 (MD5) Previous issue date: 2012-03-28 / The human actions has triggered many threats to biodiversity like land-use and climate changes, overexploitation, pollution, and introduction of invasive species, which can affect organisms both at local and global scale. The science of spatial conservation prioritization emerged as a quantitative approach to support the spatial decisions in face of these threats, while minimizing the socioeconomic and political conflicts. Here we developed spatial solutions to the conservation of non-flying mammals from Brazilian Cerrado considering the socioeconomic costs and the opportunities of environmental governance (first objective). Further, we generated solutions to face the land-use and climate change taking into account the dispersal abilities of species and uncertainties in the species distribution modeling (SDM) process (second objective). We considered the current network of reserves of the Cerrado in both objectives. We built SDMs for 154 species combining model projections weighted by their statistical fit to produce consensus maps of species distribution grouped in three distinct types of models (envelope, statistical and machine-learning models), for both current future scenarios of climate (used only in the last aim). For the first goal, we used the current predicted distribution to run spatial prioritization analyses indicating the best sites for the conservation investment considering human population density, land cost, anthropogenic land use, level of environmental governance, and the distribution of species in trade-off analyses. For the second goal, we used both current and future predicted distribution to run optimization procedures and propose priority sites for conservation, while minimizing species climate-forced dispersal distance , the mean uncertainty associated to the SDM process, and taking into account the future changes in the landscape (by our land use model). SDMs indicated that species-rich sites converge to regions with high population density, high land cost, high anthropogenic land use, and with diverse levels of environmental governance. There was a significant change in spatial priorities when socioeconomic and political dimensions were included in analyses: top priority sites moved towards the north. This spatial change reduced by 68% the potential conservation conflicts with human population, by 72% the likely conflicts arising from land cost and by 68% anthropogenic land use. It also increased by 51% the beneficial effect of environmental governance. Including land-use changes and the modeling uncertainty in the conservation planning process changed significantly the spatial distribution of priority sites in the region. While the inclusion of land-use models altered the spatial location of priority sites at the regional scale, the effects of climate change tended to take place at the local scale. Note that, our solutions already include possible dispersal corridors linking current and future priority sites for mammal conservation, as well as a formal risk analysis based on planning uncertainties. Our results allowed dealing with both complex nature of conflicts among socioeconomic and political dimensions, and the dynamic problem imposed mainly by land-use and climate change. Thus, our analyses figure as a methodological prospect supporting the decision-make process and the consequent translation of conservation planning outcomes into conservations actions / As ações humanas têm desencadeado diversas ameaças a biodiversidade como as mudanças de uso do solo e do clima, sobre-exploração, poluição e introdução de espécies invasoras, que afetas os organismos da escala local até a global. A ciência da conservação espacial para conservação emergiu como uma abordagem quantitativa que tem o objetivo de auxiliar escolhas espaciais que lidem com essas ameaças enquanto minimizam conflitos socioeconômicos e políticos. Aqui nós desenvolvemos soluções espaciais para conservação de mamíferos não voadores do Cerrado considerando os custos socioeconômicos e as oportunidades vindas da governança ambiental (primeiro objetivo). Além disso, nós geramos soluções espaciais que lidem com as mudanças do uso do solo e climáticas levando em consideração as capacidades de dispersão das espécies e as incertezas associadas ao processo de modelagem de distribuição de espécies (MDE) (segundo objetivo). Em ambos objetivos nós consideramos a atual rede de reservas do Cerrado. Nós modelamos a distribuição de 154 espécies combinando as projeções dos modelos e pesado pelo ajuste estatístico para produzir os mapas consenso de distribuição das espécies, agrupados em três distintos tipos de modelos (modelos de envelope, estatísticos e de inteligência artificial), para a atualidade e projetados para o futuro (usado apenas no último objetivo). Para o primeiro objetivo, nós usamos as predições da atual distribuição das espécies para realizar as análises de priorização espacial, indicando os melhores locais para investimento considerando a densidade humana, custo da terra, uso do solo antropogênico, nível de governança ambiental e a distribuição das espécies na perspectiva da análise de demandas conflitantes. Para o segundo objetivo, nós usamos a distribuição atual e futura das espécies para realizar o procedimento de otimização e propor locais para conservação que minimizem os efeitos da dispersão induzida pelas mudanças climáticas, incertezas associadas ao processo MDE e considerando as futuras mudanças na paisagem (através do nosso modelo de uso do solo). A MDE indicou que locais ricos em espécies convergem para locais com alta densidade populacional, alto custo de terra, alta proporção de uso do solo voltado para atividades humanas e diversos níveis de governança ambiental. Houve significativas mudanças nas prioridades espaciais quando as dimensões socioeconômicas e políticas foram incluídas nas análises, fazendo que os locais prioritários mudassem para o norte. Essa mudança espacial reduziu em 68% de potenciais conflitos com população humana, em 72% de conflitos de custo da terra, em 68% de conflitos com o uso do solo antropogênico e 51% de aumento dos possíveis benefícios da governança ambiental. Quando incluímos as mudanças de uso de solo e a incerteza da modelagem no processo de planejamento, os locais prioritários mudaram significativamente na região. Enquanto a inclusão das mudanças no uso do solo alterou a localização espacial dos locais prioritários em escala regional, os efeitos da mudança climática tenderam a ocorrem em escala local. Note que nossas soluções já incluíram possíveis corredores de dispersão para ligação entre as atuais áreas prioritárias com aquelas importantes no futuro, tão bem quanto a análise de risco baseado nas incertezas do planejamento. Nossos resultados permitiram lidar tanto com a complexa natureza dos conflitos entre dimensões socioeconômicas e políticas quanto com problema dinâmico imposto principalmente pelas mudanças do uso do solo e climáticas. Assim, nossas análises auxiliam metodologicamente a dar suporte no processo de tomada de decisão e a consequente tradução dos resultados de planejamentos de conservação em ações de conservação
196

Évolution spatiotemporelle de la diversité et du fonctionnement d'une guilde de parasitoïdes / Spatiotemporal evolution of diversity and function in a parasitoid guild

Andrade, Thiago 04 November 2013 (has links)
Cette thèse porte sur l’analyse des dimensions spatiale et temporelle du fonctionnement et de la diversité taxonomique et fonctionnelle d’une guilde. Au sein d’une guilde, les espèces exploitent un même type de ressources; pour cette raison, les niches écologiques fondamentales des membres d’une guilde sont similaires et une relation de compétition interspécifique se met en place si la ressource partagée est limitante. Quatre questions principales sur le fonctionnement d’une guilde ont été abordées : (1) à quelles échelles spatio-temporelles se structurent la guilde et les ressources exploitées, (2) quelles sont les influences respectives des filtres environnementaux et des interactions interspécifiques sur les traits fonctionnels des membres de la guilde, (3) quelle est la stratégie d’exploitation de ressources d’un membre de la guilde face à une faible disponibilité de ressources et (4) quel est l’impact du contexte climatique sur la structure d’une guilde et de son réseau trophique, et sur le degré de spécialisation écologique des espèces de la guilde sur la ressource. Le modèle biologique de cette étude a été une guilde de parasitoïdes de pucerons de céréales (Hymenoptera : Braconidae : Aphidiinae). Ces parasitoïdes s’attaquent aux pucerons (Homoptera : Aphididae) inféodés aux céréales dans les agroécosystèmes. Les variations d’abondance relative des parasitoïdes et de leurs hôtes ont été importantes aux échelles interrégionale et interannuelle, mais très faibles à l’échelle intra-régionale. La divergence des traits fonctionnels des parasitoïdes s’est maintenue sur trois régions et deux années, et le contexte local a influencé les traits de la guilde dans son ensemble. Pendant la saison hivernale, une période marquée par une faible densité de pucerons, le parasitoïde Aphidius rhopalosiphi a présenté des stratégies contrastées pour maximiser sa fitness en exploitant les hôtes Sitobion avenae et Rhopalosiphum padi, mais une forte spécialisation écologique sur le terrain a été observée en présence d’une espèce compétitrice : Aphidius avenae. Cette présence a pu être corrélée à une hausse des températures hivernales. / This thesis is an analysis of the spatial and temporal dimensions of the functioning and taxonomic and functional diversity of a guild. In a guild, species exploit the same type of resources; consequently, fundamental ecological niches of guild members are similar and an interspecific competitive relationship is established if shared resources are limiting. Four main questions on the functioning of a guild are addressed: (1) the spatiotemporal scales to which guilds the guild and its exploited resources are structures, (2) the respective weight of environmental filtering and interspecific interactions on the configuration of realized niches of guild members, (3) the strategy of resource exploitation in a guild member facing low resource availability and (4) the impact of climatic context on the structure of a guild and its food web, and the degree of specialisation on resources. The biological model chosen in this study was a cereal aphid parasitoid guild (Hymenoptera: Braconidae: Aphidiinae). Those parasitoids attack aphids (Homoptera: Aphididae) in agroecosystems, which are anthropised environments marked by high disturbance rates and in which host resources are variable in density and in quality. Relative abundance variations in parasitoids and in their hosts were considerable at interregional and interannual scales, but weak at the intra-regional scale. Functional trait divergence in parasitoids was maintained across three regions and two years, and regional and annual environmental contexts influenced guild traits as a whole. In winter, a period marked by low aphid density, the parasitoid Aphidius rhopalosiphi presented contrasted strategies to maximise fitness whilst exploiting Sitobion avenae and Rhopalosiphum padi hosts, but a high degree of ecological specialisation in the field was observed in the presence of a competitive species, Aphidius avenae. This presence was correlated to an increase in winter temperatures.
197

Går det att bevara befintlig grönska vid förtätning av staden? : En fallstudie om hur grönytor och naturvärden prioriteras på privat mark i Malmö

Ekholm, Tor January 2019 (has links)
The ongoing trend with urban infill often implicates a conflict with urban green areas, which becomes a problem when green areas in cities are declining and when biodiversity is threatened on a global scale. This case study investigates how green areas and existing biological values are prioritized in an area in Malmö where infill is taking place (Översiktsplan för del av Kirseberg). Specifically, planning process and dialogue, on detailed comprehensive planning level, between the municipality and the landowner is analysed and compared with the policy plan for the area. The methods used are semi-structured interviews combining qualitative and quantitative data.The results show that many of the planning policies regarding green areas are prioritized and considered. However, when it comes to preserving existing vegetation and biological values, these policy goals are prioritized lower than the other policies, which leads to postponed conservation measures. Arguments for planning green areas are about structural concerns and attractivity. Municipal planners are concerned about the low amount of green areas and they find that policies and the planning and building act for green areas give a poor support in the planning process.Vague policy goals for green areas make it difficult for planners to balance between the many policy goals they need to consider. Although the actors have common interests and two-sided compromises are done, profit and a high exploitation level are the priorities of the landowner,which leads to fewer green areas. Landownership therefore limits municipal influence to planfor public interests like green areas. Furthermore, the political focus on high exploitation is another reason for this. Insufficient and outdated policies and planning material are also concerns that affects the planning of green areas.Green areas and biological values are not prioritized enough on the detailed comprehensive planning level neither in the policies of the plan, in the planning process nor in other policies. To change this, both planning laws, policies and political will need to prioritize green areas higher. Many studies state that the planning and building act is insufficient for planning green areas that support ecosystem services on private properties. This seems to apply to this case study as well.
198

Hyvlad utvändig panel : Kulturarvet som ställer kvalitetskrav på skogsskötseln / Planed exterior panels : Cultural heritage that requires forestry quality considerations

Gyllenhak, Ebba January 2021 (has links)
Arbetet strävar efter ett landskapsperspektiv på erfarenhetsmässigt byggande. För en djupare förståelse för skogs- och byggnadskulturen har kulturarvet hyvlad utvändig panel undersökts. Med en kvalitativ metod har skogsbrukare, hantverkare och råvaruförädlare fått fördjupa förståelsen för ett hållbart nyttjande av skogsresurser genom ett hållbart byggande. Att bygga med trä räknas som bättre ur klimatsynpunkt än att bygga med betong. Detta arbete öppnar för slutsatsen att det kan vara mer hållbart att bygga med tradition och därmed kvalitetsvirke för landskapets uthållighet. Från ett landskapsperspektiv finns det enligt arbetet skäl att ifrågasätta hur miljömål och omställningsarbete tar hänsyn till traditionella kulturarv i skog och bebyggelse. Med rådande skogspolitik tillsammans med en statlig önskan om mer byggande i trä riskeras kulturhantverkare och skogsägare att uteslutas från det omfattande omställningsarbete vi står inför. En rationell hantering av landskap är lätt att räkna på i mål och styrmedelsarbete men riskerar att få oanade konsekvenser. En erfarenhetsbeprövad kvalitativ byggnadskultur som kan representeras i panelarkitekturen som detta arbete undersöker kan vara en av många vägar framåt för ett känt hållbart byggande och skapa efterfrågan på hållbar skogs- och virkeshantering. / This paper aims to start a discussion about the forest as a producer of quality building materials, where the cultural heritage of planed panels is the gateway to a deeper understanding of future building- and forestry culture in Sweden. Using a qualitative research method, carpenters, foresters and raw materials processors have been asked to give their views on the current situation and the future of sustainable use of forest resources through sustainable construction. The paper aims to give a landscape perspective on experiential construction. Building with wood is regarded as better from a climate point of view than building with concrete. The paper broadens the conclusion that it could even be more sustainable to build with tradition and thus quality timber.
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Bland granar och grannar : Ansvar och risk för granbarkborreangrepp i skog / Between Neighbours and Nature : Resposibility and Risk for Spruce Bark Beetle Infestations in Forests

Helmius, Lovisa January 2022 (has links)
This thesis discusses the responsibility of and risk for infestations of spruce bark beetle. The spruce bark beetle, Ips typographus, is a natural part of the Swedish forest ecosystem but causes severe financial damage in forestry. Since 2018, the spruce bark beetle infestations have been substantial in Sweden. The first task of the thesis is to evaluate the balance between the forest production interests and the environmental interests, based on the legal regulation of spruce bark beetle control. Production and environment are the equal aims of the Swedish Forestry Act. The regulation of spruce bark beetle control differs depending on whether the forest is in a conservation area or not. For example, owners of forests outside conservation areas are obliged to take care of damaged, fresh wood of spruce and pine, while such an obligation in general does not exist in conservation areas. In this evaluation, I conclude that the balance between the two interests in the spruce bark beetle regulation is good as a whole.  The second question of the thesis is the legal allocation of risk for spruce bark beetle infestations. In this investigation, it is examined whether established law presents a possibility to claim damages for spruce bark beetle infestations that may derive from an adjacent forest. The conclusion drawn is that the regulation of compensation for certain kinds of environmental damage in the Swedish Environmental Code probably would not be applicable as a legal basis for such a claim. By contrast, neighbour law and the Swedish Torts Act could be used as the basis of an action for damages. However, to prove causality regarding the origins of a specific infestation might bring problems, which altogether means that an action for damages faces considerable difficulties. Therefore lastly, some alternative ways of allocating the risk for spruce bark beetle infestations are presented. / I denna uppsats diskuteras ansvar och risk för granbarkborreangrepp. Granbarkborren, Ips typographus, är en naturlig del av skogens ekosystem men orsakar stora ekonomiska skador i skogsbruket. Sedan 2018 har granbarkborreangreppen i Sverige varit omfattande.  Uppsatsens första uppgift är att utifrån regleringen av granbarkborrebekämpning i skogen utvärdera avvägningen mellan produktions- och miljöintresset, som är skogsvårdslagens jämställda mål. Den rättsliga regleringen av bekämpning av granbarkborrar skiljer sig åt beroende på om skogen är skyddad eller oskyddad. Bland annat är ägare av oskyddad skog ålagda att ta hand om skadat, färskt barrvirke, medan en sådan skyldighet ofta saknas i skyddade områden. I utvärderingen kommer jag fram till att avvägningen mellan de två intressena över lag är god i granbarkborreregleringen.  Den andra frågan i uppsatsen är fördelningen av risk för granbarkborreangrepp. För att undersöka det utreds om det enligt gällande rätt är möjligt att få skadestånd för granbarkborreangrepp som kan härstamma från närliggande skyddad eller oskyddad skog. Slutsatsen är att 32 kap. miljöbalken förmodligen inte skulle vara tillämplig, medan däremot grannelagsrätten och skadeståndslagen kan läggas till grund för en sådan talan. Att bevisa orsakssambanden kan dock innebära problem, vilket sammantaget gör att en skadeståndstalan för granbarkborreangrepp från närliggande skog möter ansenliga hinder. Sist presenteras därför några alternativa sätt att fördela risken för barkborreangrepp.

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