La fertilisation et les amendements sont des pratiques courantes en agronomie dont l’intérêt a été prospecté dans le domaine forestier. Des dispositifs expérimentaux de fertilisation ont été mis en place et étudiés par le passé. Le but de ces dispositifs était de déterminer si l’apport d’éléments nutritifs dans des milieux forestiers initialement pauvres ou acides pouvait augmenter la croissance voire restaurer l’état des cimes des arbres en situation de dépérissement. Par ailleurs, des études physiologiques ont montré l’implication de l’eau dans l’absorption des éléments nutritifs du sol et leur transport par la sève brute mais aussi via des effets combinés dans divers processus tels que la croissance cellulaire ou la régulation stomatique. Récemment, des épisodes de sécheresse extrême, responsables de vagues de dépérissement sur de nombreuses essences forestières, ont suscité l’inquiétude des gestionnaires. De plus, les modèles climatiques prédisent une augmentation de fréquence et d’intensité de l’aléa sécheresse dans un futur proche et la gestion forestière doit être adaptée pour y faire face. Dans ce contexte et grâce aux connaissances déjà acquises sur les interactions entre nutrition minérale et hydrique, nous cherchons à savoir si l’apport d’éléments nutritionnels pourrait atténuer les effets négatifs des déficits hydriques en agissant à la fois sur les capacités à supporter les sécheresses et à retrouver des niveaux de croissance optimale après l’aléa, c’est-à-dire améliorer la résilience des arbres. A l’inverse, la vulnérabilité des arbres aux déficits hydriques se trouverait-elle augmentée ? Pour répondre à cette problématique, nous avons exploité des dispositifs expérimentaux de fertilisation situés dans trois forêts en France sur deux essences forestières, le chêne sessile et le sapin de Douglas. Sur chacun de ces sites, des arbres sélectionnés ont été carottés à cœur afin de tracer les variations annuelles de croissance radiale à partir de mesures des largeurs de cernes. Ces courbes de croissance ont servi de base au calcul des indices de résistance, récupération et résilience de la croissance à des déficits hydriques du sol, calculés quant à eux à l'aide du modèle de bilan hydrique BILJOU©. Sur le site de Bercé, l’efficience d’utilisation de l’eau a de plus été appréhendée à partir du δ13C contenu dans le bois final des cernes. La croissance radiale des chênes de Bercé et de Tronçais a significativement été augmentée par la fertilisation et les variations interannuelles de croissance ont été modélisées par le climat et le déficit hydrique du sol. La croissance du sapin de Douglas quant à elle n’a que très peu été augmentée par l’apport en nutriments en forêt des Potées. Par ailleurs, cette analyse montre que la stimulation de croissance par la fertilisation est transitoire : moins de 10 ans après l’apport d’éléments nutritifs à Bercé et 20 ans à Tronçais, plus aucun effet sur la croissance ne subsiste. Malgré cet effet positif transitoire sur les croissances radiales du chêne, aucune différence entre les traitements sur les capacités des arbres à résister et récupérer après des épisodes de sécheresse. Les résistance et récupération de la croissance sont dépendantes de l’intensité et de la durée du déficit hydrique, donc de la sévérité de l’aléa et non de l’apport de nutriments. Ces résultats corroborent les analyses du δ13C dans les cernes des chênes qui, là encore, ne sont significativement corrélées qu’avec le climat et sont indépendantes du traitement. L’absence de modification de la résilience entre les traitements, quel que soit le site et l’essence étudiés, est discutée. Plus largement, ces travaux interrogent le concept de résilience et son utilisation en dendroécologie / Fertilization and liming are usual practices in agronomy but uncommon in forestry. Experimental liming or fertilization in forest were tested in the 1970’s. The initial aim of these experimentations was to determine if the addition of nutrients on poor or acidic forest soil could increase tree growth or even restore crown condition in case of decline. Physiological studies have established the implication of water availability in soil nutrients uptake and their transport in the sap and also via combined effects in various processes such as cell growth or stomatal control. Recently, extreme drought events responsible of many forest species diebacks have aroused the concern of forest managers. In addition, climate models predict an increase in the frequency and intensity of drought hazards in the future and forest management must be adapted to face them. In this context, and thanks to the current knowledge on the interactions between mineral and water alimentation, we investigate whether nutrient supply could mitigate the negative effects of water deficits by increasing the capacity 1/ to withstand droughts and 2/ to recover optimum growth after the drought induced crisis, i.e. to improve the resilience of trees. Conversely, would the vulnerability of trees to water deficits be increased? To answer this question, we investigated fertilization experiments located in three forests in France and applied on two species, sessile oak and Douglas fir. On each of these sites, selected trees were cored to the pith to determine the annual variations of radial growth from measurements of the tree-rings widths. These growth variations were used as a basis to the calculation of resistance, recovery and resilience indices to drought events, which were quantified using a soil water deficit index computed by the water balance model BILJOU©. On the site of Bercé, the water-use efficiency was estimated from the δ13C of the latewood. Retrospective analyses shown that the radial growth of oak trees in Bercé and Tronçais was significantly increased after the fertilization. Radial growth was then modelled from climate and soil water deficit. Douglas fir radial growth was slightly impacted by the nutrient supply in the Potées site. This analysis highlights the time-limited effect of this nutrient supply on the growth stimulation: no effect subsists more than 10 years after nutrient supply in Bercé and more than 20 years in Tronçais. Despite this transient effect on oak growth, no differences between treatments on the capacity of trees to resist and to recover after drought events was observed. The main factors influencing resistance and recovery of growth were the soil water deficit intensity and duration. These results corroborate δ13C analyzes in oak rings, which, again, were only significantly correlated with climate and were independent of treatment. The lack of modification of the resilience between the treatments, whatever the site and the species studied, is discussed. More broadly, the concept of resilience and its use in dendroecology are questioned

Made available in DSpace on 2016-06-02T20:09:24Z (GMT). No. of bitstreams: 1 DissGRN.pdf: 2609082 bytes, checksum: 09147cf07533f0a088d8e1734fc80ee4 (MD5) Previous issue date: 2005-12-09 / Financiadora de Estudos e Projetos / The cooling effect of evaporation is used in dry climates buildings since ancient times. Water evaporation can remove heat of roofs, cooling the interior of buildings indirectly. This study presents the measurement results of a test bed which received two identical tiles, one of them receiving water application and the other kept dry. Its objective was to investigate the effects that the evaporation provokes on internal surface temperature of ceramic tiles and fibrocement tiles. Using regression analyses, strong correlations were found among the falls observed in tiles internal surface temperatures and the climatic conditions. The evaporation provoked reduction of until 18,7 oC in the ceramic roof and until 17ºC reduction in the fibrocement one. / O resfriamento evaporativo de ambientes é conhecido pelos habitantes de regiões de clima seco desde a antiguidade. A evaporação de água sobre coberturas retira calor das mesmas, refrigerando indiretamente o interior da edificação. Este trabalho apresenta resultados de um estudo em que foram medidos os efeitos que a evaporação provoca sobre as temperaturas superficiais internas de telhas de barro e de fibrocimento, sujeitas às variações climáticas como o vento e radiação solar. Para tanto, montou-se uma bancada de testes onde foram monitoradas telhas idênticas, uma com gotejamento de água e outra mantida seca, em situações de inverno em laboratório e em situações de verão em campo. Por meio de análise de regressão, identificou-se fortes correlações entre as quedas observadas nas temperaturas superficiais internas das telhas e as condições climáticas. A evaporação provocou redução de até 18,7 ºC na temperatura superficial interna da telha de barro e de até 17ºC na de telha de fibrocimento. Os resultados indicaram que o gotejamento de água sobre superfícies externas de telhas de barro e de fibrocimento reduz a temperatura superficial interna das mesmas por meio da refrigeração evaporativa, sendo um potencial método de resfriamento passivo de telhados de barro e de fibrocimento na região de São Carlos-SP.

Made available in DSpace on 2014-12-17T13:56:58Z (GMT). No. of bitstreams: 1 PollyanaFR.pdf: 9314419 bytes, checksum: 79ef1b1545cd4d9af2a782b4dd572f78 (MD5) Previous issue date: 2008-12-16 / This research has as its object study focus bioclimatic in architecture and its conection with projects decisions, on what regards to environmental comfort for single-family dwelling. From the analysis of five architectural projects inserted in Natal/RN, warm-moist weather, this research gather informations regarding architectural features guided by shape and space arrengement, which embody important elements for the project design development. Computer simulations assisted as foundation to verify the efficiency grade for these projects strategies from shading analysis. Related strategies for the demands of natural ventilation circulation and thermal mass for refrigeration were analysed as well. Results show that there is an hierarchizing of priorities for the decisions made when it comes to shape and space disposition variables, as well as the way these variables will consider the bioclimatic demands. The analysis, even, show that there is no single way to respond to specific bioclimatic demands, as it points out the value of examination of the projectual solutions throughtout the conception process, in order to achieve an efficient project performance for the envimonment comfort / Esse trabalho tem como objetivo estudar o enfoque bioclim?tico em arquitetura e sua rela??o com as decis?es projetuais, no que se refere ao conforto ambiental em habita??es unifamiliares. A partir da an?lise de cinco projetos inseridos em Natal/RN, clima quente-?mido, a pesquisa levanta informa??es sobre as caracter?sticas arquitet?nicas norteadas pela forma e pelo arranjo espacial, os quais englobam elementos importantes para o desenvolvimento do projeto. Simula??es computacionais serviram de base para verificar o grau de efici?ncia das estrat?gias projetuais a partir da an?lise do sombreamento. Foram analisadas tamb?m estrat?gias relacionadas ?s demandas de ventila??o natural e de massa t?rmica para resfriamento. Os resultados demonstram que h? uma hierarquiza??o de prioridades nas decis?es tomadas quanto ?s vari?veis forma e arranjo espacial, e quanto ? maneira de como essas vari?veis ir?o atender as demandas bioclim?ticas. As an?lises evidenciam, ainda, que n?o h? uma ?nica maneira de responder a demandas bioclim?ticas espec?ficas, assim como apontam para a import?ncia de verifica??o das solu??es projetuais durante todo processo de concep??o, a fim de obter um projeto com desempenho eficiente para o conforto ambiental

A evolução da forma urbana adequada ao seu contexto climático é determinante para a qualidade ambiental dos espaços abertos. Porém, em diversas cidades o crescimento urbano acelerado ocorre quase sem nenhum controle ou planejamento. Esse descontrole é apontado como causa de prejuízos ao ambiente natural e construído, entre eles, o desconforto térmico nos espaços abertos. No Brasil, o Plano Diretor é o instrumento dos governos municipais que regula o desenho urbano; no entanto, nota-se um distanciamento entre os aspectos ambientais e a formulação dos planos e leis municipais. A cidade de Umuarama, no noroeste do Paraná, tem assistido a um intenso crescimento urbano, porém, ainda há na cidade uma flexibilidade para a gestão da forma urbana. Atualmente, está em fase de aprovação o novo Plano Diretor Municipal, que propõe a ampliação da área urbana onde é permitida a verticalização, e o Plano Municipal de Arborização Urbana, que busca promover o controle e o aumento da arborização urbana. Face ao proposto pelos planos, essa pesquisa tem como objetivo principal verificar as tendências de estresse térmico no nível do pedestre em futuros cenários de cânions urbanos na área central de Umuarama. O cânion urbano, referente ao espaço conformado pela via e edifícios adjacentes, foi adotado como objeto de estudo por se constituir na menor unidade microclimática urbana e no principal espaço aberto de uso público. A metodologia aplicada se baseia em levantamento de dados em campo; simulação de diferentes cenários de configuração urbana através de modelagem microclimática com o programa ENVI-met, para situação de verão e inverno; e aplicação do índice de conforto térmico Temperatura Fisiológica Equivalente - PET. Os resultados demonstraram que diferentes combinações dos parâmetros da forma urbana, especificamente, da geometria do cânion urbano e arborização presente no seu interior, resultam em tendências diversas de estresse térmico para o pedestre. Os maiores níveis de estresse térmico no nível do pedestre foram observados no período diurno, em situação de verão; esses níveis tendem a ser menores com o aumento da relação H/W e da arborização no interior dos cânions urbanos. Além disso, verificou-se menor amplitude térmica em cânions com maior cobertura verde. Em cânions urbanos com orientação N-S, o aumento da cobertura verde no interior do cânion urbano foi mais importante para a redução do índice PET do que em cânions com orientação L-O; por outro lado, nesses cânions com orientação L-O, o aumento da relação H/W foi mais representativo para minimizar o PET. A compreensão do comportamento do PET nos diversos cenários demonstrou que novas configurações da forma urbana são compatíveis com a qualidade ambiental dos espaços abertos desde que aplicadas estratégias do desenho urbano climaticamente orientado. Ao final, com base nos resultados, foram traçadas recomendações relacionadas à geometria e cobertura verde das vias urbanas a favor do conforto térmico dos usuários desses espaços. / The appropriate evolution of urban form for your climate context is determinant to open spaces environmental quality. However, it is observed that in several cities the accelerated urban growth occurs almost without any control or planning. This lack of control is pointed as the cause of damage to the built and natural environment, including the thermal discomfort in open spaces. In Brazil, the Master Plan is the instrument of the municipal governments that regulates the urban design; however, there is a gap between environmental aspects and the formulation of plans and municipal laws. The city of Umuarama in the Northwest of Paraná, has seen an intense urban growth, however, there is still a flexibility to the management of urban form. Actually, the new municipal Master Plan is in the aproval phase, it proposes the expansion of the urban area where verticalization is permitted, and the municipal urban afforestation plan, that seeks to promote and control the increase of urban afforestation. In view of proposed plans, this research has as main objective to verify the trends of thermal stress in the pedestrian\'s level in future scenarios of urban canyons in the central area of Umuarama. The urban canyon, referring to the space formed by the via and adjacent buildings, was adopted as object of study because it is the smallest unit microclimatic and the main urban open space for public use. The methodology applied is based on in loco data collection; simulation of different scenarios of urban setting through microclimatic modeling with the ENVI-met program, for summer and winter condition; and application of thermal comfort index Physiological Equivalent Temperature - PET. The results showed that different combinations of the urban form parameters, specifically, the urban canyon geometry and afforestation present in your interior, result in various trends of thermal stress to the pedestrian. The highest levels of thermal stress in the pedestrian level were observed during the day, in summer; these levels trend to be smaller with increasing H/W ratio and afforestation in urban canyons. In addition, there has been less thermal amplitude in canyons with more green coverage. In urban canyons with N-S orientation, increasing the green coverage inside the urban canyon was more important for the reduction of the PET index than in the canyons with L-O orientation; on the other hand, in those canyons with L-O orientation, increasing the H/W ratio was more representative to minimize the PET. Understanding PET behavior in different scenarios demonstrated that new urban form settings are compatible with the open spaces environmental quality since applied urban design strategies climatically guided. In the end, based on the results, were delineated recommendations related urban streets geometry and green coverage in favour of thermal comfort of the users of these spaces.

Ce travail de doctorat a été effectué sous l’encadrement du Professeur Catherine SEMIDOR du laboratoire GRECAU (Groupe de Recherche Environnement Conception Architecturale et Urbaine). Il propose une approche scientifique visant à évaluer les performances réelles des habitats Saoudiens traditionnels et contemporains ainsi que la façon dont ces logements sont perçus par les habitants.L’architecture vernaculaire en Arabie Saoudite a longtemps été considérée comme performante et confortable. Pour la recherche d’une architecture respectueuse du climat dans ce pays il est alors essentiel de se pencher sur les constructions du passé, les comparer avec celles du présent afin de comprendre les forces et faiblesses de chacune des architectures. La présente thèse traitera donc le sujet de deux dimensions fondamentales de l’architecture en Arabie Saoudite, celle qui relève du climat et celle qui relève de la culture, au travers d‘un élément majeur, la satisfaction de l’habitant. Ces deux critères seront complétés d’une étude approfondie sur l’évaluation de l’espace intérieur de l’habitat ainsi que d’une analyse de l’impact du tissu urbain sur le confort dans l’habitat.Une première partie théorique va permettre de définir les principes inhérents à ce travail de recherche et ainsi définir les enjeux de celui-ci. Les notions de confort dans l’habitat et de durabilité seront ainsi développées en expliquant comment le corps humain réagit aux différents facteurs d’ambiances et comment ces mêmes facteurs sont régulés dans les espaces bâtis. Puis nous allons voir comment les villes arabes, et notamment d’Arabie Saoudite se sont transformées dans le temps en même temps que la manière de vivre des saoudiens. Toutes ces théories seront interprétées et mise en situation dans la seconde partie de la thèse avec une étude de cas précis.Une deuxième partie très concrète consistera à définir le cas d’étude, celui-ci sera effectué sur la ville de Djeddah et ses différents types d’habitats majoritaires. Les appartements, les maisons mitoyennes et les maisons isolées seront les trois types d’habitations analysés. Plusieurs sujets seront traités en parallèle pour bien comparer architecture traditionnelle et contemporaine, avec d’une part le niveau d’éclairage naturel et d’une autre les éléments d’ouverture des façades, avec notamment « Le Rowshan » pour le cas de l’architecture traditionnelle. Cette partie de l’étude sera effectuée via trois méthodes d’analyse différentes, l’enquête, l’analyse in situ et la simulation sur outils numériques.- Une enquête spécifique sur la satisfaction du confort physique et socio-culturel des habitants de Djeddah diffusé via les réseaux sociaux.- Une analyse in situ grâce à des mesures effectuées dans les contextes d’architecture vernaculaire et contemporaine avec des enregistreurs spécifiques mesurant la température, l’humidité et la lumière dans les espaces.- Une mise en relation avec des études quantitatives via des simulations numériques sur les principaux facteurs physiques du confort précisés dans la première partie : le rayonnement solaire et l’éclairage naturel à l’intérieur de l’espace bâti.Une conclusion permettra de comprendre comment nous pouvons prendre des leçons du passé quant à la conception d’architectures bio-climatiques en Arabie Saoudite. Nous détaillerons également l’impact de la dimension socio-culturelle sur l’habitat saoudien contemporain. / Vernacular architecture in Saudi Arabia has long been regarded as efficient and comfortable. As to search for sustainable architecture in this country then, it is essential to consider the past constructions in order to understand how it works and learn from it.This PhD work was carried out under the supervision of GRECAU laboratory (Research Group in Environment Architecture and Urban Design) and offers a scientific approach to assess the actual performance of traditional and contemporary habitats and how the locals perceive those.A first theoretical part will help to define the inherent principles in this research and thereof to define issues. Notions of comfort and sustainability in homes will be developed and explain how the human body reacts to different environments factors and how these factors are regulated in built-up areas. Then we'll see how the Arab cities, especially those from Saudi Arabia, have turned in time, as well as the way of life Saudis have.A second part will define a more concrete study case: the city of Jeddah and its major different types of habitats: apartments, attached houses and detached houses. A qualitative study through a survey on the physical and socio-cultural comfort of the inhabitants of this city distributed via social networks, widely used in Saudi Arabia, will be conducted, analysed and put in relation with quantitative studies, via simulations computer about the main physical factors of comfort noticed in the first part: solar radiation and day lighting within the built environment.These simulations will evaluate the rate of solar radiation arriving in the different types of urban patterns of Jeddah city, as well as the comfort of the interior spaces with the radiation transmitted through the opening facades elements, both traditional and contemporary ones, but also the level of natural lighting to suit them. We will see that physical comfort and socio-cultural comfort are related: when physical comfort increases, the socio-cultural comfort decreases, because the Saudis are willing to sacrifice physical comfort to satisfy their need for privacy.Three study cases will be analysed through in-situ measurements during 67 days with specific loggers measuring temperature, humidity and light spaces, as to allow a better understanding of the relationships observed previously.A final explanatory part will understand how we can take lessons from the past about the sustainable architecture design in Saudi Arabia via quantitative and qualitative studies conducted previously.

El presente trabajo de suficiencia profesional propone el Diseño Interior de un Centro de Educación Ambiental ubicado en la Ciudad Comercial Minka, Callao. La propuesta busca, a través del adecuado diseño de espacios, incrementar y reforzar el cuidado del Medio Ambiente y el estilo de vida sostenible, por medio de la enseñanza de cursos, talleres y exhibiciones con la metodología ASIRI (hacer, sentir y pensar). En primer lugar, se realizó el Levantamiento del predio a intervenir, el análisis de contexto comprendido por vías principales, accesos, circulación, uso de suelos e hitos, contaminación, plantas y estaciones de reciclaje, tanto a nivel Callao como Minka; el Análisis de preexistencia que abarca zonificación, ingresos, circulación, sistema constructivo, asoleamiento y vientos del predio y el Diagnóstico FODA con oportunidades y amenazas de Minka, y fortalezas y debilidades del establecimiento a intervenir. Después, se realizó un análisis de usuario y funciones para posteriormen- te poder plantear las estrategias necesarias como la organizativa, formal, espacial y de experiencia. Luego, se diseñó el Master Plan con los planos de distribución de los dos niveles, techos, cortes y elevaciones necesarias. Por último, se priorizó un sector por las actividades a realizar y el sistema constructivo; y se diseñaron las plantas de distribución en 1/25, techos, cortes, 2 cortes escantillón, pisos, muebles fijos y móviles, mobiliarios y detalles de los mismos, carpintería, FCR, rociadores,INDECI, iluminación e instalaciones eléctricas. / The present work of professional sufficiency proposes the Interior Design of an Environmental Education Center located in Minka’s Commercial City, Callao. The proposal seeks, through the adequate design of spaces, increase and reinforce the care of the Environment and the sustainable lifestyle, through the teaching of courses, workshopsand exhibitions with the ASIRI methodology (doing, feeling and thinking). In the first place, the drawing up of the property to be intervened was realized, as same as the context analysis with main roads, accesses, circulation, land use and milestones, pollution, plants and recycling stations, both at Callao and Minka levels; the Analysis of preexistence with zoning, circulation, construction system, sunlight and winds of the property and the SWOT Diagnosis with opportunities and threats of Minka, and strengths and weaknesses of the establishment to intervene. Afterwards, a user and function analysis was realized to be able to use the necessary strategies such as organizational, formal, spatial and experience. Then, the Master Plan was designed with the distribution plans of the two levels, ceilings, cuts and necessary eleva- tions. Finally, a sector was prioritized by the activities to be carried out and the system constructive, and the distribution plants were designed in 1/25, ceilings, cuts, 2 scantlings cuts, floors, fixed and mobile furniture, and details thereof, carpentry, FCR, sprinklers, INDECI, lighting and electrical installations. / Trabajo de Suficiencia Profesional

Los manglares representan un área natural que ofrece distintas oportunidades de simbiosis entre varios elementos de la naturaleza y personas. En el caso de Perú, el Santuario Nacional Los Manglares de Tumbes y sus zonas colindantes que comparten el mismo ecosistema son la única área de manglar en todo el país por lo que su puesta en valor es importante. Así también como lo es la oportunidad de generar un espacio que promueva su conservación. El proyecto busca representar y responder a esta necesidad y así generar un impacto positivo de acuerdo a los requerimientos del lugar en relación a las amenazas existentes y con la participación conjunta de las áreas del gobierno encargadas de la preservación de las Áreas Naturales Protegidas. El centro de interpretación reúne los espacios necesarios para crear una participación conjunta entre los diferentes actores que buscan el cuidado del manglar y los que pueden aprender sobre la importancia de la protección de este. La educación sobre esta biósfera es clave para evitar su depredación y conocer las oportunidades que ofrece. Desde la apreciación de su entorno desde un punto de vista turístico hasta su capacidad de ser un sistema de alta producción biológica. El proyecto se emplaza con espacios establecidos de modo que se mantenga una constante conexión con el entorno natural en donde se sitúa y promueva un circuito de integración entre naturaleza y aprendizaje. / A mangrove ecosystem offers different opportunities for symbiosis between various elements of nature and with people. In Peru, “El Santuario Nacional Los Manglares de Tumbes” sanctuary and protected area as well as its adjacent zones that share the same type of ecosystem are the only mangrove in the entire country. Therefore, its enhancement is significant, and the opportunity to create a space that promotes its conservation. The project seeks to represent and respond to this demand and thus generate a positive impact according to the place’s requirements concerning existing threats and with the joint participation of the government areas in charge of the preservation of Protected Natural Areas. The visitor center gathers the spaces required to set a collective participation between the different users who seek to care for the mangrove and those who can learn about the importance of protecting it. Education about this biosphere is vital to avoid its predation and knowing the opportunities provided from the appreciation of nature from a tourist point of view to its capability to be a high biological production system. The project is located with spaces arranged to maintain a constant connection with the natural environment and promote an integrated circuit between nature and information. / Tesis

Thesis (PhD)--Stellenbosch University, 2010. / ENGLISH ABSTRACT: Biological invasions are a growing threat to biodiversity, trade and agriculture in South Africa. Though alien reptiles and amphibians (herpetofauna) are not currently a major issue, escalating problems worldwide and increased trade in South Africa suggest a possible increase in future problems. In this thesis I explore practical measures for risk assessment implementable under national legislation. I began by documenting record-keeping and legislative differences between provinces in South Africa. This revealed some serious deficiencies, complicating attempts to compile accurate inventories and discern import trends. International trade data, however, revealed an exponential increase in the number of imports to South Africa over the last 30 years. Characterising the abundance of species in this trade is important as species introduced in large numbers pose a higher establishment risk. In South Africa, I found a tendency for venomous and expensive species to be traded in low numbers, whereas species that are easy to breed and handle, or that are colourful or patterned are traded in higher numbers. Unlike South Africa, California and Florida have had a large number of well-documented herpetofaunal introductions. These introductions were used to verify the role of several key predictors in species establishment. I first evaluated the role of each variable separately. I examined different approaches for bioclimatic modelling, the predictive power of different sources of distribution data, and methods of assigning a climate-match score. I also present the first test of Darwin’s naturalization hypothesis for land vertebrates using two new phylogenies inferred for native and introduced reptiles in California and Florida. I then used boosted regression trees (BRT) to infer the relative contribution of each factor to species establishment success. Results from the BRTs were incorporated into a user-friendly spreadsheet model for use by assessors inexperienced in complex modelling techniques. Introduction effort was found to be the strongest contributor to establishment success. Furthermore, species with short juvenile periods were more likely to establish than species that started breeding later, as were species with more distant relatives in regional biotas. Average climate match and life form were also important. Of the herpetofaunal groups, frogs and lizards were most likely to establish, while snakes and turtles established at much lower rates, though analysis of all recorded herpetofaunal introductions shows slightly different patterns. Predictions made by the BRT model to independent data were relatively poor, though this is unlikely to be unique to this study and can be partially explained by missing data. Though numerous uncertainties remain in this field, many can be lessened by applying case by case rules rather than generalising across all herpetofaunal groups. The purpose for import and potential trade volume of a species will influence the threat it poses. Considering this in conjunction with a species’ environmental tolerances and previous success of species with similar life histories, should provide a reasonable and defendable estimate of establishment risk. Finally, a brief summary of the potential impacts of introduced alien herpetofauna is provided in the thesis. / AFRIKAANSE OPSOMMING: Indringer spesies hou ‘n al groter bedreiging in vir die biodiversiteit, handel en landbou van Suid- Afrika. Alhoewel uitheemse reptiele en amfibieërs (herpetofauna) tans nie ‘n groot bedreiging in Suid-Afrika is nie, dui groeiende probleme wêreldwyd asook 'n toename in plaaslike handel op moontlike toekomstige probleme. In hierdie tesis, ondersoek ek praktiese metodes vir risikobepaling wat onder nasionale wetgewing toegepas kan word. Ek begin deur die verskille in stoor van rekords en wetgewing tussen provinsies te dokumenteer. Hierdie proses het ernstige tekortkominge uitgewys, wat pogings om akkurate inventarisse saam te stel en invoertendense te bepaal, bemoeilik. Internasionale handelsdata het egter getoon dat daar ‘n eksponensiële toename in die hoeveelheid invoere na Suid-Afrika oor die laaste 30 jaar was. Die hoeveelheid spesies in hierdie handel is belangrik omdat spesies wat in groot hoeveelhede ingevoer word, ‘n hoër vestigingsrisiko het. In Suid-Afrika is ‘n tendens gevind vir handel in giftige en duur spesies teen lae hoeveelhede, terwyl spesies wat maklik teel, maklik hanteer kan word en kleurvol is of mooi patrone het, in groter hoeveelhede mee handel gedryf word. Kalifornië and Florida, in teenstelling met Suid-Afrika, het ‘n hoë aantal goed-gedokumenteerde gevalle van herpetofauna wat in die natuur vrygestel is. Hierdie introduksies was gebruik om die rol van verskeie belangrike faktore in die vestiging van populasies te bepaal. Eerstens het ek die rol van elke faktor apart ondersoek. Ek het verskillende benaderinge vir bioklimatiese model-bou ondersoek, die akuraatheid van verskillende bronne van distribusiedata getoets en drie metodes om ‘n “climate match score” te bereken, voorgestel. Ek bied ook die eerste toets van Darwin se naturalisasie-hipotese vir landwerveldiere aan, deur gebruik te maak van twee nuwe filogenieë wat ek gebou het vir inheemse en ingevoerde reptiele in Kalifornië en Florida. Ek het verder gebruik gemaak van “boosted regression trees” (BRT) om die relatiewe bydrae van elke faktor tot die vestigings-potensiaal van spesies te bepaal. Resultate van hierdie BRTs was ingekorporeerd in ‘n gebruikersvriendelike ontledingstaat wat deur bestuurders, onervare in komplekse modelboutegnieke, gebruik kan word. Invoer-hoeveelheid was die faktor wat die sterktste bygedra het tot suksesvolle vestiging. Verder is spesies met kort jeugperiodes en dié met verlangse familie in streeks-biotas, meer geskik om suksesvol te vestig. Gemiddelde klimaatooreenstemming en lewensvorm was ook belangrik. Paddas en akkedisse was die mees waarskynlikste van die herpetofauna groepe om populasies te vestig, terwyl slange en skilpaaie teen laer tempo’s populasies gevestig het, alhoewel analise van alle gedokumenteerde gevalle van herpetofauna-invoerings wêreldwyd effens verskillende tendense toon. Voorspellings wat deur die BRT-model vir onafhangklike data gemaak is was redelik swak, alhoewel hierdie resultaat onwaarskynlik nie uniek aan die studie is nie, en word gedeeltelik verduidelik deur die gebrek aan data. Alhoewel talle onsekerhede steeds bestaan, kan dié verminder word deur geval-tot-geval reëls toe te pas eerder as om vir herpetofauna as ‘n groep te veralgemeen. Die doel van invoer en potensiële handel-volumes van ‘n spesie, sal die bedreiging wat die spesie toon, bepaal. Hierdie faktore moet saam met omgewingstoleransie en voorafgaande sukses van spesies met soortgelyke lewenswyses oorweeg word, om ‘n aanvaarbare en verdedigbare beraming van vestigingsrisiko te gee. Laastens, word ‘n kort opsomming van die effekte wat uitheemse herpetofauna mag hê, verskaf.

Réalisé en cotutellle avec Gaétan Bourgeois et avec la participation de Guy Boivin, d'Agriculture et Agroalimentaire Canada, du Centre de Recherche et Développement en Horticulture à Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada / On dénombre divers modèles de simulation de la mouche du chou (Delia radicum L.), mais plusieurs comportent d’importantes lacunes au niveau des différences génotypiques de l’insecte et des paramètres utilisés. L’objectif principal de ce projet est de rassembler les informations manquantes afin de créer dans le futur un modèle bioclimatique permettant de simuler efficacement la dynamique des populations de ce ravageur. L’effet de la température et de l’humidité du sol a été mesuré sur les œufs et les larves de la mouche du chou. L’humidité n’influence la survie des œufs qu’en dessous de 25% [m/m]. L’exposition graduelle des œufs à des températures élevées au dessus de 33°C affecte également la survie. La survie des larves augmente avec la hausse des températures et de l’humidité. Nous croyons que la mouche du chou est bien adaptée aux conditions des sols organiques au Québec, et nous recommandons l’intégration de la température du sol pour les stades au sol plutôt que de l’air dans l’élaboration d’un nouveau modèle. La ponte a également été étudiée à partir de différents critères préétablis pour chacun des génotypes hâtifs et tardifs, à différentes températures. Excepté pour la pré-oviposition qui est plus longue chez les hâtifs, aucune différence n’a été observée entre les génotypes. La majorité des critères, excepté la durée d’un épisode de ponte et la mortalité des œufs, a réagit à la température. Les nouvelles informations serviront à l’élaboration ou le perfectionnement d’un modèle de simulation de la dynamique de la ponte de la mouche du chou. / Few simulation models for the cabbage maggot (Delia radicum L.) had been seen, but several include significant weaknesses for the insect genotypic differences and parameters used. The main objective of this project is to collect the missing information to create, in the future, a bioclimatic model that will efficiently simulate the dynamics of the populations of this pest. The effect of soil temperature and moisture had been measured on eggs and larvae of the cabbage maggot. Humidity affects egg survival below 25% [w/w]. Gradual exposure of eggs to high temperature above 33°C also affects survival. Under tested conditions, larvae survival increases with rising temperatures and humidities. We believe that the maggot is well adapted to muck soil in Quebec, and we recommend to incorporated soil temperature rather than air temperature for above-ground stages into the development of a new model. Egg-laying activity has also been studied from various pre-established criterions for each of the early- and late-emerging genotypes, at different temperatures. Except for the pre-oviposition which is longer for the early genotype, no differences were observed between genotypes. The majority of criterions, except for the duration of oviposition bouts and egg mortality, responded to temperature. The new information will be used for the preparation and development of a simulation model of the egg-laying dynamic of the cabbage maggot.

Une taxonomie révisée et une connaissance des limites d’espèces demeurent toujours importantes dans les points chauds en biodiversité comme les Antilles où de nombreuses espèces endémiques sont retrouvées. Des limites d’espèces divergentes impliquent un différent nombre d’espèces retrouvées dans un écosystème, ce qui peut exercer une influence sur les décisions prises face aux enjeux de conservation. Les genres Gesneria et Rhytidophyllum qui forment les principaux représentants de la famille des Gesneriaceae dans les Antilles comprennent plusieurs taxons aux limites d’espèces ambigües et quelques espèces qui ont des sous-espèces reconnues. C’est le cas de Gesneria viridiflora (Decne.) Kuntze qui comprend quatre sous-espèces géographiquement isolées et qui présentent des caractères végétatifs et reproducteurs similaires et variables. Une délimitation d’espèces approfondie de ce complexe d’espèce est effectuée ici à partir d’une approche de taxonomie intégrative considérant des données morphologiques, génétiques et bioclimatiques. Les données morphologiques quantitatives et qualitatives obtenues à partir de spécimens d’herbier sont utilisées pour délimiter des groupes morphologiques à l’aide d’une analyse en coordonnées principales. Ces groupes sont ensuite testés à l’aide de séquences d’ADN de quatre régions nucléaires en utilisant une méthode bayesienne basée sur la théorie de la coalescence. Finalement, les occurrences et les valeurs de variables de température et de précipitation qui y prévalent sont utilisées dans une analyse en composantes principales bioclimatique pour comparer les groupes délimités morphologiquement et génétiquement. Les résultats de l’analyse morphologique multivariée supportent la distinction entre les groupes formés par les sous-espèces actuellement reconnues de G. viridiflora. Les résultats, incluant des données génétiques, suggèrent une distinction jusqu’ici insoupçonnée des populations du Massif de la Hotte au sud-ouest d’Haïti qui sont génétiquement plus rapprochées des populations de Cuba que de celles d’Hispaniola. Bioclimatiquement, les groupes délimités par les analyses morphologiques et génétiques sont distincts. L’approche de taxonomie intégrative a permis de distinguer cinq espèces distinctes plutôt que les quatre sous-espèces acceptées jusqu’à aujourd’hui. Ces espèces sont : G. acrochordonanthe, G. quisqueyana, G. sintenisii, G. sylvicola et G. viridiflora. Une carte de distribution géographique, un tableau de la nouvelle taxonomie applicable et une clé d’identification des espèces sont présentés. La nouvelle taxonomie déterminée dans cette étude démontre un endémisme insoupçonné dans plusieurs régions du point chaud en biodiversité des Antilles et souligne l’importance d’investiguer les limites d’espèces dans les groupes diversifiés comprenant des taxons aux limites d’espèces incomprises. / An accurate taxonomy and knowledge of species limits is of great importance in endemic species-rich biodiversity hotspots like the Caribbean. Indeed, conflicting species limits can alter biodiversity estimates and influence the decisions taken on conservation issues. The genera Gesneria and Rhytidophyllum constitute the main representatives of the Caribbean Gesneriaceae and comprise a few species with unclear boundaries as well as species having several recognized subspecies. Gesneria viridiflora (Decne.) Kuntze is a good example of the latter and consists of four geographically isolated subspecies that possess similar but variable vegetative and reproductive characters. We conducted a thorough investigation of species delimitation in this species complex using an integrative taxonomic approach that includes morphology, genetics and bioclimatic data. Qualitative and quantitative morphological data obtained from herbarium specimens were used to circumscribe morphologically distinct groups using a principal coordinates analysis. These groups were then tested at the genetic level using a Bayesian Phylogenetics and Phylogeography (BPP) species delimitation approach based on four nuclear regions. Bioclimatic multivariate analyses of temperature and precipitation variables obtained from occurrence data were used to compare the groups delimited by morphological and genetic data. The results suggest the presence of five distinct species in this complex. Four of these broadly correspond to the actually defined subspecies: G. quisqueyana, G. sintenisii, G. sylvicola and G. viridiflora. An additional highly endemic species was recognized, G. acrochordonanthe, that consists of the populations found at the Massif de la Hotte in Southwestern Haiti. A distribution map, a table of the new taxonomy and an identification key to the species are provided. The new taxonomy proposed in this study shows an unsuspected species endemism in some regions of the Caribbean biodiversity hotspot and underlines the importance of investigating species boundaries in diversified groups containing taxa with poorly understood boundaries.