Os manguezais são ecossistemas complexos, que estão sujeitos a processos que ocorrem ao longo de diferentes escalas temporais e espaciais. Essa complexidade reforça a importância de se empregar abordagens que possam alcançar essas escalas. As florestas de mangue, entre outras funções, funcionam como sequestradoras e fixadoras de carbono, sendo importantes para o equilíbrio do balanço global de gás carbônico. Estudos relacionados a diversos biomas mostram que há diferença de teor de carbono para espécies diferentes. Diversas estimativas de estoque e sequestro de carbono em florestas de mangue adotam o valor de 45% para o teor de carbono nas espécies de mangue. O presente estudo realizado em Guaratiba, Rio de Janeiro, coletou ramos, folhas, troncos, partes reprodutivas e raízes subterrâneas das espécies ali encontradas: Avicennia schaueriana, Laguncularia racemosa e Rhizophora mangle, essa última teve ainda a coleta de rizóforos, para determinação do teor de carbono nos diferentes compartimentos das diferentes espécies. As amostragens foram realizadas nos diferentes tipos fisiográficos (franja, bacia e transição). O material seco foi triturado e determinado por autoanalisador CHN. Os resultados foram testados estatisticamente, através de análise de variância (ANOVA) e teste de Tukey para identificação de diferenças entre os tipos fisiográficos, espécies e compartimentos (para p<0,05). Foi obtido um valor de teor de carbono orgânico para as partes lenhosas (44,1%) para todas as espécies; um valor para partes verdes de A. schaueriana e L. racemosa de 42,6% e R. mangle de 44,9%; e um valor para raiz de A. schaueriana e L. racemosa de 42,6% e R. mangle de 40,0%. Não foi detectada influência dos tipos fisiográficos sobre o teor de carbono na floresta de mangue estudada. Os resultados aqui obtidos demonstram ainda que deve-se ter cautela na utilização de um valor único e global para o teor de carbono em espécies de mangue.

Les deux grands phénomènes contemporains que sont le tourisme et les changements climatiques traversent et questionnent les territoires. Le tourisme comme modèle de développement structure et organise le territoire pour son fonctionnement et permet de créer une activité économique pour la population locale. Quant aux changements climatiques, ils rendent visible la vulnérabilité intrinsèque des territoires en remettant en question la durabilité d'un modèle économique basé sur l'émission de gaz à effet de serre.L'histoire des sports d'hiver français a engendré un modèle de stations spécifique : la station de 3ème génération, exportée à l'étranger depuis les années 1980. Après la Seconde Guerre mondiale, la Tarentaise, en Savoie, devient le laboratoire d'expériences pour le développement de ce type de stations. En 2014 les huit grandes stations de Tarentaise représentent 37 % de la fréquentation des stations de sports d'hiver français (soit 220 stations). Cette recherche doctorale analyse donc la trajectoire territoriale des stations de haute altitude de Tarentaise, comme un modèle de développement à travers ses les évolutions : socioéconomiques, politiques, environnementales et climatiques.Retracer et comprendre les différentes phases de l'implantation d'un modèle de développement sur un territoire permet de questionner sa vulnérabilité et sa résilience face aux changements climatiques.Les politiques climatiques comme la gestion du tourisme sont aujourd'hui territorialisées, comment sont intégrées ces deux dimensions à l'échelle d'un Pays (l'Assemblée Tarentaise-Vanoise) ? Les politiques climatiques territoriales non contraignantes ont-elles la capacité de remettre en cause une économie unique basée sur une ressource naturelle unique : la neige, dont la fiabilité va être de plus en plus problématique ?Dans un premier temps, nous interrogerons les vulnérabilités des modèles de développement et la construction politique du problème climat, à travers le tourisme comme levier de modernisation de la montagne (Chapitre 1), les changements climatiques comme révélateurs des vulnérabilités liées aux modèles de développement (chapitre 2) et les territoires comme l'échelle de pertinence pour l'action politique climatique (chapitre 3). La partie 2 questionnera un modèle de développement alpin à l'intersection entre évolution sociétale et changements climatiques par la création du modèle des stations de 3ème génération et les évolutions de la stratégie touristique (chapitre 5) pour déboucher sur l'analyse de la vulnérabilité des stations de sports d'hiver et la vulnérabilité territoriale (Chapitre 6). Enfin la troisième partie met en avant comment les politiques climatiques territoriales renforcent le tourisme hivernal, par la construction et le renforcement d'une échelle territoriale : la Tarentaise-Vanoise (chapitre 7), celle-ci peut-elle déboucher sur un nouveau modèle ? (Chapitre 8). / Tourism and climate Change are two major contemporary phenomena wicht cross and question territories. The tourism as the model of development structures and organizes the territory for its functioning and allows to create an economic activity for the local population. When climate change, they make visible the intrinsic vulnerability of the territory by questioning the sustainability of an economic model based on the emission of greenhouse gases.The story of the French winter sports has generated Specific Model of resorts: the resort of 3rd generation, Exported abroad since the 1980s. After the Second World War, Tarentaise becomes the laboratory of experiment for the development of this specifique of resorts, even today (in 2014) eight big resorts of Tarentaise represent French 37 % of the attendance of winter sports resorts (that is 220 resorts). This Phd research thus analyzes the territorial trajectory of the resorts of high height of Tarentaise since the 1930s, as a model of development co-built by the evolutions: socioeconomic, political, environmental and climatic.To Trace and understand the different phases of the implementation of a development model on territory, allows to question its vulnerability and resilience to climate change.Climate policies such as tourism management are now territorialized, how these two dimensions are integrated at the level of a regional (Assembly Tarentaise-Vanoise) ? Non-binding territorialized climate policies, have they ability to question a only economy based on a only natural resource: the snow, the reliability is going to be increasingly problematic.First, we will examine the vulnerabilities of development models and climate problem political construction, through tourism as mountain modernization lever (Chapter 1) climate change as indicative of the development models as revelations vulnerabilities (Chapter 2) and the territories as relevance scale climate for political action (Chapter 3). Part 2 will question an Alpine development model at the intersection between societal evolution and climate change through the creation of the third-generation model of the stations and changes in the tourism strategy (Chapter 5) to lead the analysis of the vulnerability of ski resorts and territorial vulnerability (Chapter 6). Finally, the third section highlights how local climate policies strengthen winter tourism by building and strengthening a territorial level: the Tarentaise-Vanoise (Chapter 7), it can it lead to a new model? (Chapter 8).

Os manguezais são ecossistemas complexos, que estão sujeitos a processos que ocorrem ao longo de diferentes escalas temporais e espaciais. Essa complexidade reforça a importância de se empregar abordagens que possam alcançar essas escalas. As florestas de mangue, entre outras funções, funcionam como sequestradoras e fixadoras de carbono, sendo importantes para o equilíbrio do balanço global de gás carbônico. Estudos relacionados a diversos biomas mostram que há diferença de teor de carbono para espécies diferentes. Diversas estimativas de estoque e sequestro de carbono em florestas de mangue adotam o valor de 45% para o teor de carbono nas espécies de mangue. O presente estudo realizado em Guaratiba, Rio de Janeiro, coletou ramos, folhas, troncos, partes reprodutivas e raízes subterrâneas das espécies ali encontradas: Avicennia schaueriana, Laguncularia racemosa e Rhizophora mangle, essa última teve ainda a coleta de rizóforos, para determinação do teor de carbono nos diferentes compartimentos das diferentes espécies. As amostragens foram realizadas nos diferentes tipos fisiográficos (franja, bacia e transição). O material seco foi triturado e determinado por autoanalisador CHN. Os resultados foram testados estatisticamente, através de análise de variância (ANOVA) e teste de Tukey para identificação de diferenças entre os tipos fisiográficos, espécies e compartimentos (para p<0,05). Foi obtido um valor de teor de carbono orgânico para as partes lenhosas (44,1%) para todas as espécies; um valor para partes verdes de A. schaueriana e L. racemosa de 42,6% e R. mangle de 44,9%; e um valor para raiz de A. schaueriana e L. racemosa de 42,6% e R. mangle de 40,0%. Não foi detectada influência dos tipos fisiográficos sobre o teor de carbono na floresta de mangue estudada. Os resultados aqui obtidos demonstram ainda que deve-se ter cautela na utilização de um valor único e global para o teor de carbono em espécies de mangue.

Various aspects of population ecology of Daubenton?s bat (Myotis daubentonii) were analyzed based on long-term data (1968?1984 and 1999?2009) gathered in a single model study area (ca. 10 km2) in South Bohemia, Czech Republic. Among others, population structure, roosting dynamics, movements between roosts and long-term trends in numbers of bats were described. Results of the study on patterns in reuse of tree cavities suggest that tree cavities may be reused for many consecutive seasons and that this has to be taken into consideration by conservation practices. The results of the study on microclimate of one maternity and one male colony roosting in man-made structures revealed that microclimatic differences may be one of the key factors in roosting preference between the two sexes. Further, a profound effect of changing energetic demands in females during different phases of the reproductive cycle may greatly influence their activity rhytms. In further two studies, the effect of climate on reproductive parameters of bats and abundance of ectoparasitic mites was analyzed. The results suggest that climatic variation greatly influenced reproductive parameters and parasitation of Daubenton?s bats. Last but not least, the seasonal dynamics of parasitation by ectoparasitic mites and the possible effect on bats? condition was analyzed. It was found out that seasonal dynamics in abundance of parasites is adjusted to the reproductive cycle and roosting dynamics of its host.

abstract: This is a study of the plight of smallholder agriculture in Northwest Costa Rica. More specifically, this is the story of 689 rice farms, of an average size of 7.2 hectares and totaling just less than 5,300 hectares within the largest agricultural irrigation system in Central America. I was able to define the physical bounds of this study quite clearly, but one would be mistaken to think that this simplicity transfers to a search for rural development solutions in this case. Those solutions lie in the national and international politics that appear to have allowed a select few to pick winners and losers in Costa Rican agriculture in the face of global changes. In this research, I found that water scarcity among smallholder farms between 2006 and 2013 was the product of the adaptations of other, more powerful actors in 2002 to threats of Costa Rica's ratification of the Central American Free Trade Agreement. I demonstrate how the adaptations of these more powerful actors produced new risks for others, and how this ultimately prevented the rural development program from meeting its development goals. I reflect on my case study to draw conclusions about the different ways risks may emerge in rural development programs of this type. Then, I focus on the household level and show that determinants of successful adaptation to one type of global change risk may make farmers more vulnerable to other types, creating a "catch-22" among vulnerable farmers adapting to multiple global change risks. Finally, I define adaptation limits in smallholder rice farming in Northwest Costa Rica. I show that the abandonment of livelihood security and well-being, and of the unique "parcelaro" identities of rice farmers in this region define adaptation limits in this context. / Dissertation/Thesis / Ph.D. Sustainability 2014

Cette étude a utilisé une approche interdisciplinaire pour évaluer les effets de l'acidification de l'océan sur des ptéropodes et les foraminifères Méditerranéennes. Une comparaison d'échantillons conservés et modernes de 2 espèces de ptéropodes a été réalisée pour étudier les effets du pH sur les propriétés de la coquille. Des populations de ptéropodes ont également été analysées à l'aide des données de séries temporelles. Pour permettre l'amélioration de futures expériences de perturbation, une revue collaborative des techniques de culture de ptéropodes a été produite. Enfin, le foraminifère O. universa a été cultivé dans des conditions de pH et de [CO32-] découplés pour évaluer les effets des changements dans la chimie du carbonate sur la composition en bore et le ?11B. Les coquilles des échantillons conservés de ptéropodes étaient plus épaisses que celles collectées en 2012 et les coquilles de C. inflexa recueillies en 1910 étaient nettement plus denses que celles de 2012, probablement en raison d'un effet de pH. Les abondances de ptéropodes ont montré une tendance croissante entre 1967-2003 et se sont révélées être influencées par les changements de température interannuelles, sans que des changements dans les propriétés des coquilles n'ai eu d'impacts négatifs. Lors de la dernière étude le pH était le seul paramètre du système de carbonate a affecter le ?11Bde la calcite de O. universa. Le B/Ca a diminué avec la diminution du [CO23-] à pH constant mais n'a pas montré de tendance cohérente avec une [CO23-] constant et un pH variable. Au lieu de cela, une étroite corrélation entre les B / Ca et [HCO3-] suggérant que le bore est contrôlé par la [HCO3-]. / This study used an interdisciplinary approach to assess the effects of ocean acidification on Mediterranean pteropods and foraminifers. A comparison of museum and modern samples of two pteropod species investigated the effects of pH on shell properties. Pteropod populations were analysed using time series data. To improve future perturbation experiments, a collaborative review of pteropod culture techniques was produced. Finally, the foraminifer O. universa was cultured under decoupled pH and [CO32-] to assess the effects of changes in the carbonate chemistry on boron incorporation and isotope fractionation. Museum pteropod samples were thicker than shells from 2012 and C. inflexa shells collected in 1910 were significantly denser than those from 2012, possibly due to a pH effect. Pteropod abundances displayed an increasing trend between 1967-2003 and are influenced by inter- annual temperature changes, with no sign of the observed changes in shell properties having had negative impacts. pH was the sole parameter of the carbonate system that affected the δ11B of O. universa calcite. The B/Ca ratio decreased with decreasing [CO32-] at constant pH but did not show consistent trends at constant [CO32-] and varying pH. Instead, a close correlation of B/Ca ratios and [HCO3-] was observed suggesting that boron is controlled by the [HCO3-].

Climate change is arguably the greatest environmental and economic challenge of our time. There are considerable documented and projected impacts to both human and natural systems as a result of climate change. These impacts include changes in temperature, sea level, precipitation patterns, and biogeography of ecologically and economically relevant species, including pathogens. One of the main drivers of climate change is elevated levels of atmospheric carbon dioxide (CO2), a greenhouse gas. Since pre-industrial times, atmospheric CO2 levels have increased from approximately 280 ppm to over 400 ppm, as a result of fossil fuel combustion, cement production and land use change. In addition to being a driver of climate change and a direct contributor to the increase in global average temperatures, elevated atmospheric CO2 also affects biogeochemical cycles. When ocean surface waters equilibrate with higher levels of atmospheric CO2, there is an increase in acidification and resulting effects on marine biota, such as changes to community composition and decreases in calcifying organisms. Freshwater systems are less understood, but many freshwater systems are experiencing acidification and the resulting ramifications as well. Microalgae, as the primary producers in these systems, are often studied as sentinels of such change. Here, I present studies using microalgae to monitor and mitigate elevated CO2. The goals of the investigation were to conduct 1) a field study to determine if microalgae in a freshwater stream were impacted by an elevated CO2 treatment; 2) a meta-analysis of elevated CO2 effects on freshwater microalgae; and 3) a laboratory study to optimize growth of microalgae for biofuels production. In the first chapter, I provide background information and the framework for the studies that follow. Past, present and future atmospheric carbon dioxide levels are discussed as well as their impacts to marine and freshwater systems. The importance of microalgae to these aquatic systems is described. Then I discuss the role of microalgae in elevated CO2 monitoring and mitigation. In the second chapter, I present a field study of elevated CO2 effects on a freshwater stream. The study took place at the University of Michigan Biological Station at the Stream Research Facility. Once-through artificial stream channels were employed to grow microalgae in simulated natural stream conditions. The stream channels were subjected to ambient or elevated CO2 treatments and impacts to stream water chemistry and microalgae were measured. Stream water chemistry was impacted by the elevated CO2 treatment such that there were significant decreases in pH and significant increases in dissolved inorganic carbon. However, these chemical changes did not have a measured impact on the stream microalgae, as measured by microalgal biomass, elemental composition, and community composition. Perhaps microalgae will not be the first to be impacted by increasing levels of atmospheric CO2, though freshwater systems vary considerably and more research is needed to confirm this conclusion. In the third chapter, I present the results of a meta-analysis of elevated CO2 effects on freshwater algae. We conducted a literature search in ISI Web of Science of all publications on freshwater microalgal response to elevated CO2 and chose studies that used elevated CO2 levels of less than or equal to 2,000 ppm, which is the highest level projected for the future by the Intergovernmental Panel on Climate Change. From the twenty-two papers that met the inclusion criteria, qualitative and quantitative data were extracted and categorized into response classes including water chemistry, microalgal growth, carbon fixation and photosynthesis, nutrient uptake, and consumer response. Effect sizes for elevated CO2 were calculated, and CO2 enrichment significantly increased water acidity and dissolved inorganic carbon concentrations, microalgal growth, carbon fixation and photosynthesis, and algal nutrient uptake. Algal consumers (e.g., herbivores) in general were negatively affected, but the overall result was not statistically significant. We also analyzed a variety of experimental parameters and determined that experimental design and algal culture conditions did not impact elevated CO2 effects on freshwater microalgae in the studies conducted to date. In the fourth chapter, I provide the results of a laboratory-based study of the marine microalgae Picochlorum oculatum, which has shown promise as a source of biofuel because of its high lipid production and relative ease of growing in culture. We ran a series of lab experiments to optimize growth conditions and maximize growth of P. oculatum. Experiments included tests of light source (LED or metal halide), CO2 delivery (continuously or in pH-controlled pulses), inoculum size (10%, 15% or 20%), and culture pH (7.0, 7.5, or 8.0); these variations did not significantly impact growth so future experiments were run in the most cost-effective manner using LED lights, with pH-controlled pulses, 10% inoculum size and at culture pH of 7.5. We also tested different sources of supplied nitrogen in an effort to reduce culture costs and potentially improve sustainability by using urea and ammonium, sources of nitrogen readily available from wastewater treatment. Growth was comparable using the standard artificial nitrogen source, nitrate, and the wastewater-constituent urea, indicating that urea may be a cost-effective and sustainable source of nitrogen for microalgal cultures grown on an industrial scale for biofuel production. Growth using ammonium was not successful even when concentrations were reduced and a buffer was added to reduce acidification of the growth medium resulting from ammonium uptake by the algae. More research is needed to determine if ammonium can be a suitable nitrogen source for microalgae. Experiments were also conducted in an outdoor setting to determine if high growth levels were maintained when the cultures were grown at a larger scale and in variable natural conditions; successful growth was demonstrated over 68 days, indicating that P. oculatum may be a promising candidate for biofuel production. Additional research is needed to further optimize culture growth and streamline operations. The body of work herein examines the role of microalgae in elevated CO2 monitoring and mitigation. There is considerable evidence that elevated atmospheric CO2 impacts aquatic chemistry through increases in dissolved inorganic carbon and acidity. These chemical changes have varied impacts on aquatic biota, including microalgae, which play foundational roles in ecosystems as primary producers and bases of food webs. Microalgal responses to elevated CO2 may impact other trophic levels and have widespread effects on aquatic ecosystems. Additional research is needed on elevated CO2 effects on microalgae, particularly in freshwater systems, which are less understood than marine systems and perhaps less predictable due to the wide variability in their physical, chemical and biological compositions. Microalgae may also play a significant role in elevated CO2 mitigation because of their potential in biofuel production. With additional research focused on reducing costs and improving sustainability, microalgae may play an important role in reducing elevated CO2, one of the main drivers of climate change.

In alpine regions worldwide, climate change is dramatically altering ecosystems, affecting biodiversity across habitats and taxonomic scales. For streams, the associated recession of mountain glaciers and snowfields, paired with altered precipitation regimes, are driving shifts in hydrology, species distributions, and basal resources – often threatening the very existence of some habitats and biota. Globally, alpine streams harbor particularly substantial species and genetic diversity due to significant habitat insularity and environmental heterogeneity: however, anthropogenic warming threatens to homogenize habitats through the reduction of the cryosphere, thereby reducing biodiversity from micro- to macroscopic organisms and genes to communities. Still, alpine stream biodiversity, particularly in North America, is poorly understood, making it difficult to predict future changes without baselines for comparison. For my dissertation, I used genetic tools to assess biodiversity in alpine streams of the central Rocky Mountains in North America. Here, I begin by reviewing the current state of alpine stream biology from an organismal perspective. Next, I provide two perspectives on macroinvertebrate diversity. The first, a population genetic comparison of three highly similar species, is followed by a fine-scale genomic study of one species, Lednia tumana. I follow these largely macroinvertebrate-centric chapters with a modern synthesis of the microbial ecology of mountain glacier ecosystems. Finally, I conclude with a study of microbial diversity that addresses how microbial diversity is shaped by geography, habitat, and hydrological source in North America. Collectively, this research refines existing themes in alpine stream biology by revealing unexpected differences in population genetic patterns among closely related species, the influence of recent deglaciation on population genetic structure and demographic history of a threatened stonefly, and clarification of the environmental drivers shaping microbial diversity.

Au cours du siècle dernier, le développement des activités anthropiques a engendré une augmentation des pressions sur les écosystèmes marins côtiers. Les données scientifiques pour aborder ce phénomène sont fragmentaires et d’une précision insuffisante (de l’ordre du km) pour la prise de décisions locales. La gestion de ces menaces multiples et simultanées exige pourtant des données fiables et précises sur la répartition des pressions et la localisation des écosystèmes les plus sensibles. Ces constations ont été à la base de la rédaction de deux directives européennes (la DCE, directive cadre eau et la DCSSM, directive cadre stratégie sur le milieu marin). Afin de répondre à ces directives, les objectifs de ce projet doctoral ont été de caractériser la vulnérabilité et d’aborder la sensibilité de deux écosystèmes marins prioritaires : les herbiers de posidonie et les communautés coralligènes. Ce projet focalisé sur la méditerranée française a permis la quantification et la localisation de ces écosystèmes et des pressions anthropiques auxquelles ils sont soumis, ainsi que l’estimation de leur état écologique à une résolution fine (de l’ordre de 20 m). Le déclin des herbiers a également pu être modélisé en relation avec les pressions et la profondeur et a permis de définir des seuils de résistance de cet habitat aux différentes pressions et des zones prioritaires de gestion. Ce travail devrait contribuer à améliorer l'élaboration d'indicateurs pour l'évaluation de l'état de santé des systèmes côtiers. Il pourrait également aider à mieux appliquer et coordonner les mesures de gestion à une échelle pertinente pour la conservation de la biodiversité. / During the last century, human activities were at the origin of increasing pressures impacting marine coastal ecosystems. Scientific data concerning this phenomena are fragmentary and the grid scale (1 x 1 km pixel) is insufficient to permit relevant local decision making. The management of these multiple and simultaneous threats necessitates reliable and accurate data concerning the distribution of pressures and the localization of the most sensitive ecosystems. This is at the origin of two European directives: the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD). In response to these directives, the objectives of this work were to characterize the vulnerability and sensitivity of two priority ecosystems: Posidonia oceanica seagrass beds and coralligenous reefs. Focusing on the French Mediterranean coastline (depth ranging from 0 to – 100 m), results were: the fine-scale (20 x 20 m pixel size) quantification and localization of the encountered anthropogenic pressures, the quantification and localization of these two priority ecosystems, and the assessment of their ecological state. Seagrass beds decline was modelled in link with depth and pressures; resistance thresholds to pressures, but also management priority areas were defined. This work should contribute to improve the development of indicators for the ecological state of coastal ecosystems. It should also help to better apply and coordinate management actions at a relevant scale for biodiversity conservation.

Spruce-Fir forests are relicts from the Pleistocene and have migrated back north after the previous warming period as well as up in elevation in the southern Appalachian mountains. This in turn created sky islands of isolated, endemic, and disjunct species. These refugal forests require certain climatic parameters similar to Canada’s boreal mountains but also need additional cloud immersion and precipitation. These forests have experienced stressors in the past, but face continued threats such as air pollution and climate change. Due to limited immigration for the majority of the species on these mountains, a significant number of organisms are at risk of being endangered or extinct. Analyzing the relationships and patterns between species distribution and climatic parameters both in the past and present will help create future prediction maps. These will potentially anticipate where habitat reduction might occur and will benefit management and conservation purposes. The first study will analyze current distributions of Spruce-Fir forests to see which model and variable combination best approximates the unique mountain forests environments. Using the optimal model from the first study, the second study will examine which distributional changes may occur in the future and how these changes compare to paleo-environmental distributions. Anticipated results will show a reduction of habitat in lower peaks with minimal impact at higher peaks based on the known projected trends of cloud ceilings. This research will help with forest and conservation management and will impact a multitude of species that rely on this forest to survive.