The goal of this research was to improve ocean colour chlorophyll a (Chla) retrievals in the coastal Case 2 waters of the Salish Sea by characterizing the main drivers of optical variability and using this information to parameterize empirical algorithms based on an optical classification. This was addressed with three specific objectives: (1) build a comprehensive spatio-temporal data set of in situ optical and biogeochemical parameters, (2) apply a hierarchical clustering analysis to classify above-water remote sensing reflectance (Rrs) and associated bio-optical regimes, (3) optimize and validate class-specific empirical algorithms for improved Chla retrievals. Biogeochemical and optical measurements, acquired at 145 sites, showed considerable variation; Chla (mean=1.64, range: 0.10 – 7.20 µg l-1), total suspended matter (TSM) (3.09, 0.82 – 20.69 mg l-1), and absorption by chromophoric dissolved organic matter (a_cdom (443)) (0.525, 0.007 – 3.072 m-1), thus representing the spatial and temporal variability of the Salish Sea. A comparable range was found in the measured optical properties; particulate scattering (b_p (650)) (1.316, 0.250 – 7.450 m-1), particulate backscattering (b_bp (650)) (0.022, 0.005 – 0.097 m-1), total beam attenuation coefficient (c_t (650)) (1.675, 0.371 – 9.537 m-1), and particulate absorption coefficient (a_p (650)) (0.345, 0.048 – 2.020 m-1). Empirical orthogonal function (EOF) analysis revealed 95% of the Rrs variance was highly correlated to b_p (r = 0.90), b_bp (r = 0.82), and TSM concentration (r = 0.80), suggesting a strong influence from riverine systems in this region. Hierarchical clustering on the normalized Rrs revealed four spectral classes. Class 1 is defined by high overall Rrs magnitudes in the red, indicating more turbid waters, Class 2 showed high Rrs values in the red and well defined fluorescence and absorption features, indicated by a high Chla and TSM presence, Class 3 showed low TSM influence and more defined Chla signatures, and Class 4 is characterized by overall low Rrs values, suggesting more optically clear oceanic waters. Spectral similarities justified a simplification of this classification into two dominant water classes – (1) estuarine class (Classes 1 and 2) and (2) oceanic class (Classes 3 and 4) – representing the dominant influences seen here. In situ Chla and above-water remote sensing reflectance measurements, used to validate and parameterize the OC3M/OC3S3, two-band ratio, FLH and, modified FLH (ModFLH) empirical algorithms, showed a systematic overestimation of low Chla concentrations and underestimation of higher Chla values for all four algorithms when tuned to regional data. FLH and ModFLH algorithms performed best for these data (R2 ~ 0.40; RMSE ~ 0.32). Algorithm accuracy was significantly improved for the class-specific parametrizations with the two-band ratio showing a strong correlation to the Chla concentrations in the estuarine class (R2 ~ 0.71; RMSE ~ 0.33) and the ModFLH algorithm in the oceanic class (R2 ~ 0.70; RMSE ~ 0.26). These results demonstrated the benefit of applying an optical classification as a necessary first step into improving Chla retrievals from remotely sensed data in the contrasted coastal waters of the Salish Sea. With accurate Chla information, the health of the Salish Sea can be viably monitored at spatial and temporal scales suitable for ecosystem management. / Graduate / 0416 / stephen.uvic@gmail.com

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No. of bitstreams: 1 DissRSL.pdf: 2218443 bytes, checksum: 6c095cccc15f22c3fe747197514a5b16 (MD5) Previous issue date: 2017-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Throughfall (TF) is affected by different biotic and meteorological factors that can interact, resulting in high variability in estimates, increasing the uncertainty in hydrological models and the forecast of environmental impacts in watersheds. The knowledge of the relationship between rainfall (RF) and TF is a key factor for the definition of sampling strategies that result within commonly accepted error thresholds. Therefore, the main objective of this study was to analyze sources of TF variability in a secondary forest in SE Brazil, in order to understand the response of TF in function of different environmental drivers and sampling strategies. To attain these objectives, the influences of RF, sampling strategies, and stand structure on TF were analysed. The results indicated significant influence of RF on the response variables [TF volume (TFmm), TF fraction (TF%), and coefficient of variation of TF (CVTF)]. Whereas the linear model showed the best fit for TFmm, nonlinear models presented better fits for TF% and CVTF in response to RF. Regarding the influence of sampling strategies, there were no significant effects on average estimates of TFmm and CVTF. Based on the magnitude of the error, only treatments with 16 fixed gauges and nine roving gauges were able to provide estimates with errors smaller than 10%, both for all rainfall events and for those higher than 10.44 mm (median value). The results suggest that different vegetation structures affect TFmm at different spatial scales. For instance, a significant effect of canopy cover was observed on the point estimates of TFmm. However, no vegetation influences on this variable were observed at the plot scale. Regarding the temporal variability, significant effects were verified at two scales: distance to the nearest trunk at the point scale; and metrics of trees greater than 20 m at the plot scale. Finally, it was verified that combined effects of tree sizes and canopy cover influenced CVTF, indicating that the these variables reflect vegetation complexity. In general, the results suggest that RF is the main source of TF variability in the studied area. Therefore, it is necessary to consider both meteorological factors and characteristics of rainfall events to sample TF with adequate accuracy. Nevertheless, the interactions between biotic and meteorological factors affect their relative influences on TF, highlighting the need for further research in this area. / A precipitação interna (PI) é afetada por diferentes fatores bióticos e meteorológicos que podem interagir entre si, resultando numa elevada variabilidade em suas estimativas, aumentando a incerteza em modelos hidrológicos e na previsão de impactos ambientais em bacias hidrográficas. A compreensão da relação entre a precipitação em aberto (PA) e a PI é importante para a definição de estratégias de amostragem com limiares de erros aceitáveis. Portanto, o objetivo geral deste estudo foi analisar os fatores de variação da PI em uma floresta secundária, localizada no sudeste brasileiro, a fim de compreender o comportamento desse processo em função de diferentes fatores ambientais e de estratégias de amostragem. Para isto, foram analisadas as influências da PA, das estratégias de amostragem e da estrutura da vegetação sobre a PI. Os resultados indicaram influência significativa da PA sobre as variáveis resposta [volume de PI (PImm), fração de PI (PI%) e coeficiente de variação da PI (CVPI)]. Enquanto o modelo linear apresentou o melhor ajuste para PImm, os modelos não lineares tiveram melhores ajustes para PI% e CVPI em função de PA. Quanto à influência das estratégias de amostragem, não houve efeitos significativos sobre as estimativas médias de PImm e CVPI. Com base na magnitude do erro, apenas tratamentos com 16 pluviômetros fixos e nove rotativos foram capazes de fornecer estimativas com erros inferiores a 10%, tanto para o conjunto completo de dados quanto para chuvas superiores a 10,44 mm (valor mediano). Os resultados sugerem que diferentes estruturas da vegetação afetam a PImm em diferentes escalas espaciais. Por exemplo, foi verificado efeito significativo da cobertura do dossel sobre as estimativas pontuais de PImm. No entanto, não foram verificadas influências da vegetação sobre esta variável na escala da parcela. Em relação à variabilidade temporal, verificaram-se efeitos significativos nas duas escalas: da distância para o tronco mais próximo na pontual; e de métricas de árvores maiores que 20 m na escala parcela. Por fim, verificou-se que os efeitos combinados do tamanho das árvores e da cobertura do dossel influenciaram CVPI, indicando que essas variáveis refletem a complexidade da vegetação. Em geral, os resultados sugerem que PA é a principal fonte de variabilidade de PI na área estudada. Portanto, é necessário considera características meteorológicas e dos eventos de chuva para amostrar a PI com precisão adequada. Contudo, as interações entre fatores bióticos e meteorológicos afetam suas influências relativas sobre a PI, destacando a necessidade de mais pesquisas nessa área.

Made available in DSpace on 2014-12-17T14:08:41Z (GMT). No. of bitstreams: 1 BrunoCPC_1-100_DISSERT.pdf: 2356033 bytes, checksum: ce14b7bf1ae1fe35ca852675e9da4636 (MD5) Previous issue date: 2010-07-19 / Among the various effects caused by the climate change and human intervention, the mangrove ecosystem changes through of the years has been worth mentioning, which hasn t known which are the pros and cons for the adjacent coastal and estuarine environments yet. It happens due to the present dynamism in these areas, besides of the difficult understanding of the processes associated with evolution. This study aimed to environmentally evaluate adjacent mangroves from the Macau and Serra oil fields, located on Rio Grande do Norte northern coast, to support the mitigating actions related to the containment of the erosive process, as well as, according to the principles of the Clean Development Mechanism (CDM), to assess the amount of atmospheric carbon sequestered by the studied ecosystem. An inventory was conducted through mangrouve mapping which has supplied this research, especially regarding to the structural characterization of mangrove areas. To understand the local mangrove behavior in a greater level detail, techniques of remote sensing, GIS and GPS were used to make an analogy between the current and past states of the mangrove studied, allowing to make anticipated projections for the future impacts or changes in that region. This study combined data from multispectral LANDSAT 5 TM, Landsat 7 ETM+ with radar microwave data from SAR RADARSAT-1, which increased the interpretation capacity of the data from optical sensor systems. The interpretations have been supported by the data field, representing a better and innovative methodology for the environmental and taxonomic characterization of mangrove forests considered. The results reveal that mangroves of the Ponta do Tubar?o Sustainable Development Reserve are biologically representative areas and providing a variety of benefits, especially for local communities, constituting the priority sites for actions development aimed at conservation. They also have been showing the necessity to make mitigating measures in order to recover degraded areas through reforestation or creating new areas of mangrove, as currently 7.1% of the mangrove forests studied are dead or in an advanced state of decomposition. The amount of atmospheric carbon sequestered proved very significant when analyzed for the whole area, which is able to sequester atmospheric 4,294,458 Ton CO2 per year / Dentre os diversos efeitos provocados pelas mudan?as clim?ticas e pela interven??o humana, as altera??es no ecossistema manguezal v?m merecendo destaque, cujas implica??es para os ambientes estuarinos e costeiros adjacentes ainda est?o distantes de serem conhecidas. Isto ocorre devido ao dinamismo presente nessas ?reas, assim como a dif?cil compreens?o dos processos associados ? evolu??o das mesmas. O presente estudo teve como principal objetivo avaliar ambientalmente manguezais adjacentes aos campos petrol?feros de Macau e Serra, localizados no litoral setentrional do Rio Grande do Norte, como subs?dio ?s medidas mitigadoras ao processo erosivo, al?m de, dentro dos princ?pios do chamado Mecanismo de Desenvolvimento Limpo (MDL), avaliar a quantidade de carbono atmosf?rico sequestrado para o ecossistema estudado. Atrav?s de mapeamento do manguezal, foi realizado um invent?rio, o que forneceu subs?dios para o delineamento desta pesquisa, principalmente, no que diz respeito ? caracteriza??o estrutural da ?rea de manguezal. Para entender o comportamento do manguezal em quest?o em um n?vel maior de detalhe, buscaram-se explica??es em unidades espaciais maiores. T?cnicas de Sensoriamento Remoto, SIG e GPS forneceram informa??es de compara??o entre os estados atual e passado do manguezal, possibilitando proje??es antecipadas para os futuros impactos ou altera??es desta regi?o. Este trabalho combinou dados multiespectrais do LANDSAT 5 TM, LANDSAT 7 ETM+ com dados de microondas de radar do tipo SAR do RADARSAT-1, ampliando a capacidade de interpreta??o dos dados de sistemas de sensores ?ticos. As interpreta??es foram apoiadas com dados de campo, objetivando uma melhor e inovadora metodologia para a caracteriza??o ambiental e taxon?mica das florestas de mangue em quest?o. Os resultados encontrados revelam que os manguezais da Reserva de Desenvolvimento Sustent?vel Estadual Ponta do Tubar?o s?o ?reas representativas biologicamente e que fornecem uma variedade de benef?cios, principalmente para as comunidades locais, constituindo-se de s?tios priorit?rios para o desenvolvimento de a??es com vistas a sua conserva??o. Revelam tamb?m a necessidade de se tomar medidas mitigadoras no sentido de recuperar as ?reas degradadas ou atrav?s do reflorestamento se criar novas ?reas de manguezal, pois atualmente 7,1% das florestas de mangue estudadas encontram-se mortas ou em estado de decomposi??o bem avan?ado. A quantidade de carbono atmosf?rico sequestrado se mostrou bem significativa quando analisado para toda a ?rea em quest?o, sendo esta, capaz de sequestrar 4.294.458 Ton CO2 atmosf?rico/ano

Theory suggests that plant interactions at the neighbourhood scale play a fundamental role in regulating biodiversity–productivity relationships (BPRs) in tree communities. However, empirical evidence of this prediction is rare, as little is known about how neighbourhood interactions scale up to influence community BPRs. Here, using a biodiversity–ecosystem functioning experiment, we provide insights into processes underlying BPRs by demonstrating that diversity-mediated interactions among local neighbours are a strong regulator of productivity in species mixtures. Our results show that local neighbourhood interactions explain over half of the variation in observed community productivity along a diversity gradient. Overall, individual tree growth increased with neighbourhood species richness, leading to a positive BPR at the community scale. The importance of local-scale neighbourhood effects for regulating community productivity, however, distinctly increased with increasing community species richness. Preserving tree species diversity at the local neighbourhood scale, thus seems to be a promising way for promoting forest productivity.

Cette thèse a pour objectif principal de contribuer à la compréhension des facteurs environnementaux agissant sur la diversité et la productivité des communautés végétales alpine, et dans un deuxième temps de mettre en évidence des changements récents dans la structure de la végétation dans un contexte tempéré alpin, les Alpes françaises. L’approche adoptée se base sur des méthodes issues de la télédétection et également de l’écologie végétale, en combinant des relevés de végétation avec les données de climat de l’imagerie à haute résolution. Dans le premier chapitre, je démontre l’intérêt de quantifier la durée d’enneigement afin de pouvoir prédire les patrons de diversité taxonomique et fonctionnelle, en montrant aussi que la modélisation spatiale de la productivité primaire reste un défi important dans le contexte des paysages alpins. Dans le deuxième chapitre, je teste l’utilité de l’imagerie satellitaire pour quantifier les conditions environnementales au niveau des communautés végétales, et je mets en évidence que l’habitat des communautés dominantes peut être différencié à l’échelle régionale par la date de déneigement et le pic en productivité. J’essaie également de voir si la diversité fonctionnelle influe sur la réponse NDVI dans le cadre de trois années de durée d’enneigement contrastées. Le troisième chapitre marque un changement d’approche, dans lequel je passe à l’analyse de la dynamique observée de la végétation pendant les dernières décennies dans deux sites : la Réserve Naturelle des Hauts Plateaux du Vercors (RNHPV) et le Parc National des Ecrins (PNE). L’analyse diachronique de l’écotone forêt-prairie dans la RNHPV montre une forte expansion de la forêt à Pinus uncinata pendant les soixante dernières années, en réponse à un réchauffement global et également des changements spatio-temporels dans les usages des terres en lien avec le pâturage. Dans la deuxième partie, je montre qu’avec les satellites on observe une tendance de verdissement à l’échelle du PNE pendant les dernières décennies. Je propose qu’une réduction dans la durée d’enneigement et un réchauffement depuis les années 1980s ont contribué à une augmentation de la productivité des canopées dans des contextes alpins de haute altitude, et ceci indépendamment des effets d’utilisation des terres. Pris ensemble, au lieu d’avancer un aspect précis de l’écologie alpine, mon travail sert à compléter nos connaissances du fonctionnement des communautés végétales alpines et à confirmer certaines hypothèses basées sur l’observation terrain avec des analyses spatiales robustes. / The central aim of this thesis is to contribute to current understanding of environmental drivers of plant diversity and productivity as well as of recent changes in vegetation structure in a temperate alpine context, the French Alps. My approach draws on methods from remote sensing and plant ecology by combining plot-based measures of plant diversity and climate data with high-resolution imagery. Chapter I demonstrates the importance of quantifying snow cover duration for predicting patterns of plant taxonomic and functional diversity, and also highlights the ongoing challenge of modeling spatial gross primary productivity dynamics in alpine landscapes. In Chapter II, I explore the utility of satellite imagery for quantifying environmental conditions experienced by alpine plant communities, and further show how metrics of snow cover duration and peak productivity can be used to differentiate habitat for dominant alpine plant communities. I also explore how functional diversity mediates NDVI responses to highly contrasting snow years. Chapter III provides new evidence of recent shifts occurring in high-elevation plant communities in the French Alps in response to climate and land-use change. Analysis of the forest-grassland ecotone in the Vercors Regional Park shows a strong dynamic of forest expansion in response to overall climate warming and local shifts in grazing-related land-use practices, which supports findings from other studies conducted elsewhere in the Alps and Pyrenees. In the second part of Chapter III, for the first time I present evidence of greening dynamics in a protected area of the French Alps, the Ecrins National Park. I propose that a decrease in snow cover duration and pronounced warming occurring in the 1980s likely contributed to increased canopy productivity in high alpine contexts, and are driving long-term greening in the absence of land-use change. Taken collectively, rather than pushing a specific aspect alpine ecology forward, my work helps to fill out our working knowledge of alpine plant communities and serves to solidify a number of field-based observations by carrying out robust spatial analyses.

Different types of man-made retention systems (polder, small water reservoir, large water reservoir) have been characterized by means of their retention potential and cost of retention per one cubic meter. As part of these man-made retention systems, wetland area has been created. Its acreage and build expense has been counted up inreference to total area, which differed within various types of retention systems. The results of these calculations, Hessenian method, and the metohod of agricultural land use were used to evaluate natural river basin and its retention potential. The calculations reveal, that model locality of natural river basin has the lowest value, when used for agriculture cultivation. Hessenian method showed the highest value. The expense of substituting the natural retention of the model locality with different man-made retention systems is estimated to be 0.5?1.6 billion CZK.

The thesis focuses on the study of arboreal ant communities in a highly diverse tropical rainforest in Papua New Guinea. In the first study of its kind, whole patches of forest were sampled extensively for ants foraging and nesting in tree trunks and canopies. An extraordinary amount of material collected from 684 felled trees and 260 bait stations in plots of primary and secondary forest was used to study the mechanisms structuring the diversity and species coexistence of this ecologically important insect group at the local scale. The first chapter addresses the question "Why are ant communities more species rich in primary than in secondary forests?" and explores the main environmental traits that influence their diversity in tropical trees. The second chapter compares the community diversity and composition and nesting preferences of ant species between both forest types. The final third chapter introduces a novel method, involving large-scale manipulation of ant communities that could serve as a template for future studies focused on complex tropical food-webs of canopy arthropods and plants. In summary, the results of the thesis highlight the importance of primary vegetation in conserving the diversity of native ant communities and the relevance of nesting microhabitats and their turnover between trees, rather than tree taxonomic diversity, for sustaining the diverse arboreal fauna in tropical forests.

Ethiopia has been challenged by multidimensional poverty. However, it has the potential to minimize the threat through an integrated multipurpose development process. In this regard, hydropower has a significant role to reduce energy poverty and enhance the multipurpose use of natural resources efficiency. Hydropower is a source of clean, sustainable and renewable energy. It has a contribution to reducing carbon emission and maintaining environmental sustainability. In Ethiopia, it is the major source of electricity. The country is rich in natural resources, including water to produce energy, however, electricity supply is still uncertain. The data shows that the country has the potential to produce 50,000 MW energy from water resources. Yet, it exploited 3,822 MW in 2018, approximately 7.6 % of its potential. Moreover, the country faces issues with energy security. Additionally, water and food supply also face an uncertain future. In this case, the country has planned the growth and transformation plan I and II for 2015 and 2020 to increase the energy production to 10,000 MW and 17,000 MW energy respectively. Consequently, the government launched different multipurpose hydropower plant projects. This project focuses on the multipurpose use of the Grand Ethiopian Renaissance Dam, particularly for the sustainable energy-water-food-ecosystem service nexus at the national level. I applied the combination of methods such as the energy-water-food-ecosystem nexus, the SWOT analysis and the sustainability assessment as they are suitable for the complexity of such a project. Indeed, the GERD has benefits for the country in producing renewable and clean energy, generating income and increasing the water storage capacity at the national level. However, the project neglected the values of ecosystem services integration with the dam and its sectors. As a result, the dam affected the existed terrestrial biodiversity and ecosystem. Therefore, the GERD had not been the well-prepared plan that considers institutional cooperation and sectoral integration to use for multipurpose function and its sustainability. In these regards, unless the dam to take proper management of the project and natural resources, the hydropower plant would not have been generating sustainable energy production. / <p>The paper shows that how to use the reservoir hydropower plant for multipurpose, such as for energy, water, food, ecosystem services integration at local level</p>

The African Coelacanth Ecosystem Programme (ACEP) was established in 2002 after the discovery of a colony of coelacanths off the Maputaland coast at Sodwana Bay, KwaZulu Natal. The environmental education and awareness sub-programme developed learning support materials (LSM's) for use in schools and the materials were disseminated annually through teacher education workshops. This study aimed to uncover the use of these LSM's in the rural schools of Maputaland. The active learning framework was used to analyse the materials. Collectively, the ACEP materials cover a range of active learning aspects; however alignment with the curriculum has resulted in an increased focus on experiments, accompanied by a loss of environmental content and a narrowing scope for active environmental learning. Workshop questionnaires and four school case studies revealed the patterns of practice of use of materials in schools. The stated use of materials by teachers is not fully realized in the actual classroom practice which centres on learning content and concept definitions. There is no culture of use of materials in the schools following the annual introduction of ACEP materials. It was also found that the marine and coastal knowledge holding power is outside the realm of the teachers' practice and control. The findings of this study come at a time when there is uncertainty over the future of South African education and the curriculum. This research may inform the environmental education and coastal and marine education field as to their role in education and more specifically the development of learning support materials.

L’équilibre de l’écosystème microbien du caecum (Ca) et du colon ventral droit (Cn) équin peut être rompu par un changement brusque d’aliments et par une ration riche en amidon, et conduire à l’apparition de coliques. Chez des chevaux soumis à ces deux pratiques alimentaires, nous avons étudié les modifications de ces écosystèmes, de l’écosystème microbien fécal et de paramètres sanguins. Nous avons également testé la supplémentation composée de Saccharomyces cerevisiae et de microalgues Schizochytrium limacinum dans le cadre d’une collaboration avec Alltech. Nous avons montré que les écosystèmes microbiens du Ca et du Cn, stables lors d’un régime foin, pouvaient être rapidement modifiés par le stress provoqué par les deux pratiques alimentaires. Chez les chevaux supplémentés certains taxons bactériens potentiellement fibrolytiques ont augmenté dans le Ca et le Cn, et les dysbioses résultant d’un régime riche en amidon ont été limitées. Nous avons identifié plusieurs paramètres fécaux et sanguins reflétant les variations de l’écosystème microbien du Ca et Cn lors d’un changement de régime: les groupes bactériens fonctionnels, les abondances relatives de taxons bactériens (la famille XIII de Clostridiales, Succinivibrionaceae et des genres appartenant à Ruminococcaceae, Lachnospiraceae ou Prevotellaceae), les proportions et le ratio d’AGV, la concentration de valerate, les lipopolysaccharides fécaux ainsi que le beta-hydroxybutyrate sanguin. Ces paramètres semblent prometteurs pour diagnostiquer les dysbioses du gros intestin équin et prévenir l’apparition des coliques chez le cheval. / The balance of the microbial ecosystem of the caecum (Ca) and the right ventral colon (Cn) of the horse can be disturbed by an abrupt change of feed and by a high-starch diet, and lead to appearance of colic. We investigated the alterations of these ecosystems, of the faecal microbial ecosystem and of blood parameters in horses subjected to these two dietary practices. In addition, we tested a supplementation combining the yeast Saccharomyces cerevisiae and the microalgae Schizochytrium limacinum, in a context of partnership with Alltech. We showed that the Ca and Cn microbial ecosystems were stable under a hay diet, and can rapidly be modified under a stress caused by the two dietary practices. In supplemented horses, some potential fibrolytic bacterial taxa increased in the Ca and Cn, and the dysbiosis resulting from a high-starch diet were limited. We identified several faecal and blood parameters reflecting the variations of the Ca and Cn microbial ecosystem under a change of diet: the bacterial functional groups, the relative abundances of bacterial taxa (family XIII of Clostridiales, Succinivibrionaceae and genera belonging to Ruminococcaceae, Lachnospiraceae or Prevotellaceae), the proportion of acetate and propionate, the VFA ratio, the valerate concentration, the faecal lipopolysaccharides and the blood beta-hydroxybutyrate. These parameters appeared promising to diagnose dysbiosis in the proximal hindgut and thus prevent colic appearance in horses.