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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1451

Building resilience to climate-driven regime shifts

Sadauskis, Rolands January 2011 (has links)
There is increasing concern about potential climate-driven regime shifts– large abrupt shifts in social-ecological systems that could have large impacts onecosystems services and human well-being. This paper aims to synthesize the potentialpathways for building resilience to such regime shifts. Ten examples from the RegimeShift Database provided the cases for analysis. Causal loop diagrams were used toanalyze feedback mechanisms at different scales and identify “leverage points” –places to intervene in the system in order to build resilience. Sixteen of these leveragepoints were identified, most of which relate to agricultural management. Mostfeedback mechanisms include at least one leverage point highlighting the potential forbuilding resilience to climate-induced regime shifts. The most common leverage pointsidentified in our analyses were vegetation cover, algae volume and atmospherictemperature. These leverage points were compared to mitigation strategies discussedby the IPCC. This comparison indicates that current climate change mitigationstrategies do not alter most of the leverage points directly. This suggests that IPCCstrategies should be broadened in order to reduce the risk of regime shifts, and theassociated impacts on human well-being.
1452

Small Businesses and how they connect to the Sustainable City : A list of actions for the transformation to a sustainable Paris

Pessot, Olivier January 2011 (has links)
The City relies on Nature‟s products and services for its wellbeing and its very existence. Smallbusinesses, the socio-economic fabric of the City, are mostly mainstream and not engaged insustainability. From their point of view, how do they connect to the Sustainable City?In one of the most competitive areas of central Paris, mainstream businesses and also frontrunners, thelatter already engaged in sustainability, were interviewed as a pilot to further explore transformationinto the Sustainable City. All were asked to reflect on their experience in managing change. They werethen encouraged to propose actions in face of the challenges of sustainability and the sustainable city,and react on a vision of the Sustainable City for Paris and its larger region. They expressed barriers tochallenges and to the vision proposed. And they also proposed ideas, expressed desires, opportunitiesand overall bridges for sustainability to be practically implemented. The findings presented theenterprises‟ interpretation of the concepts of trust and innovation. Reflecting on how the results couldcontribute to a transformation into a Sustainable City resulted in a practical list of actions. This pilotstudy showed a potential for sustainable development to emerge throughout the City through its mostimpactful yet promising actors, the small businesses.In order to contribute in building bridges between City and Nature, the exploration is inspired bysocial ecological research, looking for ways to harmonize the various elements and actors to transformcities into sustainable ones. The framework is mostly based on a business-inspired research design anda construct from the European Union Sustainable City challenges, resilience theory approaches and theFrench national strategy for sustainable development.
1453

Esthétique et biodiversité des écosystèmes sous-marins / Aesthetics and biodiversity of marine ecosystems

Tribot, Anne-Sophie 27 November 2017 (has links)
La valeur esthétique des paysages et des espèces est un élément central de la conservation de la biodiversité, puisqu’elle fait intervenir les dimensions affectives et émotionnelles de notre rapport à la nature. Le lien entre biodiversité et perception esthétique demeure cependant peu étudié dans le cadre des services écosystémiques.Suite à un premier travail de synthèse ayant permis de poser les bases conceptuelles et méthodologiques de l’esthétique des paysages, trois études menées sur des systèmes sous-marins à différentes échelles ont permis de mieux comprendre et de quantifier le lien entre les différentes facettes de la biodiversité et la perception esthétique.Les résultats ont permis de mettre en évidence que la nature du lien entre biodiversité et préférences esthétique est dépendante de l’échelle de perception : à une échelle multi-spécifique, la biodiversité et la composition en espèces ont un effet positif sur les préférences esthétiques, tandis que les préférences à l’échelle spécifiques sont déconnectées du fonctionnement écologique des écosystèmes.Ces résultats confirment l’importance de la valeur esthétique dans notre perception de la biodiversité, qui pourrait avoir des conséquences majeures sur la façon dont nous protégeons notre environnement. L’approche fonctionnaliste de l’expérience esthétique est proposée et décrite afin de promouvoir une perception esthétique basée sur la compréhension et la reconnaissance des processus écologiques. Des pistes d’éducation à la biodiversité basée sur une expérience esthétique engagée sont également proposées afin de reconnecter les besoins écologiques et les préférences esthétiques. / The aesthetic value of landscapes and species is a central element for the conservation of biodiversity, since it involves the emotional and emotional dimensions of our relationship to nature. However, the links between biodiversity and aesthetic perception remains poorly studied and recognized within the ecosystem services framework.Following a first critical review, that described the conceptual and methodological bases of landscape aesthetics, three studies on underwater systems at different scales have been computed in order to better understand the link between the different facets of biodiversity and aesthetic perception.The results revealed that the link between biodiversity and aesthetic preferences is dependent on the scale of perception: at a multi-specific scale, biodiversity and species composition have a positive effect on aesthetic preferences, while preferences at a specific scale are disconnected to the ecological functioning of ecosystems.These results confirm the importance of aesthetic value in our perception of biodiversity, which could have major consequences in the way we protect our environment. The aesthetic experience based on the understanding of ecological functioning is proposed and described in order to promote an aesthetic perception relevant to ecological processes. Education to biodiversity based on engaged aesthetic is also proposed, in order to reconnect ecological needs and aesthetic preferences.
1454

The ecology of Sabellaria spinulosa reefs

Pearce, Bryony January 2017 (has links)
Reef habitats built by the tubiculous polychaete Sabellaria spinulosa have been identified as a habitat with significant conservation importance, based on their historic decline across Europe and the assumption that, like many other biogenic reef systems, S. spinulosa reefs enhance biodiversity. Despite the high conservation status of this habitat very little work has been undertaken to explore the role that S. spinulosa reefs play in marine ecosystems, or their sensitivity to anthropogenic disturbance. Observations of the reproductive ecology and population dynamics of the reef building organism indicate that S. spinulosa exhibit life-history traits typically associated with r-strategists, indicating that this species is likely to have the ability to recover quickly following most anthropogenic disturbance events. A series of surveys on S. spinulosa reefs identified at the Thanet Offshore Wind Farm site, where the extent of the reef habitat was found to have increased between the pre-construction and post construction survey despite extensive cable laying and turbine installation, corroborates these findings. Detailed investigations into the macrofauna associated with S. spinulosa reefs in the eastern English Channel revealed that S. spinulosa reefs support macrofaunal communities that are comparable to those associated with adjacent muddy sandy gravel and gravelly muddy sand in terms of species composition, taxonomic breadth and beta-diversity. A consistent enhancement in species richness, abundance and biomass was identified in samples collected from S. spinulosa reefs when compared with adjacent sedimentary deposits, as well as a corresponding reduction in the equitability of species, indicating that some macrofauna are able to exist in higher densities within this habitat. The increase in macrofaunal biomass associated with S. spinulosa reefs was found to influence the diet of demersal fish species, with some species feeding on the reef organism itself while others feed on species found in high densities on the reefs. The high abundance of juvenile flatfish associated with this habitat also suggests that S. spinulosa reefs may provide an important nursery habitat.
1455

Who benefits and who loses? : Evaluating the impacts of community-based marine protected areas on ecosystem services and human wellbeing

Mahajan, Shauna January 2014 (has links)
Coral reef ecosystems are some of the most biologically diverse systems in the world, and provide a number of ecosystem services that humans depend on for their wellbeing. Marine protected areas (MPAs) are a social-ecological intervention that while conserving these ecosystems, also have significant impacts on the communities that depend on them for their wellbeing. Community-based MPAs are growing in popularity with the assumption that by putting communities at the forefront of their planning and management, more participation will occur, ensuring positive social and ecological impacts. This study, through mixed qualitative and quantitative methods, examines two community-based MPAs in coastal Kenya (called tengefus) to understand how each tengefu was incepted, and how resource users perceive the impacts of the tengefu on ecosystem services and human wellbeing. Participation in and donor support for the tengefu were found to influence how resource users perceived impacts. Individuals who were more engaged in the project or held some type of leadership position perceived more positive impacts on ecosystem services and human wellbeing compared to those not involved. In the two cases, tangible benefits (e.g. fisheries spillover and ecotourism) from the marine enclosure itself are too few to benefit the community as a whole. For tengefus to be social successes, more attention should be given to engaging all resource-dependent community members in their planning, implementation and management, and to understanding the multifaceted role of donor funding in supporting these initiatives.
1456

Managing Innovation Networks : Exploring Coopetition Dynamics in Innovation Ecosystems

Mankevich, Vasili January 2014 (has links)
Companies increasingly rely on external partners when starting their innovation initiatives. Emergent innovation ecosystems of heterogeneous actors proved to be successful in leveraging combined competence for the creation of the new ventures. However, constantly changing environment of simultaneous competition and cooperation – coopetition, presents a challenge for the ecosystem management. Drawing on the network orchestration and coopetition research, I analyze management practices and coopetition dynamics in the digital creative industry in Northern Sweden. Based on the analysis, I offer two main contributions. First, I provide a detailed account of innovation ecosystem orchestration within the digital creative industry, including its chronological evolution and the challenges related to it. Second, the application of coopetition notion to the innovation ecosystem context brings forward tensions that should be further scrutinized in order to develop better management practices for such innovation networks.
1457

The Cloud Marketplace : A Capability-Based Framework for Cloud Ecosystem Governance

Falk, Sebastian, Shyshka, Andriy January 2014 (has links)
Within the last five years, the market of cloud computing has shown rapid growth. However, despite the increasing popularity, researchers highlight numerous concerns regarding limited interoperability of systems hosted by different cloud providers as well as restricted customization of cloud solutions. In order to counter aforemen-tioned challenges, this study investigates the idea of introducing a marketplace for cloud services that leverage the service-oriented architecture (SOA) paradigm and of-fers software solutions, computing capabilities from cloud providers, components developed by third parties, as well as access to integration and audit services. The goal of the study lies in conceptualizing the idea and the evaluation of demand it may raise from the key cloud actors. In this regard, existing frameworks of cloud compu-ting and SOA contributed to the development of an initial model that was further improved through the interviewing process. The results of this study include a capa-bility-based framework for the cloud marketplace which not only clarifies the role and activities of the different actors but also contains the necessary features of the marketplace that are needed to ensure the proper workflow. In addition to that, the actors’ incentives and concerns regarding the marketplace were analyzed by applying SWOT-analysis. While the analysis revealed both positive interest and present de-mand among the actors, the identified weaknesses and threats highlight the need for further investigations in order to put the idea into practice.
1458

Konkretisierung und Management von Gemeinwohlleistungen öffentlicher Forstbetriebe / Management of public welfare services in public forest enterprises

Over, Elisabeth Ingeborg 05 April 2018 (has links)
No description available.
1459

Trophic Dynamics and Feeding Ecology of the Southeast Florida Coastal Pelagic Fish Community

Moore, Travis Allan 01 March 2014 (has links)
The combined methods of stomach content analysis and stable 15N and 13C isotope biochemistry analysis were used to investigate the trophic dynamics and feeding ecology of coastal pelagic fishes in the waters off southeastern Florida, USA. The coastal pelagic fish complex includes blackfin tuna Thunnus atlanticus, dolphinfish Coryphaena hippurus, king mackerel Scomberomorus cavalla, little tunny Euthynnus alletteratus, skipjack tuna Katsuwonus pelamis, and wahoo Acanthocybium solandri. These coastal teleosts, particularly the tunas and wahoo, are primarily targeted by recreational anglers. However, there is a shortage of available trophic and diet composition data concerning these fishes of the coastal pelagic ecosystem. Stomach and muscle tissue samples were collected from the species of various lengths over a three-year period from March 2010 and March 2013. Across all six species, teleost fishes dominated the prey with an average 64.5% by occurrence, 63.7% by number, and 89.9% by weight. There were two dominant prey families: Clupeidae and Carangidae. Dolphinfish showed the lowest diet overlap among the six species, due to the highly diverse diet. The highest diet overlap occurred between king mackerel and little tunny. The mean δ15N ranged from 8.21 ‰ (wahoo) to 13.18 ‰ (king mackerel), and the mean δ13C ranged from -18.41 ‰ (king mackerel) to -16.70 ‰ (dolphinfish). Blackfin tuna exhibited the largest δ15N range (7.22 to 13.21 ‰), as well as the largest δ13C range (-19.13 to -12.99 ‰). The δ15N and δ13C signatures in the muscle tissue showed evidence of shifts to higher trophic levels with an increase in fish size and the formation of distinct trophic groups among the coastal pelagic predators. The δ13C also suggested an inshore-offshore spatial relationship among the coastal pelagic fish. The trophic dynamics and feeding ecology data generated by this study will provide valuable baseline data for the coastal pelagic complex and future ecosystem studies.
1460

Assessment of yield and economic losses caused by pests and diseases in a range of management strategies and production situations in coffee agroecosystems / Évaluation du rendement et des pertes économiques causées par les ravageurs et les maladies dans une gamme de stratégies de gestion et de situations de production dans les agroécosystèmes du café

Cerda, Rolando 21 February 2017 (has links)
Les pertes de récolte dues aux ravageurs et aux maladies constituent une menace sérieuse pour les revenus et la sécurité alimentaire de milliers de familles rurales dans le monde entier. L'évaluation de ces pertes de récolte (baisse de rendement et préjudice économique) et de leurs causes est nécessaire pour améliorer la mise au point d'agroécosystèmes capables d'offrir de bons rendements de culture, une régulation des ravageurs et des maladies et d'autres services écosystémiques. Ce mémoire de doctorat vise à contribuer à la recherche dans le domaine des pertes de récolte en proposant des approches expérimentales et de modélisation susceptibles d'être utilisées pour estimer les pertes primaires et secondaires subies dans les cultures pérennes, et analyser leurs causes. La culture pérenne étudiée est celle du caféier à Turrialba au Costa Rica, où la culture du café se pratique dans des plantations qui vont de la monoculture à pleine exposition solaire à des systèmes agroforestiers hautement diversifiés, et qui sont soumises à une gamme de situations de production (topolimat, fertilité du sol, types d'ombrage) et de stratégies de gestion (pratiques culturales et intrants). Les trois questions de recherche principales ont été les suivantes : Quel est l'impact des stratégies de gestion et des situations de production sur les ravageurs et les maladies et les rendements en café ? Comment les pertes de rendement en café associées à des profils de dégâts donnés varient-elles en fonction des stratégies de gestion et des situations de production ? Quels types d'agro-écosystèmes à base de caféiers permettent de minimiser les pertes en café (baisse de rendement et préjudice économique) et de maximiser les avantages globaux retirés (services écosystémiques) ? / Crop losses due to pests and diseases are a major threat to incomes and food security of thousands of rural families worldwide. The assessment of crop losses (yield and economic losses) and their causes is needed to improve the development of agroecosystems capable to offer good crop yields, regulation of pests and diseases, and other ecosystem services. This doctoral research aimed to contribute to the research field of crop losses, by providing experimental and modeling approaches that could be used in perennial crops to estimate primary and secondary losses and analyze their causes. We worked in a perennial crop such as coffee, in Turrialba, Costa Rica, where coffee is grown in plantations from monocultures at full sun exposure to highly diversified agroforestry systems, and under a range of production situations (topoclimate, soil fertility, types of shade) and management strategies (agricultural practices and inputs). The three main research questions were: What is the impact of management strategies and production situations on pests and diseases and coffee yields? How do coffee yield losses caused by injury profiles vary in function of management strategies and production situations? Which types of coffee agroecosystems are capable to obtain the lowest coffee losses (yield and economic) and highest overall benefits (ecosystem services)? This research was developed through two experimental designs. The first was an experimental coffee parcel under controlled conditions (three-year experiment) to quantify primary and secondary yield losses by comparison of treatments, and to identify the main predictors of yield losses by structural equation modeling. The second experimental design was based on surveys in a coffee research plot network (coffee plots of smallholder farmers), where, during two years, we measured indicators of yields and indicators of four ecosystem services: regulation of pests and diseases, provisioning of agroforestry products, maintenance of soil fertility, and carbon sequestration. Yield losses in this network were estimated through modeling using the predictors identified in the experimental coffee parcel. Analyses of data included several statistical techniques, from analysis of variances, linear regressions to multivariate techniques. The results were organized in four manuscripts, and then discussed integrally. The main findings were: i) Both production situations and management strategies determine coffee yield and pest and disease injuries, effects of interactions altitude x management x types of shade must be considered; ii) Injury profiles depend on particular combinations of production situations and management strategies, with impacts on yield losses especially in a year of high coffee production (primary yield losses), but compromising also the yields of the next year (secondary yield losses); iii) Diversified agroforestry systems have better chances to regulate pests and diseases (reduce yield and economic losses), and simultaneously provide goods for family benefits, maintain soil fertility, and increase carbon sequestration, without implying trade-offs among these ecosystem services. The main prospects of this research are related to perform similar studies in coffee and other perennials at regional levels, develop an injury profile simulator for coffee, and prototyping of coffee agroforestry systems to optimize the provision of multiple ecosystem services.

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