Dissertationen: „Ecosystem“

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Simpson, Roderick F. „EcoSystem-Sim a virtual ecosystem simulator /“. [Gainesville, Fla.] : University of Florida, 2001. http://purl.fcla.edu/fcla/etd/UFE0000352.

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Thesis (M.S.)--University of Florida, 2001.
Title from title page of source document. Document formatted into pages; contains x, 60 p.; also contains graphics. Includes vita. Includes bibliographical references.

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2

Varkey, Divya Alice. „Marine ecosystem restoration with a focus on coral reef ecosystems“. Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30117.

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The declines of fish populations in ecosystems around the globe have triggered considerable interest in marine ecosystem restoration. In addition to focusing on individual fish populations, there is increased emphasis on understanding inter-species interactions and on understanding the human relationships with the ecosystems. My thesis approaches marine restoration from (a) practical aspects of considering multispecies interactions in the ecosystem (Ecopath with Ecosim models), estimating unreported and illegal catches (influence tables) and policy that considers the concerns of multiple stakeholders (Bayesian influence diagram modeling); (b) theoretical aspects of carrying capacity and fish life history analyzed using life history parameters (Population dynamics modeling). I begin my thesis by exploring the technological, socio-economic, and political history of Raja Ampat in Eastern Indonesia (my geographical focus) to understand resource management challenges and to calculate the trends in relative misreporting of fisheries catch. The unreported fish catch exceeds the reported fish catch by a factor of 1.5. My next chapter explores the ecological benefits of establishing marine protected areas for coral reef ecosystems in Raja Ampat using Ecopath, Ecosim and Ecospace models. I estimate an ideal minimum size of no-take areas— the size of no-take area at which the biomass density of reef fish reached an asymptote—to be 16 to 25 km². Analysis of biomass density of reef fish in MPAs led to questions about ecosystem carrying capacity. To explore carrying capacity, I reconstruct ancient snapper population biomass using archaeological data obtained from fish middens using equilibrium age structure model. The results show that the ancient snapper population was about 2 to 4 times higher than the modern population biomass. To model the differing utilities of different stakeholders, in the next chapter, I develop a bayesian influence diagram model. The results indicate that restricting net fisheries and implementing 25% fisheries closure are robust scenarios favored under several combinations of the modeled variables and utility functions. The final chapter explores how the life history parameters of fish species affect the population response to restoration. It is expected that slow growing species would show a greater response to protection than fast growing species.

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Ruiz, Jaen Maria. „The Relationship between Biodiversity and Ecosystem Function in Tropical Ecosystems“. Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104676.

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Experimental studies, in temperate grasslands, assessing the role of biodiversity and its effects on ecosystem functioning have generally shown that a decline in species number has negative effects on ecosystem functioning. Even though, this relationship has been intensively studied in the last ten years, little is known about it in complex and hyperdiverse tropical ecosystems and where species diversity is not manipulated. My research examines the relationship between biodiversity and ecosystem functioning in natural tropical forests with a special focus on scale. This research centers on field studies. The field studies address the relationship between natural tree biodiversity and aboveground biomass, as the ecosystem function of interest, in forest plots of similar physiognomy but different species composition. Specifically, I explored the following questions: (1) How can the relationship between biodiversity and ecosystem functioning be detected in a naturally varying environment and space?, (2) How can different measures of diversity (species versus function) explain tree carbon stocks?, (3) Can we confound the effect of species diversity on tree carbon storage with that of forest structure?, (4) How does this relationship change with different spatial scales?, and (5) Can we extrapolate the results of biodiversity-ecosystem functioning found in experimental plantations to natural forests? Overall, my thesis has found that environmental factors related to topography, soil physical factors, and nutrients have little effect on aboveground biomass in tropical ecosystems. Species richness alone cannot be used as a predictor for aboveground biomass, however, if reduced to functional types, its explanatory power increases. Functional traits can be useful to unveil the relationship of aboveground biomass and tree diversity, by reducing species to functional types. Forest structure correlates strongly with aboveground biomass independently of scale, but forest structure is interlinked with species functional traits. Finally, we have to be cautious in extrapolating results found in experimental plantations to natural forests.
Des études expérimentales qui ont été effectuées dans des systèmes expérimentaux herbacés du milieu tempéré afin d'évaluer le rôle de la diversité biologique et ses effets sur le fonctionnement de l'écosystème ont généralement pu montrer que le déclin dans le nombre d'espèces a un effet négatif sur le fonctionnement de l'écosystème. Même si cette relation a été étudiée de façon intensive au cours des dix dernières années, très peu est encore connu à ce propos dans les écosystèmes tropicaux, beaucoup plus complexes et mégadiversifiés. Mes travaux de recherche examinent la relation entre diversité biologique et fonction de l'écosystème dans les forêts naturelles tropicales, en mettant l'emphase sur la question d'échelle. Cette recherche est basée sur une approche de terrain, en opposition avec une approche théorique. L'approche de terrain aborde la relation entre la diversité biologique à l'état naturel et les fonctions d'écosystème dans des parcelles forestières de physionomies similaires mais d'une composition en espèces différente. De façon plus spécifique, j'explore les questions suivantes : (1) Comment la relation entre diversité biologique et fonction d'écosystème peut-elle être détectée dans un environnement et un espace naturel changeant?, (2) Comment différentes mesures de diversité (espèces vs fonction) expliquent-elles les stocks de carbone dans les arbres?, (3) Pouvons-nous confondre l'effet de la diversité en espèces sur l'entreposage du carbone dans les arbres avec l'effet de la structure de la forêt? (4) Comment cette relation change-t-elle avec différentes échelles spatiales? (5) Pouvons-nous extrapoler les résultats obtenus dans des plantations expérimentales aux forêts naturelles dans les tropiques en ce qui a trait à la relation entre biodiversité et fonction d'écosystème? Ainsi, ma thèse montre que pour les écosystèmes tropicaux, les facteurs environnementaux tels que ceux reliés à la topographie, les facteurs physiques et les nutriments des sols ont peu d'effet sur l'entreposage du carbone dans les arbres. De plus, la richesse en espèces ne peut pas à elle prédire de l'entreposage de carbone dans les arbres, cependant lorsque celle-ci est divisée par types fonctionnels, sa puissance explicative augmente. Les traits fonctionnels peuvent donc être utiles pour révéler une relation entre le stockage du carbone et la diversité en arbres en réduisant les espèces en des types fonctionnels. La structure de la forêt est le moteur principal du stockage arboricole du carbone indépendamment de l'échelle, par contre cette dernière est reliée aux traits fonctionnels des espèces. Finalement, nous avons pu montrer que la prudence est de mise en ce qui concerne toute possible extrapolation de résultats provenant de plantations expérimentales à des forêts naturelles dans les tropiques.

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Cenamor, Javier. „Managing Platform-Mediated Ecosystems : Investigating ecosystem interdependencies and strategic choices“. Doctoral thesis, Luleå tekniska universitet, Innovation och Design, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26396.

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The rapid and ubiquitous spread of information technologies (IT) is creating unprecedented effects that challenge traditional fundamentals of the business world. Platform-mediated ecosystems are increasingly attracting the attention of practitioners from diverse industries, from telecommunications to video consoles, as well as academics from different fields ranging from management to economics, and information systems (IS) and innovation management. A platform-mediated ecosystem can be defined broadly as an industrial architecture with an infrastructure in the center that facilitates value co-creation among different agents (platform owners, and providers and users of complementary products) and a set of rules governing their interdependencies. The speed and the magnitude at which platforms diffuse are inspiring numerous analyses from diverse perspectives, mainly focused on drivers of success and ecosystem interdependencies in different contexts. This thesis highlights the importance of detangling the different interdependencies within platform-mediated ecosystems, while building a comprehensive approach based on the ecosystem as a whole. The wide range of platform types and their rapid evolution makes it difficult to establish a consensual categorization of platforms. A common aspect among most of them is that platform-mediated ecosystems usually present network effects that is the value of products depend on the number of peers within the ecosystem. In this sense, the number of adopters, known also as the size of the installed base, in a market has traditionally had a central importance in the literature. The platform-mediated ecosystems, however, are becoming more and more complex due to rising competition. Thus, there is a need for advancing understanding of the fundamentals of platform-mediated ecosystems and the management alternatives inherent in designing such systems which would enable a comprehensive platform approach to be built. Consequently, the main purpose of this thesis is to advance the understanding of the strategic management of platform-mediated ecosystems. Specifically, this thesis aims to unravel the ecosystem interdependencies and to identify strategic choices as a source of competitive advantage. To achieve this aim, different methodologies are applied in this thesis. Specifically, Paper I was based on a structured literature review of relevant papers in platform-mediated ecosystems for the period 2000 through 2014. The empirical analyses conducted in Papers II, III, and IV use different secondary samples from the video console ecosystem. Finally, the results in Paper V were based on a qualitative, multiple case study of global manufacturing firms implementing product-service systems (PSS) through a platform architecture. Overall, the findings within this thesis present the following main theoretical contributions. First, the thesis presents a comprehensive approach toward platform mediated ecosystems covering new ways of value creation and value capture, new governance regimes, and new agents making interdependent choices. Precisely, platform ecosystems offer unprecedented efficiencies and innovation enhancements, and the possibility of establishing rules for new role participation and interaction. Thus, the findings shed light on the fundamentals and future trends in the platform approach. Second, different ecosystem interdependencies may increase the platform adoption and performance. Specifically, the thesis highlights the importance of the positive effects from different agents in the complementary product markets. Accordingly, the findings contribute on unraveling the interdependencies within platform ecosystems. Third, platform performance can be enhanced by exploiting complementarities among strategies and regions. Precisely, the findings show significant complementarities from the joint management of different activities related to the complementary products and the platform, and from the presence in several countries. Consequently, the findings provide strategic choices as a source of competitive advantage. Finally, transformation toward global PSS may be guided by a platform approach, which may be helpful to explain the origins in building a platform ecosystem. In this respect, the findings shed light on how platform-mediated ecosystems are created. In sum, these findings have important implications for researchers in strategic management, economics, and information systems as well as managers from highly innovative industries and traditional sectors under structural transformation. This thesis concludes with the limitations that should be considered when interpreting the findings and some suggestions for future researchers.
Godkänd; 2015; 20150917 (javcen); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Javier Cenamor Gómez Ämne: Entreprenörskap och innovation/Entrepreneurship and Innovation Avhandling: Managing Platform-Mediated Ecosystems: Investigating Ecosystem Interdependencies and strategic Choises Opponent: Biträdande professor Andreas Larsson, Institutionen för maskinteknik, Blekinge tekniska högskola, Karlskrona. Ordförande: Biträdande professor Vinit Parida, Avd för innovation och design, Institutionen för ekonomi, teknik och samhälle, Luleå tekniska universitet, Luleå. Tid: Tisdag 10 november, 2015 kl 13.00

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Espinosa, Romero Maria Jose. „Towards ecosystem-based management : integrating stakeholder values in decision-making and improving the representation of ecosystems in ecosystem models“. Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/28127.

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Ecosystem-based management (EBM) is increasingly seen as the new paradigm for managing the use of marine resources and ecosystems. Although EBM has been defined in theory, its implementation has faced challenges worldwide. This research aims to examine two approaches to contribute to the operationzalization of EBM by incorporating stakeholder values in the decision-making process, and by better representing ecosystem dynamics in ecosystem models. First, I illustrate a decision-making framework for EBM rooted in structured decision-making (SDM), a well-known systematic approach for planning and stakeholder-consultation processes. SDM helps to identify the values of the constituents and define objectives and indicators that are consistent with those values. I demonstrate how SDM can enable managers to evaluate the performance of management alternatives using indicators specifically chosen to reflect values. This can help managers make more systematic, transparent and informed decisions with respect to the use of marine resources. As a case study, I apply SDM to the marine planning process on the west coast of Vancouver Island (WCVI). Second, as ecosystem models play an important role in EBM, I strive to improve the representation of marine ecosystems using ecosystem models in Ecopath with Ecosim (EwE). I focus on incorporating mediating effects and species reintroductions, both common situations that can strongly influence ecosystem dynamics. These considerations are essential when applying holistic approaches to management but they are not generally included in EwE. I use EwE to model the reintroduction of sea otters (Enhydra lutris) and the mediating effects provided by kelp forests in nearshore ecosystems of the WCVI. Because EwE does not have the functionality to represent reintroductions, I created two scenarios to work around the assumptions of Ecospace on the initial state of the ecosystem. In addition, I demonstrate how mediating effects can be represented using the ‘mediation’ function in Ecosim. These methods and results can contribute to advance EBM on the WCVI and offer insights to other marine planning processes. Both strengths and limitations of this work are presented and analyzed.

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Xu, Y. (Yueqiang). „How new business ecosystems emerge:a study on Finnish cloud business ecosystem“. Master's thesis, University of Oulu, 2013. http://urn.fi/URN:NBN:fi:oulu-201303041077.

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It is an emerging phenomenon that the leading multinational companies are studying how to use the engagement experiences of customers and communities as the foundation of value co-creation. To achieve this, the business leaders have increasingly adopted an ecological organizational form, namely business ecosystem. Google, Amazon and Microsoft are the real world examples and pioneers in this field. However, in the academic research, it is addressed by a number of researchers that there is significant lack of empirical studies that examines the emergence and formation of business ecosystem, especially in ICT industry. In essence, this study takes Cloud as the context to develop concepts on the emergence of business ecosystem and examine the manifestation of such evolution in the emerging business field. Through extensive literature reviews and empirical interviews, the current study developed answers to the research question, “How do new business ecosystems emerge, in the context of Cloud computing?” at qualitative level. In general, it is considered in the study that business ecosystem is a type of more advanced business form emerged recently. It has the characteristics as follow: provision of value, integration with external partners, requiring multiple participants, shifting from individual to collaborative thinking, interdependence of the participants, value co-creation, co-petition, open innovation and shared fate of success or failure. From a macro level viewpoint, the emergence of business ecosystem is the result of the continuous evolution of business forms, from linear type towards a more complex networked type. At a micro level, for an ecosystem to emerge in a given industry, it involves strategic design and appropriate execution. Furthermore, a set of critical elements need to be in the right place for a business ecosystem to emerge, which including: prerequisite conditions for ecosystem to emerge, external environmental and resource, shared vision, leadership of the ecosystem, common platform, mechanisms of the ecosystem, ecosystem healthiness, and IT infrastructure. The study further suggests that the emergence of business ecosystem as a new business form is not out of luck or probability. It is a natural path that under governance of the evolution forces existing in the social-economic contexts, just as the evolution of all the living creatures in the natural environment. For this broader perspective, the emergence of ecosystem is inevitable due to the social-economic and technological driving forces.

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Folkersen, Maja. „Ecosystem Valuation of Vulnerable Marine Ecosystems in the South Pacific Islands“. Thesis, Griffith University, 2018. http://hdl.handle.net/10072/385544.

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One of the greatest challenges for sustaining the ecosystem services that we, as a society, derive from marine ecosystems is to minimize the knowledge gap relating to marine ecosystem values. That is, identifying, eliciting and understanding the economic value of the ecosystem services that marine systems provide for societies world-wide is key to ensuring sustainable resource use and environmental management of these ecosystems. This is particularly problematic for the ecosystem services derived from the deep sea as a tremendous knowledge gap exists for the many marine ecosystems that comprise the deep sea. Addressing this gap in knowledge may, directly and indirectly, facilitate actionable strategies for successful climate change adaptation and reduce the degradation of these important marine ecosystems. Estimating values for certain types of marine ecosystem services in particular the deep sea is imperative for understanding the economic trade-offs associated with human actions and resource use of marine resources. Identifying, exploring and understanding the economic benefits and costs associated with the human resource use of marine systems is also crucial for circumventing irreversible damage to ecosystems, and for addressing the growing problem of ecosystem degradation of marine ecosystems. However, a knowledge gap remains in terms of eliciting and understanding how vulnerable marine ecosystems, such as coral reefs and the deep-sea, generate economic value to local economies, and for societies on a global scale. By employing a variety of quantitative and qualitative methodologies, this thesis explores the economic value of the ecosystems of coral reefs and the deep-sea, respectively. The thesis investigates various aspects of the economic contribution of these ecosystems, namely: (i) the local economic contribution of ) Fiji's coral reefs to tourism; and ii) the economic value of the deep- sea's ecosystems to human societies, globally. Moreover, it discusses the importance of exploring the social and non-monetary value of coral reefs to human well-being in the South Pacific Island Countries (SPICs). The research of this thesis therefore constitutes a genuine contribution to understanding how changes in these marine ecosystems impact on economies and human well-being, now and in the future. Although the full extent to which ecosystem degradation of marine ecosystems will impact economies and societies globally remains uncertain, its impacts are already being witnessed, e.g. through ocean acidification, sea-level rise, reduced fish stocks and changing environmental conditions. In turn, these impacts affect human survival and well-being by negatively impacting fishery incomes, food security and coastal protection in many countries around the world. Action and investment plans for reducing the ecosystem degradation of marine systems are urgently needed to protect the value of those ecosystem services to human societies. Deepening our understanding of marine ecosystems' economic contributions constitutes a crucial component of facilitating action plans and investments for sustainable resource use and development. Valuation of vulnerable marine ecosystems is important for several reasons. First, valuation of an ecosystem's contribution to society demonstrates the importance of that ecosystem for social stability, economic growth and human well-being, thereby improving public awareness of that ecosystem's significance. Second, ecosystem valuation can inform policy and decision-making for future conservation programs and legislation pertaining to the human use of marine resources. Third, ecosystem valuation creates important incentives to invest in the protection of marine systems as it outlines the connection between the ecological functioning of marine systems on the one hand, and economic output and stability on the other hand. Fourth, ecosystem valuation can also raise awareness about the importance of protecting biodiversity. Finally, ecosystem valuation of marine ecosystems is especially important for supporting decision-making related to the resource-use of marine ecosystems for which very limited information exists on their economic contribution. The thesis starts with an introduction and a literature review of the main themes and concepts along with the problems, challenges and opportunities associated with the ecosystem valuation of coral reefs and the deep-sea. Subsequently, the research studies of this thesis, which constitutes chapters 2, 3, 4 and 5 are presented. Specifically, chapter 2 explores the economic impacts of future (hypothetical) deep-sea mining activities on Fiji's tourism industry, through a contingent behaviour study; chapter 3 discusses the need for developing non-monetary and social ecosystem valuation methodology in order to elicit marine ecosystems' importance for human well-being in the SPICs; chapter 4 explores current knowledge about the deep-sea's economic value through a systematic review and meta-analysis; and chapter 5 identifies the four main priorities for future ecosystem valuation, policy-making and research pertaining to the deep-sea. This thesis makes a small but significant contribution to the knowledge base of the economic value of the ecosystems of coral reefs and the deep-sea, respectively, and to developing future ecosystem valuation by means of introducing the social willingness-to commit (Social WTCommit) technique. Finally, this thesis can contribute to policy-making, decision-making and legislation pertaining to the deep-sea and coral reefs, locally and globally.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Dept Account,Finance & Econ
Griffith Business School
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Linnik, Juliana. „Ecosystem services“. Thesis, Вид-во СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/8148.

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9

Xofis, Panteleimon. „Post-fire vegetation dynamics and ecosystem recovery in north-east Mediterranean ecosystems“. Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429282.

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Quested, Helen M. „Root hemiparasitic angiosperms in subarctic ecosystems : their potential role in ecosystem function“. Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246953.

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11

Nichter, Ashlee N. „Population dynamics of hybrid ecosystems: Implications for marginal ecosystem conservation and management“. Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1510839367571419.

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12

Thomas, Christopher Kent. „Global warming and world ecosystem distribution : toward quantifying ecosystem change“. Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/67126.

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Loo, Clement K. „Ecosystem Health Reconsidered“. University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1311605312.

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14

Liu, Shuang. „Valuing Ecosystem Services:“. ScholarWorks @ UVM, 2007. http://scholarworks.uvm.edu/graddis/139.

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Ecosystem services are the benefits people obtain from ecosystems. Ecosystem service valuation (ESV) is the process of assessing the contributions of ecosystem services to human well-being. Its goal is to express the effects of changes in ecosystem services in terms of trade-offs against other things that also support human welfare. Ecologists tend to use biophysical-based methods while economists have developed preference-based tools for ESV. In this dissertation I attempt to bridge these two worlds by writing six papers using methods and insights from both disciplines. In paper 1, my coauthors and I (thereafter “we”) reviewed (1) what has been done in ESV research in the last 45 years; (2) how it has been used in ecosystem management; and (3) prospects for the future. One conclusion is that researchers and practitioners will have to transcend disciplinary boundaries and synthesize methodologies and tools from various disciplines in order to meet the challenge of ecosystem service valuation and management. Ninety-four peer-reviewed environmental economic studies were used to value ecosystem services in the State of New Jersey in paper 2. We translated each benefit estimate into 2004 US dollars per acre per year, computed the average value for a given eco-service for a given ecosystem type, and multiplied the average by the total statewide acreage for that ecosystem. The total value of these ecosystem services was estimated as $11.6 billion/year and we believe that this result is conservative. This aggregate value of New Jersey’s ecosystem services is a useful, albeit imperfect, basis for assessing and comparing these services with conventional economic goods and services. In paper 3 we present a conceptual framework for non-market valuation of ecosystem services provided by coastal and marine systems and review the peer-reviewed literature in this area. Next we selected a subset of this literature and conducted the first meta-analysis of the ecosystem service values provided by the costal and nearshore marine systems in paper 4. Using regression we found that over 75% of the variation in willingness to pay (WTP) for coastal ecosystem services could be explained. Our metaregression models also predicted out-of-sample WTPs and showed that the overall average transfer error was 24%, with 40% of the sample having transfer errors of 10% or less, and only 2.5% of predictions having transfer errors of over 100%. In the final two papers our focus is on the linkage between biodiversity and ecosystem function (BEF) which connects ecosystems with human welfare. In paper 5 we first present an overview of the main concepts and findings from a decade of the BEF literature. After a discussion on how agrobiodiversity relates to stability and resilience in agricultural systems at both the species and the landscape scales, we conclude with observations on the research needs in assessing the BEF relationship and the implications for agrobiodiversity ESV research. Finally, in paper 6, by using multiple regression analysis at the site and ecoregion scales in North America, we estimated relationships between biodiversity (using plant species richness as a proxy) and Net Primary Production (NPP, as a proxy for ecosystem services). We tentatively conclude that a 1% change in biodiversity in the high temperature range (which includes most of the world’s biodiversity) corresponds to approximately a 1/2% change in the value estimate of ecosystem services.

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ROGELJA, MANJA. „Benthic ecosystem functioning“. Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2908054.

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The main aim of this doctoral research project was to assess the benthic ecosystem functioning in areas subjected to multiple and diffuse impacts. The Aeolian Islands, originated by the volcanic activity and characterised by continuous gas emissions and presence of thermal vents on the surrounding seabed, represent a good natural laboratory for global warming and carbon capture and storage (CCS) leakage studies. The aim of this work was to investigate to what extend the high CO2 alone and in combination with the high temperature affects the microphytobenthic abundance and its community composition (Chapter 1). A further objective was to detect a possible change in the primary production rate in relation with these two variables. Higher microphytobenthic densities were recorded at the vent stations and values were even more pronounced in relation with high temperature. On the other hand, high microphytobenthic abundances were coupled with low community richness and diversity. The gross primary production estimates were strongly coupled with the microphytobentic abundance values. We observed several diatoms with morphological deformities, The Port of Trieste represents an area with a diffuse sediment contamination as it is subjected to diverse impacts: the shipbuilding activities, the iron and steel plant, the petroleum industry and the port activities. The aim of this study (Chapter 2) was to detect any variation in the structure of the microbenthic community, both as active phototrophic and resting microbenthos, and the possible differences in the primary production and respiration at stations subjected to different anthropogenic impacts. The total microbenthic abundance did not vary among stations. On the other hand, the structure of the community gave more information. In particular, the analysis based on the active and resting microbenthic community structure highlighted a clear separation among stations close to the productive activities from the more distant ones and the reference station, indicating a contamination effect on those communities. As an example of an area severely contaminated by heavy metals and synthetic organic compounds, the Mar Piccolo of Taranto was chosen. Firstly, the microphyto- and macrozoobenthic communities were investigated and a marked influence of contamination on the abundance and biodiversity of those two communities was detected (Chapter 3). To further asses the overall trophic status of the benthic ecosystem, an integrated study of the active phototrophic and resting microbenthic stages, combined with the main photoautotrophic pathways, was conducted (Chapter 4). Furthermore, although the Mar Piccolo is very shallow, the benthic system was scarcely productive, likely as a consequence of the accumulated contaminants in the surface sediments that probably interfere with the proper functioning of the benthic ecosystem. Contrary to the benthic ecosystem, the pelagic one was very productive and a clear seasonal succession of different sized plankton phototrophs was observed (Chapter 5). To have a better overall view and provide some insights into the benthic-pelagic coupling, the primary production and heterotrophic prokaryotic production in the water column were integrated with those in the sediments and related to the origin of the organic matter pools based on the analysis of stable isotopes (Chapter 6).

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Thomas, Llewellyn. „Ecosystem emergence : an investigation of the emergence processes of six digital service ecosystems“. Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/18315.

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This thesis investigates processes of ecosystem emergence. Ecosystem research has thus far focused on understanding the structure and dynamics of already existing ecosystems. However much less attention has been devoted to the emergence of ecosystems. I first theoretically develop an institutional approach to ecosystems, arguing that the ecosystem is an organisational field which has value co-creation as its recognised area of institutional life. Synthesising the theories of dominant design, social movements, and institutional entrepreneurship, I identify four activities that drive the processes of ecosystem emergence: resource, technological, institutional and contextual activities. Empirically, I compare the emergence sequences of six digital service ecosystems – Amazon, eBay, Facebook, Google, Salesforce and Wikipedia – using a narrative explanation methodology, applying event colligation, optimal matching, direct inspection, frequency analysis and an innovative statistical bootstrapping technique. I find that emergence sequences of each case are significantly dissimilar and that there are three phases of emergence – Initiation, Momentum, Control. The first of these phases is similar across cases, but subsequent phases exhibit increasing dissimilarity as the ecosystem evolves and takes on idiosyncratic characteristics. To explain these findings, I develop an ecosystem perspective that explicitly integrates value co-creation processes as an important regulator of the evolution of ecosystems. I suggest that idiosyncratic logics of value co-creation result in differing value creation processes. I show that the three distinct phases of ecosystem emergence form a coherent, distinctive whole when considered from the perspective of value co-creation. Emphasising that value appropriated must first be co-created, I propose the ‘ecosystem model’ as an analytic tool to better conceptualise value co-creation and appropriation in ecosystems. I discuss the implications of these contributions for ecosystem research, institutional theory, and strategic management practice.

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Clay, Larry Clinton Jr. „Integrative Ecosystem Management: Designing Cities and Co-creating the Flourishing Ecosystem“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case162584034740029.

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18

Ehrlich, Julia [Verfasser]. „The role of biodiversity for ecosystem functions in polar sea-ice ecosystems / Julia Ehrlich“. Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2021. http://d-nb.info/1236695062/34.

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19

Cardoso, Tiago Oliveira Machado de Figueiredo. „Proactive services ecosystem framework“. Doctoral thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/7499.

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Dissertation presented to obtain the degree of Doctor in Electrical and Computer Engineering, specialization on Collaborative Enterprise Networks
Collaborative-Networks (CN) have experienced a fast evolution in the last two decades. The collaboration among independent entities or professionals supported by Information and Communication Technology (ICT) has attracted the research community to establish the conceptual basis for this scientific discipline. Service Orientation has been one of the key selected paradigms for that conceptual basis. Nevertheless, the service concept itself does not have a common understanding in the Business and ICT worlds. In the former, client satisfaction, resources management and business process models are some example concerns, whilst the later deals with interoperability, remote function calling or communication protocols. If for example an enterprise provides some service, it may hire specialists to wrap such service into web-services, expecting to reach worldwide potential new clients. In fact, nowadays Web Services and Service Oriented Architectures (SOA) are the technological elements most commonly used. However, these are passive elements in the sense they do not perform any action towards pursuing business interests, which constitute a limiting factor from a business perspective. Another approach for the above mentioned enterprise is to follow the Multi-Agent Systems (MAS) approach, as the pro-activity is a keyword in such contexts. Nevertheless, as MAS approaches are not so commonly used and not so robust yet, the worldwide potential set of new clients is reduced; which also constitutes an inhibitor factor from the business perspective. This dissertation proposes a Pro-Active Services Ecosystem Framework, gathering inspiration from both the SOA and MAS research areas, trying to bridge the business and ICT worlds through the base concepts for the creation of a Services’ Ecosystem where business services are represented in a pro-active manner towards pursuing business interests, like finding collaboration opportunities or improving the chances each CN member has to see its services selected among competitors, for example. This work also includes a prototype system applied / validated in the area of a Professional Virtual Community of Senior Professionals.

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Baruti, Abdala Yussufu. „Biodiversity and ecosystem services“. Thesis, Вид-во СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/8082.

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Petrovich, Olesya. „Ecosystem services providing shelterbelts“. Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/31699.

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In Ukraine, the largest user of natural resources is the agricultural complex. About 60% of the country's lands are used for agricultural purposes. During the years of independence, the system of land use in agriculture has completely changed. Emergence of a large number of owners and lessees of farmland increases the range of stakeholders in Agriculture and Natural Resources. New land users, in most cases, have no agronomic knowledge and take land and agro-ecosystems as a source of quick profits. Farmland cannot be considered only as an economic object, place to work and receive products or food. Fields, pastures, fallow and other farmland with surrounding elements and components of the ecosystem are a dynamic complex of vegetation, animals and microorganisms with nonliving environment interacting as a functional unit. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31699

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Asres, Kidanu Salomon, Yudith Cardinales, Richard Chbeir, Ponte Víctor De, Alejandro Figueroa, Figueroa Rodríguez und Ibañez Carlos Arturo Raymundo. „MMDES: Multimedia Digital Ecosystem“. Computational Science and Engineering, 2016. http://hdl.handle.net/10757/620995.

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19th IEEE International Conference on Computational Science and Engineering (CSE 2016), is the event, in a series of highly successful International Conferences on Computational Science and Engineering, held mainly as the International Workshop on High Performance Scientific and Engineering Computing for 11 editions. August 24-26, 2016 - Paris, France
Currently multimedia contents dominate the information exchanged in Internet, particularly through social networks. Each actor on the Internet becomes producer and consumer of contents. Nevertheless, social network and other traditional collaborative environments present limitations regarding content selection, categorization, aggregation, linking and interoperability, and usage control and privacy. In [1], we proposed the architecture (based on a peer-to-peer infrastructure and Semantic Web) of a MultiMedia Digital EcoSystem (MMDES), as a new environment for collaboration and sharing of multimedia resources, multimedia processings, as well as for computing and storage capabilities. In this paper, we describe MMDES framework and functionalities related to managing the collective knowledge and equilibrium in MMDES. We also describe the implementation of MMDES using a mobile platform in order to provide resources’ sharing for the Archivo Nacional de Arte Rupestre (ANAR) in Venezuela

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Le, Page Sophie. „Understanding the Phishing Ecosystem“. Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39385.

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In “phishing attacks”, phishing websites mimic trustworthy websites in order to steal sensitive information from end-users. Despite research by both academia and the industry focusing on development of anti-phishing detection techniques, phishing has increasingly become an online threat. Our inability to slow down phishing attacks shows that we need to go beyond detection and focus more on understanding the phishing ecosystem. In this thesis, we contribute in three ways to understand the phishing ecosystem and to offer insight for future anti-phishing efforts. First, we provide a new and comparative study on the life cycle of phishing and malware attacks. Specifically, we use public click-through statistics of the Bitly URL shortening service to analyze the click-through rate and timespan of phishing and malware attacks before (and after) they were reported. We find that the efforts against phishing attacks are stronger than those against malware attacks.We also find phishing activity indicating that mitigation strategies are not taking down phishing websites fast enough. Second, we develop a method that finds similarities between the DOMs of phishing attacks, since it is known that phishing attacks are variations of previous attacks. We find that existing methods do not capture the structure of the DOM, and question whether they are failing to catch some of the similar attacks. We accordingly evaluate the feasibility of applying Pawlik and Augsten’s recent implementation of Tree Edit Distance (AP-TED)calculations as a way to compare DOMs and identify similar phishing attack instances.Our method agrees with existing ones that 94% of our phishing database are replicas. It also better discriminates the similarities, but at a higher computational cost. The high agreement between methods strengthens the understanding that most phishing attacks are variations, which affects future anti-phishing strategies.Third, we develop a domain classifier exploiting the history and internet presence of a domain with machine learning techniques. It uses only publicly available information to determine whether a known phishing website is hosted on a legitimate but compromised domain, in which case the domain owner is also a victim, or whether the domain itself is maliciously registered. This is especially relevant due to the recent adoption of the General Data Protection Regulation (GDPR), which prevents certain registration information to be made publicly available. Our classifier achieves 94% accuracy on future malicious domains,while maintaining 88% and 92% accuracy on malicious and compromised datasets respectively from two other sources. Accurate domain classification offers insight with regard to different take-down strategies, and with regard to registrars’ prevention of fraudulent registrations.

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Gunasekara, Sandya Nishanthi. „Governance of the bay of Bengal large marine ecosystem through ecosystem-based fisheries management“. Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/213832/1/Sandya%20Nishanthi_Gunasekara_Thesis.pdf.

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This thesis assessed the current prospect for implementing an ecosystem-based management for fisheries (EBFM) in the Bay of Bengal Large Marine Ecosystem from national and regional level perspectives. A central result of the study is that the governance concept had been defined and used imprecisely in the literature. The way the different elements constitute EBFM revealed that both Bay of Bengal LME countries and existing regional fisheries organisations are unlikely to satisfy all the elements on the EBM checklist. The study also observes that the Bay of Bengal countries do not share a common understanding of EBFM.

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Singh, Gerald Gurinder. „Effects of sea otters on nearshore ecosystem functions with implications for ecosystem services“. Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30488.

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Sea otters are nearshore predators whose impacts have potential implications for the provision of ecosystem services on the west coast of Vancouver Island. Sea otter predation on herbivorous sea urchins can allow kelp beds to flourish. Increased kelp production can act as a food subsidy to mussels which can promote faster growth. Otters also depredate mussels, which can affect the habitat provision function of mussels and limit them to sizes that are vulnerable to other predators. In this thesis I describe two empirical studies that explore these possible effects of otters on ecosystem processes that have implications for ecosystem services. First I investigate the impact of greater kelp productivity on carbon flow and productivity by using stable isotope analysis on kelp, water samples, and mussels in regions where otters are absent and present. I observed that mussels do not consistently assimilate higher proportions of kelp-derived carbon and do not grow faster where otters are present and kelp more abundant. This finding may be explained partly because kelp does not seem to be limiting for mussel diets where otters are absent – high observed phytoplankton biomass may dilute the kelp-derived carbon assimilated in mussel tissue. The second study explores the impact of otters as predators of mussels by sampling mussel bed characteristics in regions along a gradient of time since otters established. Mussel bed characteristics vary predictably between regions: e.g., depth and biomass are lower in regions of comparably higher otter influence. Aggregate community biomass is also lower where otters are present, and differences in dominant species may drive differences in community structure between regions. By restricting mussels to smaller sizes, otters may also subject a greater proportion of mussel growth to predation by seastars, potentially facilitating a greater proportion of energy flow through marine food webs. Otter may increase secondary productivity only where primary productivity is limiting, and they seem to constrain the habitat provisioning services of mussels. This study’s quantitative characterization of otter impacts on an ecosystem engineer (mussels), and the intertidal habitat they provide, complements existing studies of otter impacts on subtidal ecosystem processes that affect ecosystem services.

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Roy, Eric Daniel. „Modeling Interactions Between Environmental Management and Ecosystem Services in a Dynamic Freshwater Ecosystem“. The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218487995.

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Igu, Nwabueze. „Freshwater swamp forest ecosystem in the Niger Delta : ecology, disturbance and ecosystem services“. Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/15511/.

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Freshwater swamp forests are wetland ecosystems of global importance, especially because they provide very valuable ecosystem services such as regulation of flood and maintenance of water quality, and provide suitable habitat for the conservation of wetland ecosystems (flora and fauna). Though they are hosts to important biodiversity as in other tropical ecosystems, their ecology, function and contribution to ecosystem services are poorly understood. With poor baseline data on this threatened ecosystem across the Niger Delta region and the entire West African region, this thesis explores its ecology, biogeography and the capacity to which this ecosystem sequester carbon, in a bid to better prioritize and inform effective conservation and management. Floristic compositions of the ecosystem were varied in density, diversity and rarity across undisturbed, disturbed and transition (mangrove-freshwater) zones. A total of 138 species within 100 genera and 41 families of taxa were identified across the 24 one hectare forest plots; with variations in dominance according to each of the zones. With a stem density which ranged from 94 – 506 stems ha-1, the ecosystem was seen to be comparable with other tropical forest ecosystems, but were poorer in species richness as a result of the environmental constraints associated with the swamp. Though disturbance (local factors) influenced the pattern of species distribution to a great extent, environmental (regional factors) equally contributed to this variation. Above ground carbon estimates (AGC) were also similar to other African forest ecosystems, with the estimates varying at the plot level mainly due to disturbance gradients. Other variables that contributed to AGC variations included the floristic composition (which were found to be more carbon dense towards the transition zones), tree structure and climatic variables. Other ecosystem services derived from the ecosystem (timber and non-timber forest products) were found to be a major source of sustenance and income generation at varying levels. Household usage and dependence on the forests were mainly influenced by the degrees of remoteness of each community, and whether each of the households had other alternative sources of livelihood. With a poor perception of decline in ecosystem services with usage, the forests has steadily shrunk and degraded.

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Ford, Hilary. „Biodiversity, ecosystem function and ecosystem service provision in saltmarsh and sand dune grasslands“. Thesis, Bangor University, 2012. https://research.bangor.ac.uk/portal/en/theses/biodiversity-ecosystem-function-and-ecosystem-service-provision-in-saltmarsh-and-sand-dune-grasslands(d96624cd-2324-40db-9ce8-ee30ada754fc).html.

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Coastal grasslands, such as salt marshes and sand dunes, provide many important ecosystem services including 'supporting services' (soil formation, primary productivity and nutrient cycling), 'provisioning services' (fresh water supply, food and fibre products, biochemical or genetic resources), 'regulating services' (equable climate, pollution control, flood prevention, invertebrate pollination and pest regulation) and 'cultural services' (recreation, education and aesthetic appreciation). Historically, salt marsh and sand dune grasslands were commonly used as agricultural livestock grazing land. Currently, some of these coastal grasslands are 'conservation grazed' (i.e. extensively grazed to maximise plant diversity and to provide a suitable habitat for over-wintering bird species), others have been 'abandoned' (i.e. large herbivores removed) due to the removal of agricultural subsidies or remain historically 'un-grazed'. Grazing management of coastal grasslands influences biological and physical habitat characteristics, ecosystem function, biodiversity and ecosystem service delivery. Understanding the impact of grazing is therefore vital to enable future robust management recommendations. Biodiversity is often used as an indicator of ecosystem health and ecosystem service provision with conservation priorities allocated accordingly. It is therefore essential to critically assess just how important biodiversity is to the provision of ecosystem services within a wide range of habitats. The review chapter draws together evidence for this argument from salt marsh and sand dune habitats with the conclusion that functional diversity and composition are more important than biodiversity per se (Chapter 2). The experimental chapters of this thesis deal with the impact of grazing upon temperate salt marsh and sand dune grassland biodiversity and ecosystem service provision. 'Grazed' (cattle grazed < 8 cm) and historically 'un-grazed' upper salt marsh plots were compared. 'Fully grazed' (ponies 0.2 ha⁻¹, cattle 0.05 ha⁻¹ and rabbits 45 ha⁻¹), 'rabbit grazed' and 'un-grazed' (for 8 years) fixed sand dune grassland plots were also evaluated. Firstly, how grazing management affected ecosystem service provision of sand dune grassland was examined, by measuring a wide range of biophysical variables as proxies for ecosystem services (Chapter 3). 'Supporting' and 'regulating' services were provided predominantly by the un-grazed, 'provisioning' and 'cultural' services by the extensively grazed grassland. Secondly, the impact of short sward cattle grazing on the abundance, composition and diversity of the ground dwelling invertebrate community of an upper salt marsh was assessed using pitfall traps (Chapter 4). The findings showed that both cattle grazed and un-grazed saltmarsh habitat should be maintained to maximise invertebrate abundance and diversity and provide suitable habitat for coastal specialists. Thirdly, greenhouse gas emissions from grazed and un-grazed salt marsh were measured monthly for one year. Additionally, below-ground gas sampling tubes were used to measure soil methane concentrations (Chapter 5). Carbon dioxide efflux was greater from the un-grazed marsh soil but 'hotspots' of methane efflux were only found on the grazed marsh. Finally, the influence of grazing on the soil microbial community of both salt marsh and sand dune grasslands was measured by microbial biomass (fatty acid phospholipids: PLFAs), bacterial growth rate (Leucine incorporation) and respiration rates (Chapter 6). Microbial biomass, PLFA markers and bacterial growth rate were all influenced by grazing management. In summary, this work concludes that grazing management clearly affects biological and physical habitat characteristics, biodiversity, ecosystem function and ecosystem service delivery (Chapter 7). Management of coastal grasslands evidently involves trade-offs between biodiversity conservation and multiple ecosystem service provision.

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Pan, Yuan. „Using an ecosystem services approach to protect freshwater ecosystems : linking ecology, ecotoxicology and cultural values“. Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19656/.

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Gomez, Yannick. „Le rôle et les motivations d’une firme leader dans l’essai de transformation de son écosystème d’affaires en écosystème de l’innovation : le cas du site de Marcoule et du démantèlement nucléaire“. Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE3037.

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L’américain James MOORE a été le premier à évoquer le concept d’écosystème d’affaires dans un article de 1993 et dans un ouvrage paru en 1996. Plusieurs questions théoriques nous paraissent cependant devoir être complétées : - La place et le rôle d’une firme leader au sein d’un écosystème d’affaires - La question du cycle de vie d’un écosystème d’affaires - L’apparition du terme « écosystème de l’innovation » et son positionnement par rapport à ce concept d’écosystème d’affaires. Pour étudier ces différentes questions de recherche, nous avons observé durant une longue durée l’évolution de la plate-forme nucléaire de Marcoule. En 2013, le CEA Marcoule a lancé l’initiative du Pôle de Valorisation des Sites Industriels. L’objectif de la firme leader est donc de transformer son écosystème d’affaires en écosystème de l’innovation.Dans la première partie de l’étude de cas, nous avons étudié les motivations de la firme leader pour transformer son écosystème d’affaires en écosystème de l’innovation.Le démantèlement nucléaire conduit à sept grands paradoxes (humain, contractuel, déchets, sûreté, financier, territorial, technologique). Le cas Marcoule démontre que si les paradoxes sont majeurs, l’entreprise peut ne pas trouver en interne, par ses propres forces, les moyens d’y répondre. Certains paradoxes imposent des innovations d’exploration sur les plans conceptuels, managériaux et technologiques.La deuxième partie de l’étude de cas a été consacrée à l’étude du rôle du CEA Marcoule, leader de l’écosystème d’affaires territorial, pour transformer celui-ci.Dans ce cadre, nous avons pu observer et décrire trois actions concrètes d’enrôlement des acteurs, dans l’objectif de promouvoir une dynamique d’innovation :- La traduction marché de la montée en gamme de l’écosystème - La création d’un objet-frontière autour de la labellisation écosystèmique - L’ouverture de l’innovation Cette phase d’observation des actions d’enrôlement initiées par le leader de l’écosystème s’est déroulée durant la période de 2013 à mi 2017. Nous avons pu observer les débuts prometteurs de l’initiative PVSI et l’enrôlement réussi des acteurs autour des premiers projets lancés. L’observation du terrain de recherche Marcoule à travers le prisme de notre cadre conceptuel, la sociologie de la traduction, permet de mettre en évidence deux résultats importants.En premier lieu, l’étude du cas Marcoule nous permet de compléter l’approche théorique sur le cycle de vie d’un écosystème d’affaires, en particulier sur la notion d’intentionnalité. En effet, les changements de phase, de la naissance à l’expansion, de l’expansion à l’autorité et de l’autorité au déclin, ne résultent pas des actions prévisibles d’acteurs déterminés par la biologie, mais résultent des intentions stratégiques d’acteurs intelligents. Cette approche nous permet de proposer un nouvelle vision du cycle de vie d’un écosystème d’affaires : Naissance  Expansion  Transformation en écosystème de l’innovation  Déclin et MortEn second lieu, l’observation du cas Marcoule et de la firme leader de son écosystème d’affaires territorial permet de compléter les travaux académiques qui existent sur l’articulation des différentes formes d’ambidextrie. Le cas étudié permet ainsi de mettre en évidence l’existence d’une concurrence ambidextrielle pour l’allocation des ressources qui s’appuie sur l’instrumentalisation des paradoxes internes à l’organisation
The American James MOORE was the first to discuss the concept of business ecosystem in an article from 1993 and in a book published in 1996. Several theoretical questions seemingly need to be completed:- The place and role of a leading firm within a business ecosystem - The question of the life cycle of a business - The emergence of the term "ecosystem of innovation" and its positioning in relation to the concept of business ecosystem.In order to study those different research questions, we have observed for a long time the evolution of the nuclear platform of Marcoule. In 2013, the CEA Marcoule launched the Industrial Sites Valorisation Pole initiative, which aims to promote the upgrading of the ecosystem. The objective of the leading firm is therefore to transform its business ecosystem into an ecosystem of innovation. In the first part of the case study, we studied the motivations of the leading firm for transforming its business ecosystem into an innovation ecosystem.Nuclear dismantling leads to seven major paradoxes (human, contractual, waste, safety, financial, territorial, technological). The case of Marcoule demonstrates that if the paradoxes are major, the company may not find, internally, by its own forces, the means to respond. Some paradoxes impose innovations of exploration on the conceptual, managerial and technological levels. The second part of the case study was devoted to the study of the role of the CEA Marcoule, leader of the territorial business ecosystem in order to transform it. Then we observed and described three concrete enrolment actions of the actors,- The translation on the market of the ecosystem upgrading- The creation of a frontier object around ecosystem labelling- The opening of the innovation This phase of observation of the enrolment actions initiated by the leader of the ecosystem took place during the period from 2013 to mid 2017. We were able to observe the promising start of the PVIS initiative and the successful enrolment of the actors around the first projects that were launched. The observation of the Marcoule research field through the prism of our conceptual framework, the sociology of translation, makes it possible to highlight two important results.First, the study of the Marcoule case allows us to complete the theoretical approach on the life cycle of a business ecosystem, in particular on the notion of intentionality. Phase changes - from birth to expansion, from expansion to authority and from authority to decline - do not result from the foreseeable actions of actors determined by biology, but are the result of the strategic intentions of intelligent actors who continually calculate the gains and losses they can derive from their participation in the business ecosystem.We suggest replacing the traditional life cycle of a business ecosystem proposed by James MOORE (Birth  Expansion  Authority  Renewal  Decline and Death) by the following sequence (Birth  Expansion  Transformation in ecosystem of innovation  Decline and Death).Secondly, the observation of the Marcoule case and the leading firm of its territorial business ecosystem completes the academic work that exists on the articulation of different forms of ambidexterity. The CEA/Marcoule case shows us that all the implemented ambidextrous actions were legitimised by highlighting the problems needing to be solved, linked to the paradoxes of nuclear dismantling. purchasing needs to achieve a competition respecting all the rules of the public procurement

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Bas, Silvestre Maria. „Ecosystem functioning of Mediterranean confined coastal lagoons: ecosystem metabolism, main drivers and phytoplankton community“. Doctoral thesis, Universitat de Girona, 2021. http://hdl.handle.net/10803/673080.

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Confined coastal lagoons are shallow and dynamic water bodies that play an important ecological role. Considering the severe degradation they have been facing in the last years, understanding the functioning of these habitats for their proper management and conservation is essential. Nowadays, one of the most important descriptors of ecosystem functioning is the metabolism, the use of which has increased with the application of the free dissolved oxygen (DO) technique and the development of more affordable and reliable sensors. Quantifying metabolic rates as well as identifying the factors that contribute to their temporal and spatial variation are very important in assessing these ecosystems behaviour and their response to future changes. Thus, the aim of the thesis was to estimate the ecosystem metabolism of a set of Mediterranean confined coastal lagoons in La Pletera salt marsh identifying the main drivers of its variation and its application to study phytoplankton
Les llacunes costaneres mediterrànies de tipus confinat són cossos d’aigua poc profunds i dinàmics, amb un paper ecològic molt important. Davant la regressió que han patit durant els darrers anys, entendre el funcionament d’aquests habitats per una correcta gestió i conservació esdevé fonamental. Avui dia, un dels descriptors més importants del funcionament ecosistèmic és el metabolisme, l’ús del qual s’ha incrementat amb l’aplicació de la tècnica de l’oxigen lliure i el desenvolupament de sensors cada cop més assequibles i fiables. La quantificació de les taxes metabòliques i la identificació dels factors que contribueixen a la seua variació temporal i espacial són molt importants per avaluar el comportament dels ecosistemes i la seua resposta a futurs canvis. Així, l’objectiu d’aquesta tesi va ser estimar el metabolisme ecosistèmic d’un conjunt de llacunes costaneres mediterrànies confinades a la maresma de la Pletera, identificar els seus principals factors de variació i la seua aplicació per estudiar el fitoplàncton
Programa de Doctorat en Ciència i Tecnologia de l'Aigua

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Antypas, Alexios R. „Translating ecosystem science into ecosystem management and policy : a case study of network formation /“. Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/5485.

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Kwayu, Emmanuel Jonas. „The potential of agro-ecosystems payments for ecosystem services to provide ecosystem services and poverty reduction in developing countries : a case study of the EPWS program in Tanzania“. Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15716/.

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This thesis investigates the effectiveness of agro-ecosystem based PES programs to provide ecosystem services and achieve poverty reduction. A case study from Tanzania known as the “equitable payments for watershed services (EPWS) program” piloted between 2008 and 2012 in Morogoro region has been used as the basis for an in-depth empirical study of an agro-ecosystem based PES program. The case-study approach has combined mixed methods quasi experimental research design and propensity score matching technique to prioritise attribution of the livelihood and environmental outcomes of the intervention, which remain under-utilized in evaluation of conservation interventions. The thesis findings provide insights that while the poor can participate in agro-ecosystem PES programs, their participation can be hindered by initial investment costs of inputs such as on manure, improved seeds, hoes and spades. Farm size, farmers’ access to information, participation in the design phase, and the change in farm management required by the program are significant determinants of program participation. Also, while PES payments contribute to local livelihoods, the indirect financial and non-financial benefits provide greatest contributions to livelihoods. In relation to additionality impact, program participation increases the number of sustainable land management practices and land under agro-forestry and reforestation amongst program participants. Furthermore, expected benefits such as crop yields from constructed terraces and manure, fire wood and timber products from agro-forestry and afforestation interventions are likely to increase the life span of the practices. The design of agro-ecosystem PES programs should include upfront payments in addition to other incentives which should be made timely in phases to ensure compliance. Local training and paraprofessional, external training and both enhancement of local formal and informal rules are essential to enhance the adoption of practices and to stop illegal activities such as forest reserve encroachment, illegal logging and fire.

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Behl, Stephan. „Diversity effects on ecosystem processes“. Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-147384.

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Lejon, Anna G. C. „Ecosystem response to dam removal“. Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55586.

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This thesis aims to improve our understanding of how riverine ecosystems respond to dam removal. Riverine and particularly riparian ecosystems are among the most variable and important features of all landscapes. They connect landscape elements both longitudinally and laterally, and are governed by processes such as flooding, erosion and deposition that create dynamic, diverse and heterogeneous habitats. In fact, riparian zones are among the world’s most species-rich habitats. Worldwide there are millions of dams that fragment stream and river systems, regulate flows and degrade ecosystems. Dams impact freshwater, marine and terrestrial ecosystems and threaten biodiversity by disrupting organism movements and energy flows in the landscape. An important upstream effect of dams is inundation of habitats and development of new shorelines around impounded areas. Effects downstream of dams are mainly caused by changed hydrological regimes and retention of organic and inorganic materials in reservoirs, leading to reduced transport and dispersal of for example seeds to reaches downstream. The removal of dams create expectations that biota will eventually recover. We have studied a number of dam removal projects in Sweden. Our experimental results showed that following dam removal, newly exposed soils in former impoundments were rapidly colonized by pre-removal species. Their species richness increased slightly with time and their species composition indicated a slow change towards that in the reference site. In addition, the vegetation in formerly impounded areas showed a direction of change from lentic riparian plants (high proportion of aquatics) towards lotic ones, consisting of native perennials typical of free-flowing streams. We also found that the apprehensions that former impoundments would turn into pools of mud did not come true; in fact, a process towards more pristine channel morphology was observed. After removal there was erosion and downstream transport of sediment. We found only minor effects on macroinvertebrate communities. For example, a few species decreased over the years, suggesting that dam removal in itself might cause a temporary disturbance. This highlights the importance of long-term studies after dam removal, and also the importance of comparisons with pre-removal conditions and stretches unaffected by dams. Thorough documentation of executed dam removal projects and distribution of the results and experiences are tremendously important in the planning process of future decommissioning projects. Also, our experiences have taught us that in order to attain a successful dam removal it is important to involve stakeholders such as non-governmental organizations and local inhabitants in the process.

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Giannoutakis, Konstantinos N. „Studying a digital business ecosystem“. Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445346.

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Kadykalo, Andrew. „Evaluating and Predicting Ecosystem Services“. Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26087.

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The valuation of ecosystem services requires first and foremost, that the current level or stock of a service first be estimated. Here, I investigate the relationship between the fields of environmental science and ecological economics in their research effort of ecosystem services and the implications this may have on the ecosystem valuation research program. I investigate two ecological functions described as ecosystem services within specific ecosystem types: the flood control provisioning services of wetlands and pollination service provisioning by pollinator populations in agroecosystems. I examined the environmental literature to provide quantitative estimates of a) the distribution of the level of service delivered as well as b) the ability of environmental scientists to predict this level of service. The results presented here suggest a moderately strong correlation between research efforts in environmental science and ecological economics at the pooled level of ecosystem types and services. I suggest however, an integrated research enterprise between social and environmental scientists may provide greater efficiency by means of a global ecosystem service research network and repository. I found that, on average, consistent with conventional wisdom, wetlands do indeed have a positive effect by reducing the frequency and magnitude of floods, increasing low flows, and increasing water storage. In the same vein, I found on average and consistent with conventional wisdom, there is a consistent and comparatively strong association between pollinator abundance and agroecosystem productivity as inferred from measures of plant fertilization success. In both investigations however, metaregression analysis indicated that our current ability to predict either pollination or flood control services is poor to modest at best. The low predictive power combined with the observed heterogeneity in effect size in both investigations suggest that flood control service delivered by wetlands or pollination services delivered by natural pollinator populations in agroecosystems and the expected changes in the level of services delivered under a candidate management scenario, will have a large uncertainty. Such uncertainty should be explicitly incorporated into estimates of both the current economic value of ecosystem services, as well as estimates of how these values are likely to change under alternative management scenarios. Given these, I suggest that the implications for the development of Market-based instruments (MBIs) or any payment of ecosystem services to conserve ecosystem services: that the associated ecological function(s) must be few and well characterized, and we must agree on what endpoints ought to properly be used to characterize these functions. If this condition is not met, an ordinal ranking is the best we can do and in the absence of obvious enthusiasm for more detailed scientific research which leads to the conclusion that perhaps alternate strategies like command and control may be the better alternative to protect ecosystem services.

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Stoughton-Jackson, Courtney. „Maintaining a hill prairie ecosystem“. Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1061874.

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Fire has been an important influence on the structure and health of the North American grasslands for hundreds of years. In Jersey County Illinois, two natural loess hill prairies were studied to compare the effectiveness of varying management regimes. The purpose was to determine how a burn vs. a nonburn management regime enhances or hinders the establishment of the prairie grasses and forbs in a tallgrass hill prairie ecosystem. The variables studied included: the vegetational abundance, the frequency, and the biomass of the species that were present. In addition the soil's organic matter content and pH were measured. Overall, the Fire Road Prairie, or the unburned prairie, proved to be the community that was deteriorating and becoming unproductive. Whereas, the Osage Prairie contained a balance of grasses and forbs that were representative of a healthy and thriving community. The data supported the existing theory that a burn management plan does help the overall stability and productivity of a tallgrass ecosystem.
Department of Natural Resources and Environmental Management

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Staples, Juliet. „Ecosystem management in navigated waters“. Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317246.

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Aldridge, D. R. „Suicidal behaviour : An ecosystem approach“. Thesis, Open University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371025.

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41

De, Schryver Vera. „Mixotrophy and pelagic ecosystem dynamics“. Thesis, Brest, 2013. http://www.theses.fr/2013BRES0045/document.

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Les espèces protistes ont été traditionnellement classifiées comme des plantes ou des animaux en raison de l’absence ou présence des chloroplastes. L’état actuel de la connaissance indique qu’un grand nombre d’espèces protistes portent des chloroplastes mais que physiologiquement elles sont capables d’utiliser l’autotrophie (photosynthèse) ou l’hétérotrophie pour se nourrir. La combinaison de ces deux modes trophiques par une même cellule est nommée mixotrophie. Chez les protistes l’hétérotrophie peut s’effectuer soit par la consommation des particules par phagocytose, e.g. des proies bactériennes, ou bien par l’absorption des composants organiques dissouts, i.e. osmotrophie. La mixotrophie est de plus en plus décrit chez les protistes dans tous les habitats aquatiques. Les écologistes du plancton constatent la récurrence de la mixotrophie chez les formes traditionnelles « phyto»plancton et micro »zoo »plancton. Cependant, identifier et quantifier la mixotrophie reste toujours un défi méthodologique. Dans cette étude nous nous sommes intéressés à la mixotrophie chez les espèces phytoplanctoniques marines, en particulier à leur nutrition phagotrophique de proies bactériennes. Nous avons testé des techniques modernes afin d’identifier la mixotrophie dans des cellules phytoplanctoniques. La technique cytogénétique d’hybridation in situ Card-FISH en utilisant de sondes d’ARN ribosomique 16S a été effectuée suivant des protocoles existant pour des bactéries et des protistes. Cette technique s’est avérée être un outil précieux pour visualiser des groupes phylogénétiques bactériens en association avec le phytoplancton à l’aide de la microscopie à épifluorescence, sans avoir besoin d'un isolement préalable des cellules ou des interférences avec l'association microbienne. Cependant, la méthode a échoué pour visualiser mixotrophie chez le phytoplancton car la sonde eubactérienne générale(EUB338) combine une large gamme d'espèces phytoplanctoniques, ce qui rend impossible de discriminer les signaux fluorescents provenant de tissus bactérienne ou phytoplanctonique. Le contexte de ces études est le phytoplancton et les bactéries hétérotrophes lesquels constituent des principaux concurrents pour les nutriments inorganiques dissouts. Dans le cas où la croissance bactérienne est limitée par le carbone, l'augmentation de la concentration de carbone organique dissous(DOC) renforce la croissance bactérienne et la consommation de nutriments dissous et ainsi affecte négativement la croissance du phytoplancton autotrophe. Cependant, les consommateurs de bactéries, i.e.phytoflagellés mixotrophes, peuvent être favorisés dans de telles situations car la hausse de DOC donne lieu à l'abondance plus élevé des proies bactériennes.En outre, nos résultats indiquent un potentiel effet positif de la température sur le mode de nutrition hétérotrophe de l’espèce, ainsi qu’une croissante contribution des espèces mixotrophes au sein des communautés de phytoplancton dans des conditions des hautes températures des eaux de surface de la mer
Protist species were traditionally classified morphologically as either „plants“ or „animals“, based on the absence or presence of chloroplasts. State of science is that a high number of protist species carrychloroplasts but are nutritionally able to employ both autotrophy (photosynthesis) and heterotrophywithin a single cell. This combination of autotrophic and heterotrophic mode of nutrition within a single species is named mixotrophy. In protists, heterotrophy can be realized either by the uptake of food particles (e.g. bacterial prey) through phagocytosis or by the uptake of dissolved organic compounds (i.e.osmotrophy). Mixotrophy is globally and increasingly described in protists from all types of aquatic habitats. Plankton ecologists nowadays assess mixotrophy among the traditionally typified “phyto”plankton and mikro”zoo”plankton species as regularity. Nevertheless, detection and quantification of mixotrophy is still a methodological challenge. In this study, we focused on mixotrophy in marine phytoplankton species and put emphasis on its phagotrophic nutrition from heterotrophic bacterial prey. State of the art methodology was tested to visualize mixotrophy in single phytoplankton cells. Catalyzedreported deposition-fluorescence in situ hybridization (Card-FISH), using 16S ribosomal RNA probes,was employed based on existing protocols for bacteria and protists. The method proved to be a valuable tool to visualise bacterial phylogenetic groups in association with phytoplankton by epifluorescence microscopy without need for prior isolation of cells or interference with the microbial association.However, the method failed to visualize mixotrophy in phytoplankton since the general eubacterial probe(EUB338) hybridised a broad range of phytoplankton species making it impossible to discriminate fluorescent signals originating from bacterial or phytoplankton tissue. Background of these studies is phytoplankton and heterotrophic bacteria being major competitors for dissolved inorganic nutrients. In case that bacterial growth is carbon limited, increasing concentrations of degradable dissolved organic carbon (DOC) enhance bacterial growth and consumption of dissolved nutrients and there by negatively affect autotrophic phytoplankton growth. Bacteria consuming mixotrophic phytoflagellates, however, may gain in importance in such situations since DOC provokes higher bacterial prey supply.In addition, our results indicate a potential positive effect of temperature on O. minima´s heterotrophic nutrition mode, and indicate a potential increasing contribution of mixotrophic species to phytoplankton communities under increasing sea surface water temperatures

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Qiu, Peipei S. M. Sloan School of Management. „Build Alipay ecosystem in Brazil“. Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/117940.

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Thesis: S.M. in Management Studies, Massachusetts Institute of Technology, Sloan School of Management, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 35-37).
Digital payment has proven to be an effective tool to narrow the gaps in financial inclusion. In this area, China has outperformed most developed countries, with Alipay taking the leading role. After achieving critical mass in the domestic market through building a comprehensive ecosystem, Alipay, like many other Chinese tech giants, is also considering expanding its reach into the global market. Among emerging countries, Brazil stands out as being an ideal target for many reasons. Currently, large portions of Brazilian population and a significant number of small businesses are underserved by a concentrated and highly profitable banking system. Additionally, the domestic Brazilian FinTech market is still nascent and fragmented. By building up an Alipay-like payment ecosystem in Brazil, Alipay could create synergy with the local financial system and enable players and users to capture more value from it. This study analyzes the dynamics and structure of Alipay's ecosystem, decodes the key drivers of its success in China and reviews some of its first experiments in the global market. This study also assesses the FinTech market in Brazil by evaluating opportunities Alipay could capture, and risks and challenges it has to take into consideration. This study also includes an analysis of Alipay's Artificial Intelligence development domestically and internationally. Finally, this study develops strategic suggestions for Alipay to enter the Brazilian market.
by Peipei Qiu.
S.M. in Management Studies

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Cranford, Matthew. „Positive incentives for ecosystem services“. Thesis, London School of Economics and Political Science (University of London), 2014. http://etheses.lse.ac.uk/990/.

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Use of payments for ecosystem services (PES) has grown around the world in recent years. Although there has been extensive discussion of how best to define PES and what is PES or ‘PES-like’, at the core of all definitions and all PES programmes is the delivery of a positive incentive to induce socially preferred environmental behaviour. Despite this, research on PES design has to date focused more on broader policy design than on incentive choice and design. In the developing world, PES are broadly perceived as a useful tool for environmental policy, but it is here that a continuing proliferation of programmes is occurring in many varied contexts. That has motivated a variety of approaches to be taken to PES, and prompted revisionists to call PES ‘incentives’, ‘rewards’, ‘compensation’, or something else besides ‘payments’. There are two primary academic objectives of this Ph.D. The first is to conceptualise PES as a broad category of positive incentives and explore the variation within that category. That is done through a) a conceptual review of PES; b) a review of empirical research on incentive design for PES; and c) an empirical study creating a typology of PES. The literature review also highlights a few key considerations for incentive design relevant to developing country contexts that have not yet been adequately addressed. The second objective of the Ph.D. is to contribute, albeit in a small way, to addressing those key considerations through three empirical studies. The contribution of this work to academic knowledge is twofold: 1) Through literature reviews and empirical methods, this paper offers an overarching synthesis of conceptualising and researching PES as incentives, and 2) it explores a few specific, novel ideas in incentive design to help adapt PES to the contexts in which it is applied.

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Johansson, Linnea. „Ecosystem Learning Center in Umeå“. Thesis, Umeå universitet, Arkitekthögskolan vid Umeå universitet, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-148582.

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Davis, Zachary Edward. „Toward A Healthcare Services Ecosystem“. Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/82853.

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This research examines the healthcare services ecosystem and the impact and role service interventions made by providers and patients have on this ecosystem. Each area has an important role in contributing to the value and sustainability of the ecosystem. Healthcare, as a community service, requires a minimum of two counterparts: the providers and the customers, in this case the patients. Healthcare is a unique ecosystem because often the customers are not conscious of the interplay of the ecosystem but are reliant upon the system for their health and wellbeing. The first section of this dissertation examines the effects that occur in the healthcare ecosystem when part of the system experiences a disaster and the impact and role of other areas of the system in response to the disaster, particularly regarding the resilience. Similar to a biological ecosystem that is undergoing a flood, in the healthcare services ecosystem if too many patients present to the Emergency Department (ED) at the same time disaster level overcrowding will occur. We aim to measure the resilience of the healthcare ecosystem to this disaster level overcrowding. The second section of this dissertation examines how the components of the healthcare ecosystem maintain sustainability and usability. Healthcare professionals are assessed regarding their ability to maintain the healthcare ecosystem, with a specific focus on what occurs after patients are in the hospital system. To examine the ability of the healthcare professionals to maintain the ecosystem we analyze the usability and adaptability of the electronic health record and the professional's workflows to determine how they use this tool to sustain the healthcare ecosystem. The third section of this dissertation examines patient self-management and the influence this has on the healthcare ecosystem. Much of the management of health in patients, particularly those with chronic illnesses, occurs outside of the hospital, thus examining this aspect of self-care provides insight on the overall system. This research examines patients with a chronic illness and their use of online health communities, with a particular focus on their reciprocal behaviors and the impact this support system has on their overall health state. By examining these aspects of the healthcare services ecosystem, we can better improve our understanding of these phenomena.
Ph. D.

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Rosado, Joana Isabel Caeiro Condeço. „Ecosystem functioning of temporary rivers“. Doctoral thesis, Universidade de Évora, 2012. http://hdl.handle.net/10174/12178.

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O presente estudo abrange questões relevantes sobre o funcionamento de rios temporários. São abordados diferentes tópicos tais como a problemática da escassez de água particularmente na bacia Mediterrânica, a biodiversidade aquática e ripícola, a dinâmica de nutrientes e fatores fundamentais para a gestão e conservação de rios temporários Mediterrânicos. O principal objetivo é estudar alguns dos processos que ocorrem ao nível da bacia de drenagem e galeria ripícola associada, fazendo sempre a ligação dos resultados obtidos com a importância de uma correta gestão da bacia hidrográfica. Os resultados obtidos demonstraram uma necessidade urgente de implementação de estratégias de gestão adequadas ao nível das bacias hidrográficas de forma a reduzir a vulnerabilidade dos rios temporários. A tese pretende acima de tudo adicionar informação sobre rios temporários dada a sua importante representatividade a nível mundial; ### Ecosystem functioning of temporary rivers Abstract: This research intended to address some relevant issues concerning the functioning of temporary rivers. It will be approached different topics such as water scarcity particularly in the Mediterranean basin, aquatic and riparian biodiversity, nutrients dynamics and key factors in the management and conservation of temporary Mediterranean streams. The main aim is to study some of the processes that occur within the river basin and subjacent riparian gallery, always linking the obtained data with the importance of a correct river basin management. The results showed an urgent need to implement suitable management strategies at river basin level to reduce the vulnerability of temporary rivers. This thesis intends most of all to increase the knowledge on temporary rivers given their important worldwide representativity.

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Ghayur, Adeel. „Latrobe Valley circular industrial ecosystem“. Thesis, Federation University Australia, 2019. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/169979.

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Climate change, energy security, pollution and increasing unemployment in the face of automation are four critical challenges facing every region in the twenty-first century, including the Latrobe Valley in Victoria, Australia. The Valley – location of the largest brown coal deposits and forest industry in the southern hemisphere – is undergoing unprecedented and rapid changes. Its ageing brown coal power plants are retiring and replacements are not planned, leading to job insecurity. Solutions are needed that ensure continued economic activity in the region whilst allowing for the Valley to contribute its fair share in the fight against the climate change. The aim of this study is to investigate a possible local solution that could help tackle these issues of the Latrobe Valley in addition to plastic pollution and energy insecurity. Transitioning from linear to circular materials flow is one possible solution that favours sustainability and job security. Consequently, a multiproduct succinic acid biorefinery is modelled, acting as an industrial hub in a potential Latrobe Valley circular economy. This allows for employment creation in the value-addition of its platform chemicals into carbon negative and environment-friendly products. Additionally, such a biorefinery concept has the capacity to tackle Post-combustion CO2 Capture (PCC) industry’s wastes. It is anticipated that any future utilisation of brown coal as an energy vector would entail PCC to ensure carbon neutrality. A PCC industry produces CO2 and amine wastes that require adequate disposal. The modelled biorefinery has the capacity to valorise both. The simulation and the techno-economic analysis show the modelled Carbon Negative Biorefinery consumes 656,000 metric tonnes (t) of pulp logs and 42,000 t of CO2 to produce 220,000 t of succinic acid, 115,000 t of acetic acid and 900 t of dimethyl ether, annually. Biorefinery’s CAPEX and OPEX stand at AU$ 635,000,000 and $ 180,000,000 respectively. The calculated Minimum Selling Price for succinic acid is $ 990/t, only 6.4% higher than a typical biorefinery. Subsequently, biorefinery’s capacity as an anchor tenant is also simulated via technical evaluations of four value-added products: • Poly(butylene succinate) as biodegradable polymer replacing petro-plastics – simulation results show 1 t of succinic acid produces 0.19 t of tetrahydrofuran and 0.44 t of poly(butylene succinate); • Carbon fibre for insulation products, sporting goods and foams – 1 t of lignin and 0.8 t of acetic anhydride produce 0.8 t of carbon fibre; • Succinylated lignin adhesive for replacing urea-formaldehyde in the wood industry – simulation results show the biorefinery concept having the capacity to valorise both waste amine and CO2 from a PCC plant; and • Renewable fuels like hydrogen as energy vectors – a small biorefinery can potentially provide dozens of gigawatt hours of stored power for backup and peak demands, annually. In summary, results of this research are: • A biorefinery can valorise PCC plant wastes; • Multiproduct succinic acid biorefinery is economically viable; • Renewable fuels are ideally suited as energy storage vectors for a renewable energy grid both in developing and developed countries; • Bioproducts can reduce CO2 emissions thereby mitigate climate change; • Bioproducts can replace petro-products and reduce pollution; • Bioproducts can replace construction industry materials associated with CO2 emissions; • Biorefineries can help a region transition from a linear to a circular economy; and • Circular economies have the potential to generate secure jobs. In conclusion, this research identifies platform biochemicals as potential key drivers in a linear economy’s transition to a circular economy.
Doctor of Philosophy

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Turunen, J. (Jarno). „Responses of biodiversity and ecosystem functions to land use disturbances and restoration in boreal stream ecosystems“. Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526217826.

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Abstract Streams and rivers have been extensively altered by humans. Channelization and land use have changed stream habitats and water quality with adverse effects on biota and ecosystem functions. Impacted streams have been targets for restoration, but there is considerable lack of understanding how streams should be restored in an ecologically effective way. In this doctoral thesis, I studied the impacts of channelization (for timber floating) and agricultural diffuse pollution on stream biota. I also studied the effectiveness of restorations of forestry impacted streams stressed by excessive sand sedimentation from catchment drainage. Finally, I also studied the effects of mosses, fine sediment and enhanced dispersal on stream macroinvertebrate communities and ecosystem functions. I found that channelization did not have effect on diatom, macrophyte, macroinvertebrate and fish assemblages, whereas diffuse pollution had strong effects, with no interactions between the two stressors. I showed that excessive sedimentation from forest drainage was harmful for stream biota but had no effect on leaf decomposition and algal accrual rate. Restoration with boulders reduced sand cover and was more beneficial for in-stream biodiversity, whereas restoration with wood tended to increase hydrological retention of stream channels, thereby altering riparian plant assemblages toward more natural composition. In a mesocosm experiment, I found mosses to have a strong impact on macroinvertebrate communities and ecosystem functions. Mosses increased organic matter retention and reduced algal accrual rate and leaf decomposition. The effect of mosses on macroinvertebrates was stronger than that of sand sedimentation, and mosses mitigated some of the negative effects of sand. Extensive dispersal had a distinct imprint on invertebrate community composition but did not blur the effect of mosses and sand on communities, suggesting strong local-scale environmental control of composition. My thesis emphasizes that priority in stream restoration should be in the mitigation of diffuse pollution rather than restoration of channel morphology, especially in streams where channel alteration has been fairly modest, as in the case of timber floating. Addition of both boulders and large wood likely yields the best biodiversity response in the restoration of forestry impacted streams. Mosses are a key component of boreal lotic ecosystems; therefore, the recovery of mosses may be a prerequisite for the full recovery of biodiversity and ecosystem integrity of boreal streams
Tiivistelmä Ihmisen toiminta on laajasti muokannut virtavesiä. Uomien kanavointi ja maankäyttö ovat muuttaneet virtavesien elinympäristöjä ja veden laatua, millä on ollut haitallisia vaikutuksia virtavesien luonnon monimuotoisuuteen ja ekosysteemin toimintaan. Huonokuntoisia virtavesiä on kunnostettu paljon, mutta ymmärrys siitä, kuinka virtavesiä tulisi kunnostaa parhaan ekologisen lopputuloksen saavuttamiseksi, on edelleen vajaata. Tutkin tässä väitöskirjassa uittoperkausten ja maatalouden hajakuormituksen merkitystä ja yhteisvaikutusta virtavesien eliöyhteisöihin. Tutkin myös kunnostusten vaikutusta hiekasta kärsivissä metsätalouden muokkaamissa puroissa, sekä vesisammalten, hiekan ja eliöiden levittäytymisen merkitystä purojen pohjaeläinyhteisöjen ja ekosysteemin toimintojen muovautumisessa. Havaitsin, että uoman perkauksilla ei ollut vaikutusta virtavesien eliöyhteisöihin, mutta hajakuormituksen vaikutus oli voimakas. Perkauksella ja hajakuormituksella ei ollut yhteisvaikutuksia eliöyhteisöihin. Osoitin, että metsäojituksista aiheutuva ylimääräinen hiekan sedimentaatio on haitallista virtavesien eliöille, mutta sillä ei ollut vaikutusta lehtikarikkeen hajotukseen tai päällyslevien tuotantoon. Kunnostukset joissa käytettiin kiveä vähensivät hiekan peittävyyttä ja olivat hyödyllisempiä uoman eliöstölle kuin kunnostukset, joissa tehtiin puurakennelmia. Puukunnostukset kuitenkin lisäsivät uoman vedenpidätyskykyä ja siten muokkasivat rantavyöhykkeen kasvillisuutta luonnontilaisemmaksi. Havaitsin, että vesisammalilla on voimakas vaikutus pohjaeläinyhteisöjen koostumukseen. Sammalet vaikuttivat ekosysteemin toimintoihin lisäämällä eloperäisen aineksen pidättymistä ja vähentämällä lehtikarikkeen hajotusta ja päällyslevien tuotantoa. Sammalten vaikutus pohjaeläimiin oli voimakkaampi kuin hiekan, ja sammalet kykenivät jopa lieventämään joitakin hiekan negatiivisia vaikutuksia. Eliöiden levittäytymisellä oli selvä vaikutus yhteisöjen koostumukseen, mutta se ei hävittänyt hiekan ja sammalen vaikutusta, mikä viittaa korkeaan ympäristötekijöiden merkitykseen yhteisöjen rakentumisessa. Tutkielmani korostaa, että maatalousjokien tilan parantamisessa hajakuormituksen hallinta tulisi olla ensisijainen kunnostustavoite uoman rakenteen kunnostamisen sijaan. Metsätalouden vaikutuksista kärsivissä puroissa kivi- ja puumateriaalin käyttö samanaikaisesti tuottaa luultavimmin laajimman vaikutuksen purojen monimuotoisuuteen. Sammalilla on merkittävä vaikutus muiden eliöiden yhteisökoostumukseen ja ekosysteemin toimintoihin, joten sammalten palautuminen on tärkeä kunnostustavoite virtavesissä, joissa on luonnostaan paljon sammalkasvustoa

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Wilson, Gregory B. „Ecosystem-Based Management of the Lake Erie Ecosystem: A Survey-Based Approach to Assessment of Management Needs“. Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1302202900.

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50

Eriksson, Björn. „Diversity of ecosystems : Variation in network structure among food webs“. Thesis, Linköpings universitet, Biologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-130467.

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Biodiversity loss is one of the major threats to humanity. This has led to an increasing amount of research on biodiversity on genetic and species levels. Studies of diversity at the ecosystem level has however been neglected. An important aspect of ecosystems is food webs that describe the predation-prey interactions between species. Properties explaining the topological structure of food webs can be used to compare and highlight differences between ecosystems. In the present study, topological network properties are used to compare the diversity of network structures between groups of empirical food webs. Differences between 45 aquatic and 45 terrestrial food webs are compared as well as the effects of species richness on lake network structure diversity. Network structure diversity is measured as the average Euclidean distance from food webs to their group centroid in a multidimensional space of network properties. While the average network structure differs between aquatic and terrestrial food webs, no significant difference in variation is found. For 128 Swedish and 48 North American lake food webs, increasing species richness is shown to decrease network structure diversity. A higher diversity of network structures could potentially indicate a more ways to cope with disturbances or provisions of a higher variety of ecosystem services. Preliminary tests of ecosystem diversity effects on stability were conducted but proved inconclusive.

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Dissertationen zum Thema „Ecosystem“

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