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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Exploring connections in social-ecological systems : The links between biodiversity, ecosystem services, and human well-being in South Africa

Hamann, Maike January 2016 (has links)
A key challenge of the Anthropocene is to advance human development without undermining critical ecosystem services. Central to this challenge is a better understanding of the interactions and feedbacks between biodiversity, ecosystem services and human well-being, which interact in dynamic and complex social-ecological systems. These relationships have been the focus of much work in the past decades, however more remains to be done to comprehensively identify and quantify them, especially at larger scales. In this thesis, a social-ecological systems approach is adopted to investigate connections between biodiversity, ecosystem services and human well-being in South Africa. The country’s high levels of biological and socio-economic diversity, as well as its emerging economy make South Africa an interesting case for exploring these connections. Using data from a variety of public sources, and at different sub-national scales, the thesis first identifies and analyses a variety of bundles of ecosystem service use. Based on these bundles, three social-ecological system archetypes were identified and mapped in South Africa, namely the green-loop (high overall use of local ecosystem services), transition, and red-loop (low overall use of local ecosystem services) systems. Further analysis explored the social and ecological drivers of these patterns, and found the distribution of systems mainly influenced by social factors including household income, gender of the household head, and land tenure. Second, this thesis uses human well-being indicators to construct, analyse and map multi-dimensional human well-being bundles. These bundles were found to spatially cluster across the landscape, and were analysed for congruence with the ecosystem service use bundles. Discrepancies in the expected overlap of ecosystem service use and human well-being were highlighted and concur with findings elsewhere and the ongoing debate in the literature on the impacts of time-lags, indicator choice and scale of these interactions. Third, biodiversity in South Africa was analysed by employing an indicator of biodiversity intactness (BII) at the population level. The BII was found to have declined by 18.3% since pre-industrial times. Biodiversity loss was linked to the potential supply of ecosystem services, as well as human well-being patterns. A potential threshold at 40% biodiversity loss was detected, beyond which population abundances decline sharply. Finally, the thesis examines multiple perspectives on ecosystem services in sustainability research, including the social-ecological systems perspective, and discusses the complementarity of the different perspectives in furthering a deeper understanding of the connections between people and ecosystems. The social-ecological systems perspective employed throughout the empirical work presented in this thesis contributed towards cross-cutting insights, the testing of new kinds of data and the development of new approaches, all of which represent important steps towards unravelling the connections between biodiversity, ecosystem services and human well-being, and contributing to the key Anthropocene challenge of sustainable development. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Manuscript. Paper 4: Manuscript.</p>
32

L'approche socio-écologique appliquée à la gestion côtière : concepts et application / The socio-ecological approach applied to coastal management : concepts and application

Leenhardt, Pierre 15 June 2017 (has links)
Les zones côtières à travers le monde sont soumises à de fortes pressions dues aux changements climatiques globaux, à la destruction d'habitats ou encore à la surexploitation des ressources marines. Ces différentes pressions peuvent induire des changements rapides d'état des écosystèmes caractérisés par de fortes modifications de la biodiversité, avec des écosystèmes entiers cessant de fonctionner dans leur forme courante. En conséquence, la pérennité des biens et des services écosystémiques produits par les zones côtières n'est plus assurée. Il en résulte des perturbations économiques et sociales évidentes pour les populations dont le mode de vie dépend de manière directe ou indirecte de la biodiversité côtière. Afin d'appréhender ces interactions homme-environnement, l'approche socio-écologique est de plus en plus utilisée pour illustrer le rôle de l'Homme sur la dynamique des écosystèmes marins côtiers ainsi que les bénéfices qu'il tire de ces derniers. Cette thèse a pour objectif principal d'explorer les concepts de l'approche socio-écologique appliquée à la gestion côtière. Ainsi, dans le premier chapitre de cette thèse nous résumons les spécificités, les défis et les enjeux de l'approche socio-écologique appliquée à la gestion côtière. Les chapitres 2, 3 et 4 s'intéressent à l'analyse du système socio-écologique et explorent des scénarios exploratoires d'évolution des principaux services écosystémiques du lagon de Moorea en Polynésie française. Enfin, nous discutons des avantages et des faiblesses de notre approche ainsi que des potentiels d'applicabilité en tant qu'outil de gestion des zones côtières. / Coastal areas around the world are under intense pressures from climate change, habitat destruction, and over-exploitation of marine resources. These different pressures can induce rapid changes in the state of ecosystems characterized by strong changes in biodiversity, with whole ecosystems ceasing to function in their current form. As a result, the sustainability of goods and services produced by coastal areas is no longer assured. This results in economic and social disruptions for populations whose livelihood depends directly or indirectly on coastal biodiversity. In order to understand these linked social and environmental interactions, the socio-ecological approach is increasingly used to illustrate the role of humans in the dynamics of coastal marine ecosystems and the benefits it derives from them. However, the majority of current research remains theoretical and few case studies applied to the management of coastal areas test this concept in a transdisciplinary approach. The main objective of this thesis is to fill this gap by exploring the concepts of the socio-ecological approach applied to coastal management. Thus, in the first chapter of this thesis, we summarize the challenges insights and perspectives of the socio-ecological approach applied to coastal management. Chapters 2, 3 and 4 focus on the analysis of the coral reef resource system and explore the social-ecological trade-offs revealed by a set of multiple driver’s scenarios in order to explore the potential evolution of the main ecosystem services of Moorea island lagoon in French Polynesia.
33

Upland landscapes : what do people want, who wants it and can they have it all?

Tinch, Dugald January 2009 (has links)
The objective of this thesis is to investigate the preferences of individuals for the management of upland landscapes in the UK. Environmental valuation techniques are becoming an increasingly important tool in the development of environmental management policy, however, they are not without their detractors. In particular a school of thought, developed from the work of Bentham, takes issue with the behavioural foundations of the dominant welfare economic doctrine which underpins many of the valuation techniques commonly adopted. They identify that heuristic rules, experience and memory can all play a role in the development of ‘value’ for a good. This thesis aims to investigate the roles of these, along with the role of association with an environmental good, in the development of value for upland landscapes using the Peak District National Park as a case study. This objective is developed in three parts. Part I introduces the topic, identifies the background of research against which this thesis is presented and introduces the case study. This part also attempts to identify how well the complex economy – ecology interactions in this landscape are understood by stakeholders. It shows that, given the complexities of the systems, there are key omissions in stakeholder knowledge and understanding. Part II uses Discrete Choice Experiments to analyse the impact on value of experience, memory, heuristics and association. A series of experiments are applied to the same landscape characteristics in order to achieve this. The results show that value can be impacted in a number of ways with implications for the development of future valuation studies. This thesis concludes with a discussion of the policy implications, limitations and future work associated with this research.
34

Trophic interactions of ants, birds and bats affecting crop yield along shade gradients in tropical agroforestry

Gras, Pierre 10 December 2014 (has links)
No description available.
35

Ekosystemtjänstbedömningar : Utvärdering av metodik för att synliggöra värdet av naturen inom stadsplanering / Ecosystem service assessments : Evaluation of methodology to assess and represent the value of nature in urban planning

Emilsson, Håkan January 2015 (has links)
The purpose of this study was to analyze and develop a workflow for assessing and representing the value of ecosystems to professionals involved in municipal planning. A thorough literature review was conducted and supplemented by interviews and observations. Frameworks for ecosystem service assessments were analyzed and combined with methods in urban planning in order to assess social and ecological conditions. A workflow was set up and methods were evaluated by applying them to a case study in the area Åstråket in Uppsala. Experience from the case study was compiled in order to improve the workflow. Complex assessments were identified and simplified for the method to be useful for practitioners. A list of relevant urban ecosystem services was compiled. Eleven activities were chosen and divided into three blocks: planning, situation analysis and redesign. In the planning phase strong civil dialogue would be used to identify user needs and based on them formulate goals for the planned change. In the situation analysis the extent to which ecosystem services were utilized, and how much potential there were to increase the use of them without exceeding the area's biophysical conditions, were assessed. The different ecosystem services in the area were evaluated according to how well they helped to achieve designated goals for the area. In the design stage social-ecological urbanism were used to create a design that will increase the value of ecosystem services for the users of the site. Arrow diagram were used to show how the proposed design supports species in the ecosystem that generates an increased value of the prioritized ecosystem services and contribute to achieving the objectives of the area. The study showed that the value of ecosystem could be made visible by showing how different actors contribute to goal achievement. The methods for quantifying ecosystem services are still trivial and ignore some fundamental social-ecological relations. The methods for social assessments could not be fully tested in the case study because there was ongoing consultation on a plan proposal that prevented any interviews with the users to be done. Assumptions that were important to simplify ecosystem service assessment was that 1) a broad definition of value was used, not just monetary, and that 2) the focus was on increasing the value of ecosystem services rather than replacing some services with others. To improve the method more knowledge on social-ecological interactions is required, a broader discussion about values need to be raised and a more standardized set of indicators needs to be agreed upon. Ecosystem services can also be used as a pedagogical tool for learning about systems thinking, complexity and a diversity of values. / Syftet med studien var att utveckla och testa en arbetsgång för att synliggöra värdet av naturen för yrkesutövare inom kommunal planering. En grundlig litteraturstudie genomfördes och kompletterades med intervjuer och observationer. Ramverk för ekosystemtjänstbedömningar analyserades och kombinerades med metoder inom samhällsplanering för att bedöma sociala och ekologiska förhållanden. En arbetsgång utarbetades och metoder bedömdes genom att tillämpa dem i en fallstudie på området Åstråket i Uppsala. Erfarenheter från fallstudien sammanställdes för att utveckla arbetsgången. Komplexa bedömningar identifierades och förenklades för att arbetsgången skulle bli praktiskt användbar. En lista med relevanta urbana ekosystemtjänster sammanställdes. Elva aktiviteter valdes och delades in i blocken planering, nulägesanalys och redesign. I planeringsskedet användes aktiv medborgardialog för att kartlägga användarnas behov och utifrån dem formulera mål för förändringsprocessen. I nulägesanalysen bedömdes i hur stor omfattning ekosystemtjänsterna nyttjades och hur stor potentialen var för att öka nyttjandet av dem utan att överstiga områdets biofysiska förutsättningar. De olika ekosystemtjänsterna i området värderades efter hur väl de bidrog till att uppnå utpekade mål för området. I designsteget användes social-ekologisk urbanism för att skapa en design som kommer öka värdet av ekosystemtjänsterna för användarna av området. Pildiagram användes för att visa hur den föreslagna designen stödjer arter i ekosystemet som genererar ett ökat värde av prioriterade ekosystemtjänster och bidrar till uppfyllelse av målen i området. Studien visade att värdet av ekosystem kan synliggöras genom att visa hur olika aktörer bidrar till måluppfyllelse. Metoder för kvantifiering av ekosystemtjänster bedömdes inte representera fundamentala social-ekologiska relationer. Identifierade metoder för sociala bedömningar kunde inte testas fullt ut i fallstudien på grund av att samråd precis hade genomförts för aktuellt planförslag. Antaganden som var viktiga för att förenkla ekosystemtjänstbedömningen var att 1) en bred definition av värde användes, inte bara monetär, och att 2) fokus var på att öka värdet av ekosystemtjänsterna snarare än ersätta vissa tjänster med andra. För att förbättra metoden behövs mer kunskap om social-ekologiska relationer, en bred debatt om värderingar och en överenskommelse om en standardiserad uppsättning av indikatorer. Ekosystemtjänster kan även användas som ett pedagogiskt hjälpmedel för att lära ut system-tänkande, komplexitet och en mångfald av värden.
36

Régulations écologiques d'un complexe de bioagresseurs du bananier dans un gradient de complexité végétale des agroécosystèmes / Ecological regulations of multiple banana pests along a gradient of agroecosystem plant complexity

Poeydebat, Charlotte 14 December 2016 (has links)
L’intensification de l’agriculture et la simplification biologique des agroécosystèmes conduit à une perte des fonctions écosystémiques tandis que le contrôle chimique des bioagresseurs (BAG) n’est pas durable. La diversification des agroécosystèmes est plébiscitée de manière croissante pour restaurer les interactions positives entre les plantes, telles que la régulation des BAG, au bénéfice des cultures. Mais la diversification bien qu’elle implique un partage des ressources ne doit pas se faire au détriment des rendements. Si la diversité végétale est le support de services de régulation des BAG, quel devrait être le niveau de ces régulations pour compenser les pertes de rendement liées à la compétition pour les ressources ? Quelles devraient-être la composition et la structure de la communauté de plantes pour optimiser de façon synergique les régulations de multiple BAG et la production ? J’ai d’abord quantifié par modélisation théorique les niveaux minimum de régulation des BAG requis pour compenser les pertes de rendement dues à la compétition, dans différents scénarios d’association et de ressources. J’ai ensuite réalisé une étude de terrain pour étudier les régulations écologiques de trois importants BAG du bananier dans un gradient de complexité végétale. Enfin, j’ai quantifié la part d’écart de rendement attribuable aux BAG et aux ressources. Je discute des interactions entre dégâts des BAG et compétition pour les ressources à l’échelle de la plante, des mécanismes de régulations écologiques des BAG du bananier et de la gestion de la végétation à l’échelle de la parcelle pour la régulation synergique des BAG et l’optimisation des rendements. / Agriculture intensification and biological simplification of agroecosystems lead to the loss of ecosystem functions while chemical control of pests is not sustainable. Agroecosystem plant diversification is increasingly recognized as a way to restore positive interactions among plants benefiting crops, such as pest regulations. But diversification that causes resource sharing must not be done at yields’ expense. If vegetation complexity is the basis for pest regulation services, what should be the level of the regulations to compensate for yield losses due to competition for resources? What should be the composition and structure of the plant community to synergistically optimize multiple pest regulations and yields? First, I quantified by theoretical modeling the minimal levels of pest regulation required to compensate for yield losses due to competition in various association and resource scenarios. I then conducted a field study to study the ecological regulations of three important pests of bananas along a vegetation complexity gradient. Finally, I quantified the amount of yield losses attributable to pests and resources. I discuss the interactions between pest damage and resource competition at plant scale, the mechanisms implied in ecological regulations of the three banana pests and the management of the plant community at field scale for the synergic regulation of multiple pests and yield optimization.
37

Landscape heterogeneity affects arthropod functional diversity and biological pest control

Bosem, Aliette 01 February 2017 (has links)
No description available.
38

En solklar taklösning: En fallstudie på synergieffekter av bifacialsolceller och extensiva gröna tak / A sunny green roof solution: A study of the synergy effects of bifacial solar cells and extensive green roofs

Knudsen, Clara January 2020 (has links)
The master thesis has evaluated the specific combination of bifacial solar cells and extensive green roofs. This was done in terms of energy production per year, profitability as well as discussions around ecosystem services. Three cases have been simulated with different temperature profiles for both bifacial, vertical bifacial and monofacial. The reason for three cases was due to the uncertainty in temperature decreasing properties of vegetation i Sweden. One case was simulated for a normal black bitumen roof for the three types of solar PV. The result with the best energy production was found in the configuration with azimuth -10o, inclination 40o and height above roof at 40 cm. This was the case with the largest simulated temperature decrease. Albedo was set to 0.2 and this resulted in a bifacial gain of 9-10% for the three cases with green roofs installed. Albedo was found to be a larger factor in the energy production outcome than the temperature decrease from the vegetation. The solar cells contributes to shading the green roof partially which increases the local biodiversity as well as expands the lifetime of the vegetation. The combination was deemed profitable since the middle case had an annuity of 1841 SEK/year, but the case with the bitumen roof was found to be even more profitable with an annuity of 4160 SEK/year. This indicates that the extra cost of installing a green roof does not pay itself back with a higher energy production. / Det här examensarbetet har undersökt kombinationen bifacialsolceller med extensivt grönt tak med avseende på optimal utformning av en sådan anläggning på ett tak samt systemproduktion och lönsamhet hos anläggningen. Då det inte finns något klart modelleringsverktyg för hur stor temperatursänkning det gröna taket kan åstadkomma så har tre olika fall med olika temperaturprofil simulerats. Resultaten visade på att ju högre temperatursänkning det gröna taket kan bidra med desto lägre höjd bör bifacialsolcellerna installeras på. Den bästa systemproduktionen fås vid vinkeln 40o samt azimuth -10o för alla tre fall. Detta gav för medelfallet en bifacial gain på 9,6% vid jämförelse mot vanliga enkelsidiga solceller. Resultatet för vertikalt installerade bifacialsolceller gav minst 12% lägre systemproduktion än de med vinkel 40o men med hög osäkerhet kring tillförlitligheten i resultatet. Vertikal bifacial kan vara intressant då det ligger ett värde i att producera elektricitet efter ett normalt hushålls elkonsumtionskurva, men är mindre intressant för kontorsbyggnader där elkonsumtionen är relativt konstant under dagen. Lönsamhetskalkylen visade att kombinationen bifacialsolceller med grönt tak var lönsam, men inte lika lönsam som att installera på svart tak. För medelfallet gav bifacialsolceller på grönt tak en annuitet på 1841 kr/år medan annuiteten för bifacialsolceller på svart tak var hela 4160 kr/år. Ur ett rent ekonomiskt perspektiv är kombinationen alltså inte den mest lönsamma. Från känslighetsanalyserna konstaterades att albedo är den aspekt som har störst påverkan på systemproduktionen och denna är relativt låg för det gröna taket. Ett högre albedo hade därför varit att föredra till bifacialsolceller, vilket kan erhållas genom att exempelvis varva grönt tak med vita stenar. Vidare är kombinationen en platseffektiv lösning för tak som oftast är en outnyttjad ytresurs, där de olika installationerna bidrar med olika positiva nyttor var för sig. Bifacialsolcellerna bidrar till en ökad självförsörjningsgrad samt hjälper till att driva på den tekniska innovationen framåt. Gröna tak bidrar med många ekosystemtjänster såsom bullerreducering, dagvattenfördröjning, rening av luftpartiklar, lokal temperatursänkning. Kombinationen bidrar till en ökad biologisk mångfald och en lägre växtperiod för det gröna taket mot om den hade varit fristående.
39

Adoption of effective improved cookstoves in sub-Sahara Africa: case study in the Arua District

Bubendorfer, Alwin January 2012 (has links)
In rural areas of least developed countries, the preparation of meals remains the predominant energy consuming activity. Cooking is mostly performed with firewood – using the ancient “technology” of the 3-stone fire. This practice results in numerous challenges that hinder the transformation envisioned by the Millennium Development Goals and it therefore contributes towards slowing the development of rural areas. Activities focussing on amending this status-quo can be termed insufficient in scope- and sustainability. The main deficiencies of most projects are that the prime focus of the mainstream of these endeavours has been on demand side management, mainly performed by disseminating cookstoves, and that there has been little innovation in respect to raising stove adoption rates. As the strict efficiency focus obviously only captures one side of the problem – merely focussing on treating symptoms rather than providing an effective solution, this thesis stresses the need for a paradigm shift towards more holistic interventions. This work very much focuses on the topic of stove adoption. This is a complex topic - very much linked to attaining behavioural change. Deliberations concluded that the identification of enabling factors for adoption, which can be termed a prerequisite for developing sustainable methods for stove projects, requires a mix of instruments. To suffice the required data demand the initial literature review was complemented by a thorough assessment of the kitchen environment and the cooking behaviour of stove owners. The fieldwork concentrated on 210 beneficiaries of an efficient cookstove project. The applied methods included interviews, observations and pictorial documentation. As a remedy to the challenges and current shortcomings identified during field work and literature review, the author herein develops a novel and more holistic implementation strategy for stove projects – the so- called 3-Step approach. This is based on the simultaneous implementation of availing cookstoves, building capacity in respect to kitchen management, as well as performing small-scale household level tree planting. The research, which further encompassed the piloting of the 3-Step approach, led to the overall conclusion that the proposed increase in project scope holds a multitude of opportunities for improving the livelihoods of the rural target groups. The main impact of this innovative strategy lies in a decrease of average transaction costs as well as in a considerable increase in project sustainability. As will be extensively elaborated, the former is achieved by a more effective utilisation of the extensive infrastructure of trained artisans. The latter refers to the expected income increase on household level, as well as to improvements in environmental- and human health. In combination these enable rural communities to better adapt to climate change.
40

Spatiotemporal Variation of Karst Ecosystem Service Values and Its Correlation With Environmental Factors in Northwest Guangxi, China

Zhang, Mingyang, Zhang, Chunhua, Wang, Kelin, Yue, Yuemin, Qi, Xiangkun, Fan, Feide 01 November 2011 (has links)
In this investigation we analyzed the spatiotemporal variation of ecosystem service values (ESVs) and its correlation with numerous environmental factors (EFs) for the karst region of Northwest Guangxi, China, from 1985 to 2005 using remote sensing, geographic information systems (GIS) and statistical techniques. The results indicate that historically ESVs for this karst region decreased from 1985 (109.652 billion Yuan) to 1990 (88.789 billion Yuan) and then increased at the turn of the twenty-first century. However, the ESVs in both 2000 (103.384 billion Yuan) and 2005 (106.257 billion Yuan) never achieved the level recorded in 1985. The total of nutrient cycling, organic production and gas regulation combined were 72.69, 64.57, 70.18 and 72.10% of ESVs in 1985, 1990, 2000 and 2005, respectively. In contrast, the ESVs of water conservation, soil reservation, recreation and culture were determined to be relatively low contributing only 17.44, 23.82, 19.26 and 24.76% of total ESVs, respectively, during these four years. With regards to the spatial distribution of ESVs, larger values were recorded in the west and smaller ones recorded in the east. The most significant factors that were deemed to influence ESVs are annual rainfall, per capita cropland, slope and vegetation coverage. Annual rainfall and slope exert a negative force, whereas per capita cropland and vegetation coverage exert a positive force on ESVs. The results of the study would suggest that ecosystem conditions of this important karst region have been improved as the result of the implementation of rocky desertification control policies.

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