• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 322
  • 105
  • 70
  • 51
  • 15
  • 15
  • 7
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 685
  • 685
  • 179
  • 127
  • 113
  • 107
  • 103
  • 91
  • 88
  • 87
  • 85
  • 81
  • 81
  • 79
  • 74
  • 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.
521

Auctioning Payments for Ecosystem Services (PES) Contracts: A Behavioural and Experimental Economic Analysis

Kouakou, Abel-Gautier 08 June 2021 (has links)
The goal of the PhD thesis is to investigate the role of behavioural economics considerations for the performance of conservation auctions. The findings of the three scientific articles suggest that behavioural economics considerations like social (distributional) preferences and reference-dependent preferences may affect the attractiveness and economic performance of conservation auctions, respectively. The results of the first and second articles are based on laboratory experiments conducted with university students, in Germany. The third article implements a field experiment to measure farmers’ preferences over Payments for Ecosystem Services (PES) allocation mechanisms and the role of fairness therein, in the context of agrobiodiversity loss in Benin.
522

Landscape Changes and Loss of Ecosystem services of Houay Mak Hiao River : a Study in a Rapidly Developing City (Vientiane, Laos)

Kolehmainen, Janne, Axén, Pontus January 2013 (has links)
This project was conducted in Vientiane, Laos where wetlands, channels and rivers play an important role for the water quality maintenance. Now, large landscape changes like backfilling of wetlands and channelization is affecting the condition of the urban waters which has become extremely polluted. For that reason this survey has focused on the past and present status of Houay Mak Hiao River, who receives basically all drainage water from the city. The purpose of this project is to find out how the condition of Houay Mak Hiao River has changed over time and to describe how historical and current landscape changes have affected the river. Group interviews were conducted in seven villages along the river to find out about the past and present status. The groups consisted of 3-6 respondents in each village. To get as relevant answers as possible, elders, fishermen, farmers and the head of village in each village were participating in the interviews. Water samples were collected at nine sampling sites to determine the water quality of today. The results show that the condition of the river started to significantly decrease about ten years ago and has since then become worse and worse. Today, the water is extremely polluted which has affected the fish population and the vegetation along the river in a very negative way. The deterioration can be connected to channelization and wetland area loss in Vientiane.The level of contamination decreases closer to the outflow into Mekong River which can be due to uptake by floating plants and dilution effects.
523

Uppföljning av ekosystemtjänster i den urbana miljön : Kartläggning av kommuners användning av indikatorer och metoder samt hinder på vägen

Rohdin, Jessica January 2021 (has links)
I Sverige beräknas ett behov av ytterligare 592 000-664 000 byggda bostäder till år 2029 och med populära samhällsbyggnadsstrategier som förtätning finns en risk att de urbana ekosystemtjänster som kan erbjuda klimatanpassning och värde för invånarnas hälsa och boendekvalitet går förlorade. Åtgärder som avser främja urban ekosystemtjänster behöver följas upp för att säkerställa en hållbar stadsutveckling. Boverket har identifierat ett utvecklingsbehov av indikatorer och metoder som kan mäta denna utveckling. Så hur gör kommunerna? Enkätundersökning och intervjuer genomfördes för att öka kunskapen kring vilka indikatorer och metoder som landets kommuner använt och har goda erfarenheter av för att följa upp arbetet med integrering av ekosystemtjänster i den urbana miljön. Även hinder i uppföljningsarbetet identifierades och goda erfarenheter delades. Resultaten visade att knappt hälften av respondenterna i enkäten hade etablerade indikatorer och metoder för uppföljningsarbetet. I linje med tidigare studier visade resultaten på en komplexitet i arbetet med ekosystemtjänster som förutsätter en viss samordning av både tid och kompetens för att lyckas. De kommuner som hade erfarenheter av uppföljningsarbetet använde i många fall indikatorer kopplade till geografiska informationssystem och metoder som byggde på tillgänglig data från tex myndigheter. Fördelarna med dessa var att de i hög grad kunde utföras av kommunerna själva och med viss flexibilitet. Hinder som förekommit var brist på resurser i form av tid, budget och kompetens. Dessa kunde stävjas med en konkret politisk förankring och tydligt formulerade målbilder. / In Sweden, an additional 592,000-664,000 homes built by 2029 are estimated and with popular urban development strategies such as densification, there is a risk that the urban ecosystem services that can offer climate adaptation and value for residents' health and quality of living will be lost. Measures to promote urban ecosystem services need to be followed up to ensure sustainable urban development. Boverket has identified a development need for indicators and methods that can measure this development. So how do municipalities follow up on measures to promote urban ecosystem services? Survey and interviews were conducted to increase knowledge about the indicators and methods used by the country's municipalities and have good experience of following up the work on integrating ecosystem services into the urban environment. Obstacles in the follow-up work were also identified and good experiences were shared. The results showed that just under half of the respondents in the survey had established indicators and methods for follow-up work. In line with previous studies, the results showed a complexity in the work with EST that requires some coordination of both time and competence to succeed. In many cases, municipalities with experience of follow-up work used indicators linked to geographical information systems and methods based on available data from, for example, authorities. The advantages of these were that they could be largely carried out by the municipalities themselves and with some flexibility. Obstacles that occurred were a lack of resources in terms of time, budget, and competence. These could be curbed with concrete political support and clearly formulated objectives.
524

Marina ekosystemtjänster för Hav i balans samt levande kust och skärgård : En kvalitativ analys av lokal förvaltning av Höga Kusten och Sankt Anna-Missjö / Marine ecosystem services for A Balanced Marine Environment, Flourishing Coastal Areas and Archipelagos : A qualitative analysis of local management in the High Coast and St. Anna-Missjö

Augustinsson Malmberg, Elliot, Lagerhjelm, Charlotte January 2021 (has links)
Östersjön omfattas av en stor mångfald marina ekosystemtjänster som livnär närliggande samhällen. Deras funktion är hotad av en mängd terrestra och akvatiska aktiviteter som har förorenat havet, vilket kräver en långsiktig hållbar förvaltning. Syftet med denna uppsats är att bidra med kunskap om och förstå utmaningar och möjligheter i att uppnå en god ekologisk status i Östersjön. Studien baseras på en granskning av förvaltningsmetoder hos länsstyrelser och kommuner i två områden som är skyddade av den regionala överenskommelsen Helsingforskonventionen; Höga Kusten i Västernorrland och S:t Anna-Missjö i Östergötland. Till grund för det analytiska ramverket ligger Havs- och vattenmyndighetens rapport, som beskriver ekosystemtjänster som Östersjön bidrar med, samt även tjänsternas status, åtgärder och utmaningar som uppstår vid förvaltning. Resultatet baseras på kvalitativa metoder för att samla in data, genom att specifikt studera dokument samt intervjuer med lokala tjänstemän. Den insamlade empirin har blivit kategoriserad och analyserad i linje med Havs- och vattenmyndighetens rapport, därefter har innehållet diskuterats. Resultatet visar att mest fokus lades på hantering av övergödning, ohållbart fiske och reglering av föroreningar, samt deras trade-off- och synergieffekter som påverkar förvaltningen av just dessa ekosystemtjänster. Följaktligen, är det nödvändigt för tjänstemän att samverka med lokalbefolkningen för att uppnå en hållbar förvaltning av de skyddade områdena och deras ekosystemtjänster. Generella utmaningar ansågs vara tid, resurser och kunskap för förvaltning av marina miljöer. Dock genomsyrar myndighetens ramverk om ekosystemtjänster stora delar av länsstyrelserna och kommunernas arbete med marin förvaltning på Höga Kusten och S:t Anna-Missjö. Ekosystemtjänsternas status och funktioner är integrerade i länens och kommunernas förvaltningsmetoder av de skyddade områdena. Ekosystemtjänster som begrepp är däremot frånvarande och inte explicit nämnt i arbetet. / The Baltic Sea offers a diversity of marine ecosystem services which is providing support to nearby human communities. Their functions are jeopardized by terrestrial and aquatic activities which have heavily polluted the sea, necessitating long-term sustainable management. The aim of this bachelor thesis is to provide a scientific contribution to understanding the challenges and opportunities for reaching a good ecological status in the Baltic Sea, as well as insight into the ongoing management practices of Swedish county administrative boards and municipalities. Practices that involve conserving ecosystem services in two different marine protected areas the High Coast and St. Anna-Missjö, both of which have been designated important by a regional convention; the Helsinki Commission. Therefore, the Swedish Agency for Marine and Water Management has adopted a report on which ecosystem services the Baltic Sea provides, and the status of the services in different parts of the sea. This study is based on qualitative methods to gather data by a thorough reading of documents written by the counties and semi-structured interviews of local officials. The data has summarily been categorised and analysed in line with the national agency’s report, then discussed afterwards. The results show that the management practices were heavily emphasised on dealing with activities that lead to eutrophication, unsustainable fishery as well as regulation of polluting substances; where trade-offs and synergy-effects converge that impacts the management of other marine ecosystem services. Hence, it is necessary for officials to network with locals to have sustainable management of the protected areas and their ecosystem services. The officials pointed to the presence of a lack of time, resources and expertise in managing marine environments. Although the agency’s perspective on marine ecosystem services permeates large parts of county administrative boards and municipalities' work with marine management in the High Coast and St. Anna-Missjö. The status and functions of ecosystem services are integrated in their management practices of the protected areas. However, the concepts themselves are more absent and not mentioned explicitly.
525

Exploring Social-Ecological Response Capacity to Drought of Swedish Farms

Ohlsson, Moa January 2019 (has links)
Ecosystem services are intrinsically social-ecological. The capacity to provide them over time is both dependent on the functional attributes of species that contribute to ecological processes and social assets underpinning management practices. Yet, these two dimensions are rarely integrated or empirically assessed, even though their interaction contributes to the overall capacity of a social-ecological system to respond. In this study, theoretical frameworks of resilience, adaptive capacity, and ecosystem services are combined to explore “social-ecological response capacity” as the ability of a social-ecological system to respond to extreme weather events. This study focuses on Swedish livestock farms and was set up in response to the drought of 2018 and concerns raised about the general lack of drought mitigation and adaptation strategies in Europe. 15 surveys and semi-structured interviews were conducted and combined with ecological data collected before the drought, to create a baseline for the capacity to respond before the disturbance. The relationship between assets and drought impact on farm performance was indirect and results revealed that social-ecological response capacity was not a mitigating factor of the impacts of drought on the financial and subjective success of farms. However, financial capital and diversification of income might have a disproportionate influence on the farms performance. Moreover, results showed that farms used a wide diversity of strategies to handle drought effects that focused on increasing current and future fodder supply. These findings can provide useful information for all stakeholders that rely on the stability and provision of essential ecosystem services when navigating similar, as well as other disturbances in the future. Additionally, this study contributes to insights on the empirical assessment of properties that are essential for specified and general resilience.
526

Zhodnocení souladu ochrany přírody v ČR s mezinárodními strategickými závazky / Assesing the complience of nature conservation in the Czech republic with international strategic objectives

Daněk, Jan January 2015 (has links)
The subject of the master thesis is the assessment of the compliance of nature conservation in the Czech Republic with international strategic objectives, analysing the mainstreaming of biodiversity across government and society and analysing the fulfilment of the commitments rising for the Czech Republic as a member of the Convention on Biological Diversity (CBD). The thesis is focused on an assessment of strategic goal A of the Strategic Plan for Biodiversity 2011-2020 and its 4 Aichi targets related to the mainstreaming of biodiversity and ecosystem services in society and policy. The methodology used is a systematic search of available relevant documents and other related sources, especially the national reports from the Ministry of the Environment to the Secretariat of the Convention on Biological Diversity and other associated analysis and reports. Another aim of the thesis is summarizing the current state of the mainstreaming of biodiversity to governance and decision making and identifying the areas which are not included in the national strategic documents or are not included sufficiently. In addition to the theoretical analysis, the thesis suggests specific actions and indicators for reaching the targets included in the international strategic documents, particularly the Strategic plan of...
527

Captation des particules fines par les arbres : cas des grands parcs montréalais

Cyr, Dominic 09 1900 (has links)
La matière particulaire est un agent nocif pour la santé humaine et la réduction de sa concentration atmosphérique est nécessaire dans une approche de santé publique. L’atteinte de cet objectif passe par, entre autres, la captation des particules par la végétation. La question que nous nous sommes posés est: quel est le potentiel de captation des arbres publics dans la ville de Montréal. Comme site à l’étude, nous avons choisi les grands parcs, car leur végétation arborescente couvre un pourcentage important de leur surface. Le modèle de captation de la matière particulaire du logiciel i-Tree a été utilisé pour définir la capacité de purification de l’air selon les caractéristiques spécifiques de chaque parc. Ces caractéristiques comprennent l’indice de surface foliaire des arbres (LAI) et l’étendue des canopées, les conditions météorologiques ainsi que les concentrations des particules dans l’air. Plusieurs méthodes et techniques de calcul de ces paramètres ont été testés et les plus appropriées retenues pour le calcul des intrants. Les calculs ont été faits sur une base journalière pour l’ensemble de l’année 2017. Les résultats montrent que le total des particules captées pendant l’année 2017 s’élève à un peu plus que 3.5 tonnes pour les quatorze parcs évalués. Selon nos calculs, la majeure partie de ces particules a été lessivée au sol par les pluies et un faible pourcentage a été remis en circulation. Un test de validation des résultats in situ n’a pas été concluant. Il n’en demeure pas moins que les résultats sont similaires aux résultats des recherches effectuées dans d’autres villes Nord-Américaines avec le modèle d’i-Tree. Ces résultats montrent que le rôle des arbres pour la purification de l’air est important tout au moins localement. Les possibilités d’améliorer les méthodes de calcul des intrants du modèle de captation sont également discutées. / Particulate matter is an agent harmful to human health and reducing its atmospheric concentration is necessary from a public health approach. Achieving this objective requires, among other things, the capture of particles by vegetation. Our research question was what is the potential of public trees in the city of Montreal for capturing such particles. We chose large parks as our study site, because trees cover a significant percentage of their surface. The particulate matter capture model of the i-Tree software was used to define the air purification capacity according to the specific characteristics of each park. These characteristics include tree leaf area index (LAI) and canopy extent, weather conditions, and particulate matter concentrations in the air. Several methods and techniques for calculating these parameters were tested and the most appropriate ones used for the calculation of inputs to the model. Calculations were made on a daily basis for the whole of 2017. The results show that just over 3.5 tonnes of particles were captured for the fourteen parks evaluated over this period. According to our calculations, most of these particles were leached to the ground by rain and a small percentage were put back into circulation. A validation test of the results in situ was inconclusive. The fact remains that the results are similar to those of research carried out in other North American cities with the i-Tree model. These results show that the role of trees for air purification is important at least locally. Possibilities for improving the methods of calculating the inputs for the capture model are also discussed.
528

Des Technosols construits à partir de produits résiduaires urbains : services écosystémiques fournis et évolution / Productive Technosol made of urban waste : delivered ecosystem services and evolution

Grard, Baptiste 21 December 2017 (has links)
Les villes ne cessent de se densifier au détriment des espaces de nature qui corrélativement se réduisent, tout comme les services écosystémiques qui leur sont associés. Face à ce constat, la végétalisation du bâti apparaît comme une alternative indispensable. Dans ce cadre, les toitures végétalisées font partie des outils d'aménagement des villes qui sont en pleine expansion. Ces toitures revêtent différentes formes, s'adaptant aux contraintes et enjeux urbains. Depuis quelques années, une nouvelle forme de toiture végétalisée a émergé : les toitures végétalisées productives (e.g. de biomasse alimentaire). Encore peu développée et mal connue, l'intérêt concernant cette forme de toiture ne cesse de croître. Leur conception, leur aménagement et surtout les services écosystémiques quelles peuvent rendre sont aujourd’hui encore mal connus et nécessitent d’être mieux appréhendés. Clé de voûte des toitures végétalisées, le sol en place influence directement et indirectement les services écosystémiques rendus par celles-ci. En dépit du rôle majeur de ces sols, peu d'études leur sont consacrés. Par ailleurs, des produits non renouvelables tels que la pouzzolane, l’argile expansée ou la tourbe sont aujourd’hui très majoritairement utilisés dans leur composition. Nous avons étudié des Technosols, c’est à dire des sols reconstitués, de toitures productives composés uniquement de produits issus de résidus du milieu urbain. Ce travail a eu une double ambition : (i) évaluer quantitativement les services écosystémiques rendus et (ii) comprendre les premières phases d’évolution des Technosols. Pour cela, trois dispositifs expérimentaux, installés sur la toiture « Bertrand Ney » de l’école AgroParisTech ont été utilisés. Il s’agit de bacs de cultures dans lesquels des sols sont construits, avec des agencements divers de cinq résidus urbains: un compost de déchet vert, du bois broyé, de la brique et de la tuile concassée, un résidu de champignonnière et un compost de biodéchet. Nous avons étudié l’effet des différents types de Technosols construits sur (i) les services écosystémiques rendus, (ii) la production alimentaire (quantitative et qualitative), (iii) la fertilité physico-chimique et (iv) leur évolution temporelle. Les Technosols construits sont fertiles et permettent une production alimentaire conséquente sur une à cinq années, caractérisée par de faibles teneurs en éléments traces métalliques équivalentes à celles de la moyenne des productions maraichères. L’évaluation quantitative de services écosystémiques (production alimentaire, recyclage de résidus urbain, rétention des eaux de pluies et qualité des eaux de percolations (C et N), a souligné le caractère multifonctionnel des systèmes étudiés et met en évidence un disservice, qui est une altération de la qualité des eaux de percolation par lixiviation du carbone, pouvant être liée à celle d’autres éléments. Une première phase de pédogénèse rapide et intense est observée, marquée par une forte biodégradation des matériaux et une forte lixiviation. Nos travaux ont mis en évidence l’existence d’un double compromis dans la conception d’un Technosol productif, entre (1) la biodégradation des matériaux (assurant la fourniture des nutriments minéraux aux plantes) et le maintien de la structure et porosité du matériau, donc de sa fertilité physique d’une part et entre (2) la fourniture d’élément nutritifs par biodégradation et la lixiviation, se traduisant par une perte de ces éléments et une altération de la qualité des eaux de percolation d’autre part. La connaissance des propriétés des matériaux utilisés et de ses liens avec les services écosystémiques attendus permet déjà de concevoir des toitures productives multifonctionnelles à partir de résidus urbains et de les gérer de manière durable. / Cities are becoming denser at the expense of nature spaces that are correspondingly decreasing, as are the ecosystem services associated with them. Faced with this observation, the greening of buildings appears as a valuable alternative. Nowadays, green roofs have become a planning tool in urban planning. These roofs take different forms, adapting to urban constraints and challenges. In recent years, a new form of green roof has emerged: productive green roofs (i.e. of edible biomass). Despite a growing interest, rooftop farming is still poorly developed and known. Their design, their development and especially, the ecosystem services they could deliver are still poorly understood and need to be known. Keystone to green roofs, the soil in place directly and indirectly influences the provided ecosystem services. Despite, it’s key role, soil is still poorly studied. Furthermore, non-renewable products such as pozzolan or expanded clay or peat are today mostly used in their composition. In this work we have studied constructed soils, named Technosols, for productive roofs made only of urban wastes. The objectives of this thesis were: (i) to achieve a quantitative assessment of delivered ecosystem services (ii) analyze the first stages of Technosol pedogenesis. In order to do so, three experimental devices were implemented on the “Bertrand Ney” rooftop of the technical University AgroParisTech in Paris. The experimental devices consist of multiple plots filled with different disposal of five urban wastes: green waste compost, shredded woods, crushed tiles and bricks, spent coffee grounds used to grow mushroom and a biowaste compost. The impact of the different Technosols on (i) ecosystem services, (ii) food production (quality and quantity), (iii) fertility) and (iv) temporal evolution, were assessed. Constructed Technosol are fertile and allow a consistent food production over one to five years. The level of food production was equivalent to that of a professional producer and food quality regarding trace metal element was below existing norms. The quantitative assessment of ecosystem services (food production, urban waste recycling, rainwater retention and overflow quality (C and N)), highlighted the multifunctional nature of productive green roofs. However, we identified an ecosystem disservice which is an alteration in the quality of the leachates due to carbon leaching and presumably other elements. A first phase of rapid and strong pedogenesis was observed marked by an intense biodegradation and lixiviation of the Technosols. Our works identified two trade-offs in the design of a productive Technosol: between (i) the biodegradation or organic materials (ensuring the supply of mineral nutrient to plants) and the maintenance of the structure and porosity of the Technosol (i.e. its physical fertility) and (ii) the supply of nutrients by biodegradation and leaching, resulting in a loss of these elements and an alteration of the quality of percolation waters on the other hand. Knowledge of the properties of the materials used to build Technosols and on their link with the expected ecosystem services already makes it possible to design multifunctional productive rooftop based on urban waste and manage them sustainably.
529

Incitations économiques pour la régulation de la fourniturede bouquets de services écosystémiques dans les agroécosystèmes / Economic incentives for the regulation of the provision of bundles of ecosystem services in agroecosystems

Langlois, Barbara 11 June 2018 (has links)
Les agroécosystèmes font face à un déclin des services écosystémiques (SE) de régulation, non-marchands. Nous l’interprétons via deux concepts économiques : les biens publics qui appellent une régulation, et la production jointe qui souligne les conséquences des interactions entre SE dans leur régulation.Cette thèse étudie comment accroître la fourniture de SE non-marchands par des incitations économiques, en prenant en compte la multiplicité des SE et les interactions entre eux.Nous étudions d’abord la régulation des biens publics joints à l’aide de microéconomie théorique. Ensuite, nous menons une analyse appliquée avec des données agroécologiques simulées et des méthodes numériques pour définir les solutions coût-efficientes et les incitations pour leur mise en œuvre. Nous comparons plus particulièrement les incitations basées sur les actions et sur les résultats.Nous montrons théoriquement que les interactions entre SE rendent leur régulation plus complexe, notamment avec des incitations basées sur les résultats, et quand le coût varie selon les bouquets de SE. Dans l’analyse appliquée, nous montrons que prendre en compte le coût de la fourniture des SE est crucial pour maximiser leur fourniture avec un budget limité. Nous montrons que les incitations basées sur les résultats sélectionnent les solutions coût-efficientes mais induisent un budget plus élevé que les incitations basées sur les actions, à cause des interactions entre SE. Enfin, nous montrons que l’analyse à l’échelle du paysage et l’hétérogénéité modifient les solutions qui maximisent les SE, mais pas les propriétés des deux types d’incitations.Nos résultats soulignent que les politiques agro-environnementales doivent cibler les services écosystémiques de manière intégrée, si possible à l’échelle de la ferme ou du paysage et considérer le coût de leur fourniture. Les incitations basées sur les résultats ne sont pas la solution à tous les problèmes des politiques agroenvironnementales. / Agroecosystems show a decline in regulating, non-marketed ecosystem services (ES). We interpret this decline through two economic concepts: public goods, which call for regulation, and joint production, which underlines the role of interactions among ecosystem services in their regulation.This thesis studies how to increase the provision of non-marketed ES through the implementation of economic incentives, while accounting for their multiplicity and the complex interactions among them.We first study the regulation of joint public goods with microeconomic theory. We then carry an applied analysis with simulated agroecological data and numerical methods to define cost-efficient solutions and simulate the implementation these solutions with economic incentives. We especially compare result-based and action-based incentives.We show theoretically that interactions among ES make their regulation more complex, especially with result-based incentives and when the production cost varies among bundles of ES. In the applied analysis, we show that accounting for the cost is crucial to maximise ES with a limited budget. We show that result-based incentives select cost-efficient bundles of ES but lead to higher policy budgets than action-based ones, due to interactions among ES. Eventually, we show that considering the landscape scale and heterogeneity plays on the solutions maximising ES, but not on the comparison between result-based and action-based incentives.Our results underline that agri-environmental policies need to target ES in a integrative way, at the farm or landscape scale, and consider the cost of providing non-marketed ES. Result-based incentives don’t solve all issues of agri-environmental policies.
530

Functional Ecology and Ecosystem Services of Urban Trees

Simovic, Milos 14 September 2020 (has links)
No description available.

Page generated in 0.0724 seconds