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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.
121

Disseminating Nature-based Thinking across Local and Global Networks : the case study of Turin (IT), CONEXUS (H2020, grant agreement n. 867564)

Pastorello, Mariangela January 2022 (has links)
Nature-based Solutions (NBS) are currently considered among the most effective tools available to city administrations and urban planners to tackle the negative effects of climate change.This umbrella concept comprises a large set of different low-impact technical solutions that are inspired/supported, or copied, from nature. NBS are particularly valued as they can help cities foster sustainability and enhance resilience, while providing social benefits and new economic opportunities. NBShave been selected as a priority by the European Commission.Existing literature does not provide a clear, unique definition of NBS nor sufficient empirical support to demonstrate long-term change in communities and affected territories, particularly for participatory actions, as these are often difficult to analyse, measure, and assess. Adapting NBS-based strategies to local contexts is always a challenge – not only in terms of physical interventions, but particularly in terms of creating common understanding and long-term impact. Yet, dissemination activities, exchanges and debates across local and global actors are often considered as ‘collateral’.Starting from these premises, the study investigates the role of communication across local and global networks in NBS projects to explore which elements favour or hinder collaboration and knowledge creation, looking for possible seeds of transformation that might go undetected due to their intangible, non-quantifiable nature.Through a case study and a set of qualitative interviews, the challenges of understanding and adopting NBS will be tackled among the local and the global, revealing the importance of transdisciplinarity and a set of enabling conditions to facilitate transformative learning, and the role of flexible, adaptable participatory approaches to enhance collaborative open innovation. Possible ways forward and challenges towards forms of participatory governance will also be included.The analysis is clustered per themes to investigate the dynamics of dissemination activities, living lab settings and collaboration among international partners, as well as the overall influence of the European dimension; it ends with challenges and opportunities for the future of living labs and collaboration after the closure of the project. Meaningful examples and best practices shared by the2interviewees will guide the analysis. Additional topics and concerns as expressed freely by the participants will be outlined.As outlined in the closing section, reiteration of concepts and multiple opportunities to learn, experience and exchange about NBS are needed at local and global level. To support such collaborative effort, it takes one or more skilled facilitators as well as project frameworks to enable cross-sectoral collaboration and spontaneous inputs, towards innovative, long-lasting strategies to contribute in the global battle against climate change in cities.In the conclusions, through experiences and suggestions from the participants, possible strategies and actions will be reported, inviting for further transdisciplinary research by highlighting how intangible and practical items contribute to nature-based thinking. As to say: “to be inspired by natural processes in all aspects of urban development to create more holistic approaches to sustainable cities'' (Randrup, et al., 2020, p. 2).
122

Social-Ecological Risk and Vulnerability to Erosion and Flooding Along the Ohio Lake Erie Shoreline

Siman, Kelly 25 August 2020 (has links)
No description available.
123

Intraguild predation in Harmonia axyridis and its effects on native coccinellids / Prédation intraguilde chez Harmonia axyridis et ses effets sur les coccinelles indigènes

Hautier, Louis 18 October 2012 (has links)
During the 1990s, over a period of just a few years, the multi-colored Asian lady beetle, Harmonia axyridis (Pallas) invaded the entire area of northern Europe. In parallel with this invasion, a decline in native coccinellid species was recorded in Belgium, Britain, and Switzerland, affecting mainly one common species: the two-spot ladybird, Adalia bipunctata L. An impressive trait of H. axyridis, that could explain both its high invasiveness and the decline of native coccinellids, is its predation behaviour. Intraguild predation is a trophic interaction between species that share the same prey – in this case, aphids. In order to determine the precise impact of this predation on the native coccinellid species, the predation behaviour of H. axyridis larvae was observed in Petri dishes and on plants. The resistance of H. axyridis to predation was also studied by exposing it without dorsal spines to native predator larvae, in order to test whether or not the dorsal spines are a physical defence against intraguild predation. In addition to these laboratory experiments, an original method was developed and used to track predation under field conditions. This method is based on the gas chromatography–mass spectrometry (GC-MS) detection of exogenous alkaloids in H. axyridis, especially alkaloids from native coccinellids likely to be subject to intraguild predation. My results show that, in the absence of aphids, H. axyridis consumes both A. bipunctata eggs and all larval instars in Petri dishes. On plants, depending to aphid density, this interaction can change with regards to larvae but not eggs. In addition to intraguild predation, competitive exclusion can occur because of quite aggressive behaviour towards competitors. Dorsal spines significantly reduce the number of bites inflicted, and thereby complement the other defense mechanisms of H. axyridis that enable it to remain dominant in competition for food resources. In semi-natural conditions, predation on the native coccinellids Adalia spp. Calvia spp. Coccinella septempunctata L. and Propylea quatuordecimpunctata (L.) was detected. The number of sites where this predation was observed suggests that this interaction is frequent. It was also observed that an H. axyridis larva can ingest several native coccinellid species, confirming its status as a predator of coccinellids. We can therefore conclude that intraguild predation by H. axyridis leads, as does resource competition, to a decline in native coccinellids./Introduite pour la lutte biologique dans les années 90, la Coccinelle asiatique, Harmonia axyridis (Pallas), a envahi en quelques années toute l’Europe du Nord. Parallèlement à cette invasion, un déclin de plusieurs espèces de coccinelles indigènes dont la très commune Coccinelle à deux points, Adalia bipunctata L. a été observé dans différents biotopes en Belgique, en Angleterre ainsi qu’en Suisse. Un des traits remarquables de la Coccinelle asiatique est son comportement de prédateur intraguilde qui pourrait expliquer à la fois ce déclin mais aussi en partie son caractère hautement invasif. La prédation intraguilde est une interaction trophique entre des espèces qui se nourrissent d’une même proie, dans ce cas-ci les pucerons. Afin de mieux connaître l’impact de cette prédation sur les coccinelles indigènes, le comportement de prédation des larves d’H. axyridis a été décrit en boîtes de Petri et sur plantes. Sa résistance à la prédation a également été étudiée en exposant des larves dépourvues d’épines dorsales à un prédateur indigène, dans le but de tester le rôle de ces épines en tant que défense physique à l’égard d’un prédateur intraguilde. En plus de ces expériences de laboratoire, une méthode originale a été développée et utilisée pour suivre cette prédation en conditions semi-naturelles. Elle se base sur la détection, en GC-MS, des alcaloïdes exogènes chez H. axyridis et en particulier des alcaloïdes produits par d'autres espèces de coccinelles susceptibles de subir une prédation intraguilde. Mes résultats montrent qu'en l'absence de pucerons, H. axyridis a un comportement de prédation vis-à-vis des œufs et de tous les stades larvaires d’A. bipunctata. La présence de pucerons, suivant leur densité, peut modifier cette interaction à l’égard des larves indigènes mais pas des œufs. En plus de la prédation intraguilde, une compétition par exclusion peut être aussi suspectée et expliquée par le comportement très agressif d’H. axyridis à l’égard de ses concurrents. Quant aux épines dorsales, elles permettent de réduire significativement le nombre de morsures et complètent ainsi les autres lignes de défense utilisées par H. axyridis pour s’imposer dans des ressources déjà exploitées par d’autres prédateurs. En conditions semi-naturelles, cette prédation à l’égard des coccinelles indigènes a été confirmée vis-à-vis d’Adalia spp. Calvia spp. Coccinella septempunctata L. et Propylea quatuordecimpunctata (L.). Vu le nombre de sites où cette prédation a été détectée, elle peut être considérée comme une interaction fréquente. De plus, une même larve de coccinelle asiatique peut ingérer plusieurs espèces de coccinelles indigènes confirmant indéniablement son statut de prédateur de coccinelles. Ainsi, nous pouvons conclure que la prédation intraguilde par H. axyridis sur les coccinelles indigènes participe très certainement au déclin de celles-ci et ceci très probablement au même titre que des phénomènes de compétition pour les ressources. / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

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