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The subject of this research is intercity passenger rail transportation in the United States, approached from two perspectives: Amtrak's traditional rail services and high-speed rail projects. The aim is to understand the workings of public rail transportation policies, what they contain, and how they are developed and pursued by the different actors. The originality of the research lies in its multiscale approach, with a constant back-and-forth between the different scales of analysis, and in its use of several case studies to analyze the territorialization of intercity rail transportation policies. The analysis demonstrates the emergence of a bottom-up approach to projects, notably apparent in the Californian HSR project and in the modernization of the Cascades corridor. This process has even gone to the extreme with the proliferation of private rail projects that stress their independence from government, be it in decision-making, governance, or funding. This seems definitively to preclude any attempt to establish a national framework for high-speed rail, like those found elsewhere in the world, regardless of party-political considerations, i.e. the traditionally greater enthusiasm of the Democratic Party for large-scale federal investment. Two conclusions emerge: first, the development of uniform arguments and recommendations to encourage new rail policies, emphasizing the structuring effects and economic role of high-speed rail, congestion reduction, modal shift; second, a tangible though uneven pro-rail position among public actors at all levels. Priority is placed on improving and modernizing existing corridors for the launch of higher-speed services, and then on hybrid networks that combine different types of infrastructures. There are no publicly backed projects for new lines exclusively dedicated to high-speed rail. Most of the high-speed corridors are in fact "higher-speed" corridors, some of which are intended to become high-speed at some time in the future, such as the Northeast corridor. The territorialization of rail projects entails the design and construction of transportation networks that are more integrated – at least in terms of service provision and physical connection – and genuinely interconnected. After analyzing projects for the upgrading of higher-speed corridors and the construction of new infrastructures, we note the importance of stations and the emphasis on the need for better coordination between transportation and urbanism through support for station districts. Indeed, a rail corridor project – situated at the intersection of political, economic, technical, and territorial interests – is the nucleus of a process of territorialization that materially embeds the infrastructure within urban spaces, and of a process of politicization through the involvement of local actors. Rail projects seem to be an instrument that leads to the implantation of metropolitan scale facilities (stations, intermodal hubs) and to the shaping or reshaping of the urban fabric (station districts, larger-scale district regeneration projects) ; Cette recherche a pour objet le transport ferroviaire interurbain de passagers aux Etats-Unis dans une double acception : les services ferroviaires classiques d'Amtrak et les projets de grande vitesse ferroviaire. Il s'agit de comprendre comment les politiques publiques concernant le mode ferroviaire fonctionnent, ce qu'elles contiennent et la manière dont elles sont élaborées et portées par les différents acteurs. L'originalité de la recherche repose sur son approche multiscalaire avec un aller-retour continu entre les différentes échelles d'analyse et sur son ambition d'analyser la territorialisation des politiques en faveur du mode ferroviaire interurbain grâce à plusieurs études de cas. L'analyse met en évidence le fait que s'impose une approche bottom-up pour le portage des projets, c'est le cas notamment pour le projet californien de GVF californien et la modernisation du corridor des Cascades. Cette logique est même poussée à l'extrême avec la multiplication de ces projets ferroviaires privés qui revendiquent leur indépendance par rapport à la puissance publique tant en termes de prise de décision que de gouvernance ou de financement. Cela semble éloigner définitivement toute tentative de définition d'un schéma national pour la grande vitesse ferroviaire, sur le modèle de ce qui s'est passé dans les pays historiques de la GVF, au-delà des considérations partisanes – c'est-à-dire de l'engagement traditionnellement plus fort du parti démocrate dans les grands investissements fédéraux. Deux conclusions en ressortent : en premier lieu, une uniformisation de cet argumentaire et des préconisations pour encourager de nouvelles politiques ferroviaires – effets structurants, rôle économique de la grande vitesse, lutte contre la congestion, report modal ; en second lieu, un engagement à toutes les échelles, tangible mais à divers degrés, des acteurs publics en faveur du mode ferroviaire. Il n'y a pas de projets, portés par des acteurs publics, de nouvelles lignes exclusivement réservées à la GVF. L'essentiel des corridors à grande vitesse concerne des corridors à vitesse élevée (higher speed rail) dont certains ont vocation à devenir à plus ou moins long terme à grande vitesse comme le corridor Nord-Est. Le projet californien, quant à lui, repose en partie sur la réalisation d'une nouvelle infrastructure mais aussi sur l'utilisation de tronçons existants améliorés. La territorialisation des projets ferroviaires passe par la conception et la mise en œuvre de réseaux de transport davantage intégrés – au moins sur le plan de la desserte et de la connexion physique – selon une véritable logique réticulaire. Après analyse des projets de modernisation de corridors à vitesse élevée et de construction de nouvelles infrastructures, nous constatons l'importance des gares et une mise à l'agenda d'une meilleure coordination entre transports et urbanisme par le soutien aux quartiers de gare. En effet, un projet de corridor ferroviaire, qui se trouve au croisement d'intérêts politiques, économiques, techniques et territoriaux, est bien au centre d'un processus de territorialisation qui inscrit matériellement l'infrastructure dans les espaces urbains, et d'un processus de politisation par une mobilisation des acteurs locaux. Les projets ferroviaires apparaissent comme un instrument permettant l'implantation d'équipements à l'échelle métropolitaine (gares, pôles intermodaux) et la structuration ou la reconfiguration du tissu urbain (quartiers de gare, projets plus vastes de renouvellement d'un quartier)

Improving the long-term stability of perovskite solar cells is critical to the deployment of this technology. Despite the great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters reported. It is therefore challenging to reproduce and compare results and thereby develop a deep understanding of degradation mechanisms. Here, we report a consensus between researchers in the field on procedures for testing perovskite solar cell stability, which are based on the International Summit on Organic Photovoltaic Stability (ISOS) protocols. We propose additional procedures to account for properties specific to PSCs such as ion redistribution under electric fields, reversible degradation and to distinguish ambient-induced degradation from other stress factors. These protocols are not intended as a replacement of the existing qualification standards, but rather they aim to unify the stability assessment and to understand failure modes. Finally, we identify key procedural information which we suggest reporting in publications to improve reproducibility and enable large data set analysis. ; This article is based upon work from COST Action StableNextSol MP1307 supported by COST (European Cooperation in Science and Technology). M.V.K., E.A.K., V.B. and A.O. thank the financial support of the United States – Israel Binational Science Foundation (grant no. 2015757). E.A.K., A.A. and I.V.-F. acknowledge partial support from the SNaPSHoTs project in the framework of the German-Israeli bilateral R&D cooperation in the field of applied nanotechnology. M.S.L. thanks the financial support of National Science Foundation (ECCS, award #1610833). S.C., M.Manceau and M.Matheron thank the financial support of European Union's Horizon 2020 research and innovation programme under grant agreement no 763989 (APOLO project). F.D.R. and T.M.W. would like to acknowledge the support from the Engineering and Physical Sciences Research Council (EPSRC) through the SPECIFIC Innovation and Knowledge Centre (EP/N020863/1) and express their gratitude to the Welsh Government for their support of the Ser Solar programme. P.A.T. acknowledges financial support from the Russian Science Foundation (project No. 19-73-30020). J.K. acknowledges the support by the Solar Photovoltaic Academic Research Consortium II (SPARC II) project, gratefully funded by WEFO. M.K.N. acknowledges financial support from Innosuisse project 25590.1 PFNM-NM, Solaronix, Aubonne, Switzerland. C.-Q.M. would like to acknowledge The Bureau of International Cooperation of Chinese Academy of Sciences for the support of ISOS11 and the Ministry of Science and Technology of China for the financial support (no. 2016YFA0200700). N.G.P. acknowledges financial support from the National Research Foundation of Korea (NRF) grants funded by the Ministry of Science, ICT Future Planning (MSIP) of Korea under contracts NRF-2012M3A6A7054861 and NRF-2014M3A6A7060583 (Global Frontier R&D Program on Center for Multiscale Energy System). CSIRO's contribution to this work was conducted with funding support from the Australian Renewable Energy Agency (ARENA) through its Advancing Renewables Program. A.F.N gratefully acknowledges support from FAPESP (Grant 2017/11986-5) and Shell and the strategic importance of the support given by ANP (Brazil's National Oil, Natural Gas and Biofuels Agency) through the R&D levy regulation. Y.-L.L. and Q.B. acknowledge support from the National Science Foundation Division of Civil, Mechanical and Manufacturing Innovation under award no. 1824674. S.D.S. acknowledges the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (HYPERION, grant agreement no. 756962), and the Royal Society and Tata Group (UF150033). The work at the National Renewable Energy Laboratory was supported by the US Department of Energy (DOE) under contract DE-AC36-08GO28308 with Alliance for Sustainable Energy LLC, the manager and operator of the National Renewable Energy Laboratory. The authors (J.J.B, J.M.L., M.O.R, K.Z.) acknowledge support from the 'De-risking halide perovskite solar cells' program of the National Center for Photovoltaics, funded by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Solar Energy Technology Office. The views expressed in the article do not necessarily represent the views of the DOE or the US Government. H.J.S. acknowledges the support of EPSRC UK, Engineering and Physical Sciences Research Council. V.T. and M.Madsen acknowledge 'Villum Foundation' for funding of the project CompliantPV, under project no. 13365. M.Madsen acknowledges Danmarks Frie Forskningsfond, DFF FTP for funding of the project React-PV, no. 8022-00389B. M.G. and S.M.Z. thank the King Abdulaziz City for Science and technology (KACST) for financial support. S.V. acknowledges TKI-UE/Ministry of Economic Affairs for financial support of the TKI-UE toeslag project POP-ART (no. 1621103). RC thanks the grants for Development of New Faculty Staff, Ratchadaphiseksomphot Endowment Fund. A.D.C. gratefully acknowledges funding from the European Union's Horizon 2020 Research and Innovation Program (grant agreement no. 785219-GrapheneCore2 and no. 764047-ESPResSo). M.L.C. and H.X. acknowledges the support from Spanish MINECO for the grant GraPErOs (ENE2016-79282-C5-2-R), the OrgEnergy Excellence Network CTQ2016-81911- REDT, the Agència de Gestiód'Ajuts Universitaris i de Recerca (AGAUR) for the support to the consolidated Catalonia research group 2017 SGR 329 and the Xarxa de Referència en Materials Avançats per a l'Energia (Xarmae). ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant no. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya. ; Peer reviewed

Modern agriculture is the basis of human existence, a blessing, but also a curse. It provides nourishment and well-being to the ever-growing human population, yet destroys biodiversity-mediated processes that underpin productivity: ecosystem services such as water filtration, pollination and biological pest control. Ecological intensification is a promising alternative to conventional farming, and aims to sustain yield and ecosystem health by actively managing biodiversity and essential ecosystem services. Here, I investigate opportunities and obstacles for ecological intensification. My research focuses on 1) the relative importance of soil, management and landscape variables for biodiversity and wheat yield (Chapter II); 2) the influence of multi-scale landscape-level crop diversity on biological pest control in wheat (Chapter III) and 3) on overall and functional bird diversity (Chapter IV). I conclude 4) by introducing a guide that helps scientists to increase research impact by acknowledging the role of stakeholder engagement for the successful implementation of ecological intensification (Chapter V). Ecological intensification relies on the identification of natural pathways that are able to sustain current yields. Here, we crossed an observational field study of arthropod pests and natural enemies in 28 real-life wheat systems with an orthogonal on-field insecticide-fertilizer experiment. Using path analysis, we quantified the effect of 34 factors (soil characteristics, recent and historic crop management, landscape heterogeneity) that directly or indirectly (via predator-prey interactions) contribute to winter wheat yield. Reduced soil preparation and high crop rotation diversity enhanced crop productivity independent of external agrochemical inputs. Concurrently, biological control by arthropod natural enemies could be restored by decreasing average field sizes on the landscape scale, extending crop rotations and reducing soil disturbance. Furthermore, reductions in agrochemical inputs decreased pest abundances, thereby facilitating yield quality. Landscape-level crop diversity is a promising tool for ecological intensification. However, biodiversity enhancement via diversification measures does not always translate into agricultural benefits due to antagonistic species interactions (intraguild predation). Additionally, positive effects of crop diversity on biological control may be masked by inappropriate study scales or correlations with other landscape variables (e.g. seminatural habitat). Therefore, the multiscale and context-dependent impact of crop diversity on biodiversity and ecosystem services is ambiguous. In 18 winter wheat fields along a crop diversity gradient, insect- and bird-mediated pest control was assessed using a natural enemy exclusion experiment with cereal grain aphids. Although birds did not influence the strength of insect-mediated pest control, crop diversity (rather than seminatural habitat cover) enhanced aphid regulation by up to 33%, particularly on small spatial scales. Crop diversification, an important Greening measure in the European Common Agricultural Policy, can improve biological control, and could lower dependence on insecticides, if the functional identity of crops is taken into account. Simple measures such as 'effective number of crop types' help in science communication. Although avian pest control did not respond to landscape-level crop diversity, birds may still benefit from increased crop resources in the landscape, depending on their functional grouping (feeding guild, conservation status, habitat preference, nesting behaviour). Observational studies of bird functional diversity on 14 wheat study fields showed that non-crop landscape heterogeneity rather than crop diversity played a key role in determining the richness of all birds. Insect-feeding, non-farmland and non-threatened birds increased across multiple spatial scales (up to 3000 m). Only crop-nesting farmland birds declined in heterogeneous landscapes. Thus, crop diversification may be less suitable for conserving avian diversity, but abundant species benefit from overall habitat heterogeneity. Specialist farmland birds may require more targeted management approaches. Identifying ecological pathways that favour biodiversity and ecosystem services provides opportunities for ecological intensification that increase the likelihood of balancing conservation and productivity goals. However, change towards a more sustainable agriculture will be slow to come if research findings are not implemented on a global scale. During dissemination activities within the EU project Liberation, I gathered information on the advantages and shortcomings of ecological intensification and its implementation. Here, I introduce a guide ('TREE') aimed at scientists that want to increase the impact of their research. TREE emphasizes the need to engage with stakeholders throughout the planning and research process, and actively seek and promote science dissemination and knowledge implementation. This idea requires scientists to leave their comfort zone and consider socioeconomic, practical and legal aspects often ignored in classical research. Ecological intensification is a valuable instrument for sustainable agriculture. Here, I identified new pathways that facilitate ecological intensification. Soil quality, disturbance levels and spatial or temporal crop diversification showed strong positive correlations with natural enemies, biological pest control and yield, thereby lowering the dependence on agrochemical inputs. Differences between functional groups caused opposing, scale-specific responses to landscape variables. Opposed to our predictions, birds did not disturb insect-mediated pest control in our study system, nor did avian richness relate to landscape-level crop diversity. However, dominant functional bird groups increased with non-crop landscape heterogeneity. These findings highlight the value of combining different on-field and landscape approaches to ecological intensification. Concurrently, the success of ecological intensification can be increased by involving stakeholders throughout the research process. This increases the quality of science and reduces the chance of experiencing unscalable obstacles to implementation. ; Die moderne Landwirtschaft ist die Grundlage menschlichen Lebens, ein Segen, aber auch ein Fluch. Sie stellt Nahrung und Wohlstand für die immerfort wachsende menschliche Bevölkerung bereit, und zerstört gleichzeitig Biodiversitäts-geförderte Prozesse, welche die Produktivität unterstützen: Ökosystemdienstleistungen wie Wasseraufbereitung, Bestäubung und biologische Schädlingsbekämpfung. Ökologische Intensivierung ist eine vielversprechende Alternative zur konventionellen Landwirtschaft, und zielt darauf aus, Erträge und die Gesundheit von Ökosystemen zu erhalten indem Biodiversität und essentielle Ökosystemdienstleistungen aktiv gemanagt werden. In meiner Doktorarbeit untersuche ich die Chancen und Hürden Ökologischer Intensivierung. Das Hauptinteresse meiner Forschung liegt bei 1) der relativen Bedeutung von Boden, Bewirtschaftung und Landschaftsaspekten für Biodiversität und Weizenerträge (Kapitel II); 2) dem Einfluss regionaler Anbauvielfalt auf verschiedenen räumlichen Skalen auf die biologische Schädlingsbekämpfung in Weizen (Kapitel III) und 3) auf die gesamte und funktionelle Artenvielfalt von Vögeln (Kapitel IV). Zum Schluss 4) stelle ich einen Leitfaden vor, der Wissenschaftlern hilft die Wirkung ihrer Forschung zu erhöhen, indem die fundamentale Rolle von Stakeholdern für die Umsetzung Ökologischer Intensivierung besser genutzt wird (Kapitel V). Ökologische Intensivierung bedarf der Identifizierung von natürlichen Prozessen, die zum Erhalt landwirtschaftlicher Erträge beitragen. Zu diesem Zweck verknüpften wir eine Beobachtungsstudie, in der Schädlinge und natürliche Gegenspieler in 28 realen Weizen Anbausystem aufgenommen wurden, mit einem orthogonalen Feldexperiment (Insektizid und mineralische Düngung). Anhand einer Pfadanalyse quantifizierten wir den Einfluss von 34 Faktoren (Bodencharakteristiken, gegenwärtige und vergangene Bewirtschaftung, Landschaftsheterogenität), die direkt oder indirekt (über Räuber-Beute-Interaktionen) Einfluss auf den Winterweizenertrag ausüben. Reduzierte Bodenbearbeitung und vielfältige Fruchtfolgen erhöhten die Erträge unabhängig von der Ausbringung von Agrochemikalien. Gleichzeitig könnte die biologische Schädlingsbekämpfung durch räuberische Insekten wiederhergestellt werden, indem durchschnittliche Schlaggrößen auf der Landschaftsebene verringert, Fruchtfolgen erweitert und die Bodenbearbeitung reduziert wird. Des Weiteren senkte der Verzicht auf Agrochemikalien das Schädlingsaufkommen einiger Arten, und trug zu einer höheren Ertragsqualität bei. Regionale Anbauvielfalt ist ein vielversprechendes Mittel zur Ökologischen Intensivierung. Doch die Erhöhung der Artenvielfalt durch Diversifizierungsmaßnahmen führt nicht immer zu Vorteilen in der Landwirtschaft, vor allem auf Grund antagonistischer Wechselwirkungen zwischen verschiedenen Arten (intraguild predation). Weiterhin können positive Effekte der Anbauvielfalt durch die Wahl der falschen räumlichen Skala oder durch Korrelationen mit anderen Landschaftsvariablen (z.B. halbnatürliche Habitate) überdeckt werden. Aus diesem Grund bestehen Unklarheiten über die Wirkung von Anbauvielfalt auf Biodiversität und Ökosystemdienstleistungen in unterschiedlichen räumlichen Skalen und Kontexten. Durch Ausschlussexperimente mit Getreideblattläusen untersuchten wir die biologische Schädlingsbekämpfung durch räuberische Insekten und Vögel in 18 Winterweizenfeldern innerhalb eines Landschaftsgradienten der Anbauvielfalt. Vögel hatten keinen Einfluss auf die biologische Schädlingsbekämpfung durch Insekten. Anbauvielfalt (nicht das Vorkommen halbnatürlicher Habitate) erhöhte die Schädlingsbekämpfung um bis zu 33%, vor allem auf kleinen räumlichen Skalen. Somit kann die Steigerung der Anbauvielfalt, eine wichtige Säule der Europäischen Gemeinsamen Agrarpolitik, die biologische Schädlingsbekämpfung verbessern und den Einsatz von Agrochemikalien verringern, solange die funktionelle Gruppe der Anbaupflanzen berücksichtigt wird. Einfache Maßeinheiten wie die 'effektive Anzahl an Kulturpflanzengruppen' helfen in der Kommunikation wissenschaftlicher Ergebnisse. Obwohl die Schädlingsbekämpfung durch Vögel nicht durch regionale Anbauvielfalt beeinflusst wurde, könnten Vögel, abhängig von der Zugehörigkeit zu bestimmten funktionellen Gruppen (Ernährung, Gefährdungsstatus, Lebensraum, Nistplatzwahl), dennoch von erhöhten Ressourcen auf landwirtschaftlichen Flächen profitieren. In einer Beobachtungsstudie wurde die funktionelle Vielfalt von Vögeln auf 14 Winterweizenfeldern aufgenommen. Die Studie zeigte, dass die nicht agrarisch genutzte Landschaftsheterogenität im Vergleich zur regionalen Anbauvielfalt eine übergeordnete Rolle für die Artenvielfalt spielte, vor allem für Insektenfresser, Vögel die außerhalb landwirtschaftlicher Flächen siedeln oder nicht in ihrem Bestand gefährdet sind. Effekte waren auf allen Skalen sichtbar (bis zu 3000m). Nur Acker-nistende Agrarvögel zeigten negative Beziehungen zu Landschaftsheterogenität. Der Nutzen der Anbaudiversifizierung scheint weniger Bedeutung für den Vogelschutz zu haben als die übergeordnete Vielfalt der Landschaft, welche den Artenreichtum häufiger Vogelarten erhöhte. Spezialisierte Vogelarten dagegen bedürfen eines gezielten, angepassten Managements. Um Ökologische Intensivierung voranzutreiben und ein Gleichgewicht zwischen Naturschutz- und Produktivitätszielen zu erreichen, bedarf es der Identifikation ökologischer Prozesse, die zur Steigerung von Biodiversität und Ökosystemdienstleistungen beitragen. Doch der die Wende zu einer nachhaltigeren Landwirtschaft wird nur langsam voran schreiten, wenn Forschungsergebnisse nicht global umgesetzt werden. Während der Öffentlichkeitsarbeit im EU Projekt Liberation konnte ich Informationen über die Vor- und Nachteile Ökologischer Intensivierung und deren Umsetzung sammeln. Hier stelle ich einen Leitfaden ('TREE') vor, der Wissenschaftlern helfen soll die Wirkung ihrer Forschung zu erhöhen. TREE verdeutlicht wie wichtig es ist, Stakeholder in den Planungs- und Forschungsprozess eines Projektes mit einzubeziehen, und aktiv die Verbreitung von Wissen und die Umsetzung wissenschaftlicher Ergebnisse voranzutreiben. TREE fordert Wissenschaftler dazu auf, die eigene Komfortzone zu verlassen und sozioökonomische, praktische und rechtliche Aspekte zu berücksichtigen, welche oft in der klassischen Forschung unbeachtet bleiben. Ökologische Intensivierung ist ein bedeutender Schritt in Richtung nachhaltige Landwirtschaft. In dieser Arbeit identifiziere ich neue Wege zur ökologischen Intensivierung. Bodenqualität, Störungsgrad des Bodens und die räumliche oder zeitliche Anbauvielfalt zeigten starke positive Korrelationen mit natürlichen Gegenspielern, biologischer Schädlingsbekämpfung und Erträgen auf, wodurch die Abhängigkeit von Agrochemikalien verringert wird. Unterschiede zwischen funktionellen Gruppen verursachten gegensätzliche Beziehungen zu Landschaftsvariablen auf verschiedenen räumlichen Skalen. Entgegen unserer Erwartungen nahmen Vögel in unserem System keinen Einfluss auf die biologische Schädlingsbekämpfung durch Insekten. Die Vogelvielfalt war außerdem unbeeinflusst von der regionalen Anbauvielfalt. Doch dominante funktionelle Vogelgruppen profitieren von der Vielfalt nicht agrarisch genutzter Landschaftsaspekte. Diese Ergebnisse betonen den Wert einer Mischung aus unterschiedlichen lokalen und landschaftsbezogenen Ansätzen zur Ökologischen Intensivierung. Gleichzeitig kann der Erfolg Ökologischer Intensivierung vor allem dadurch erhöht werden, dass Stakeholder in den Forschungsprozess eingebunden werden. Dies steigert die Qualität der Forschung und reduziert die Wahrscheinlichkeit, während der Umsetzung auf unüberwindbare Hürden zu stoßen.

Dottorato di ricerca in Ecologia e gestione sostenibile delle risorse ambientali ; L'utilizzo dei satelliti a supporto degli studi oceanografici è consolidato ormai da anni, mediante l'impiego di sistemi remoti operativi a risoluzioni spaziali intermedie (SeaWifs, MODIS, MERIS), incentrati principalmente sull'acquisizione di dati di Ocean Color, che permettono di ottenere come prodotto finale la distribuzione di temperatura superficiale, clorofilla e solido sospeso, sulla base di algoritmi già sviluppati per le acque di largo. I recenti progressi nella progettazione di sensori satellitari ad alta risoluzione spaziale e spettrale e nelle tecniche di analisi dati, hanno reso i sistemi di telerilevamento più efficaci e utili anche per lo studio degli ambienti marino-costieri, dimostrandosi quindi un valido strumento di indagine a supporto delle misure di politica ambientale della Comunità europea (Cristina et al., 2015). Tali misure mirano ad ottenere il "Buono stato ecologico" GES delle acque costiere europee secondo la Direttiva Quadro sulla Strategia Marina (MSFD) (2008/56/ Commissione Europea). La MSFD indica e descrive Descrittori ed indicatori ambientali da considerare ai fini delle misure di monitoraggio per la valutazione del GES nelle aree costiere europee. Le immagini multispettrali da satellite, opportunamente corrette per i rumori atmosferici e calibrate utilizzando le misurazioni in situ, sono riconosciute come efficaci strumenti multiscala per il monitoraggio della qualità dei mari e delle acque poco profonde (Dazhao et al., 2010, Blondeau-Patissier et al., 2014). In linea con tali riferimenti, questo progetto di dottorato si pone l'obiettivo di valutare, in maniera tempestiva, efficace e a scala sinottica lo stato di qualità ecologica degli ecosistemi marino-costiero, attraverso nuove tecniche di remote sensing (RS) secondo le linee guida della Direttiva Marine Strategy. In questo contesto, sono oggetto di studio alcuni indicatori, riferiti principalmente al Descittore 1 MSFD per la Biodiversità Biologica, che prevede la stima dello stato qualitativo delle praterie di fanerogame marine e misure sulla Torbidità dell'acqua marina identificabile con il solido sospeso superficiale; infine, la clorofilla è stata osservata in riferimento al Descrittore 5 MSFD per il fenomeno dell'Eutrofizzazione. Tali variabili possono essere rilevate e mappate mediante telerilevamento per ottenere stime quantitative di distribuzione superficiale al fine di valutare l'integrità ecologica e lo stato di salute degli ecosistemi marino-costieri (Shetty et al., 2015). I sensori RS devono necessariamente soddisfare determinati requisiti per il loro utilizzo in ambiente costiero, soprattutto in termini di risoluzione radiometrica e spazio-temporale, diversi rispetto a quelli per gli studi in mare aperto. Questo è dovuto a vari fattori: l'elevata variabilità delle scale spazio-temporali dei processi ecologici costieri richiede un'alta risoluzione spaziale del sensore satellitare (1-30 m); le acque sono otticamente più complesse, acque di Caso 2 (Morel and Prieur,1977) e richiedono numerose bande spettrali per discriminare i vari tipi di segnali, legati alle diverse componenti otticamente attive dell'acqua marina e dei bassi fondali; il segnale dell'acqua che viene rilevato dal satellite è maggiormente influenzato dagli strati atmosferici rispetto al segnale terrestre e quindi è 2 richiesta un'accurata correzione atmosferica; infine la vicinanza di superfici terrestri altamente riflettenti, come le spiagge, può indurre un ulteriore disturbo (denominato "fattore di adiacenza") al segnale uscente dall'acqua. Sulla base di queste problematiche, le piattaforme satellitari utilizzate in questo studio sono state Landsat 8 Operational Land Imagery (L8OLI) per uno studio ad alta risoluzione (30 m- High Resolution HR) per la mappatura della prateria di PO (Caso Studio 1) e della distribuzione di clorofilla a (Caso Studio 3) e MODIS (Caso Studio 2) con la media risoluzione (250 m) per un'indagine su scala regionale e a lungo termine delle dinamiche di distribuzione del solido sospeso, attraverso un approccio multidisciplinare. La metodologia affrontata in tutti e tre i casi studio presentati, ha previsto l'abbinamento temporale dei dati raccolti per la verità a mare con le immagini satellitari scaricate dal sito NASA, che rende liberamente accessibili i dati satellitari compresi nel suo sistema osservativo globale della Terra. Questi dati spettrali sono stati corretti adeguatamente per il rumore atmosferico per mappare su opportune scale spaziali/temporali la distribuzione dei parametri biofisici discreti e continui (associati all'ambiente acquatico o del fondo marino) per valutare adeguatamente le distribuzioni delle variabili in esame, sulla base di diversi approcci di modellazione. In particolare, Landsat 8 OLI ha permesso di stimare le condizioni di qualità delle praterie di Posidonia oceanica lungo più di 40 km della costa settentrionale tirrenica, a sostegno di un metodo innovativo d'indagine non invasiva e quindi in linea con una gestione sostenibile delle risorse marino-costiere. Questo sensore è stato anche utilizzato per mappare la distribuzione della clorofilla a, per una caratterizzazione efficace della distribuzione del fitoplancton nelle acque del Mar Piccolo di Taranto, attraverso modelli statistici regressivi e algoritmi bio-ottici. Da questi due studi, è emersa quindi, la validità dei dati multispettrali HR, forniti dalla nuova generazione di sensori della famiglia NASA Landsat (cioè Landsat 8 OLI, Sentinel 2 MSI) per un'osservazione efficace, integrata ed operativa degli ecosistemi marino-costieri. Per quanto riguarda la media risoluzione con MODIS, questo sensore ha permesso di raccogliere 630 immagini dal 2013 al 2017 nel golfo di Gaeta, per ottenere informazioni sinottiche e continue sulla componente della colonna d'acqua superficiale di solido sospeso, strettamente connessa alle dinamiche meteo-marine su scala regionale anch'esse studiate. La risoluzione media delle immagini RS è risultata un valido strumento di supporto, all'interno di un approccio integrato per lo studio marino costiero, al fine di migliorare la strategia di gestione ambientale a lungo termine dal punto di vista delle attività umane sostenibili per gli ecosistemi costieri. Come prospettiva futura, si può considerare di pianificare una più ampia raccolta di misure in situ per i dati di colonna d'acqua, per implementare il dataset necessario all'applicazione di un modello di inversione bio-ottica, utile alla rimozione più efficace dei disturbi della componente otticamente attiva della colonna d'acqua sul segnale spettrale del fondale marino oggetto di studio. Questo fattore apporterebbe anche ulteriori informazioni a sostegno di una maggiore comprensione degli ambienti acquatici otticamente complessi e, di conseguenza, la mappatura degli ecosistemi bentonici costieri risulterebbe ancora più accurata. Sulla base delle considerazioni e dei risultati soddisfacenti ottenuti in questo lavoro di tesi, tradotti nello specifico in tre pubblicazioni, si può affermare che le nuove tecniche di telerilevamento si mostrano efficaci per lo studio operativo degli ecosistemi marini di basso fondale e della biodiversità in ambiente costiero, fornendo un utile contributo alle misure indicate dalle Direttive comunitarie per arrestare il declino della biodiversità e per garantire la conservazione degli ecosistemi marini. ; The use of satellites to support oceanographic studies has been consolidated for years, through the use of remote systems operating at intermediate spatial resolutions (SeaWifs, MODIS, MERIS), mainly focused on the acquisition of Ocean Color data, which to obtain as a final product the distribution of chlorophyll and suspended solid, based on algorithms already developed for the offshore waters. Recent advances in the design of satellite sensors with high spatial and spectral resolution and in data analysis techniques, have more effective remote sensing systems also useful for the study of marine-coastal environment, thus proving to be a valid investigation tool to support policy measures. Environment of the European Community (Cristina et al., 2015). These measures aim to achieve the "Good ecological status" GES of European coastal waters according to the Marine Strategy Framework Directive (MSFD) (2008/56/European Commission). The MSFD indicates and describes Environmental descriptors and indicators to be considered for the purpose of monitoring measures for the evaluation of the GES in the European coastal areas. Multispectral satellite images, appropriately corrected for atmospheric noise and calibrated using in situ measurements, are recognized as effective multiscale instruments for monitoring the quality of seas and shallow waters (Dazhao et al., 2010, Blondeau-Patissier et al., 2014). In line with these references, this PhD project aims to evaluate, in a timely, effective and synoptic way, the ecological quality status of marine-coastal ecosystems, through new remote sensing (RS) techniques according to the guidelines of the Marine Strategy Directive. In this context, some indicators are being studied, mainly referring to the MSFD Descriptor 1 for Biological Biodiversity, which provides for the estimation of the qualitative status of marine phanerogams and measures on the turbidity of the marine water that can be identified with the surface suspended solid; finally, the chlorophyll has been observed with reference to the MSFD Descriptor 5 for the phenomenon of Eutrophication. These variables can be detected and mapped by remote sensing to obtain quantitative estimates of surface distribution in order to evaluate the ecological integrity and health status of marine-coastal ecosystems (Shetty et al., 2015). RS sensors must necessarily meet certain requirements for their use in coastal environments, especially in terms of radiometric and spatio-temporal resolution, different from those for offshore studies. This is due to poor factors: the high variability of the spatio-temporal scales of coastal ecological processes requires a high spatial resolution of the satellite sensor (1-30 m); the waters are optically more complex, Case 2 waters (Morel and Prieur, 1977) and require numerous spectral bands to discriminate the various types of signals, linked to the different optically active components of sea water and shallow waters; the water signal that is detected by the satellite is more influenced by the atmospheric layers than the terrestrial signal and therefore an accurate atmospheric correction is required; finally, the proximity of highly reflective terrestrial surfaces, such as beaches, can induce a further disturbance (called "adjacency factor") to the signal coming out of the water. Based on these issues, the satellite sensors used in this study were Landsat 8 Operational Land Imagery (L8OLI) for a high resolution study (30 m- High Resolution HR) for mapping the PO prairie (Case Study 1) and of the chlorophyll a distribution (Case Study 3) and MODIS (Case Study 2) with the average resolution (250 m) for a regional and long-term investigation of the distribution dynamics of the suspended solid, through a multidisciplinary approach. In all three case studies presented, it provided for the combination of temporal data collected for the sea truth with satellite images downloaded from the NASA site, which makes freely available the satellite data included in its global observational system of the Earth. These spectral data have been adequately corrected for atmospheric noise to map the distribution of discrete and continuous biophysical parameters (associated with the aquatic environment or the seabed) to suitably assess the distributions of the variables under examination, on different bases. modeling approaches. Landsat 8 OLI has allowed to estimate the quality conditions of seagrass meadows supporting an innovative method of non-invasive investigation based on the sustainable management of marinecoastal resources. Using its acquisition channels, improved in terms of spectral and radiometric features and with the introduction of the new coastal band, it was possible to produce suitable PO LAI and sea beds substrate distribution maps in a significant portion of the middle Tyrrhenian coast: more than 40 km along the coast. The effectiveness of the use of new remote sensors was demonstrated for an ecological study of seagrass grasslands with various advantages: limitation of destructive sampling for PO; cost reduction with respect to sea-truth measurement campaigns; evaluation of the plant distribution on a synoptic scale to estimate the ecological quality, and a potentiality for classifying substrate types of the seafloor in the entire study area. The results achieved by the Landsat OLI sensor suggest their effectiveness for seabed/PO/chlorophyll mapping and monitoring in the optically complex shallow water, evidencing also the specific atmospheric correction relevance for reflectance data pre-processing. The complexity and variability of coastal marine environments highlights, in fact, the need to apply appropriate investigation tools and methodologies to develop an integrated and multidisciplinary study method that allows an effective assessment of the good environmental status of marine ecosystems. As a future perspective, we can consider setting up a larger collection of in situ measurements for water column and seabed data, to apply the bio-optical inversion model, which can more effectively remove the disturbances of the water column on the spectral signal of the seabed. It is also needed for continuous progress in the understanding of complex optical aquatic environments and, as a result, the mapping of benthic coastal ecosystems may be more accurate. On the basis of all these considerations and the satisfactory results achieved in this work, it can be stated that innovative and effective remote sensing technique for the operational study of the seabed coastal ecosystems could significantly contribute to the attempts of Community legislation, to halt the decline of biodiversity and to ensure the marine ecosystems preservation. Functioning ecosystems are essential for maintaining the oceans in a healthy state (Tett et al., 2013) and while being healthy, they provide numerous and diverse goods and services that contribute "for free" to the general well-being and health of humans (Van Den Belt and Costanza, 2012).