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Cayan, Umit N. "NATO's Mediterranean dialogue : challenges and prospects /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FCayan.pdf.
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Salonia, Matteo. "Genoese economic culture : from the Mediterranean into the Spanish Atlantic." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2009805/.
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This thesis investigates the economic culture that fostered the constitutional history and political cosmology of late medieval and early modern Genoa. Genoese economic actors are here studied through their diversified trades and businesses, as they moved from the shores of the Black Sea into the Atlantic. Genoa’s late medieval economic expansion is described through several case studies and briefly compared to the state-run military expansion of Venice’s empire. Genoese colonial history is found to be both peculiar and relevant, as entrepreneurial techniques, institutions and attitudes later transferred to the Atlantic first originated in the private networks built by Ligurian businessmen in the thirteenth and fourteenth centuries. The adaptability and entrepreneurial skills that allowed Genoese merchants and bankers, captains and businessmen, tax collectors and clergymen to enter the Spanish Atlantic in the sixteenth century are linked to the medieval history of the Genoese commune, to the specific idea of libertà progressively defined and protected by its fluid elite, and to the development of Hispanic-Genoese diplomatic and financial relations. Through the study of diverse documents in Italian, Genoese dialect, Venetian dialect, Spanish, Latin, and English, Genoa’s civic ideology and institutions are revealed to be intertwined with Genoese entrepreneurs’ simultaneity of careers, cosmopolitan self-perception, and mimetic imperialism. The thesis closes with a survey of the Genoese economic activities in Spain’s American kingdoms, whose most significant result is the illustration of Genoa’s multifaceted roles in the building of the Hapsburg Atlantic. This work thus constitutes the first chronologically and thematically broad attempt to explain the prolonged Genoese presence on the stage of intercontinental commerce as well as the existence of a modern Ligurian Atlantic.
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Serradilla, Avery Dan Manuel. "Seville: between the Atlantic and the Mediterranean, 1248-1492 : pre-Columbus commercial routes from and to Seville /." St Andrews, 2007. http://hdl.handle.net/10023/340.
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Slater, Deborah Ruth. "The transport of Mediterranean water in the North Atlantic Ocean." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/426647/.
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Ocean circulation is a fundamental component of the Earth's climate system. The Atlantic thermohaline circulation, driven by deep convection at high latitudes, has a central role in regulating European climate through its transport and redistribution of heat. Either directly or indirectly, Mediterranean Water (MW) provides the high salinities found in the Nordic Seas which are required to precondition for deep convection. The precise mechanisms and pathways remain undetermined and yet are fundamental to understanding the effect that any change in the Mediterranean Outflow may have on circulation and ultimately on climate. This thesis investigates the transport of MW in the North Atlantic Ocean using hydrographic and model data. The primary objective is to quantify how much MW flows northwards and how much flows westwards from its source in the Gulf of Cadiz. Two boxes (Med Boxes) were constructed using hydrographic sections in the eastern North Atlantic enclosing the Strait of Gibraltar and Mediterranean Outflow. Inverse methods were used to determine the velocity field from which volume transports and salt fluxes were calculated. The main northward flow of MW across 41°N occurs east of 12°W, at depths of 500 to 1500 m, and transports 50 to 75% of the MW. An advective westward pathway across 20°W transports MW at similar depths into the ocean interior between 35°N and 40°N. Insignificant salt fluxes across the southern section (24°N) at MW depths confirm that no MW crosses the southern Med Box boundary. The net overturning circulation of the Med Box, with inflowing surface waters and outflowing intermediate waters, is attributed both to the exchange at the Strait of Gibraltar and also to water mass transformation associated with entrainment of North Atlantic Water into the Mediterranean Outflow. The magnitude of the circulation provides an estimate of this entrainment of 1.6 ± 0.6 Sv, within the Med Box boundaries. For comparison with these observational estimates, the model used is OCCAM, a level model from the Ocean Circulation and Climate Advance Modelling Project. The primary reason for choosing this model is that experiments have been undertaken with the Strait of Gibraltar both open and closed, enabling a new approach to the investigation of MW transport. MW is identified using the salinity difference between the two model experiments. Although the model circulation (in the open-Strait run) has a similar net overturning to the hydrography, different MW transport pathways are observed. A weak and variable northward pathway along the Iberian Peninsula and a strong southwestward flow from the Gulf of Cadiz result in a higher proportion of MW flowing westwards (61%) than northwards (39%). Seasonal variability is observed, with maximum westward flow in Autumn (70%) and minimum in Spring (50%). There is no evidence in the model that the northward boundary current provides a direct route for Mediterranean salt to reach the Nordic Seas.
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Geen, Alexander F. M. J. van. "Trace metal sources for the Atlantic inflow to the Mediterranean Sea." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/52957.
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Bahamon, Rivera Nixon. "Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic." Doctoral thesis, Universitat Politècnica de Catalunya, 2002. http://hdl.handle.net/10803/6381.
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The response of phytoplankton to various ecological forcings was examined in the upper waters of the NW Mediterranean (MED) and the subtropical North Atlantic (NA) from field observations, analysis of historical data sets and numerical simulations. Particular emphasis was given to the role played by the water column structure in controlling the nitrogen diffusion and new production. Using numerical simulations, the effects of different levels of heating of surface waters and nutrient concentrations in waters below the euphotic zone were examined.Spring microplankton metabolism of surface mixed waters in MED was studied. The system was heterotrophic explained by dark community respiration (DCR) rates higher than gross primary production (GPP) rates. The GPP to DCR ratio was ~0.53, indicating that the system was far from balance between carbon production (photosynthesis) and consumption (respiration), probably caused by organic matter accumulation in the mixed layer favouring respiration over production processes.
Summer primary production and nitrogen fluxes in stratified water layers in NA were analysed. The nitrogen flux fuelling new primary production was closely linked to vertical turbulent diffusion at the nitracline rather than at the thermocline. Upward diffused nitrogen inducing new production explaining 21% of total primary production. The vertical turbulent diffusion model used to estimate new production did not explain new production in the Canary Current zone, where laterally advected nutrients from coastal upwelling areas altered the vertical nitrate gradients.
A numerical ecological model of the pelagic domain was developed to assess the plankton response to different environmental pressures. The model represents the vertical dimension of the upper and intermediate water layers of the open ocean. A comparative study of the plankton functioning in MED and NA sites was carried out using the model. The nitrate entering the euphotic zone through the lower boundary explained the low but continuous primary production in the two systems. The latitudinal variability of plankton scenarios implied a year round different solar heating of the upper waters, altering both phytoplankton photosynthesis and mixed layer processes in the water column, with the latter dominating over the former in controlling the phytoplankton biomass. The balance of light availability and nutrient concentration controlled the chlorophyll maximum depth, but the zooplankton grazing prevented this maximum to reach greater concentrations. The model structure and functioning makes it suitable for comparative ecological studies and is expected to be applicable to other studies related to coastal and marine environmental issues.
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Boyd, Meighan. "Speleothems from Warm Climates : Holocene Records from the Caribbean and Mediterranean Regions." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-121750.
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This thesis contributes to increased knowledge on Holocene climate and environmental variability from two complex and sparsely studied areas. Using a speleothem from Gasparee Cave, Trinidad, as a paleoclimate archive, the local expression of the 8.2 ka (thousand years before 1950) climate event and associated patterns of the inter-tropical convergence zone (ITCZ) and rainfall is provided. Subsequent speleothem studies using multi-proxy analysis of stalagmites from Kapsia Cave and Alepotrypa Cave, Greece, provide records of climate, vegetation and human induced changes in the cave environment during parts of the Holocene. The speleothems from the well-studied Neolithic habitation site, Alepotrypa Cave, have produced a climate and habitation record which covers the period of 6.3-1.0 ka. The cave was inhabited between 8.0-5.2 ka and was closed by a tectonic event, which has preserved the settlement. The stable oxygen record shows the first well-dated and robust expression of the 4.2 ka dry event in the Peloponnese, places the timing of the 3.2 ka dry event within an ongoing dry period, and shows a final dry event at 1.6 ka. The North Atlantic as well as more regional drivers, such as the North Sea Caspian Pattern Index is proposed to, in a complex interplay, govern many of the climate trends and events observed. Trace element variation after the site is abandoned indicate what is interpreted as two volcanic eruptions, the Minoan eruption of Thera (Santorini) around 3.6 ka and the 2.7 ka eruption of Somma (Vesuvius). Variations in trace elements during the habitation period show clear human influence, indicating an association with specific cave activities. One of the most interesting prospects for continued work on Alepotrypa Cave is this successful marriage of speleothem studies and archeology. A framework of dates which constrain some behavior of people living in the cave is only the beginning, and there is great potential to continue finding new clues in the speleothem data.Denna avhandling bidrar till ökad kunskap om klimatets variationer och miljön i två geografiskt skilda områden på låga breddgrader och under tidsperioder inom den Holocena epoken. Genom att använda en droppsten (stalagmit) från Gasparee-grottan, Trinidad, som ett paleoklimatarkiv, har det bland annat varit möjligt att visa att Trinidad upplevde torrare förhållanden under den snabba klimatförändring som observerats ske för 8200 år sedan på många platser i världen. Denna torrare klimatsituation i Trinidad föreslås vara ett resultat av en sydlig förflyttning av den intertropiska konvergenszonen. Övriga stalagmiter som studerats för denna avhandling kommer från Kapsia-grottan och Alepotrypa-grottan som finns på Peloponnesos-halvön i Grekland. Resultaten därifrån speglar dels klimat- och vegetationsvariatoner och dels graden av mänsklig aktivitet, under tiden för ca 8000 år sedan till för 1000 år sedan. Alepotrypa-grottan är känd för att vara en av de större Neolitiska boplatserna i Grekland. Isotop- och spårämnesanalyser av stalagmiterna har bidragit med ny kunskap om tidpunkten för mänsklig aktivitet, hur människorna påverkade grott-miljön samt hur klimatet varierat efter det att grottan, genom en tektonisk händelse, stängdes för människans inverkan. Snabba klimatförändringar, för 4200 och 3200 år sedan, observerade i andra regioner, rekonstrueras här för första gången på Peloponnesos. En snabb förändring mot torrare förhållanden observeras även för 1600 år sedan. De klimatstyrande processerna föreslås vara en kombination av storskaliga processer som den nordatlantiska oscillationen och mer regionala processer som det så kallade North Sea Caspian Pattern Index. Variationer i spårämnen i stalagmiterna efter att Alepotrypa-grottan stängdes kan kopplas till två vulkaniska utbrott, nämligen det Minoiska utbrottet av Thera på ön Santorini kring 3600 år sedan och utbrottet av Somma (Vesuvius) kring 2700 år sedan. Spårämnesvariationer under bo-perioden ger tydliga indikationer på människans påverkan på grottmiljön och som delvis kan länkas till specifika aktiviteter, som eldning av dynga i grottan. Avhandlingen är ett resultat av en framgångsrik kombination av klimatstudier och arkeologisk kunskap och utgör ett viktigt underlag för fördjupat interdisciplinärt forskningssamarbete i Alepotrypa-grottan.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript. Paper 6: Manuscript.
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Bubbico, Rocco Luigi. "Drivers and effectiveness of regional innovation partnerships in Mediterranean less developed regions." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/drivers-and-effectiveness-of-regionalinnovation-partnerships-in-mediterraneanless-developed-regions(c0d739d1-850f-4dc4-887b-cdb78efafb15).html.
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This work is based on the analysis of regional innovation policies and partnerships for innovation in EU 2000-2006 Objective 1 regions. The focus on the wide concept of innovation at European level and the international competitive challenges are pushing European regions to increase the effectiveness of local innovation policies, developing and strengthening their regional innovation systems in partnership with local actors. The research has the main aim to evaluate the contribution of regional innovation policies to regional development, identify levers and obstacles, analyse the structures of Regional Innovation Systems including processes of cooperation, assess the effectiveness of regional policy mix and finally evaluate the effectiveness of regional partnerships. The methodology of the research is based on a multiple case-study approach and on mixed methods. Four case studies have been selected: Puglia, Sardegna, Comunidad Valenciana and Region de Murcia. Overall, 104 semi-structured interviews have been carried out in the four regions, with regional administrators, innovation agency managers, entrepreneurs, technology centres managers and academics (involved in spinoffs or managers of collaborative/industrial research projects). The field work activities have been focused on documentation review, unstructured interviews and data collection. A database of policy interventions was created to analyse targets, beneficiaries and areas of intervention. An analysis of regional performance has been conducted to examine the socio-economical structure and regional innovation indicators. The findings show common patterns and issues in policy implementation and dilemmas in strategic choices. All case studies featured wide and multi-purpose strategies aimed at the quantitative growth of regional innovation systems and a higher degree of internal collaborations through the support to intermediate bodies. Innovation systems are taking shape: regional administrations made a significant effort but struggled to overcome structural limitations and external constraints affecting the innovation structure.
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Weiss, Aaron D. "Proposal for a Standing Mediterranean Amphibious Force for the North Atlantic Treaty Organization." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA358787.
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Thesis (M.S. in Management) Naval Postgraduate School, December 1998."December 1998." Thesis advisor(s): Richard J. Hoffman, Brad R. Naegle. Includes bibliographical references (p. 119-123). Also available online.
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Cortés, Simó Maria. "Flood damage assessment in two western Mediterranean regions. Present conditions and future scenarios." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/668768.
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Flooding is one of the main natural hazard in the world causing huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, mainly due to its pronounced sensitivity to climate change. A large number of floods affecting the western Mediterranean region of study are surface water floods that can cause catastrophic damage. These floods are caused by intense precipitation events, thus, in order to understand properly these type of events, the analysis of the relationship between precipitation and flood damage is crucial.
The overall objective of this thesis is to analyse flood damages in two Mediterranean regions, namely Catalonia and the Valencian Community, frequently affected by intense precipitation events, as well as to estimate their changes when future climate change projections and different socioeconomic scenarios are considered.
To do this, the relationship between heavy precipitation and flood damage estimates from insurance datasets, provided by the Spanish Insurance Compensation Consortium (Consorcio de Compensación de Seguros, CCS), have been analysed. Other than for the above mentioned two areas of study, this analysis was performed for the Metropolitan Area of Barcelona (MAB), a highly vulnerable urban area. The study period covers 1996-2015.
Several regression models have been tested in order to gauge the probability of large damaging events occurring given a certain precipitation amount and taking into account other variables related to the exposure of the territory. Results have shown that generalized linear mixed models are the most appropriate tool for studying the relationship between precipitation and flood damage. The probability of a damaging flood event increases with precipitation and population of the basin. Moreover, 30-min precipitation data proved to be a better predictor of the probability of large damages than daily precipitation, however, this type of information is not always available.
On the other hand, we have analysed the projected changes in precipitation extremes in the Iberian Peninsula considering the Representative Concentration Pathway (RCP) 8.5 scenario and an ensemble of seven EURO-CORDEX simulations spanning the period 1976-2100. In order to do this, different climate indices were calculated to estimate the changes in precipitation assuming global warming scenarios of 1.5, 2 and 3 °C above preindustrial levels. Results show a general decrease of the total annual precipitation and an increase in the length of dry spell in most of the Peninsula. This increase accentuates with higher levels of global warming and during summer months. In terms of heavy precipitation, we have found increases with global warming in the maximum 1-day and consecutive 5-day precipitation indices as well as in the number of days with precipitation exceeding 40 mm, especially during the months of autumn and winter and in the north and north-east of the Iberian Peninsula.
Finally, changes in the probability of occurrence of damaging flood events have been assessed for both regions when considering a global warming of 1.5, 2 and 3 °C and taking into account different climate projections and socioeconomic scenarios. To do this, the previously developed statistical climate model that links precipitation, population and flood damage estimates, has been used to assess future climate conditions. The daily precipitation data from the seven climate models used previously and population projections based on five different socioeconomic scenarios (Shared Socioeconomic Pathways, SSPs) were incorporated into the model. Results have shown a general increase in the probability of a damaging event for most of the cases and in both regions of study, being higher in the case of Catalonia. This change is
usually larger when greater warming is considered and for higher percentiles of damage. Moreover, the increase in probability is larger when both climate and population changes are included.
Our findings highlight that, when it comes to flood damage analysis, it is crucial not only to account for climate change but also consider socioeconomic conditions. Furthermore, results show that limiting global warming is a must in order to minimise the consequences of flood events in the study area.Les inundacions són un dels principals desastres naturals al món degut als grans impactes econòmics i humans que causen. La majoria d'inundacions que afecten l'oest del Mediterrani són inundacions d'aigua superficial, les quals estan causades per episodis de precipitació intensa. L'objectiu general d'aquesta tesis és analitzar els danys per inundacions que es produeixen a dues regions Mediterrànies: Catalunya i la Comunitat Valenciana, les quals es veuen freqüentment afectades per episodis de precipitació intensa, així com estimar els canvis en aquests danys tenint en compte tant les projeccions futures de canvi climàtic com diferents escenaris socioeconòmics. En primer lloc, s'ha analitzat la relació entre la precipitació intensa i els danys per inundacions estimats a partir de dades d'asseguradores. Els resultats han demostrat que els models lineals mixtes generalitzats són la metodologia més apropiada per estudiar la relació entre la precipitació i els danys causats per les inundacions. La probabilitat de que tingui lloc un episodi d'inundacions amb grans danys augmenta amb la precipitació i la població de la conca. Per una altra banda, s'han analitzat els canvis en la precipitació a la península Ibèrica quan s'assumeix un escalfament global de 1,5, 2 i 3 °C per sobre dels nivells preindustrials. Els resultats mostren una disminució general de la precipitació total anual i un augment de la precipitació extrema principalment durant els mesos de tardor i hivern i al nord i nord-est de la península Ibèrica. Finalment, s'han avaluat els canvis en la probabilitat que es produeixin episodis d'inundacions amb grans danys a les dues regions d'estudi quan es considera un escalfament global d'1,5, 2 i 3 °C i es tenen en compte diferents projeccions climàtiques i escenaris socioeconòmics. Els resultats mostren que hi ha un augment general d’aquesta probabilitat per ambdues regions d'estudi, sent més accentuada en el cas de Catalunya. Aquest canvi és major quan es considera un nivell d'escalfament superior i per percentils de danys més alts. A més a més, s’accentua quan es tenen en compte tant els canvis en la precipitació com en la població. Els nostres resultats ressalten que, quan es tracta d'analitzar els danys de les inundacions, és molt important tenir en compte tant el canvi climàtic com també les condicions socioeconòmiques. A més a més, els resultats mostren que limitar l'escalfament global esdevé una necessitat per minimitzar les conseqüències dels episodis d'inundacions a la zona d'estudi.
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Anastasiou, Evilena. "The paleoparasitology of Eastern Mediterranean and adjacent regions : understanding intestinal diseases through time." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.681238.
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Bell, Thomas G. "Dimethylsulphide and ammonia in remote marine regions : an Atlantic meridional transect study." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435128.
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Casty, Carlo. "Climate variability over the North Atlantic/European and Alpine regions since 1500 /." [S.l.] : [s.n.], 2005. http://www.zb.unibe.ch/download/eldiss/05casty_c.pdf.
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Pappa, Eleftheria. "Early Iron Age Exchange in the West : Phoenicians in the Mediterranean and the Atlantic." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519811.
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MarcoÌ, AÌ€urea Peralba. "Niche separation of Clausocalanus species in the Mediterranean Sea and in the Atlantic Ocean." Thesis, Open University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446096.
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Jamaladdeen, Rawaa. "Investigation on Wildfire Flashovers in the Mediterranean Climate Regions with Emphasis on VOCs Contributions." Electronic Thesis or Diss., Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2023. http://www.theses.fr/2023ESMA0015.
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Cette thèse apporte des réponses aux demandes de la communauté des pompiers d'étudier les facteurs probables responsables de l'intensification des régimes de feux de forêt jusqu'aux flashovers en utilisant des approches expérimentales numériques et thermochimiques. Le modèle numérique est un modèle de dispersion de gaz validant les données expérimentales des essais en soufflerie pour résoudre la controverse quant à savoir si les accumulations de composés organiques volatils (COV) dans des topographies confinées finissent par induire des incendies de forêt. Il comprend un front de feu se propageant calculé à l'aide du modèle semi-empirique de feu de surface en régime permanent de Rothermel et de la transition de Van Wagner vers les critères de comportement des feux de cime, avec un taux instable intégré d'émissions de COV simulant ceux évoluant à partir de la combustion de la végétation dans le front de feu. Pour synchroniser nos travaux avec les données de terrain, des expériences thermochimiques ont été menées sur diverses espèces de végétation méditerranéenne afin d'examiner leurs taux d'émission de COV dans des conditions environnementales normales et stressantes, car elles pourraient finir par définir différents scénarios d'inflammabilité lors d'incendies de forêt. Premièrement, deux espèces d'arbustes méditerranéens : Cistus albidus et Rosmarinus officinalis sont explorées pour leurs émissions de COV et leurs changements physiologiques après avoir été soumises à des stress abiotiques (sécheresse et chaleur), à l'aide d'analyses par chromatographie en phase gazeuse par pyrolyse et par spectrométrie de masse (Py-GC/MS). Deux autres espèces forestières méditerranéennes : Quercus suber L. et Cupressus sempervirens horizontalis L. ont été étudiées pour leurs caractéristiques d'inflammabilité distinctives à l'aide d'analyses thermogravimétriques et thermiques différentielles (TG/DTA), couplées à une analyse Py-GC/MS pour identifier les gaz émis. lors des pics exothermiques. Cette étape vise à mieux comprendre les descripteurs d'inflammabilité de ces espèces dans le cadre d'une stratégie de gestion forestière plus efficace par laquelle, en favorisant la plantation de certaines espèces moins inflammables dans les mesures sylvicoles, on pourrait protéger d'autres espèces plus inflammables mais économiquement précieuses, des dangers des incendies de forêt et leurs comportements extrêmes. Les espèces de la végétation méditerranéenne sont d'importants émetteurs de COV, en particulier lorsqu'ils sont provoqués par des stress externes lors d'incendies de forêt. Cependant, certains COV biogènes (COBV), plus particulièrement les sesquiterpènes, ne sont pas encore complètement couverts pour leurs caractéristiques d'inflammabilité, telles que leurs limites inférieure et supérieure d'inflammabilité, leur auto-inflammation, températures, points d'éclair, etc. Une telle lacune scientifique qu'il a fallu enrichir en étudiant les limites d'inflammabilité du β-Caryophyllène, l'un des plus importants sesquiterpènes émis par la végétation méditerranéenne. Des tests préliminaires pour mesurer les pressions de vapeur du β-Caryophyllène sont menés en vue d'expérimenter ses limites d'inflammabilité dans une bombe sphérique comme plans futurs. Les travaux de cette thèse doivent être considérés comme la première étape d'une approche plus globale qui devrait fournir aux personnels opérationnels de lutte contre les incendies un outil d'aide à la décision complet, capable de façonner leurs stratégies de gestion forestière pour protéger les milieux naturels et les pompiers des dangers des comportements extrêmes des incendies de forêtRequests from the firefighting communities are increasing urging the scientific communities to create operational protective and preventive tools that help them understand extreme wildfire behaviors considering not only the atmospheric conditions but also topography, and vegetation characteristics. Thus, our objective was to provide answers to such requests by investigating the probable factors responsible for intensifying wildfire regimes to flashovers using numerical, and thermobiochemical experimental approaches. The numerical model is a gas dispersion model validating experimental data from wind tunnel tests to resolve the controversy of whether or not the volatile organic compounds (VOCs) accumulations in confined topographies end up inducing wildfire flashovers. It comprises a propagating fire front calculated using the Rothermel semi-empirical steady-state surface fire model, and Van Wagner transition to crown fire behavior criteria, with an integrated unsteady rate of VOC emissions simulating the ones evolving from the vegetation burning in the firefront. To synchronize our work with field input, thermochemical experiments were conducted on various Mediterranean vegetation species to examine their VOC emission rates in normal and stressful environmental conditions as they may end up defining different flammability scenarios in wildfires. First, two Mediterranean shrub species: Cistus albidus and Rosmarinus officinalis are explored for their VOC emissions and physiological changes after being subjected to abiotic stresses (drought and heat), using pyrolysis-gas chromatography and mass spectrometry (Py-GC/MS) analyses. Two other Mediterranean forest species: Quercus suber L. and Cupressus sempervirens horizontalis L. were investigated for their distinctive flammability characteristics using thermo-gravimetric and differential thermal analyses (TG/DTA), coupled with Py-GC/MS analysis to identify the gases emitted during the exo-thermic peaks. This step aims to better understand the flammability descriptors of these species as a part of a more efficient forest management strategy by which, favoring the plantation of certain lesser flammable species in silviculture measures may protect other more flammable but economically valuable species, from the dangers of wildfires and their extreme behaviors. Mediterranean vegetation species are important VOC emitters especially when provoked by external stresses during wildfires however, some biogenic VOCs (BVOCs), more particularly sesquiterpenes, are still not thoroughly covered for their flammability characteristics, such as their lower and upper flammability limits, auto-ignition temperatures, flashpoints, etc. Such a scientific lack we found it necessary to enrich by studying the flammability limits of β-Caryophyllene, one of the most important sesquiterpenes emitted from Mediterranean vegetation. Preliminary tests for measuring the vapor pressures of β-Caryophyllene are conducted in preparation for experimenting its flammability limits in a spherical bomb as future plans. The work in this thesis should be considered as the first step in a more global approach that should provide operational firefighting staff, with a comprehensive decision-making tool capable of shaping their forest management strategies from wildfire characteristics themselves and protecting wildlands and firefighters equally from the dangers and extreme behaviors of wildfire flashovers
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Schneider, Anke [Verfasser]. "Tracers and Anthropogenic Carbon in the Tropical Atlantic Ocean and the Mediterranean Sea / Anke Schneider." Kiel : Universitätsbibliothek Kiel, 2011. http://d-nb.info/1020202092/34.
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Monteiro, Ana Rita Andril. "Genetic structure of mussel population in NE Atlantic and Mediterranean: connectivity between deep-sea habitats." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17460.
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Mestrado em Ecologia AplicadaSpecies persist over time, due to exchange of individuals between subpopulations. In the marine environment, most benthic organisms have complex life cycles including pelagic larvae that are transported by ocean currents promoting species dispersal. Larval dispersal connects geographically distant populations and determines population structure. The knowledge about this biologic process provides relevant information for conservation of marine populations. This study investigates the genetic structure and connectivity of deep-sea mussel populations between fragmented habitats in the NE Atlantic and Mediterranean. The mitochondrial Cytochrome Oxidase I (mtCOI) gene was used to analyze site-specific genetic diversity and the population structure of two mussel species, Idas modiolaeformis and “Idas” simpsoni. Populations of each species are not geographically isolated. The presence of one dominant haplotype for each species suggests shared ancestral polymorphisms between Mediterranean and NE Atlantic populations. The overall high genetic differentiation observed in I. modiolaeformis indicates that the metapopulation is structured. Distant populations, located in Atlantic and E Mediterranean, revealed low genetic distances, suggesting gene flow between the two regions. Genetic and geographical distances support an island model of I. modiolaeformis population structure. A major drawback of this study is concerned with the discrepant number of individuals among populations. Further research will be needed, using more specimens and other gene markers, to investigate connectivity patterns at different spatial scales.
As espécies persistem ao longo do tempo devido à troca de indivíduos entre subpopulações. No ambiente marinho, a maioria dos organismos bentónicos têm ciclos de vida complexos, envolvendo larvas pelágicas que são transportadas por correntes oceânicas contribuindo para dispersão das espécies. A dispersão larvar estabelece conectividade entre populações geograficamente separadas e afeta a estrutura da população. O conhecimento deste processo biológico promove informações importantes para a conservação de populações marinhas. Este estudo investiga a estrutura genética e conectividade de populações de mexilhão de profundidade entre habitats fragmentados no NE Atlântico e Mediterrânico. O gene mitocondrial, Citocromo Oxidase I (mtCOI), foi utilizado para analisar diversidade genética por local e a estrutura populacional de duas espécies de mexilhão, Idas modiolaeformis e "Idas" simpsoni. As populações de cada uma das espécies não se encontram geograficamente isoladas. A presença de um haplótipo dominante para cada espécie sugere a partilha de polimorfismos ancestrais entre populações do Mediterrâneo e do NE Atlântico. As populações de I. modiolaeformis demonstraram uma elevada diferenciação genética, indicando estruturação da metapopulação. Populações distantes umas das outras, localizadas no Atlântico e E Mediterrâneo, revelaram baixas distâncias genéticas, sugerindo fluxo genético entre as duas regiões. Distâncias genéticas e geográficas suportam o modelo de ilha como o modelo para a estrutura populacional de I. modiolaeformis. Uma grande desvantagem deste estudo está relacionada com o número discrepante de indivíduos entre populações. Para investigar os padrões de conectividade em diferentes escalas espaciais serão necessários mais estudos, utilizando mais espécimes e outros marcadores genéticos.
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Forrestal, Francesca C. "Effects of Capture-Based Aquaculture of Bluefin Tuna (Thunnus thynnus thynnus) on a Western Mediterranean ecosystem." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/20.
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The Eastern stock of Atlantic bluefin tuna (Thunnus thynnus thynnus) has experienced a steep decline, 74.2%, in recent decades, mainly driven by large unreported catches and growth of the capture-based aquaculture of this species in the Mediterranean. This study addresses the potential food-web effects on trophic linkages in the ecosystem through the removal of both small pelagic fish species and wild bluefin tuna (BFT) for capture-based aquaculture operations. An Ecopath model of the Southern Catalan Sea (Western Mediterranean) was modified to include a BFT farm supplied entirely by the area modeled (Coll et al, 2006). Six scenarios were developed to simulate possible changes to the system using Ecosim, including the continued growth of aquaculture operations, as well as changes to the total allowable catch for BFT as set by ICCAT. Species not directly connected with the production of BFT showed large fluctuations in biomass and yield as a result of these simulations. Using these models, increases in biomass of lower trophic level functional groups were observed with reductions in biomass from other top trophic level predators. Jellyfish and benthopelagic fish exhibited an increase in biomass, the largest being 8.76% for jellyfish and 69.76% for benthopelagic fish, while wild BFT biomass decreased 87.26%. Atlantic bonito and swordfish showed similar rates of decline in biomass levels. These outcomes stress that fishing at top trophic levels can have unforeseen outcomes on the structure of the ecosystem, due to the complexity of the food web. Capture-based aquaculture of Atlantic bluefin tuna can be expected to increase along the proposed scenario levels, due to the decision not to place this species on Appendix I of CITES during the CITES meeting of 2010. This study suggests that farming activity has additional impacts on the ecosystems that should be taken into account when evaluating the suitability of this industry and projecting the trends towards the future. Results suggest that, in the case of the Western Mediterranean Sea, increasing BFT farming activities will likely contribute towards further degradation of an already highly exploited marine ecosystem. The development of hatchery technology to close the life cycle and produce juvenile BFT for stocking cages as well as using artificial diets during the grow out stage are required to minimize long-term impacts and support industry expansion.
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Heger, Amandine. "In situ observations of benthic and pelagic bioluminescence in the deep Atlantic Ocean and Mediterranean Sea." Thesis, University of Aberdeen, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446583.
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In the studies presented in this thesis, bioluminescence was characterised using a low-light video camera in three deep-water ecosystems and related to bio-physical factors. In the first set of experiments, baited lander deployments were conducted at about 1000 m depth in the NE Atlantic to examine the occurrence of spontaneous bioluminescence on the seafloor. Luminescent activity was higher in an area of soft sediments with 133 events h-1, compared to seven events h-1 in a cold-water coral habitat. The ostracod Vargula norvegica was found to be the major source of these events. In situ and shipboard laboratory experiments revealed what appeared to be a luminescent defensive reaction to the presence and activity of the arrowtooth eel Synaphobranchus kaupii, which were observed preying on the ostracods. In a second study, the construction of a neutrino telescope in the NW Mediterranean provided an impetus to measure the abundance of stimulated bioluminescence at the depth of operation (1950-2300 m). Temporal changes in luminescent activity and display types were observed and it was estimated that the telescope could suffer 25,920 bioluminescent impacts h-1, leading to a detectable light production of 2.6 x 1014 photons h-1. In a third study, profiles of stimulated bioluminescence (to 3000 m) above the Mid-Atlantic Ridge revealed enhanced concentrations of luminescence at a station south of the study area compared to the north, and above the summit of the Faraday Seamount. Image analysis of the seamount profile enabled fine-scale characterisation of luminescent event, such as a layer of trapped luminous sources (possibly euphausiids) and large events (possibly gelata) close to the seamount summit. Measurements carried out within an anticyclonic mesoscale eddy also showed increased luminescent activity.
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Pilczynska, Joanna. "Clonal propagation, connectivity and genetic differentiation in Paramuricea clavata populations from the Atlantic and Mediterranean Sea." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16840.
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Doutoramento em Ciências do MarThe red gorgonian Paramuricea clavata is an engineering species, inhabiting rocky shore in the Mediterranean Sea and Portuguese coast of the Atlantic Ocean. The species was severely impacted by climatically induced mass mortality events in the NW Mediterranean. The general aim of the study was to investigate the genetic diversity of P. clavata in the Ligurian Sea (NW Mediterranean), a region highly impacted by past mass mortality events, and the Atlantic Ocean, where mass mortality was never observed due to generally lower water temperature. Microsatellites were used to study the contribution of clonal reproduction, connectivity pattern, genetic structure and diversity. Additionally one mitochondrial marker (Cytochrome Oxidase I) was used to compare the Atlantic and Mediterranean populations. The results revealed, that clonal propagation does not play an important role in P. clavata, since at four out of nine sites clones were not detected and the maximum prevalence of clones reached only 13%. The study failed to detect any genetic diversity loss in the P. clavata populations affected by mass mortality events. The migration pattern among sites affected by mass mortality and unaffected ones was described. The results confirmed that low larval dispersal capability in the red gorgonian may still be ecologically significant for population replenishment and persistence, enabling migration between local populations. This research has identified an important genetic break within the red gorgonian distribution. Both markers used in the present study, mtDNA and microsatellites, revealed the same discontinuity between the Mediterranean and Atlantic. Significant differences were found in the genetic diversity between the Mediterranean and Atlantic populations, with heterozygosity and allelic richness being slightly, but significantly, higher in the Mediterranean Sea, possibly as a result of colonization history or isolation of the Atlantic sites. The differences in genetic diversity were also detected between deep and shallow populations. Allelic richness increase with depth, being lower in the shallow, less stable populations due to past mortality events induced by warming and other interacting factors and higher in deeper, stable populations.The results should prove to be particularly valuable for the conservation of soft corals communities and thus the overall marine biodiversity.
A gorgónia vermelha, Paramuricea clavata, é uma espécie engenheira que habita costas e recifes rochosos do Mediterrâneo e do Atlântico ao longo da costa de Portugal, a profundidades que variam entre 15 e os 80 m. Esta espécie foi severamente afetada, no Mediterrâneo NO, por eventos de mortalidade induzidos por variações climáticas recentes. O objetivo geral deste estudo foi a investigação da diversidade genética de P. clavata no Mar da Ligúria (Mediterrâneio NO), uma região altamente impactada por eventos de mortalidade em massa causados por temperaturas elevadas, e no Atlântico, onde mortalidade em massa nunca foi observada em consequência de temperaturas genericamente mais baixas. Foram utilizados microsatélites para o estudo da contribuição da reprodução clonal, padrões de conectividade, estrutura genética e diversidade genética. Adicionalmente, um marcador mitocondrial (Cytochrome Oxidase I) foi usado para comparar as populações do Atlântico e do Mediterrâneo. Os resultados revelaram que a propagação clonal não desempenha um papel importante em P. clavata, uma vez que em quatro dos nove sítios não foram detetados clones e que a máxima prevalência de clones detetada atingiu apenas 13%. No entanto, a prevalência de clones detectada no presente estudo foi maior do que o previamente relatado. O estudo não conseguiu detetar qualquer perda de diversidade genética nas populações de P. clavata afetadas por eventos de mortalidade em massa. Foi possível descrever o padrão de migração entre os sítios afetados pela mortalidade em massa e os não afetados. Os resultados confirmaram que a baixa capacidade de dispersão larvar na gorgónia vermelha pode ainda ser ecologicamente significante para a recolonização e persistência populacional, permitindo a migração entre populações locais. A troca de larvas foi mais comum entre recifes separados por 200-300m, mas também foi detectada entre locais separados por 20 km. Os dados indicaram ainda migrações comuns entre recifes localizados a menores profundidades, impactados por mortalidade em massa, e recifes mais profundos, não impactados, do mesmo local. A presente investigação identificou uma importante descontinuidade genética na distribuição da gorgónia vermelha, com ambos os marcadores utilizados no estudo, mtDNA e microsatélites, revelando a mesma descontinuidade entre o Mediterrâneo e o Atlântico. Foram também encontradas diferenças significativas na diversidade genética entre o Mediterrâneo e as populações do Oceano Atlântico, com a heterozigosidade e a riqueza alélica ligeiramente, mas significativamente, mais elevadas no Mediterrâneo, possivelmente como resultado da história da colonização ou isolamento dos locais do Atlântico. Finalmente, foram ainda detectadas diferenças na diversidade genética entre as populações superficiais e mais profundas. A riqueza alélica foi menor nas populações menos profundas, menos estáveis devido a eventos de mortalidade induzidos pelo aquecimento e por outros fatores, e maior nas populações mais profundas e estáveis. Estes resultados devem revelar-se particularmente valiosos para a conservação de comunidades de gorgónias e assim a biodiversidade marinha global.
La gorgonia rossa Paramuricea clavata è una ‘engineering species’, vive sui fondali rocciosi del Mediterraneo e della costa portoghese dell’Oceano Atlantico. La specie è stata severamente impattata da eventi di mortalità di massa indotti dal CC nel Mediterraneo nord-occidentale. Lo scopo dello studio è stato di indagare la diversità genetica di P. clavata nel Mar Ligure (Mediterraneo nord-occidentale), una regione fortemente impattata da eventi di mortalità, e nell’Oceano Atlantico, dove eventi di mortalità non sono mai stati registrati grazie a valori di temperatura dell’acqua generalmente più bassi. Per studiare il contributo della riproduzione clonale, i pattern di connettività, la struttura e la diversità genetica sono stati usati i microsatelliti. In aggiunta, un marcatore mitocondriale (Cytochrome Oxidase I) è stato utilizzato per confrontare le popolazioni atlantiche con quelle mediterranee. I risultati hanno mostrato che la propagazione clonale non gioca un ruolo importante in P. clavata, in quanto in quattro siti su nove non sono stati individuati cloni e la predominanza massima di cloni ha totalizzato solo il 13%. Lo studio non ha riscontrato perdita di diversità genetica nelle popolazioni di P. clavata colpite da eventi di mortalità. Sono stati descritti i pattern di migrazione tra siti colpiti da mortalità e quelli non colpiti. I risultati hanno confermato che la bassa dispersione larvale nella gorgonia rossa può essere ancora ecologicamente significativa per il rifornimento e la persistenza di popolazioni, favorendo la migrazione tra popolazioni locali. Questa ricerca ha identificato un importante break genetico nella distribuzione della gorgonia rossa. Entrambi i marker usati in questo studio, mtDNA e microsatelliti, hanno rivelato la stessa discontinuità tra Mediterraneo ed Atlantico. Differenze significative sono state riscontrate nella diversità genetica tra popolazioni mediterranee e atlantiche, con eterozigosità e ricchezza allelica leggermente, ma significativamente più alte nel Mediterraneo, probabilmente come risultato della storia di colonizzazione o isolamento dei siti atlantici. Le differenze nella diversità genetica sono state riscontrate anche tra popolazioni profonde e superficiali. La ricchezza allelica aumenta con la profondità, risultando più bassa nelle popolazioni più superficiali, meno stabili a causa degli eventi di mortalità indotti dal riscaldamento e da altri fattori interagenti, e più alta nelle popolazioni più profonde e relativamente più stabili. I risultati sono di particolare interesse per la conservazione delle comunità di coralli molli e quindi nel complesso per la biodiversità marina.
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Cao, Quanquan. "Physiological and molecular responses of Atlantic and Mediterranean sea bass lineages to hypersalinity : A comparative study." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONG019.
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Le loup Européen ou bar (Dicentrarchus labrax) effectue des migrations saisonnières vers des habitats où la salinité peut atteindre des niveaux dépassant les 50 ‰, notamment dans les lagunes Méditerranéennes. Nous avons comparé les réponses physiologiques à l’hyper salinité de deux lignées génétiques de D. labrax, en provenance d’Atlantique et de Méditerranée Ouest. Le rôle du rein et de l’intestin dans la réabsorption d’eau dépendante du transport de solutés ont été analysés. L’expression des récepteurs de l’arginine vasotocine et de l’isotocine (AVTR et ITR) a également été mesurée. Les analyses ont été réalisées deux semaines après un transfert de D. labrax soit en eau de mer (EM, 36 ‰), soit en eau hypersalée (EHS, 55 ‰). Une taille inférieure des glomérules rénaux a été mesurée en milieu hyper salé indiquant une limitation des pertes d'eau via l’urine en milieu hypersalé. Les niveaux protéiques et l’activité de l’ATPase Na+/K+ (NKA) étaient supérieurs en milieu hyper salé indiquant un transport actif accrue à cette salinité. L’aquaporine 1a (AQP1a) est exprimée dans certains tubules proximaux n’exprimant que très peu la NKA. De plus, les transcrits aqp1a et aqp1b sont moins exprimés en EHS qu’en EM suggérant un rôle limité de l’AQP1 dans la réabsorption d’eau couplée au transport ionique. Dans l’intestin postérieur, les niveaux de transcrits nka α1a, nkcc2, aqp8ab et aqp8aa étaient supérieurs en EHS qu’en EM ainsi que le niveau protéique AQP8ab. AQP8ab est localisé dans les enterocytes au niveau subapical, exprimant également le cotransporteur Na+/K+/2Cl- (NKCC2) apicalement, suggérant un lien fonctionnel entre l’absorption de Na+, Cl- et l’eau. Parmi les gènes paralogues AVTR, v1a2 est le plus abondant au niveau intestinal et il est surexprimé en EHS. Une comparaison intraspécifique a montré que la lignée Méditerranéenne présente une pression osmotique sanguine supérieure en EHS alors que la lignée Atlantique maintient sa pression osmotique constante. Des différences entre les lignées ont été montrées au niveau de l’intestin postérieur avec des activités NKA supérieures chez les loups Méditerranéens mais aussi une expression plus importante de plusieurs gènes chez les loups Méditerranéens, reflétant des différences adaptatives dans les mécanismes d’absorption d’eau entre les lignées de D. labraxThe European sea bass (Dicentrarchus labrax) migrates towards habitats where salinity can reach levels over 50 ‰, notably in Mediterranean lagoons. We compared physiological responses of Atlantic and West Mediterranean sea bass to hypersalinity. We focused on the role of the kidney and intestine in solute-driven water reabsorption. Intestinal arginine vasotocin and isotocin receptor (AVTR and ITR) expression were also analyzed. Fish were sampled following a two-week transfer from seawater (SW, 36 ‰) to either SW or hypersaline water (HW, 55 ‰). A decreased renal glomerulus size was measured in HW compared to SW indicating that sea bass minimize water loss through urine upon salinity increase. Renal relative protein amounts and activity of Na+/K+-ATPase (NKA) were significantly higher in fish exposed to hypersalinity regardless of their origin indicating increased ion transport. Renal aquaporin 1a (AQP1a) immunolabeling was mainly detected in proximal tubules that do not express NKA and aqp1a, aqp1b were downregulated in HW suggesting a limited role of AQP1 in solute-coupled water uptake at 55 ‰. In the posterior intestine, nka α1a, nkcc2, aqp8ab and aqp8aa mRNA expressions were higher in HW compared to SW as well as relative protein expression of AQP8ab. The sub-apical localization of AQP8ab and apical localization of Na+/K+, 2Cl- cotransporter (NKCC2) in enterocytes could indicate a functional link between Na+, Cl- and water uptake. Among AVTR paralogs, highest mRNA levels were recorded for v1a2 paralog which showed a higher expression in D. labrax intestine after transfer of fish to HW. Intraspecific comparisons showed that blood osmolality was unchanged in Atlantic sea bass following salinity transfer but was higher in Mediterranean sea bass in HW compared to SW. Differences between D. labrax lineages were observed in posterior intestines of fish maintained in SW regarding NKA activities and the expression of several genes invo lved in solute-coupled water uptake with significantly higher levels in Mediterranean sea bass, most likely reflecting adaptive differences in mechanism linked to ion-driven water reuptake within D. labrax lineages
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Di, Poi Elena. "Microzooplankton grazing impact along a trophic gradient from the atlantic ocean to the western mediterranean sea." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3514.
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2008/2009Nell'ambito della crociera transmediterranea facente parte del progetto V.E.C.T.O.R. è stato quantificato il flusso di carbonio che veicola attraverso le reti trofiche pelagiche tramite la predazione del microzooplancton su un ampio spettro di prede; si è inoltre verificato la selezione delle prede e quantificato la produzione secondaria. Per questa analisi è stato adottato il metodo delle diluizioni introdotto da Landry ed Hassett (1982)che ci permette di stimare sia il tasso di crescita delle prede, che quello di mortalità delle prede indotta da predazione. In concomitanza con gli esperimenti di diluizione,si è valutato la comunità dei predatori con differenti metodi di campionamento e di conservazione dei campioni nonchè, l'attività di predazione del mesozooplancton sul comparto microplanctonico nel Mar Ligure e nel Mar Tirreno. I risultati complessivi della ricerca indicano che in condizioni di estrema oligotrofia nelle quali è avvenuta la crociera nell'estate 2007, il flusso di carbonio di maggiore entità che fluisce attraverso il comparto microzooplanctonico deriva dalle biomasse dei batteri eterotrofi, che sono le uniche consistenti in tutta l'area. Nanoplancton e microfitoplancton, contribuiscono scarsamente alla dieta del microzooplancton. Dallo studio quali-quantitativo del microooplancton si evince che la rappresentazione migliore in termini di ricchezza si ottiene con maggiori volumi di campionamento (5 L, conservati in formalina al 2%) mentre, l'abbondanza più rilevante si riscontra quando i campioni (300 mL) vengono conservati in soluzione di Lugol al 2%. I campioni ottenuti dall'esperimento di diluizione (2 L, conservati in formalina al 2%) offrono nel complesso la miglior rappresentazione della comunità dei predatori. Nel Mar Ligure, il calanoide Centropages esercita il suo impatto di predazione sia sul comparto microzooplanctonico che su quello microfitoplanctonico, sebbene sia indirizzato in questo caso, unicamente alla categoria dei dinoflagellati a dimensioni maggiori e ai coccolitoforidi. Nel Mar Tirreno, il ciclopoide Corycaeus esercita la sua selezione unicamente sul comparto microzooplanctonico. Per la stazione tirrenica si registrano valori di export seppur minimi. Nel complesso, sembra che in condizioni di oligotrofia, l'energia trasferita ai livelli trofici superiori sia molto esigua.
In the frame of the V.E.C.T.O.R. project, during the transmediterranean cruise, the carbon fluxes throughout the pelagic trophic webs were quantified by means of the grazing impact of microzooplankton on a wide variety of prey; The selection exerted by microzooplankton on its prey and the secondary production was also estimated. The dilution method introduced by Landry and hassett (1982) was applied to the research. The method assess both the growth of the prey and their mortality induced by grazing. Beside dilution experiments, a quali-quantitative analysis of the predators comunity treated with different fixatives and sampling techniques was performed. In the Ligurian and in the Tyrrhenian Sea, a further examination on mesozooplankton grazing on microplankton assemblages was estimated. Risults confirm that in extreme oligotrophic conditions as those occured during summer 2007, the major carbon flux fuelled through microzooplankton community derived from heterotrophic bacteria, that showed the most abundant biomasses along the sampled stations. Nano- and microphytoplankton were of minor importance in the diet of their direct grazers. From the quali-quantitative analysis of microzooplankton, the best representation in terms of species richness is obtained by means of higher sampling volumes (5 L, fixed in 2% formalin) whereas, the higher abundances were displayed for samples collected in 300 mL and conserved in Lugol's solution. Samples derived from dilution experiments (2 L fixed in 2% formalin) among all, displayed the best representation of the predators community. In the Ligurian Sea, the calanoid Centropages, exerted its grazing impact on both microzooplankton and microphytoplankton; on the latters, the selection is addressed only on dinoflagellates of bigger size and on coccolithophorids. In the Tyrrhenian Sea, the cyclopoid Corycaeus, selects all microzooplankton assemblage but aloricate ciliates. The Tyrrhenian Sea, recorded a minimum export. In oligotrophic conditions, the energy fuelled to the higher trophic levels seems to be very scarce.
XXII Ciclo
1972
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Preston, Joanne. "Allopatric speciation in the littoral gastropod genus Osilinus Philippi, 1847 (Gastropoda: Trochidae) at the Atlantic/Mediterranean interface." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402039.
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Celep, Ferhat. "Revision Of The Genus Salvia L. (labiatae) In The Mediterranean And The Aegean Geographic Regions Of Turkey." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12612069/index.pdf.
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A revision of the Mediterranean and the Aegean geographic regions of Turkey of Salvia L. (Labiatae) is presented. According to the results, the study area has 60 taxa, 32 of which are endemic (mainly local endemics), 5 of which are non-endemic rare, and the remaining 23 taxa are widely distributed. The rate of endemism is 53% in the area. At the beginning of the thesis, history and worldwide distribution of the family and the genus are briefly given. Phylogenetic studies and infrageneric grouping of the genus are discussed. As well as, recent studies on the genus such as taxonomical, morphological, micromorphological and karyological are provided. Geographic, phytogeographic, topographic, and climatic features of the area are explained.
Since 2005, about 2000 specimens have been collected and examined as the research materials. In addition, a large number of specimens have been seen and studied in ANK, AEF, BM, E, ERCIYES, G, GAZI, HUB, K, KNYA, LE, ISTE and ISTF herbaria. Digital photos of some specimens including type specimens have been seen from B, W and A herbaria. In the field when the specimens were detected geographical location (including GPS), habitat, phenological data and relevant field observations were all recorded.
In the study, comparative morphological characters and their variations are discussed Anatomical features, such as root, stem, leaf and petiole, micromorphological properties, such as trichome, pollen and nutlet, of the species are comprehensively studied and their taxonomic implications are discussed.
According to field studies and literature surveys, endemism, pyhtogeography, habitat, phenology, chorology, new distribution areas and conservation status of the species are determined.
Infrageneric delimitation of the species using multivariety analysis is performed. In addition, first sectional key and sectional grouping of the species are made. As well as, identification key of the species is given. At the end of the thesis, expanded and corrected description, address, photographs and some notes on taxonomy of the species are given.
The taxonomic studies revealed one new species, Salvia marashica, two new varieties, S. sericeo-tomentosa var. hatayica, S. cadmica var. bozkiriensis, one new combination, S. aucheri subsp. canescens and one new record, S. viscosa. As well as, S. sericeo-tomentosa and S. quezelii are rediscovered.
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Prasannalal, Sheena Adithi. "Feasibility Investigation of Floating PV in Hydro reservoirs : A case study on tropical and mediterranean climatic regions." Thesis, Uppsala universitet, Institutionen för elektroteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-454682.
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To secure the growing energy demand due to the rise in population and technological advancements, countries worldwide are looking for alternatives or complementary generation sources to support the existing grid infrastructure and power generating system. The increase in global temperature and climate change forces each country to switch to clean energy production. Among the renewable energy sources, the Floating Photovoltaic (FPV) market is flourishing in various countries. It is a good source of power generation avoiding land constraint issues and adding extra benefits like cooling of panels and reducing evaporation and algal bloom problems of water sources where it is installed. In fact, as a part of a complementary generation, the idea of using unused reservoir water surface of reservoir for the deployment of photovoltaic (PV) is a considerable solution for meeting energy demand. As hydropower and PV are dispatchable and non-dispatchable sources of energy, they can complement each other well. The floating PV and hydropower basics and factors that complement their mutual operation are discussed in this research work with a literature review. Case studies of tropical and mediterranean climatic countries like Myanmar and Albania are analyzed using HOMER Pro. The various challenges associated with this hybrid hydro-floating PV project are evaluated using risk analysis, and the highest risk elements are identified.
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Ikediashi, Charles Isioma. "Population level variation of Atlantic salmon in the chalk streams of southern England and neighbouring regions." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/22074.
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In this thesis, population level variation is elucidated for Atlantic salmon living in the chalk streams of southern England – a unique and unusual habitat – as well as in immediately surrounding regions. Salmon in these chalk streams have yet to be robustly investigated, despite individual populations standing out from neighbouring populations in several previous studies. This thesis attempts to identify how different they are and the reasons for it. Then, this thesis also investigates the effect of this distinction on their internal population structure, as well as the current and future trajectory. A panel of microsatellite markers from the SALSEA-merge project were used to complete four studies of population structure in Atlantic salmon. In the first study, which served primarily, as a training exercise, a multi-national baseline was used to identify the origins of salmon recolonising the river Mersey in northwest England. Fish entering the Mersey originated from multiple sources, with the greatest proportion (45–60%) assigning to rivers in the geographical region just north of the Mersey, including Northwest England and the Solway Firth. The number of fish originating from proximal rivers to the west of the Mersey was lower than expected. The results suggested that the recolonisers were straying in accordance with the predominantly clockwise gyre present in the eastern Irish Sea. In the second study, the relationship of salmon in the chalk streams of southern England to salmon outside this region was elucidated. Salmon from all five chalk streams in southern England with major salmon populations were found to all be genetically distinct from these neighbours and statistically less genetically diverse than salmon in southwest England and France. The reasons for this were relatively low immigration and a history of low effective population size. In the third study, the extent of population structure of salmon between the chalk streams and within one chalk stream, the river Frome, was explored. The results suggested these salmon were divided into three groups, i.e. 1) the Frome & Piddle, 2) the Avon and 3) the Test & Itchen. A significant pattern of isolation by distance between salmon in these five rivers was also identified. Historic samples from the Avon were assigned to the contemporary three groups. Surprisingly, most of these fish assigned to the Frome and Piddle group. Within the river Frome, further sub-structure was identified over two separate years of sampling. Salmon from 2009 comprised three genetic groups, and salmon in 2011 comprised just two. In the fourth study, historic scale samples were used to assess the current trajectory of genetic diversity and effective population size of salmon populations across Scotland, England, Wales and France. The majority of samples greater than 30 years old proved ineffective using the SALSEA panel. However, data was compiled from samples from eight rivers ranging from the Tweed in Scotland to the Scorff in France and from 1972 to 2012. Contrary to our hypothesis, most populations showed increases in allelic richness. Populations from one chalk stream show the steepest temporal decline in genetic diversity, which we speculate is partly due to the low immigration into the region. Effective population size proved difficult to determine using a number of methods and no robust pattern was identified. Together these studies indicate that low immigration of salmon into the chalk streams appears to be key to their low genetic diversity and genetic distinction. Low immigration may also have enabled marked within-river population structure and the current negative trajectory of genetic diversity. The implications for general understanding of Atlantic salmon population structure across their range, and for the conservation of this species are discussed.
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Joher, Sais Sergi. "Macroalgal-dominated coastal detritic bottoms of the Mediterranean Sea and the Northeastern Atlantic: description, distribution and sampling methodologies." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/385353.
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En aquesta tesi es van descriure els principals fons algals del detrític costaner de la plataforma continental de Mallorca i Menorca (illes Balears, Espanya), i es van proposar mètodes efectius per al seu mostreig tant a nivell de paisatge com de comunitat. Així, en primer lloc, es van identificar i caracteritzar sis paisatges algals principals a partir de les mostres recol·lectades mitjançant l’arrossegament de fons, que permet mostrejos en àrees extenses. Seguidament, es van descriure algunes de les comunitats presents en aquests paisatges (maërl de Spongites fruticulosus, bosc de Laminaria rodriguezii i llit de Peyssonnelia inamoena) a partir de mostres obtingudes amb la draga Box-Corer i el patí epibentònic, que permeten mostrejos en àrees més reduïdes que l’arrossegament de fons. Finalment, la comparació qualitativa de dades pròpies i d’altres publicades en la bibliografia va permetre avaluar la composició i la distribució de les comunitats dominades per macroalgues dels fons detrítics del Mediterrani i l’Atlàntic Nord-oriental.This thesis aims to describe the main algal-dominated coastal detritic bottoms of the continental shelf off Mallorca and Menorca (Balearic Islands, Spain), and provide effective methods for their sampling. Firstly, six main algal assemblages were identified and characterized thanks to the samples collected by means of bottom trawl, as it allows sampling in extensive areas. Moreover, the description of some communities that characterized some of the algal assemblages (maërl of Spongites fruticulosus, Laminaria rodriguezii forest and Peyssonnelia inamoena bed) were performed with samples obtained with the Box-Corer dredge and the beam trawl, which allowed sampling on smaller areas than bottom trawl. Finally, the qualitative comparison of our own data and data from published studies allowed to assess the composition and the distribution of the macroalgal-dominated communities of the coastal detritic bottoms from the Mediterranean and the Northeastern Atlantic.
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Border, Evan [Verfasser], and Norbert [Akademischer Betreuer] Frank. "Variability of δ234U in the Mediterranean Sea, Amazon Estuary, and Atlantic Ocean / Evan C. Border ; Betreuer: Norbert Frank." Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://d-nb.info/1215758243/34.
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Border, Evan C. [Verfasser], and Norbert [Akademischer Betreuer] Frank. "Variability of δ234U in the Mediterranean Sea, Amazon Estuary, and Atlantic Ocean / Evan C. Border ; Betreuer: Norbert Frank." Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://d-nb.info/1215758243/34.
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Turchyn, Daryna Tarasivna, and Дарина Тарасівна Турчин. "Mediterranean and european directions of spais`s foreign policy." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/51754.
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1.Gerry O’Reilly, Gibraltar: Sovereignty Disputes and Territorial Waters, IBRU Boundary and Security Bulletin, Spring 1999.
2.Anіkєєva N. E., Vedyushіn V. A., Volosyuk O. V., MednikovІ. YU.,
Pozhars’ka SP. Іstorіyazovnіshn’oji polіtiki Іspanji. Moskva, Mіzhnarodnіvіdnosini, 2014. 502 s.
3.Черкасова Є. Гібралтар: нелегкі шляхи вирішеннятериторіальноїпробеми. Ібероамериканськізошити, 2015, №4(6, с. 87-98.The Middle East and North Africa region has always been one of the priorities of Spain’s foreign policy. Spain’s political scene in the late twentieth and early twenty-first century is a constant rivalry between political parties and blocs. Particularly, characterizing the policy of Jose Maria Aznar, who was Prime Minister of Spain from 1996 till 2004 from the People’s Party, it is possible to note the special aspiration of activation of Spain’s participation in EU, NATO, UN and other international organizations. Meanwhile, EuroAtlantic relations and Spanish-American relations became an absolute foreign policy priority. The main contours of Spain’s modern foreign policy were shaped by successive parliamentary cabinets. These governments have increased Spain’s role and prestige in the world as a result of their effective action. The country has become an economically and politically advanced democracy with a generally consistent foreign policy. The foreign political course during the democratic transition was based on a great cohesion within Spanish society as well as broad consensus on international relations.The country’s integration has contributed to the serious economic boom of the state, the so-called Spanish Miracle
Регіон Близького Сходу та Північної Африки завжди був одним із пріоритетів зовнішньої політики Іспанії. Політична сцена Іспанії наприкінці ХХ - на початку ХХІ століття є постійним суперництвом між політичними партіями та блоками. Зокрема, характеризуючи політику Хосе Марії Аснара, який був прем'єр-міністром Іспанії з 1996 по 2004 рік від Народної партії, можна відзначити особливе прагнення активізації участі Іспанії в ЄС, НАТО, ООН та інших міжнародних організаціях. Тим часом євроатлантичні відносини та іспано-американські відносини стали безумовним пріоритетом зовнішньої політики. Основні контури сучасної зовнішньої політики Іспанії формували послідовні парламентські кабінети. Ці уряди збільшили роль і престиж Іспанії у світі в результаті їх ефективних дій. Країна перетворилася на економічно та політично розвинену демократію із загально послідовною зовнішньою політикою. Зовнішньополітичний курс під час демократичного переходу базувався на великій згуртованості в іспанському суспільстві, а також на широкому консенсусі щодо міжнародних відносин. Інтеграція країни сприяла серйозному економічному піднесенню держави, так званому іспанському диву
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Signoretta, Paola E. "Sustainable development in marginal regions of the European Union : an evaluation of the Integrated Mediterranean Programme Calabria, Italy." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318294.
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FABBRINI, ALESSIO. "Biostratigraphy, Paleoecology and Astrochronology of early Miocene planktonic foraminifera from the Mediterranean and the North Atlantic Ocean: new perspectives on the Burdigalian GSSP." Doctoral thesis, Università di Siena, 2019. http://hdl.handle.net/11365/1074571.
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This thesis investigates the early Miocene planktonic foraminifera from two sections Contessa section (Italy) and IODP Site U1406 (Newfoundland, Canada), to contribute to the open question of the Aquitanian/Burdigalian boundary. The Burdigalian stage lacks an official Global Stratotype Section and Point, and its base is provisionally set at 20.43 Ma and approximated by the calcareous nannofossil Helicosphaera ampliaperta FO. Following an integrated biostratigraphic approach, the results obtained from the two sections are reported and discussed in the manuscripts contained in this dissertation. For both sections, a new age model is proposed and their semiquantitative and quantitative analyses are presented for planktonic foraminifera, calcareous nannofossils and magnetostratigraphy. After the recognition of two hiatuses in the second section (Site U1406) other studies were performed, for a paleoecological characterisation of the planktonic foraminifera (with statistical analyses) and then a preliminary cyclostratigraphic study. This final and fourth study will eventually lead to the astronomical tuning of the Site and of the bioevents therein recognised. The successful correlation of the hiatuses to regional megahiatuses allowed us to investigate the early Neogene climate evolution from the perspective of the planktonic foraminifera assemblages. In conclusion, the Contessa section is correlated with other reference sections for the early Miocene. The first correlation was with the Santa Croce di Arcevia Section, which used to be the most complete lower Miocene section in the Mediterranean area (before its closure). The second correlation presented is with the IODP Site U1406 in order to compare the different results obtained from the Mediterranean and the North Atlantic integrated biostratigraphy. A third and final correlation is presented between the two sections here studied and the ODP Hole 926B (in the equatorial Atlantic at Ceara Rise), which is retained a reference section for biostratigraphic and chronostratigraphic schemes. These correlations also permit to enlighten the potentials of the Contessa section as a GSSP candidate for the Burdigalian stage. Concerning the Aquitanian/Burdigalian boundary as defined at the present day by the ICS, the Contessa Section contains such limit at 19.77 m where the calcareous nannofossil Helicosphaera ampliaperta first occurs. The integrated analysis allowed me to document such event in its standard stratigraphic position, within Chron C6Aar1n and occurring coherently with the other biomarkers of both foraminiferal and calcareous nannofossil biostratigraphy.
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González, Alejandro Danilo Venegas. "Tree growth response to climate change in two threatened South American Biomes: Brazilian Atlantic Forest and Chilean Mediterranean Forest." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-22032018-154156/.
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Biomes classified as Brazilian Atlantic Forest (BAF) and the Chilean Mediterranean forest (CMF) have been affected by anthropic pressure that has caused a considerable decrease of their forest surfasse. However, they are rich in biodiversity and they provide many ecosystem services and were, therefore, classified as \"hotspots\" (forests in risk). Therefore, is essential to study the natural dynamics and the climatic response of the trees of these forests to include conservation projects and strategic measures. To achieve these objectives, the scientific literature reports that tree growth rings are the only ecological indicators with annual resolution that can be efficient and highly accurate to obtain this information. In this context, the research project has as main objective the retrospective analysis of radial growth of forest species in different vegetation communities of BAF and CMF in response to climatic changes. To achieve this goal, four key questions were elaborated: 1) Which variable explains betterthe variability of radial growth at different spatial and temporal scales? 2) What is the growth resilience to recent climate changes? 3) Is there some more vulnerable population to expected climatic changes?. A total of five sites (seven populations) of Cedrela odorata and C. fissilis in BAF from the State of São Paulo in Brazil, and five sites (10 populations) of Nothofagus macrocarpa (FMC) from the central region of Chile were sampled, using a non-destructive method. Four chapters were developed to answer these questions. Chapter I seek to analyze the resilience in radial growth to changes in regional climate variability and droughts, in temporal and spatial scale, on Atlantic forest remnant forests of biogeographic region Serra do Mar. Results show that radial growth in wet sites (winter rains exceed 240 mm) depend on the moisture conditions in dry season, while the higher population is more sensitive to the favorable summer water condition, which would be explained because this population received a lower temperature than the other Cedrela spp. populations studied. Chapter II analyzed how recent climatic variability affected the radial growth in N. macrocarpa populations. It is observed that all the populations are closely linked to the precipitations of May-November (end of autumn/end of spring) and average temperature of October-December (mid-spring/early summer). In Chapter III, we continued exploring the growth responses to climate in the FMC populations in order to find biogeographic differences. In this sense, we evaluated if this significant decrease in tree growth is differentiated between populations and age classes, and determine if the positive effect of CO2 fertilization compensates the precipitation decrease and temperature increase in the last decades in the growth of older, maturer and younger trees . Results show a significant negative trend in all classes from the year 2000, which would be associated to a decrease in precipitation in all populations while temperature was more associated with the northern and southern populations (distribution limit). We did not find a positive effect of rising CO2. Finally, chapter IV integrated the results of the two biomes comparing the projections of aboveground trees biomass under two climatic scenarios of CMIP5 project (light and severe), in order to know which populations are more vulnerable to rising temperature forecasted by year 2100, using ring width data, wood density and allometric equations. This study will provide an overview of adaptation to recent and projected climatic changes of two hotspot neotropical biomes. Although they are different in structure-biodiversity-climate are in risk. Thus, we can understand the vulnerability of threatened forests in South America to global warming that, although they are in protected areas, does not guarantee their persistence.Os biomas classificados como Mata Atlancia Brasileira (MAB) e da Floresta Mediterrânea Chilena (FMC) têm sido afetados pela pressão antrópica que tem causado uma diminuição considerável de sua superfície florestal. No entanto são ricas em biodiversidade e providenciam muitos serviços ecossistêmicos, pelo que foram classificadas como hotspot (florestas em risco). Portanto, é fundamental estudar a dinâmica natural e a resposta climática das árvores dessas florestas para incluir em projetos de conservação. Para atingir esses objetivos, a literatura científica reporta que os anéis de crescimento das árvores são os únicos indicadores ecológicos com resolução anual que podem ser eficientes e de elevada precisão para obter essas informações. Neste contexto, o projeto de pesquisa tem como objetivo geral a analise retrospectivo de crescimento radial de espécies florestais em diferentes comunidades vegetacionais da MAB e FMC em resposta às mudanças climaticas. Para atingir esse objetivo foram elaboradas quatro perguntas-chave: 1) Que variable explica melhor a variabilidade do crescimento radial a diferentes escalas espaciais e temporais? 2) Qual é a resiliência em crescimento das árvores às mudanças climáticas recentes? 3) Há alguma população mais vulnerável respeito às mudanças climaticas esperadas?. Foram coletadas amostras de lenho, através de método não destrutivo, de cinco sitios (sete populações) de Cedrela odorata e C. fissilis na MAB no estado de São Paulo em Brasil, e cinco sitios (10 populações) de Nothofagus macrocarpa na FMC na região central do Chile, para aplicação de tecnicas dendrocronologicas. Para responder essas questões foram desenvolvidos quatro capitulos. O capitulo I busca analisar a resiliência em crescimento radial às mudanças na variabilidade climática regional e secas, em escala temporal e espacial, em florestas remanentes da região biogeográfica Serra do Mar da Mata Atlântica, usando as especies bioindicadoras Cedrela fissilis and C. odorata. Os resultados mostram que o crescimento radial dos sítios mais úmidos (chuvas no inverno superam os 240 mm) dependem das condições hidricas da estação seca, enquanto que a população mais alta é mais sensível à condição hídrica favorável do verão, qual seria explicado porque essa população recebi uma menor temperatura respeito às outras populações de cedrela estudadas. No capitulo II analisou-se como a variabilidade climática recente estaria afeitando o crescimento radial in N. macrocarpa populations. Observa-se que todas as populações estão estreitamente ligadas às precipitações de Maio-Novembro (fim de outono/fim de primaveira) e temperatura média de Outubro-Dezembro (mediados de primaveira/inicios do verão). Especificamente, há uma tendencia negativa significativa no crescimento radial apartir de 1980 que esta associada a uma variação do clima regional. No capitulo III, continuo-se explorando as respostas do crescimento radial ao clima nas populações da FMC com objetivo de encontrar diferencias biogeográficas. Neste sentido, foi avaliado se essa diminuição significativa de crescimento é diferenciada entre populações e classes de idade, e analisar se o efeito positivo da fertilização de CO2 compensa a diminuição da precipitação e aumento da temperatura nas ultimas decadas no crescimento de árvores velhos, maduros e jovens. Os resultados mostram uma tendencia negativa significativa em todas as clases apartir do ano 2000, qual estaria associada a diminuição da precipitação em todas as populações enquanto a temperatura teve mais associada às populações do sul. Não foi encontrado um efeito positivo do aumento de CO2. Finalmente, o capitulo IV integrou os resultados dos dois biomas comparando as proyeções de biomasa arborea sob dois escenarios climáticos do projeto CMIP5 (leve e severo), com objetivo de conocer quais populações são mais vulneraveis ao aumento da temperature previsto para o ano 2100, usando crescimento radial, densidade de madeira e ecuações alométricas. Os resultados mostram que a população com maior influencia urbana e a mais seca são as mais vulneráveis ao aumento exarcerbado de temperatura nas regiões de MAB and FMC, respectivamente. O presente estudo permitiu-nos apresentar uma visão da adaptação às mudanças climáticas recentes e projetadas de dois biomas hotspot. Embora sejam diferentes em estrutura-biodiversidade-clima estão em risco. Assim, podemos entender a vulnerabilidade de florestas neotropicais ao aquecimento global, embora estejam em áreas protegidas, não garante sua persistência.
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Smith, Brett. "The late quaternary history of Southern hemisphere mediterranean climate regions in the Western Cape, South Africa, and Southwestern Australia." Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/12162.
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Includes abstract.Includes bibliographical references (leaves 215-241).
The study is focused on four study sites, two in the Western Cape, namely the Bruno section and Lake Michelle and two in southwestern Australia, namely Wambellup Swamp and Devil's Pool. These sites were chosen as they are well situated to investigate the complex interaction between Late Quaternary climate change, the influence of fluctuating sea levels and the impact of human interaction with the environments in question and provide a regional picture of these interactions.
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Bragg, Dan L. "The application of transformational leadership among christian school leaders in the Southeast and the Mid-Atlantic North Regions." Lynchburg, Va. : Liberty University, 2008. http://digitalcommons.liberty.edu.
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Ridgway, Stephen Andrew. "The systematics, phylogeny and biogeography of the limpet genus Patella (Mollusca: Gastropoda) in the northern Atlantic Ocean and Mediterranean Sea." Thesis, Queen Mary, University of London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307706.
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Craig, Jessica. "Distribution of deep-sea bioluminescence across the Mid-Atlantic Ridge and Mediterranean Sea : relationships with surface productivity, topography and hydrography." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=186379.
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Bioluminescence is widespread in the deep sea. In this study, the density of bioluminescent zooplankton (BL) in the deep Mediterranean Sea (MS) and at the Mid- Atlantic Ridge (MAR) was measured using low light video cameras, including a novel Image intensified Charge coupled device for Deep-sea research (ICDeep). Sampling across the MS was undertaken to assess the potential optical interference from bioluminescent zooplankton at sites under consideration for the construction of a large volume deep-sea neutrino telescope. This revealed a general decrease in deep pelagic BL densities from the western to the eastern MS. Deep mesopelagic (500- 1000 m depth) BL density was significantly correlated (p
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Feng, Yang. "Study of the climate variability and the role of volcanism in the North Atlantic-Mediterranean sector during the last millennium." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS038.
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La thèse vise à étudier le rôle du volcanisme ainsi ses impacts sur la variabilité climatique hivernale (spécialement l'ONA) dans le secteur Atlantique Nord-Méditerranée à l'échelle interannuelle. La première partie est consacrée à la caractérisation du signal d'ONA en hiver à la suite d'éruptions volcaniques stratosphériques grâce à trois simulations transitoires du dernier millénaire (500-1849 CE) par IPSL-CM6A-LR dans le cadre de PMIP4. La robustesse et la sensibilité de réponse liée à la latitude, la saison et la magnitude des éruptions sont ainsi explorées. La deuxième partie étend plus loin pour décrypter le mécanisme concernant différentes composantes radiatives du forçage volcanique (le refroidissement de la surface et le réchauffement du stratosphère). Le travail est axé sur trois 25-membres ensembles de simulation par IPSL-CM6A-LR suivant le protocole VolMIP sur l'éruption tropicale Mt. Pinatubo (Philippines, juin 1991), la meilleure observée. Les expériences de sensibilité indiquent que la signature d’ONA positive de surface dans nos expériences de modèle est principalement attribuée au réchauffement dans la basse stratosphère tropicale qui génère des vents zonaux subtropicaux plus forts à travers le bilan de vent thermique et accélère le vortex polaire. Les propagations d'ondes planétaires stationnaires jouent également des effets de modulations indispensablesThe PhD work aims at studying the role of volcanism in influencing winter climate variability (especially, NAO) over the North Atlantic-Mediterranean sector at inter-annual scale. The first part is devoted to characterizing the simulated NAO signal in winters following stratospheric volcanic eruptions using three long transient simulations of the past millennium (500-1849 CE) by IPSL-CM6A-LR in the frame of PMIP4. The robustness and sensitivity of the response related to the latitude, season and strength of the eruptions are also explored. The second part extends further to decrypt the physical mechanism regarding different components of volcanic radiative forcing (the surface cooling and stratospheric warming). The work focuses on three 25-members ensemble simulations by IPSL-CM6A-LR following the VolMIP protocol for the well observed Mt. Pinatubo tropical eruption (Philippines, June 1991). Sensitivity experiments indicate that the surface positive NAO signature in our model experiments is primarily attributable to heating in the lower tropical stratosphere which generates stronger subtropical zonal winds through the thermal wind balance and accelerates the polar vortex. Stationary planetary wave propagations are also playing indispensable modulations effects
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Rosenbaum, Gideon. "Tectonic reconstruction of the Alpine orogen in the western Mediterranean region." Monash University, School of Geosciences, 2003. http://arrow.monash.edu.au/hdl/1959.1/9481.
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Domingues, Vera dos Santos. "Phylogeography and historical demography of the warm water costal fish of the Azores in the context of the recent evolution of the Atlantic and Mediterranean." Doctoral thesis, Universidade dos Açores, Horta, 2007. http://hdl.handle.net/10400.12/1637.
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Tese de Doutoramento apresentada á Universidade dos Açores, HortaIn this thesis the evolutionary relationships of the inshore fish fauna of the northeastern Atlantic and Mediterranean were assessed. Twelve coastal fish species from six families: Blenniidae, Labridae, Pomacentridae, Scaridae, Sparidae and Tripterygiidae, were studied using mitochondrial and nuclear molecular markers. Results were analyzed applying phylogeographic and histórical demography approaches. Species revealed four distinct phylogeographic patterns that were supported by genetic diversity and demographic parameters of the different populations: i) two distinct groups of populations (sometimes considered different species), one including the Mediterranean and the Atlantic coast of western Europe, and another including the Atlantic archipelagos of Canaries, Madeira and Azores (Chromis chromis/ C. limbata, Parabiennius sanguinolentus/ P. parvicornis and the two lineages of Trípterygion delaisi); ii) no appreciable genetic differentiation between any of the populations (Sparisoma cretense, Thalassoma pavo and Diptodus sargus); iií) marked differentiation of the Azorean population (Lipophrys phoíis and Coryphoblennius galeríta) and a clear divergence between Mediterranean and western European íocations as well as Madeira and Canaries (Coryphoblennius galeríta); and iv) one form in the Mediterranean and in the northeastern Atlantic coast (Parabiennius gattorugine) and another one in the Atlantic islands and European coasts (R ruber), thus in sympatry with P. gattorugine. These distinct phylogeographic patterns can be explained by a cornbination of differential effects of the Pleistocene glaciations in several areas of the Atlantic and Mediterranean and the particular thermal tolerances and dispersal capabilities of the species. The species conforming to the first pattern are warm water species that would not have been able to survive the colder glacial periods in the more affected areas such as western Europe,. eastern Canaries, the Azores and most of the Mediterranean. These species might have survived the cold periods in warmer refuges such as Madeira, the western Tropical coast of África and some southern pockets of the Mediterranean. After warmer conditions were restored, fishes surviving the glaciations in the western Tropical coast of África would have expanded northwards colonizing the northern coast of África and the Macaronesian islands, while fishes from the south of Mediterranean invaded the entire Sea and the adjacent European Atlantic coast. Isolation between the two refuges might have promoted divergence and eventually speciation. Colonization of the Azores woulid have been possible by fishes that survived in Madeira, and also in the western coast of África, with the intermediate islands of Canaries and Madeira acting as stepping stones. Species that conform to the pattern of no genetic differentiation among the populations are species with higher dispersal ability, which might have promoted a very fast mixing of the populations after warmer conditions were restored, erasing the signs of population differentiation. The third pattern was depicted for the two cold-water species studied. These species might have persisted during the Pleistocene cooling episodes in the less affected areas, among which are the Azores. The long term persistence of these species coupled with their limited dispersal ability Vera S. Domingues would have promoted the genetic differentiation of the more isolated locations such as the Azores and the Mediterranean. The fourth pattern pointed to a speciation in the Azores or Madeira followed by an invasion of the European shores. Concerning the Atiantic-Mediterranean transition, only one species, the blennild Coryphoblennius galerita, showed a clear and strong genetic differentiation between the two basins, that was accompanied by morphological differentiation. Historical isolation caused by sea level lowering at the Gibraltar Strait during the Pleistocene glaciations might have promoted the divergence between the two basins. The complex pattern of gyres and eddies of the Alboran sea can also constitute an effective physical barrier between the two regions. Other factors such as rirval behavior and the superficial currents during C. gaíeríta's spawning season my also have influenced the segregation of the two divergent lineages. Within the Mediterranean Thaíassoma pavo and Chromis chromis showed a restriction to gene flow south of the Greek Peloponnese, where a permanent anticyclonic gyre has been identified. This study contributes to further our knowledge on the evolutionary relationships of the coastal fauna of the Atlantic-Mediterranean, pointing out that features like thermal tolerances and dispersal ability of the species are amongst the important forces shaping the phylogeographic patterns of the species. ------ RESUMO ------ Nesta tese são analisadas as relações evolutivas da fauna piscícola costeira do Atlântico nordeste e do Mediterrâneo. Foram estudadas doze espécies de peixes costeiros pertencentes a seis famílias: Bienníidae, Labridae, Pomacentridae, Scaridae, Sparidae e Tripterygiidae, utilizando marcadores moleculares mitocondriais e nucleares. Os resultados foram analisados através de métodos filogeográficos e de demografia histórica. As espécies revelaram quatro padrões filogeográficos distintos, suportados peias diversidades genéticas e demografias históricas das diferentes populações: i) dois grupos distintos de populações (por vezes considerados espécies diferentes), um incluindo o Mediterrâneo e a costa oeste europeia, e outro incluindo os arquipélagos atlânticos das Canárias, Madeira e Açores {Chromis chromis/ C. limbata, Parablennlus sanguinolentus/ P. parvicornis e as duas linhagens de Trípterygion delaisi); ii) ausência de diferenciação genética entre as populações (Sparísoma cretense, Thalassoma pavo e Diplodus sargus); iií) acentuada diferenciação da população dos Açores (Lipophrys pholis e Coryphoblennius galeríta) e uma divergência clara entre o Mediterrâneo e o oeste europeu, bem como a Madeira e Canárias {Coryphoblennius galeríta); e iv) uma forma no Mediterrâneo e costa atlântica nordeste (Parablennius gattorugine) e outra nas ilhas atlânticas e na costa europeia [P. ruber), em simpatria com P. gattorugine. Estes padrões filogeográficos distintos podem ser explicados pela combinação dos efeitos diferenciados das glaciações do Pleístocénio em várias áreas do Atlântico e do Mediterrâneo com as tolerâncias térmicas e capacidades de dispersão das diferentes espécies. As espécies que se enquadram no primeiro padrão são espécies de água quente que durante os períodos glaciares mais frios não poderiam ter sobrevivido nas áreas mais afectadas como o oeste europeu, as ilhas este das Canárias, os Açores e a maior parte do Mediterrâneo. Estas espécies devem ter sobrevivido os períodos frios em refúgios mais quentes como a Madeira, a costa Tropical oeste de África e algumas bolsas de água mais quente a sul do Mediterrâneo. Após as condições mais quentes terem sido repostas, os peixes que sobreviveram às glaciações na costa Tropical oeste de África, ter-se-ão expandindo para norte, colonizando a costa norte de África e as ilhas da Macaronésia, enquanto que os peixes do sul do Mediterrâneo terão invadido todo este mar e a costa atlântica europeia adjacente, O isolamento dos dois refúgios deverá ter promovido divergência e eventualmente especiação. A colonização dos Açores deverá ter sido possível por peixes que sobreviveram na Madeira e também na costa oeste Africana, com as ilhas intermédias das Canárias e Madeira a actuar como stepping stones. As espécies que se enquadram no padrão de inexistente diferenciação populacional são espécies com maior capacidade de dispersão, o que terá permitido uma mistura rápida das populações após as condições mais quentes terem sido repostas, eliminando quaisquer sinais de diferenciação populacional. O terceiro padrão foi identificado para os duas espécies de água fria estudados. Estas espécies deverão ter persistido nas áreas menos afectadas, incluindo os Açores, durante os períodos frios do Pleistocénio. A persistência prolongada deste peixes, bem como a sua reduzida capacidade Vera S. Dorningues de dispersão terão promovido a diferenciação genética das regiões mais isoladas como os Açores e o Mediterrâneo. O quarto padrão aponta para um fenómeno de especiação nos Açores ou na Madeira, e posterior invasão das costas europeias. No que respeita à transição entre o Atlântico e o Mediterrâneo, apenas uma espécie, o biénio Coryphoblennius gaieríta, mostrou uma clara e forte diferenciação genética entre as duas bacias, acompanhada por diferenciação morfológica. O isolamento histórico causado pela redução do nível do mar no Estreito de Gibraltar durante as glaciações do Pleistocénio, poderá ter promovido a divergência entre as duas bacias. O padrão complexo de redemoinhos do Mar Alboriano pode também constituir uma barreira física efectiva entre as duas regiões. Outros factores como o comportamento larvar e as correntes superficiais durante a época de reprodução de C. gaieríta, podem ter também influenciado a segregação das duas linhagens divergentes. Dentro do Mediterrâneo, Thalassoma pavo e Chromis chromis revelaram a existência de restrição ao fluxo genético a sul da Peloponésia grega, onde um gyre anticiclónico foi identificado, Este estudo contribui para alargar o nosso conhecimento acerca das relações evolutivas da fauna costeira do Atlântico-Mediterrâneo, e aponta características como a tolerância térmica e capacidade de dispersão das espécies, como forças importantes para o delinear de padrões filogeográficos das espécies.
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Robert, Klaus Bauer. "Development of a robust index of abundance for Atlantic bluefin tuna (Thunnus thynnus) through aerial surveys in the Northwestern Mediterranean Sea." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS042/document.
Full textAbstract:
Le déclin du thon rouge de l'Atlantique nord-est et de Méditerranée (ABFT, Thunnus thynnus) qui faisait suite à une forte surexploitation a été largement médiatisé au cours de la dernière décennie. Pour contrer cette tendance et reconstituer ce stock, d’importantes mesures de gestion ont été mises en place à partir de 2007. En dehors des difficultés liées à leur mise en œuvre et à leur contrôle, la gestion des pêcheries thonières est aussi limitée dans les capacités à suivre précisément les variations d’abondance de ces espèces dont les observations reposent principalement sur les données de pêche. Le manque d’indice d’abondance fiable fait que l’évaluation du thon rouge, comme celle des autres espèces de poissons grands pélagiques, est entachée d’importantes incertitudes. Cependant, les suivis aériens pourraient permettre de fournir un indice d’abondance du thon rouge. Ils sont en effet fréquemment utilisés pour l'évaluation de l'abondance des mammifères marins et aussi par les pêcheurs pour détecter les poissons épipélagiques, comme les thons. Dans ce contexte général, cette thèse a pour objectifs : (i) d'évaluer des facteurs qui affectent potentiellement la détectabilité des thons pendant les suivis aériens, (ii) d’analyser leur comportement horizontal et vertical et les facteurs environnementaux qui l’influencent, et (iii) d’intégrer les connaissances acquises pour développer un indice abondance robuste du thon rouge en Méditerranée Nord Occidentale. Les analyses reposent sur des suivis aériens conduits depuis 2000 dans le golfe du Lion, une zone de nourricerie importante pour le thon rouge. Une modélisation des données basée sur le « distance sampling » montre des effets significatifs des observateurs, de la taille des bancs de thons et de l'état de la mer sur l’estimation d’abondance. Cette étude confirme par ailleurs une augmentation importance des abondances entre 2003 et 2009, probablement en réponse aux mesures de gestion mises en œuvre depuis 2007 (notamment la taille minimale de débarquement de 30 kg). Pour évaluer les effets du comportement sur les estimations d'abondance, une étude a porté sur les trajectoires de thons issues du marquage électronique. Ces analyses montrent une disponibilité des thons rouge ainsi qu’une présence en surface dans la zone et la période (Août-Octobre) des suivis aériens ; résultat confortant la fiabilité de l’indice d’abondance. On note également des changements saisonniers du comportement, avec un approfondissement des thons à partir de mi-Novembre correspondant à la dé-stratification de la colonne d’eau. Le comportement de plongée profonde était particulièrement fréquent pendant les mois de forte productivité biologique (février-Mai), mais des plongées profondes ont également été observées à la fin de l'été en relation avec des fronts thermiques. La variabilité des schémas migratoires sur l’horizontale et du comportement sur la verticale indique une forte composante opportuniste, probablement liée à la disponibilité des ressources alimentaires. Les résultats obtenus durant cette thèse démontrent la faisabilité d’obtenir un indice d’abondance de thon rouge robuste à partir des suivis aériens (donc indépendants des données de pêche) et fournissent un cadre théorique et méthodologique pour une extension de ce type de suivi afin de diminuer les incertitudes autour de l’évaluation de ce stock. Outre le thon rouge, les suivis aériens ont également permis un suivi du rorqual commun (Balaenoptera physalus) et des dauphins rayés (Stenella coeruleoalba). La présence des mammifères marins semble également être liée à la productivité élevée et l'activité méso-échelle de la zone d'étude. Si les dauphins présentent une distribution spatiale en partie corrélée à celle du thon rouge, les rorquals ne présentent pas de forte co-occurrence avec le thon rouge, résultat qui confirmerait une certaine proximité des régimes alimentaires des thons et des dauphinsDeclines in Atlantic bluefin tuna stocks (ABFT, Thunnus thynnus), due to extensive over-fishing, have been widely publicized in recent decades. To counteract this trend, regulatory measures have been introduced by the fisheries managers, aiming at the rebuilding of ABFT stocks. However, apart from difficulties in controlling the implementation of these measures, fisheries management is limited in its capabilities to track their efficiency due to major uncertainties in the stock assessment. Indeed, there is a general need of reliable indicators of ABFT abundance. Aerial surveys may provide a helpful tool for the abundance monitoring of this highly exploited fish species. They are frequently used for the abundance assessment of marine mammals and also by fishermen to detect epipelagic fish, such as tunas. The aim of this thesis was to address these issues and to create a robust fishery-independent abundance index for ABFT through aerial surveys. To achieve this goal, the focus was set on (i) the assessment of factors that potentially affect the detectability of ABFT during the aerial surveys, (ii) the habitat use of ABFT, i.e. their horizontal and vertical behaviour as well as the factors driving it, and (iii) the integration of the knowledge gained through these analyses in the development of a robust index of ABFT abundance. Surveys were conducted from 2000 onwards in the Gulf of Lions, an important nursery ground for ABFT in the Northwestern Mediterranean Sea. Line transect modelling of the sighting data revealed significant effects of detectability changes on abundance estimates, related to the observer teams employed, the size of detected ABFT schools and the sea state during the aerial surveys. Derived estimates of ABFT abundance confirmed a significant increase from 2003 to 2009, likely reflecting the success of recently implemented management measures (e.g. minimum landing size of 30 kg since 2007). To assess behavioural effects on abundance estimates, auxiliary archival tagging experiments, conducted since 2007, focused on the presence and surface availability of ABFT during the aerial surveys, and aimed to identify factors influencing these variables. The data gained from these experiments demonstrated seasonal changes in the migratory behaviour of ABFT, but also a high area and surface presence of ABFT in the study zone during the survey period (August–October), supporting the reliability of the abundance index. Surface presence of ABFT decreased with the breakdown of the thermal stratification of the water column (mid-November), when the fish left the survey zone and moved South. By contrast, deep diving behaviour was particularly frequent during months of high biological productivity (February--May), although deep and unusual long spike dives were also observed during late summer in relation to thermal fronts. However, the variability in the migration patterns indicates a strong opportunistic component in both, the horizontal and vertical behaviour of ABFT, probably related to the availability of food resources. Apart from ABFT, the aerial surveys also allowed an abundance monitoring of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) as well as an analysis of their co-occurrence with ABFT. In fact, similar to ABFT, the presence of these species appeared to be related to the high productivity and mesoscale activity of the study zone, improving our understanding of their habitat use, essential for the conservation of these much less abundant and endangered species. Regarding the stock assessment of ABFT, the results gained through this thesis prove the feasibility to derive robust fishery independent abundance indicators for ABFT through aerial surveys, providing the theoretical and methodological background for an extension of these efforts for a more sustainable management of the stocks of this species
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Leone, Agostino <1986>. "Genomic applications in fish traceability and fishery stock management: phylogeography and population structure of the Mediterranean-Atlantic blue shark, Prionace glauca." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8672/1/Leone_Agostino_Tesi.pdf.
Full textAbstract:
The abundance of blue sharks, Prionace glauca, Linnaeus 1758 (BS), has dramatically declined over the last century in the Mediterranean Sea (a reduction of 75% over the last 30 years). In this study, the combination of a near-capillary sampling strategy of BS in several areas of the basin together with the development and use of genomic markers - that can represent both neutral and selective markers - offers the opportunity to assess and visualize for the first time for this poorly studied and vulnerable species population structure and potentially local adaptation.
The phylogeography between Mediterranean Sea and North-Eastern Atlantic Ocean, inferred using mtDNA (control region, Cytb), highlighted no obvious haplotypic pattern of geographical differentiation, while Φst analyses indicated significant genetic structure among four geographical groups.
Successively, spatial genetic differentiation of 203 Mediterranean and North-eastern Atlantic BS was estimated using 3,451 species specific SNP loci, developed using the ddRAD technology.
Neutral SNPs differentiation was null or very low (pairwise Fst ranged from 0.2 to 0.5%) indicating a near or fully-panmictic population. A subpanel of potentially under-selection loci revealed significant higher Fst values (pairwise Fst ranging from 0.01 to 0.09), clustering analyses failed to evidence strong signals of differentiation among areas, probably due to the combination of migrants-mediated gene flow and the big population size.
Based on these results, combined with the biology of this species, such the extreme vagility e complex population dynamics, it seems fair to suggest that the Mediterranean BS population could represent a meta-population, with spatially separated populations which interact through migrant specimens. This work has advanced knowledge on Mediterranean Blue Shark population biology and ecology relating ex-novo the Mediterranean BS population and the fishery stock to the Atlantic biological and management units, being the Mediterranean BS often not considered in the review of data and ecological relationships.
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Theraroz, Adélaïde. "Ressources génétiques du pin maritime : variabilité géographique, pressions de sélection et adaptation future." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0245.
Full textAbstract:
Le changement climatique affecte déjà les écosystèmes forestiers sur tous les continents, comme en témoignent la migration des espèces vers le nord et vers les plus hautes altitudes et l'augmentation du dépérissement des forêts en réponse, non seulement à des conditions climatiques plus rigoureuses, mais aussi à des épidémies de ravageurs et de maladies résultant d'événements climatiques sans précédent ainsi que de l'intensification des activités humaines. Ces phénomènes ont des conséquences négatives sur le fonctionnement des écosystèmes forestiers et la persistance des espèces et des populations, car ils menacent la disponibilité des ressources, perturbent la dynamique des populations et remettent en question les limites physiologiques et la résistance aux agents pathogènes. L'avenir des populations d'arbres de forêts naturelles face au changement climatique, compte tenu de leur nature sessile et de leur long temps de génération, est donc préoccupant, que ce soit en termes d'extinction, de capacité à migrer ou à s'adapter par le biais de changements génétiques. Du point de vue de la conservation, nous devons comprendre dans quelle mesure les arbres forestiers seront capables de survivre face au changement climatique actuel et futur. L'énorme quantité de données génomiques disponibles grâce aux outils de séquençage de nouvelle génération révolutionne notre compréhension de la base génétique de l'adaptation. À son tour, elle accélère le développement de nouvelles méthodes statistiques qui peuvent prédire la vulnérabilité génomique des arbres forestiers au changement climatique dans l'espace et dans le temps, et déterminer le potentiel de maladaptation génétique dans des conditions climatiques changeantes. Dans cette thèse de doctorat, j'ai utilisé le pin maritime (Pinus pinaster Ait.), un conifère à longue durée de vie originaire de la partie occidentale du bassin méditerranéen, comme étude de cas pour démêler les schémas spatiaux de la variation génétique à l'échelle de l'aire de répartition et à l'échelle régionale en fonction de différents gradients, anticiper les réponses des populations au changement climatique et donner un aperçu des tendances actuelles en matière de sélection naturelle. Le premier chapitre vise à comprendre comment, à l'échelle de l'aire de répartition de l'espèce, la variation génétique, l'adaptabilité et le potentiel d'inadaptation à court terme aux conditions climatiques futures sont distribués du coeur de l'aire de répartition vers les marges géographiques et climatiques. Le deuxième chapitre examine les 2 schémas spatiaux de la sélection naturelle contemporaine en analysant les changements phénotypiques en réponse aux pressions sélectives actuelles, et donne un aperçu des tendances actuelles de l'adaptation locale au changement climatique pour le pin maritime à l'état sauvage. Le troisième chapitre vise à identifier les schémas spatiaux de variation génétique du pin maritime dans l'île de Corse, caractérisée par des particularités spécifiques et constituant des ressources génétiques précieuses pour l'espèce, et à analyser leurs capacités d'adaptation actuelles et futures au changement climatique. Dans l'ensemble, cette thèse de doctorat étudie les facteurs sous-jacents et le potentiel des réponses adaptatives du pin maritime aux conditions environnementales changeantes à différentes échelles spatiales et temporelles, contribuant ainsi au développement d'un cadre intégratif essentiel pour anticiper les réponses des populations au changement climatique, sur la base duquel des prédictions solides pour les stratégies de conservation et de gestion peuvent être développéesClimate change is already affecting forest ecosystems on all continents, as evidenced by the northward and upward migration of species and the increase of forest dieback in response to not only harsher climate conditions but also to pest and disease epidemics resulting from unprecedented climatic events as well as the intensification of human activities. These phenomena have negative consequences for the functioning of forest ecosystems and the persistence of species and populations, as they threaten the availability of resources, disrupt population dynamics and call into question physiological limits and resistance to pathogens. The future of natural forest tree populations in the face of climate change, given their sessile nature and long generation times, is therefore worrying, whether in terms of extinction, ability to migrate or adapt through genetic change. From a conservation point of view, we need to understand the extent to which forest trees will be able to survive in the face of current and future climate change. The huge amount of genomic data available from next-generation sequencing tools is revolutionising our understanding of the genetic basis of adaptation. In turn, it is accelerating the development of new statistical methods that can predict the genomic vulnerability of forest trees to climate change in space and time, and determine the potential for genetic maladaptation under changing climatic conditions. In this PhD thesis, I used maritime pine (Pinus pinaster Ait.), a long-lived conifer native to the western part of the Mediterranean basin, as a case study to unravel the spatial patterns of genetic variation at the range-wide and regional scales function of different gradients, anticipate population responses to climate change and provide insight into current trends in natural selection. The first chapter aims to understand how, at the scale of the species range, genetic variation, adaptability and the potential for short-term maladaptation to future climatic conditions are distributed from the range core towards the geographical and climatic margins. The second chapter examines the spatial patterns of contemporary natural selection by analysing phenotypic changes in response to current selective pressures, and provides an overview of current trends in local adaptation to climate change for maritime pine in the wild. The third chapter aims to identify the spatial patterns of genetic variation of maritime pine in the Corsica Island, characterized by specific features and constituting valuable genetic resources for the species, and to analyse their current 4 and future adaptive capacities to climate change. Overall, this PhD thesis studies the underlying drivers and potential of maritime pine adaptive responses to changing environmental conditions at different spatial and temporal scales, thus contributing to the development of an integrative framework essential for anticipating population responses to climate change, on the basis of which robust predictions for conservation and management strategies can be developed
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Gamboa, Badilla Nancy. "The role of species niche, species dispersal and landscape factors in the assembly of novel woody communities in metropolitan Mediterranean regions." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/462039.
Full textAbstract:
Biological diversity in a global scale has been threaten seriously by anthropogenic disturbances in ecosystems. Changes in land cover and land use affect biodiversity, causing habitat loss and species extinction, or colonization and establishment of new communities. Such effects could happen in an outdated way between the time of the disturbance and species extinction or colonization. Landscape history, connectivity between habitat fragments and the dispersion of organism, shapes species diversity and influences extinction and colonization process. On the other hand, exotic plant invasion could drive the assembly of plant community in newly formed forests as a result of changes in land use. The present thesis aims to contribute to the knowledge of the assembly of new woody communities in forests and bushes of the metropolitan region of Barcelona. For this, the legacy of five historical land use trajectories and the environmental factors on the richness, diversity and equity of woody species in shrubland were analyzed. In addition, we evaluated the relationship between environmental and historical factors and species composition (Chapter 3). The results revealed that species richness and diversity are associated with both elevation and historical trajectories of land use, while equity only to elevation. The study did not detect spatial effects attributable to dispersion. The results indicated that both trajectories and environmental factors (niche) equally drive local community assembly, while dispersal seems to play a secondary role. The richness and diversity of species are affected by the use of the soil in the recent past (1956) and the composition by the oldest uses (1900). Additionally, the effect of urbanization on plant community assembly process in new periurban forests (Chapter 4) was evaluated. We explored the relationship between plant species richness and composition (dispersed by vertebrates and non-vertebrates), and forest patches history (pre-existing and recent), landscape pattern (forest connectivity and urbanization), habitat condition (forest, prairie grass, synanthropic, other) and environmental variables. The results showed that landscape habitat and structure are the main drivers of plant community assembly. However, as a side effect of forest history, extinction debt of scrub-meadow species must be considered. In addition, we found a greater colonization of synanthropic species and a credit for colonization of forest species dispersed by vertebrates in recent forests. The assemblage of new forests was characterized by the presence of species of previous habitats, rapid colonization of specialists and an increase of synanthropic species. Finally, the patterns of invasion by exotic plants and the influence of dispersal mechanism, environmental variables and landscape anthropization in these newly formed periurban forests were analyzed (Chapter 5). The presence, richness and abundance of exotic species dispersed by vertebrates and non - vertebrates in recent and preexisting forests were compared, taking into account landscape and environmental correlations. The results showed that metropolitan forests are more invaded than the rest of the province and the exotic flora on these forests are dominated by species dispersed by vertebrates. However, at the regional level a bias was found towards species dispersed by non-vertebrates. Forest fragmentation was associated with the presence, richness and coverage of plants dispersed by vertebrates; while urbanization was related with coverage of species dispersed by non-vertebrates. We suggest an association between forest history and plant dispersion syndromes, with species dispersed by vertebrates in ancient forests. No associations between exotic species composition and environmental factors were found, but not with forest history. The study notes a high degree of invasion of forests by alien species dispersed by vertebrates, which could colonize unaltered forests and persist and even expand throughout forest succession.Las alteraciones antrópicas en los ecosistemas amenazan gravemente la diversidad biológica a escala global. Cambios en las cubiertas y usos del suelo afectan la biodiversidad, causando pérdida de hábitats y extinción de especies o bien colonización y establecimiento de especies que forman nuevas comunidades. Tales efectos podrían suceder de forma desfasada entre el momento de la perturbación y la extinción o colonización de las especies. Podrían además verse condicionados por la historia del paisaje, que influye sobre la diversidad de las especies, la conectividad entre fragmentos de hábitat y la dispersión de los organismos. Por otra parte, la invasión por plantas exóticas podría conducir el ensamblaje de la comunidad vegetal en bosques recién formados, como resultado de cambios en el uso de la tierra. La presente tesis tiene como objetivo aportar al conocimiento del ensamblaje de las nuevas comunidades leñosas en bosques y matorrales de la región metropolitana de Barcelona. Para ello se analizó el legado de cinco trayectorias históricas del uso del suelo y los factores ambientales sobre la riqueza, diversidad y equidad de especies leñosas en matorrales. Además, se evaluó la relación entre los factores ambientales e históricos y la composición de las especies (Capítulo 3). Los resultados revelaron que la riqueza y diversidad de estas especies se asocia tanto a la elevación como a las trayectorias históricas del uso de la tierra, mientras que la equidad sólo a la elevación. El estudio no detectó efectos espaciales atribuibles a la dispersión. Los resultados indicaron que tanto las trayectorias como los factores ambientales (nicho) impulsan de igual forma el ensamblaje de la comunidad a escala local, mientras que la dispersión parece desempeñar un papel secundario. La riqueza y diversidad de especies son afectadas por el uso del suelo en el pasado reciente (1956) y la composición por los usos más antiguos (1900). Por otra parte, se evaluó el efecto de la urbanización sobre el proceso de ensamblaje de las comunidades vegetales en los nuevos bosques periurbanos (Capítulo 4). Se exploró la relación entre la historia de parches forestales (preexistentes y recientes), el patrón del paisaje (conectividad forestal y urbanización), la condición del hábitat (bosque, matorral-pradera, sinantrópico, otro) y las variables ambientales con la riqueza y composición de las especies de plantas (dispersadas por vertebrados y no vertebrados). Los resultados mostraron que el hábitat y la estructura del paisaje son los principales impulsores del ensamblaje de la comunidad vegetal. Sin embargo, hay un efecto secundario de la historia del bosque, constituido por la deuda de extinción de especies de matorral-pradera. Además, se encontró una mayor colonización de especies sinantrópicas y un crédito de colonización de especies forestales dispersadas por vertebrados en los bosques recientes. El ensamblaje de bosques nuevos se caracterizó por la presencia de especies de hábitats anteriores, rápida colonización de especialistas y un aumento de especies sinantrópicas. Finalmente, se analizaron los patrones de invasión por plantas exóticas y la influencia del mecanismo de dispersión, las variables ambientales y la antropización del paisaje en estos bosques periurbanos recién formados (Capítulo 5). Se comparó la presencia, la riqueza y la abundancia de especies exóticas dispersadas por vertebradas y no vertebradas en bosques recientes y preexistentes, teniendo en cuenta las correlaciones paisajísticas y ambientales. Los resultados mostraron que los bosques metropolitanos están más invadidos que los del resto de la provincia y la flora exótica en estos bosques está dominada por especies dispersadas por vertebrados. Sin embargo, a nivel regional se encontró un sesgo hacia las especies dispersadas por no vertebrados. La fragmentación de los bosques se asoció con la presencia, riqueza y cobertura de plantas dispersadas por vertebrados; mientras que la urbanización con la cobertura de especies dispersadas por no vertebrados. Se sugiere una asociación entre la historia de los bosques y los síndromes de dispersión de las plantas, con especies dispersadas por vertebrados en bosques antiguos. No se detectaron asociaciones entre la historia del bosque y la composición de especies exóticas, sí con factores ambientales. El estudio advierte alto grado de invasión de bosques por especies exóticas dispersadas por vertebrados, las cuales podrían colonizar bosques inalterados y persistir e incluso expandirse a lo largo de la sucesión.
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Antobreh, Andrew Akwasi. "Channelised and open-slope processes of mass sediment transport their morphological and seismic characterisation from selected Atlantic high productivity regions /." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979703700.
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Sitjà, Poch Cèlia. "The bathyal connections between the Mediterranean Sea and the Northeastern Atlantic Ocean: An assessment using deep-water sponges as a case study." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/672200.
Full textAbstract:
The general outline of this thesis was to assess the potential of the Mediterranean water masses to transport deep-sea fauna towards the Atlantic Ocean. By examining the effects that the bathyal water mases moving from the Eastern Mediterranean basin towards the Northeastern Atlantic Ocean may have on the relationships of the deep-water sponge fauna, a case study is provided. Prior to using the sponge fauna as a deep-water biogeographic tool, new collections of deep-sea sponges needed to be conducted in order to increase the faunal resolution at the two most important transitional areas across the bathyal trajectory from the Eastern Mediterranean to the Atlantic, the Strait of Gibraltar and the Strait of Sicily, which remained poorly studied.
In this context, the specific objectives of this thesis were as it follows:
1. To complete the previous limited knowledge on the deep-water sponge fauna at key transition areas along the trajectory of the bathyal water mases.
1.1. To provide the missing qualitative and quantitative knowledge of the bathyal sponge fauna at the most Eastern-Atlantic side of the Strait of Gibraltar, focusing on a mud volcano system at the Gulf of Cádiz that spans the entire range of bathyal depths.
1.2. To underpin the qualitative knowledge of the deep-water sponge fauna at the most Western-Mediterranean side of the Strait of Gibraltar, focusing on the deep shelf and upper slope of the Alboran Island.
1.3. To underpin the qualitative knowledge of the deep-water sponge fauna at the Eastern-Mediterranean side of the Strait of Sicily, focusing on the deep shelf and slope of the Maltese Islands.
1.4. To put into practice basic genetic techniques to aid in the identification of species that remain unresolvable through the classical phenetic approach, providing an example case for a more integrative sponge taxonomy.
2. To assess the effects of local environmental variables on the qualitative and quantitative distribution of abundances of the sponges across a complete bathymetric bathyal range, focussing on the mud volcanoes of the Gulf of Cádiz as a case study.
3. To examine the affinities of the deep-water sponge fauna across the trajectory of the bathyal water masses running from the Eastern Mediterranean to the Northeastern Atlantic.
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Fortuny, Didac. "Climate change and precipitation trends in the northern Mediterranean." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/323369.
Full textAbstract:
According to climate projections for the end of the twenty-first century, regional responses to global warming include a strong and widespread drying over the northern Mediterranean, particularly intense in summer. Many authors have reported observed negative precipitation trends in the last decades and have considered them evidences that the projected drying is already detectable. Because of the strong decadal variability of precipitation series, however, it is not straightforward to discern whether observed trends are attributable to an external signal or whether they are consistent with internal variability alone. In order to assess if precipitation series in the northern Mediterranean region are compatible with the presence of a persistent signal, we examine the sensitivity of trend estimations to the choice of time interval: since internal variability is expected to be random, the magnitude of natural precipitation changes varies greatly when estimated for intervals with different arbitrary initial and final years. Instead, series under the influence of a persistent signal exhibit trends of similar magnitude in a wide range of consecutive intervals. In this regard, our results indicate that only in winter and from mid-twentieth century onwards the evolution of precipitation series is consistent with what one would expect if a persistent signal was superimposed to internal variability. Trends for other seasons and periods, instead, are sensitive to the choice of time interval. In addition, we find that the recent observed winter drying trends are largely explainable by an upward trend in the North Atlantic Oscillation (NAO) observed in the last decades of the twentieth century.
The role played by climate change and internal variability in the observed winter northern Mediterranean drying is examined using historical (forced) and pre-industrial (unforced) CMIP5 climate simulations. For area-averaged precipitation we find that neither historical nor pre-industrial simulations contain trends as strong as the observed ones. We consider two explanations for this result: (1) observed trends have a forced origin but the forcing (or the response to the forcing) is underestimated in historical simulations, and (2) observed trends are mainly natural but climate models underestimate the range of internal variability of northern Mediterranean precipitation. Consistent with the fact that the NAO plays the main role in the evolution of northern Mediterranean precipitation, observed NAO trends are also stronger than those present in historical and pre-industrial simulations. Considering trends at grid-point scale, instead, observed precipitation trends are within the spread of unforced simulated trends and, therefore, no drying signal is detectable.
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Volakakis, Nikolaos. "Development of strategies to improve the quality and productivity of organic and 'low input' olive production systems in semi-arid Mediterranean regions." Thesis, University of Newcastle Upon Tyne, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610977.
Full textAbstract:
The project reported here took place in Messara plain, Crete, Greece, a semi-arid Mediterranean region. It involved a literature review (Chapter 1), a field survey (Chapter 2), two field experiments (Chapters 3 and Chapter 4) and associated laboratory analyses. The survey took place in three crop years using pairs of neighbouring organic and conventional commercial olive orchards of the cultivar Koroneiki at the valley and the surrounding hills. Both field experiments took place in a 2.4 ha table olive orchard consisted of trees of Kalamon and Manzanila olive cultivars for three crop years. Results from the field survey (Chapter 2) indicate that organic olive oil production systems developed in the Messara plain can produce the same or higher yields of oil than conventional production in the same area. Although olive oil produced from both systems is of similar quality, slightly but significantly higher levels of acidity were detected in organic olive oil. Pesticide contamination was identified as a problem in both organic and conventional production with endosulphan sulphate being the main pesticide residue. This will have to be resolved to preserve the reputation of the region for high quality oil production. Improvement in cover cropping was the main target in the 1st field experiment (Chapter 3). There were few significant effects of cover crops/cover crop mixtures on nutrient availability, invertebrate activity, and yield parameters. Rhizobium inoculation had a negative effect on Vicia sativa establishment but did not affect any of the nodulation parameters assessed. The highest levels of Hymenoptera activity were found in the cover crop mixture consisting of vetch, peas and barley. Also, the non-inoculated vetch and the cover crop mixture reduced the concentrations of olive leaf boron. The development of improved olive fruit fly management strategies was the main target in the 2nd field experiment (Chapter 4). Wind direction, humidity, rainfall and temperature were identified as important potential environmental drivers for olive fly pest pressure in the Messara region. Also, results indicate that soil survival is probably not an important over-wintering mechanism for the olive fly in the Messara plain and other semiarid Mediterranean regions. The two mass trapping systems compared differ significantly with respect to number of non-target invertebrates killed, but caught similar numbers of olive fruit flies. Results also indicated that the dates for placing mass-traps into orchard may need to be revised and related to the drivers of olive fly pressure.
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Urso, Ilenia. "First assessment on genetic structure and phylogeography of Mediterranean blue shark (prionace glauca, L. 1758) population using mitochondrial gene variation: a comparison with the Atlantic." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/9765/.
Full textAbstract:
The blue shark, Prionace glauca, is one of the most vagile shark species worldwide distributed. The particular body shape allows blue sharks make transoceanic movements, leading to a circumglobal distribution. Due to its reproductive cycle, an extraordinarily high number of specimens is globally registered but, even if it is still a major bycatch of longline fishery rather than a commercial target, it is characterized by a high vulnerability. In this perspective it is important to increase the amount of informations regarding its population extent in the different worldwide areas, evaluating the possible phylogeographic patterns between different locations. This study, included in the "MedBlueSGen" European project, aims exactly at filling a gap in knowledges regarding the genetic population structure of the Mediterranean blue sharks, which has never been investigated before, with a comparison with the North-Eastern Atlantic blue shark population. To reach this objective, we used a dataset of samples from different Mediterranean areas implementing it with some samples from North-Eastern Atlantic. Analyzing the variability of the two mitochondrial markers control region and cytochrome b, with the design of new species-specific primer pairs, we assessed the mitochondrial genetic structure of Mediterranean and North-Eastern Atlantic samples, focusing on the analysis of their possible connectivity, and we tried to reconstruct their demographic history and population size. Data analyses highlighted the absence of a genetic structuring within the Mediterranean and among it and North-Eastern Atlantic, suggesting that the Strait of Gibraltar doesn't represent a phylogeographic barrier. These results are coherent to what has been found in similar investigations on other worldwide blue shark populations. Analysis of the historical demographic trend revealed a general stable pattern for the cytochrome-b and a slightly population expansion for the control region marker.