Tesis sobre el tema "Ecosystem modelling"
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Bennett, Victoria Jane. "Computer modelling the Serengeti-Mara ecosystem". Thesis, University of Leeds, 2003. http://etheses.whiterose.ac.uk/1553/.
Texto completoCropp, Roger Allan y R. Cropp@griffith edu au. "A Biogeochemical Modelling Analysis of the Potential For Marine Ecosystems to Regulate Climate By the Production of Dimethylsulphide". Griffith University. Australian School of Environmental Studies, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030703.101310.
Texto completoCropp, Roger Allan. "A Biogeochemical Modelling Analysis of the Potential For Marine Ecosystems to Regulate Climate By the Production of Dimethylsulphide". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367734.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
Ogutu, Booker. "Modelling terrestrial ecosystem productivity using remote sensing data". Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/341720/.
Texto completoVaughan, Louise. "Trophic modelling of the Lough Neagh ecosystem, Northern Ireland". Thesis, University of Ulster, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.554276.
Texto completoFerguson, Claire Ann. "Univariate and multivariate statistical methodologies for lake ecosystem modelling". Thesis, University of Glasgow, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437930.
Texto completoMori, Mitsuyo. "Modelling the krill-predator dynamics of the Antarctic ecosystem". Doctoral thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/8734.
Texto completoThe main objective of this thesis is to model the krill-predator dynamics of the Antarctic ecosystem so as to determine whether predator-prey interactions alone can broadly explain observed population trends of the species considered in the model without any appeal to systematic effects possibly caused by environmental change. The history of human harvesting in the Antarctic is summarized briefly, and the central role played by krill is emphasized. The background to the hypothesis of a krill surplus in the mid 20th Century is described, and the information, particularly regarding population trends, that has become available since the postulate was first advanced is discussed. By reviewing the consumption and abundance estimates for various species in the Antarctic, it is evident that among the baleen whales, blue, fin, humpback and minke whales feed mainly on krill, and could collectively be consuming up to 120 million tons of krill in this region for each of the years around 1990. Of the seals, the Antarctic fur seals and crab-eater seals also feed mainly on krill, and these two species could be consuming up to 70 million tons of krill each year. Consumption estimates for other krill predators (birds, fish and cephalopods) are relatively poorly determined by comparison. Of these four baleen whale species, minke whales currently make the greatest impact on krill due to their large number at present compared to the other larger whale populations which are still depleted. Trend information suggests that the large baleen whales that were heavily depleted during the commercial whaling period are now recovering at rates in the vicinity of 10% per year, but there are some indications of a recent decrease in minke whale numbers. Thus, the consumption of krill by these large baleen whales has probably been increasing over recent years, though decreasing for minke whales. Updated and refined catch-at-age analyses of minke whales for the International Whaling Commission (IWC) Management Areas IV and V suggest an increase in abundance of this species in the middle decades of the 20th Century to peak at about 1970, followed by a decline for the next three decades. Fitting the recruitment time trend obtained from these analyses to a stock-recruitment model suggests that minke whale carrying capacity first increased from about 1940 to 1960 followed by a 60% decrease from the 1960s to the present. General trends in the biological parameters of this species are consistent with such a decline. A predator-prey interaction model is developed including krill, four baleen whale (blue, fin, humpback and minke) and two seal (Antarctic fur and crab-eater) species. The model commences in 1780 (the onset of fur seal harvests) and distinguishes the Atlantic/Indian and Pacific sectors in view of the much larger past harvests in the former. A reference case and six sensitivities are fit to available data on predator abundances and trends, and the plausibility of the results and the assumptions on which they are based is discussed, together with suggested areas for future investigation. Amongst the key inferences of the study are that: i) species interaction effects alone can explain observed predator abundance trends, though not without some difficulty; ii) it is necessary to consider other species in addition to baleen whales and krill to explain observed trends, with crab-eater seals seemingly playing an important role and constituting a particular priority for improved abundance and trend information; iii the Atlantic/Indian region shows major changes in species abundances, in contrast to the Pacific which is much more stable; iv) baleen whales have to be able to achieve relatively high growth rates to explain observed trends; v) species interaction effects impact the dynamics of these predators in ways that differ from what might be anticipated in a conventional single-species harvesting context, and they need to be better understood and taken into account in management decisions, and vi) Laws' (1977) estimate of some 150 million tons for the krill surplus may be appreciably too high as a result of his calculations omitting consideration of density dependent effects in feeding rates. . A priority for future work is to obtain improved estimates of the amount of krill consumed by other species, such as birds, cephalopods and fish as well as to obtain consensus on current abundance estimates for crab-eater seals and baleen whales (especially minke whales and also the associated abundance trend). Once such information is improved, more thorough sensitivity tests to the assumptions of the model and uncertainties in the abundance estimates of the species considered need to be explored. With such further development, it is hoped that such a model may ultimately assist in providing scientific advice for appropriate sustainable harvesting strategies for the Antarctic marine ecosystem taking species interactions into account, as this is a matter of key importance for the IWC and for the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).
Pang, Xi. "Trade-off analysis of forest ecosystem services – A modelling approach". Doctoral thesis, KTH, Hållbarhet, utvärdering och styrning, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216432.
Texto completoQC 20171023
Limer, Laura Michelle Clare. "Biodiversity and ecosystem function : modelling soil biota and carbon cycling". Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442353.
Texto completoMohamad, Nordin Bin Haji. "Optimal management of a renewable resource in a multispecies ecosystem". Thesis, City University London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255341.
Texto completoBarciela, FernaÌndez Rosa MariÌa. "Modelling ecosystem dynamics in the turblent surface layers of the ocean". Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252437.
Texto completoNobre, Ana Maria Domingos. "Integrated ecological-economic modelling and assessment aproach for coastal ecosystem management". Doctoral thesis, Faculdade de Ciências e Tecnologia, 2008. http://hdl.handle.net/10362/3978.
Texto completoOver the past few decades, policy-makers have defined new instruments to address coastal ecosystem degradation. Emerging coastal management frameworks highlight the use of the best available knowledge about the ecosystem to manage coastal resources and maintain ecosystem’s services. Progress is required, however, in translating data into useful knowledge for environmental problem solving. This thesis aims to contribute to research assessing changes in coastal ecosystems and benefits generated due to management actions (or to the lack thereof). The overall objectives are to assess the ecological and economic impacts of existing management programmes, as well as future response scenarios and to translate the outcomes into useful information for managers. To address these objectives, three different approaches were developed: A multilayered ecosystem model A multilayered ecosystem model was developed to simulate management scenarios that account for the cumulative impacts of multiple uses of coastal zones. This modelling field is still at an early stage of development and is crucial, for instance, to simulate the impacts of aquaculture activities on the ecosystem, accounting for multiple farms and their interactions with other coastal activities. The multilayered ecosystem model is applied in this thesis to test scenarios designed to improve water quality and manage aquaculture. An ecological-economic assessment methodology (ΔDPSIR approach) The Differential Drivers-Pressure-State-Impact-Response (ΔDPSIR) approach further develops the integrated approach by providing an explicit link between ecological and economic information related to the use and management of coastal ecosystems. Furthermore, the ΔDPSIR approach provides a framework to synthesise scientific data into useful information for the evaluation of previously adopted policies and future response scenarios. The ΔDPSIR application is tested using different datasets and scales of analysis, including: (i)assessment of the ecological-economic impacts of the scenarios at the waterbody/watershed level, using the multilayered ecosystem model outputs, and (ii) evaluation of the ecologicaleconomic effects of aquaculture options at the individual aquaculture level, using data from an abalone farm. These are two important scale of analysis for the development of an ecosystem approach to aquaculture.A dynamic ecological-economic model (MARKET model) One of the missing links in ecosystem modelling is with economics. The MARKET model was developed to simulate the feedbacks between the ecological-economic components of aquaculture production. This model was applied to simulate shellfish production in a given ecosystem under different assumptions for price and income growth rates and the maximum available area for cultivation. Further application of the MARKET model at a wider scale might be useful for understanding the ecological and economic limitations on global aquaculture production. This integrated ecological-economic modelling and assessment approach can be further applied to address new coastal management issues, such as coastal vulnerability to natural catastrophes. It can also support implementation of current legislation and policies, such as the EU Integrated Coastal Zone Management recommendation or the development of River Basin Management Plans following the EU Water Framework Directive requirements. On the other hand, the approach can address recurring coastal management needs, such as the assessment of the outcomes of past or on-going coastal management plans worldwide, in order to detect symptoms of the overuse and misuse of coastal ecosystems.
Portuguese Foundation for Science and Technology(FCT) as a Ph.D. scholarship (SFRH/BD/25131/2005.European Union, Sixth Framework Programme FP6-2002-INCO-DEV-1 SPEAR (INCO-CT-2004-510706) project
Blamey, Laura Kate. "Ecosystem effects of a rock-lobster 'invasion': comparitive and modelling approaches". Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/6234.
Texto completoRyan, Edmund. "The limitations and robustness of data assimilation in terrestrial ecosystem modelling". Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/4293/.
Texto completoMoore, Jonathan Richard. "Aspects of land surface modelling : role of biodiversity in ecosystem resilience to environmental change and a robust ecosystem demography model". Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/22649.
Texto completoAydogdu, Ali. "A Coupled Modelling Attempt Of Hydrodynamics And Ecosystem Of Northern Levantine Basin". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614580/index.pdf.
Texto completoGirardin, Raphaël. "Ecosystem and fishers’ behaviour modelling : two crucial and interacting approaches to support ecosystem based fisheries management in the eastern english channel". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10018/document.
Texto completoThe implementation of the ecosystem approach to fisheries management (EAFM) requires an enhancement of our knowledge of ecosystem complexity. Understanding the ecosystem reaction to management regulation is a key to achieve conservation objectives. Ecosystem modelling improves our knowledge on ecosystem functioning in interaction with human activities, and it is now widely used to evaluate management strategies. The fishers’ behaviour of the French demersal fisheries in the Eastern English Channel (EEC) has been investigated. Results showed that fishers tended to adhere to past annual fishing practices and maritime traffic may impact on fishing decision. A global analysis of the fisheries science literature during the last three decades evidenced the influence of tradition and species targeting in fishers’ behaviour. The exploration of ecosystem dynamics required the use of the ecosystem model Atlantis with a focus on two commercial flatfish species, sole (Solea solea) and plaice (Pleuronectes platessa). The importance of estuary areas and of nutrient inputs has been revealed as well as the role of discards and of two key species, cod (Gadus morhua) and whiting (Merlangius merlangius). Sole and plaice did not have a strong influence on the trophic network excepted on the benthic invertebrates’ dynamics. Finally, we investigated the consequences of area closure and effort reduction on fishers’ behaviour and the ecosystem impacted. We observed a noticeable benefit of combining area closure and effort reduction on the biomass of most commercial species and on the total value landed per unit effort
Girardin, Raphaël. "Ecosystem and fishers’ behaviour modelling : two crucial and interacting approaches to support ecosystem based fisheries management in the eastern english channel". Electronic Thesis or Diss., Lille 1, 2015. http://www.theses.fr/2015LIL10018.
Texto completoThe implementation of the ecosystem approach to fisheries management (EAFM) requires an enhancement of our knowledge of ecosystem complexity. Understanding the ecosystem reaction to management regulation is a key to achieve conservation objectives. Ecosystem modelling improves our knowledge on ecosystem functioning in interaction with human activities, and it is now widely used to evaluate management strategies. The fishers’ behaviour of the French demersal fisheries in the Eastern English Channel (EEC) has been investigated. Results showed that fishers tended to adhere to past annual fishing practices and maritime traffic may impact on fishing decision. A global analysis of the fisheries science literature during the last three decades evidenced the influence of tradition and species targeting in fishers’ behaviour. The exploration of ecosystem dynamics required the use of the ecosystem model Atlantis with a focus on two commercial flatfish species, sole (Solea solea) and plaice (Pleuronectes platessa). The importance of estuary areas and of nutrient inputs has been revealed as well as the role of discards and of two key species, cod (Gadus morhua) and whiting (Merlangius merlangius). Sole and plaice did not have a strong influence on the trophic network excepted on the benthic invertebrates’ dynamics. Finally, we investigated the consequences of area closure and effort reduction on fishers’ behaviour and the ecosystem impacted. We observed a noticeable benefit of combining area closure and effort reduction on the biomass of most commercial species and on the total value landed per unit effort
Karlsson, Olof Magnus. "Predicting Ecosystem Response from Pollution in Baltic Archipelago areas using Mass-balance Modelling". Doctoral thesis, Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-144120.
Texto completoFelaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 736
Kisaka, Lily. "Modelling payment systems for environmental services in the Mt Elgon ecosystem of Kenya". Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1013123.
Texto completoGregr, Edward James. "Sea otters, kelp forests, and ecosystem services : modelling habitats, uncertainties, and trade-offs". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58818.
Texto completoScience, Faculty of
Resources, Environment and Sustainability (IRES), Institute for
Graduate
Neves, de Araújo Julio. "Modelling trophic interactions, fishing and climatic variations affecting the western English Channel ecosystem". Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/29739.
Texto completoCorrales, Ribas Xavier. "Ecosystem modelling in the Eastern Mediterranean Sea : the cumulative impact of alien species, fishing and climate change on the Israeli marine ecosystem". Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/666490.
Texto completoLos ecosistemas marinos del Mediterráneo oriental han sufrido cambios ecológicos importantes debido a múltiples presiones antropogénicas, incluido el impacto de especies invasoras, la sobrepesca y el calentamiento del mar. En primer lugar, he revisado los modelos que se han utilizado para evaluar el impacto de las especies invasoras en los ecosistemas acuáticos. De acuerdo con esta revisión, predominan los modelos mecanísticos de carácter multiespecífico/ecosistémico, siendo los modelos dinámicos y no espaciales los más frecuentes. La mayoría de los modelos incluyen un impacto antropogénico adicional, principalmente la pesca, el cambio climático y el aporte de nutrientes. Además, he resumido las principales características de estos modelos y he analizado sus capacidades y limitaciones. En base a las conclusiones de esta revisión, se han mostrado posibles direcciones para futuros desarrollos de los modelos y la aplicación de modelos adecuados. En esta revisión, he observado que el modelo Ecopath with Ecosim (EwE) ha sido utilizado frecuentemente para evaluar los impactos de las especies invasoras ya establecidas. Además, la revisión ha destacado las capacidades de EwE de pronosticar los futuros impactos de las especies invasoras establecidas, emergentes y potenciales. Otras revisiones disponibles en la literatura han demostrado las capacidades de EwE para evaluar los impactos de la pesca y el cambio climático. Por lo tanto, he desarrollado dos modelos estáticos Ecopath que representan la red trófica de la costa Mediterránea de Israel en los años 1990 y 2010 para caracterizar la estructura y funcionamiento del ecosistema y evaluar los impactos de las especies invasoras y la pesca en el pasado y en el presente. Después he utilizado el módulo dinámico-temporal Ecosim para ajustar el modelo de 1990 a series temporales de datos disponibles entre ambos periodos y para explorar la dinámica histórica del ecosistema considerando el efecto de las especies invasoras, la dinámica de la flota pesquera y el calentamiento del mar. Finalmente, el módulo dinámico-temporal ha sido utilizado para realizar simulaciones futuras de cambios en el ecosistema. En particular, he evaluado los efectos de un nuevo conjunto de regulaciones de pesca que se están implementando actualmente en Israel, futuros cambios en la temperatura del mar siguiendo las proyecciones del Panel Intergubernamental sobre el Cambio Climático (IPCC por sus siglas en inglés) y posibles aumentos de la biomasa de las especies invasoras. Primero he investigado los diferentes impactos por separado y, luego, los he combinado para evaluar sus efectos acumulativos. Los resultados de los modelos estáticos Ecopath han destacado que el ecosistema marino israelí, a pesar de un patrón de productividad diferente, comparte algunas características estructurales y funcionales con otros ecosistemas mediterráneos como el dominio del hábitat pelágico en términos de flujos tróficos, el importante papel del detritus a través de niveles tróficos bajos y la importancia del acoplamiento bentónicopelágico. Los mismos grupos funcionales clave fueron identificados en ambos periodos investigados, a excepción de la merluza en 2010, lo que puede indicar que la merluza ha perdido su papel ecológico debido al declive de su población. La mayoría de los grupos funcionales identificados como especies clave ya han sido identificados previamente como tales en otros ecosistemas mediterráneos como por ejemplo los delfines, los grandes peces pelágicos, los tiburones y los calamares. El módulo dinámico-temporal Ecosim indicó que las interacciones tróficas, el aumento de la temperatura del mar y la pesca jugaron un papel clave en la dinámica del ecosistema. En general, las tendencias temporales de la biomasa revelaron que los depredadores demersales nativos (por ejemplo, la merluza) y los peces demersal nativos de nivel trófico medio (por ejemplo, los salmonetes) disminuyeron en gran medida con el tiempo, mientras que se observó un aumento de las especies invasoras con el tiempo. Los resultados de los indicadores ecológicos sugirieron un patrón de degradación del ecosistema con el tiempo. Los escenarios futuros utilizando el módulo dinámico-temporal Ecosim mostraron los beneficios potenciales generales de las reducciones del esfuerzo pesquero y los impactos negativos del aumento de la temperatura del mar y el aumento de la biomasa de las especies invasoras. Los escenarios acumulativos resaltaron que los efectos beneficiosos de la reducción de la pesca pueden verse disminuidos por el impacto del aumento de la temperatura del mar y las especies invasoras cuando actúan al mismo tiempo. Estos resultados respaldan la necesidad de reducir los impactos antropogénicos locales y regionales como la pesca y las especies invasoras, para mantener los ecosistemas marinos dentro de un “espacio operativo seguro (SOS por sus siglas en inglés)” y promover la resiliencia de los ecosistemas en un mar en continuo calentamiento y altamente impactado.
Els ecosistemes marins de la Mediterrànea oriental han patit canvis ecológics importants a causa de múltiples pressions antropogèniques, inclòs l’impacte d’especies invasores, la sobrepesca i el calentament del mar. En primer lloc, he revisat els models que s’han utilitzat per avaluar l’impacte de les espècies invasores en ecosistemes aquàtics. D’acord amb aquesta revisió, predominen els models mecanístics de caràcter multiespecífic/ecosistèmic, sent els models dinàmics i no espacials els més freqüents. La majoria dels models inclouen un impacte antropogènic adicional, principalment la pesca, el canvi climàtic i l’aport de nutrients. A més, he resumit les principals característiques d’aquest models i he analitzat les seves capacitats i limitacions. En base a les conclusions d’aquesta revisió, s’han exposat possibles direccions per futurs desenvolupaments dels models i l’aplicació de models adecuats. En aquesta revisió he observat que el model Ecopath with Ecosim (EwE) ha estat utilitzat freqüentment per avaluar els impactes de les espècies invasores ja establertes. A més, la revisió ha destacat les capacitats d’EwE de pronosticar els futurs impactes de les espècies establertes, emergents i potencials. Altres revisions disponibles a la literatura han demostrat les capacitats d’EwE per avaluar els impactes de la pesca i el canvi climàtic. Per tant, he desencolupat dos models estàtics Ecopath que representen la xarxa tròfica de la costa Mediterrànea d’Israel en els anys 1990 y 2010 per caracteritzar l’estructura i funcionament de l’ecosistema i avaluar els impactes de les espècies invasores i la pesca en el passat i el present. Després he utilitzat el mòdul dinàmic-temporal per ajustar el model de 1990 a sèries temporals de dades disponibles considerant l’efecte de les espècies invasores, la dinàmica de la flota pesquera i l’escalfament del mar. Finalment, el mòdul dinamic-temporal ha estat utilitzat per realitzar simulacions futures de canvis en l’ecosistema. En particular, he avaluat els efectes d’un nou conjunt de regulacions de pesca que s’estan implementant actualment a Israel, canvis en la temperatura del mar seguint les projeccions del panell intergovernamental sobre el Canvi Climàtic (IPCC per les seves sigles en anglès) i possibles augments de la biomass de les espècies invasores. Primer he investigat els diferents impactes per separat i, després, els he combinat per avaluar els seus efectes acumulatius. Els resultats dels models estàtics Ecopath han destacat que l’ecostema marí d’Israel, malgrat un patró de productivitat diferent, comparteix algunes característiques estructurals i de funcionals amd altres ecosistemes marins mediterrànis com el domini de l’hàbitat pelàgic en termes de fluxes tròfics, l’important paper del detritus a través de nivells tròfics baixos i la importància de l’acoplament bentònic-pelàgic. Els mateixos grups funcionals clau van ser identificats en els dos períodes investigats, a excepció del lluç en el 2010, que pot indicar que el lluç ha perdut el seus paper ecològic a causa del declivi de la seva població. La majoria del grups funcionals identificats com a espècies claus ja han estat identificats com a tals en altres ecosistemes mediterranis com ara els dofins, els gran peixos pelàgics, els taurons i els calamars. El mòdul dinàmic-temporal Ecosim ha indicat que les interaccions tròfiques, l’augment de la temperatura del mar i la pesca van jugar un paper clau en la dinàmic de l’ecosistema. En general, les tendències temporals de la biomasa van revelar que els depredadors demersals natius (per exemple, el lluç) i els peixos dersals natius de nivell tròfic mitjà (per exemple, els rogers) van disminuir en gran mesura amb el temps, mentre que es va observar un augment de les espècies invasores amb el temps. Els resultats dels indicadors ecològics van suggerir un patrò de degradació de l’ecosistema amb el temps. Els escenaris futurs van mostrar els beneficis potencials generals de les reduccions de l’esforç pesquer i els impactes negatius de l’augment de la temperatura del mar i ’augment de la biomasa de les espècies invasores. Els escenaris acumulatius van ressaltar que els efectes beneficiosos de la reducció de la pesca poden ser reduïts per l’impacte de l’augment de la temperatura del mar i les espècies invasores quan actuen al mateix temps. Aquests resultats recolzen la necessitat de reduir els impactes antropogènics locals i regionals com la pesca i les espècies invasores, per mantenir els ecosistems marins dins d’un “espai operatiu segur (SOS per les seves sigles en anglès)” i promoure la resiliència dels ecosistemes en un mar en continu escalfament i altament impactat.
Trolle, Dennis. "The influence of sediment nutrient dynamics on the response of lake ecosystems to restoration and climate change". The University of Waikato, 2009. http://hdl.handle.net/10289/2808.
Texto completoSpall, Steven Andrew. "The impact of mesoscale jet activity on plankton heterogeneity and primary production : a numerical modelling study". Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243174.
Texto completoJiang, Lei. "On human gut microbial ecosystem : in vitro experiment, in vivo study and mathematical modelling". Thesis, Swansea University, 2013. https://cronfa.swan.ac.uk/Record/cronfa42214.
Texto completoMesa, Christian Requena. "The ecosystem services of the Cerrado trees : modelling, distribution mapping and implications for conservation". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/170195.
Texto completoThe interest in valuing the ecosystem services provided by the natural vegetation has increased in an effort to mitigate the effects of land use change. In this line of thinking, we developed an index to value the tree communities -from an anthropocentric point of view- of the Brazilian savannah (Cerrado). The index and the cartography produced will serve as a tool for prioritization of conservation, has well as to unveil how colonization and agriculture expansion has taken place. In order to develop the index: new environmental layers at 90m resolution were produced; the most common 93 species’ distribution was modelled; and cartography for each use humans derive from the trees (food, aromatic, fiber, cosmetic, cork, etc., totaling 20 uses) and a total value index were developed. The new index of value, namely the Sum of Uses (SoU), represent the expected number of uses for the potential species assemblage that could be taking place under optimal conditions. The impact of agriculture was assessed by accounting for the area that has been converted to croplands. Our results strongly indicate that human settlement and cropland expansion have cleared the trees of areas that once were better than average ecosystem service providers. On the other hand, we also observe that protected areas in the Cerrado are located where we expect to find marginal value for the optimal communities. These results lead us to think that the conservation strategy might be far from optimal for the largest remaining arable patch in the world.
Radanovic, Marko. "Adaptive self-governed aerial ecosystem by negotiated traffic". Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/665322.
Texto completoEn los últimos años, se han llevado a cabo varios proyectos de investigación importantes en el marco de las iniciativas de Single European Sky Air Traffic Management (ATM) Research y Next Generation Air Transportation System, que abordan la automatización en ATM. Esas iniciativas han previsto la automatización como un proceso impulsado por el rendimiento global de ATM, centrado en los objetivos y limitaciones del sistema. En un ámbito más amplio, los objetivos se definen como una disposición de la separación requerida entre las aeronaves para alcanzar los niveles de seguridad objetivo, mientras que la competitividad del tráfico se mantiene mediante un sistema eficiente, respetuoso con el medio ambiente y socialmente valioso. Una mayor densidad operativa junto con la falta de capacidad de control de tráfico aéreo (ATC), al manejar una mayor complejidad de tráfico, impone esencialmente una disposición de separación que se implementará como cooperativa y distribuida, incorporando también a los usuarios del espacio aéreo (AU). En este contexto, es necesario pasar de un modelo de intervención táctica puramente centralizado a una planificación estratégica más eficiente y operaciones tácticas proactivas, que supongan cambios significativos en los roles y responsabilidades de todas las partes interesadas. Eso anticipa una integración operacionalmente fluida de los mecanismos y procedimientos de la red de seguridad de tal manera que cualquier par de aeronaves involucradas en un conflicto, junto con la aeronave de tráfico circundante, se comporten como un sistema de tráfico aéreo estable, eficiente y libre de conflictos. El trabajo de investigación en esta tesis elabora un nuevo marco de red de seguridad que se basa en el concepto de ecosistemas aéreos para transformar los objetivos no coordinados entre la gestión de la separación a nivel táctico y la prevención de colisiones en el nivel operacional, en una cooperativa y eficiente, libre de conflictos sistema. Los ecosistemas aéreos se pueden entender como un paradigma de los complejos sistemas adaptativos, en los que las trayectorias de los aviones cambian y evolucionan con el tiempo debido a las interacciones entre las aeronaves involucradas y su entorno en constante cambio. La tesis comprende pocos resultados analíticos utilizados por medio de métodos cuantitativos para la identificación de las interdependencias espaciotemporales y el cálculo de las soluciones totales del nivel del ecosistema y el punto muerto dentro del tiempo del ecosistema disponible. Los métodos analíticos están más orientados a las aplicaciones que a la teoría, desarrollados con un enfoque de modelado discreto y cuantitativo, y personalizados según las demandas actuales de tráfico y el entorno operativo. Como resultado, el marco del ecosistema tiene la capacidad de seguir explorando la capacidad de resolución potencial en un espacio de búsqueda de las soluciones del sistema. Una tasa decreciente de los recursos del ecosistema disponibles y un tiempo transcurrido describen un camino potencial en una determinación explícita de la dinámica de resolución, lo que significa que cada momento perdido al hacer un acuerdo de resolución podría repercutir en un menor número de maniobras libres de conflicto, pero también mantenerlos o aumentarlos en algunas circunstancias. El enfoque ha demostrado la importancia de proporcionar la capacidad de tiempo para un conjunto de ciertas maniobras a nivel operacional, cuando la gravedad de la situación de conflicto ocurre muy rápidamente. Con un incremento causal en una serie de aeronaves de ecosistema y diversas geometrías de trayectoria, la estructura de las interdependencias espaciotemporales se hace más grande, lo que puede producir una menor capacidad de resolución y un tiempo de toma de decisiones más corto. La metodología de modelado se puede implementar como herramienta de apoyo a la decisión tanto en el aire como en tierra. La investigación de seguimiento se formalizará multidireccionalmente a través del avance conceptual de las regiones de resolución, la integración de los modelos de performance de la aeronave, el desarrollo de un modelo de aprendizaje automático para la complejidad del tránsito circundante y la implementación de ecosistemas cooperativos y competitivos para vehículos aéreos no tripulados.
In recent years, several important research projects under the Single European Sky Air Traffic Management (ATM) Research and the Next Generation Air Transportation System initiatives, addressing the automation in ATM have been conducted. Those initiatives have envisaged the automation as a process driven by the overall ATM performance, focused on the system objectives and limitations. In a broader scope, the objectives are defined as a provision of the required separation between aircraft to meet the safety target levels, while the traffic competitiveness is maintained by means of an efficient system, environmentally friendly and socially valuable. An increased operational density together with a lack of the air traffic control (ATC) capacity, in handling a higher traffic complexity, essentially imposes a separation provision to be implemented as cooperative and distributed, engaging also the airspace users (AUs). In this context, it is necessary to shift from a purely centralized tactical intervention model towards a more efficient strategic planning and proactive tactical operations, which assume significant changes of the roles and responsibilities of all involved stakeholders. That anticipates an operationally seamless integration of the safety net mechanisms and procedures in such a way that any pair of aircraft involved in a conflict, together with the surrounding traffic aircraft, behave as a stable and efficient, conflict-free air traffic system. The research work in this thesis elaborates a novel safety net framework relying on the concept of aerial ecosystems to transform the non-coordinated targets between separation management at the tactical level and collision avoidance at the operational level, into a cooperative and efficient, conflict-free system. The aerial ecosystems can be understood as a paradigm of the complex adaptive systems, in which aircraft trajectories change and evolve over time because of interactions among involved aircraft and its ever-changing environment. The thesis comprises few analytical outcomes utilized by the means of quantitative methods for identification of the spatiotemporal interdependencies and computation of the total ecosystem-level solutions and deadlock within available ecosystem time. The analytical methods are applications-oriented rather than a theory-based, developed with a quantitative and discrete modelling approach, and customized to the current traffic demands and the operational environment. As a result, the ecosystem framework has an ability to further explore the potential resolution capacity in a search space of the system solutions. A decreasing rate of the available ecosystem resources and an elapsed time describe a potential path in an explicit determination of the resolution dynamics, meaning that each missed moment in making a resolution agreement might reprobate in a less number of the conflict-free maneuvers, but also maintain or increase them in some circumstances. The approach has shown a significance in providing the time capacity for a set of certain maneuvers at the operational level, when a severity of the conflict situation occurs very rapidly. With a causal increment in a number of ecosystem aircraft and diverse trajectory geometries, the structure of spatiotemporal interdependencies becomes larger which can produce less resolution capacity and a shorter decision-making time. The modeling methodology can be deployed as both the airborne and ground-based decision support tool. Follow-up research will be multi-directionally formalized throughout conceptual advancement of the resolution regions, integration of the aircraft performance models, development of a machine learning model for the surrounding traffic complexity, and implementation of the cooperative and competitive ecosystems for unmanned aerial vehicles.
Pereira, Ana Carina Santos. "Linking exposure of mediterranean freshwater ecosystems to pesticides mixtures with their environmental side-effects". Doctoral thesis, ISA, 2017. http://hdl.handle.net/10400.5/14958.
Texto completoIn freshwater ecosystems associated with agricultural areas, organisms are exposed to a multitude of toxicologically and structurally distinct pesticides in concentrations that may fluctuate over time. However, the environmental risks of chemicals are traditionally evaluated and regulated on the basis of single substance. Understanding and improving the link between effects and exposure assessment is an important step in the current challenges of risk assessment in order to increase its ecological relevance. To this end, integrated approaches of different hierarchical levels of complexity and ecological realism have been developed and applied, including: exposure modelling, laboratory testing with individual organisms, species sensitivity distribution, ecosystem models and assessment of aquatic community interactions to evaluate the effects of realistic pesticide combinations on water bodies associated with rice, tomato and maize typical agroecosystems of Mediterranean conditions. Contributing to the overall knowledge of the adequacy of the prospective risk assessment and demonstrating that pesticide risk may be underestimated during the actual registration procedure. The data generated in the present study contributed to the derivation of optimized programs of measures under the scope of European legislation; the identification of sites with the highest expected impacts of pesticide mixtures; the evaluation of the major pesticide compounds that contributed mostly to the identified aquatic risks. Furthermore contribute to a deeper knowledge and unravel the effects of co-occurring chemicals, environmental and biological stressors in aquatic ecosystems considering the effects of biotic and abiotic interactions at community and ecosystem levels. The results contribute to reducing the risks of pesticides in freshwater
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Konovalenko, Lena. "Element transport in aquatic ecosystems – Modelling general and element-specific mechanisms". Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-110064.
Texto completoAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
Snyman, Anchen. "Modelling of ecosystem change on rehabilitated ash disposal sites based on selected bio-indicators / A. Snyman". Thesis, North-West University, 2006. http://hdl.handle.net/10394/1185.
Texto completoThesis (M. Environmental Science (Biodiversity and Conservation Biology))--North-West University, Potchefstroom Campus, 2007.
Hafezi, Mohammad Mehdi. "A Hybrid Modelling Framework for Ecosystem-Based Climate Change Adaptation Using System Dynamics and Bayesian Networks". Thesis, Griffith University, 2020. http://hdl.handle.net/10072/398439.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
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Blanco, González Víctor. "Modelling adaptation strategies for Swedish forestry under climate and global change". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/25380.
Texto completoArias, Mauricio Eduardo. "Impacts of Hydrological Alterations in the Mekong Basin to the Tonle Sap Ecosystem". Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2013. http://hdl.handle.net/10092/8913.
Texto completoMOVEDI, ERMES. "MODELLING THE INTERACTION BETWEEN WILD AND CULTIVATED SPECIES". Doctoral thesis, Università degli Studi di Milano, 2023. https://hdl.handle.net/2434/950804.
Texto completoMieres, Dinamarca Francisco. "Production, sorption and pathways for dissolved organic carbon flow in the Krycklan catchment. : Modelling with focus on the terrestrial forest ecosystem". Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190613.
Texto completoNightingale, Joanne M. "Modelling carbon dynamics within tropical rainforest environments using the 3-PG and 3-PGS ecosystem process models /". [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18498.pdf.
Texto completoCERRETELLI, STEFANIA. "The role of ecosystem services in the spatial assessment of land degradation: a transdisciplinary study in the Ethiopian Great Rift Valley". Doctoral thesis, Università degli Studi di Trieste, 2018. http://hdl.handle.net/11368/2924524.
Texto completoSvensson, Magnus. "Carbon dynamics in spruce forest ecosystems - modelling pools and trends for Swedish conditions". Doctoral thesis, Stockholm : Department of Real Estate and Construction Management, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4240.
Texto completoStolk, Henk. "Emergent models in hierarchical and distributed simulation of complex systems : with applications to ecosystem and genetic network modelling /". [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19095.pdf.
Texto completoGuo, Tong [Verfasser]. "The role of diversity in savannas: modelling plant functional diversity and its effects on ecosystem functioning / Tong Guo". Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1132582512/34.
Texto completoCollins, Victoria Anne. "The role of microheterotrophs in nitrogen cycling : an experimental and modelling assessment on their impact on ecosystem function". Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446492.
Texto completoHinners, Jana [Verfasser] y Inga [Akademischer Betreuer] Hense. "A Phytoplankton Species under Global Warming - Insights from Resurrection Experiments and Ecosystem Modelling / Jana Hinners ; Betreuer: Inga Hense". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2018. http://d-nb.info/1169358578/34.
Texto completoMoor, Helen. "Function follows Form : Trait-based approaches to climate change effects on wetland vegetation and functioning". Doctoral thesis, Stockholms universitet, Stockholm Resilience Centre, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-133488.
Texto completoAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
López-Blanco, Efrén. "Ecosystem-atmosphere interactions in the Arctic : using data-model approaches to understand carbon cycle feedbacks". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33101.
Texto completoMiller, David Charles Moorcroft. "An individual-based modelling approach to examine life history strategies of sardine Sardinops sagax in the southern Benguela ecosystem". Doctoral thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/8917.
Texto completoHypotheses regarding the spawning strategy and recruitment of sardine (Sardinops sagax) in the southern Benguela ecosystem are tested using an individual-based Lagrangian particle tracking model linked with a 3-D hydrodynamic model of the region. Experiments focus on the dispersion of eggs and larvae among possible spawning and nursery areas. The two main areas of interest were the west coast upwelling region and the south coast shelf region (Agulhas Bank). A stage-based temperature-dependent development model is incorporated and vertical positioning schemes are tested. The spatial distribution and size structure of the sardine spawning stock for the period 1991-1999 are presented and a simple size-based fecundity model, combined with modelled recruitment, is used to determine the relative importance of each spawning and nursery area. The area of spawning plays a fundamental role in determining the destination of spawned eggs, and recruitment of sardine in the southern Benguela ecosystem appears to be divided into three recruitment systems by the circulation of the region: eggs spawned west of Cape Agulhas recruiting on the west coast (the WAB/WC-WC system), eggs spawned east of Cape Agulhas recruiting on the west coast (the CAB-WC system), and eggs spawned east of Cape Agulhas recruiting to the south coast (the SC-SC system). There is a slight increase in retention in the two nursery areas during winter, but the transport of eggs and larvae from the Agulhas Bank to the west coast is optimal during spring to early summer. Slow development arising from cold temperatures on the west coast could negatively impact recruitment by increasing offshore loss of individuals before they develop to a stage when they are able to actively avoid offshore currents and through its effect on mortality rate. This could explain the spatial separation of spawning and nursery areas in this system. The vertical position of individuals has an effect on the level of modelled recruitment and mortality rate, but observed vertical distributions of sardine egg and larvae do not significantly increase the level of modelled recruitment to optimal nursery areas. This suggests that efficient transport and retention are traded-off against other factors such as predator avoidance or prey abundance. Observed size structure and spatial distribution of the sardine spawning stock for 1991-1999 fluctuated greatly with most spawning centred on the western Agulhas Bank. When spawning was centred east of Cape Agulhas, recruitment was poor. No significant relationship could be established between potential reproductive output reaching the west coast and estimated recruitment, but positive recruitment anomalies required good transport to, and retention on, the west coast. A conceptual model of the early life history of sardine is proposed in light of limitations imposed by transport and retention of individuals. Lower primary production and the possibility of higher predation on the Agulhas Bank suggest that the south coast supports less recruitment than the west coast. The hypotheses tested using available data and model results could improve the understanding of recruitment of sardine in this complex ecosystem. These need to be validated by field observations. Additionally, further avenues for research that could help in developing a better understanding of the sardine life history in the southern Benguela ecosystem are suggested.
Bourdaud, Pierre. "Impact of a landing obligation on coupled dynamics ecosystem-fishers : individual-based modelling approach applied to Eastern English Channel". Thesis, Littoral, 2018. http://www.theses.fr/2018DUNK0474/document.
Texto completoThe objective of this thesis was to anticipate the effects if the EU Landing Obligation (LO) implemented since the beginning of 2015 in the Eastern English Channel (EEC). To achieve these objectives, it was planned to : i) better understand seasonal spatial distribution of commercial species using on-board commercial vessels observation data, ii) compare them with the final scale fishing effort distribution of EEC bottom otter trawlers (OTB), and iii) develop an individual-based model of fleet-dynamics, DSVM, to be integrated within the ecosystem model OSMOSE to simulate a LO. The usefulness of on-board observation data was proved for a main part of a species sample, using validation from the literature and a geostatistical indicator. Then the comparison of fine scale fishing effort provided an improvement of the quantification of effective fishing effort and emphasized the importance of cuttlefish and red mullet for the global distribution of EEC OTB. In addition, the targeting intensity of OTB was quantified in October using a newly-developed indicator, and demonstrated the attractiveness of the same species, but also the constraint of low cod quota for fishers. Results of the OSMOSE-DSVM coupling show that the LO would have short-term negative effects on fishers' revenue, induced by a large reallocation of their fishing effort to avoid quota over-shooting, but would be profitable in the medium-term. However, the LO would induce an increase of the predatory pressure operated by cod and withing on the other species, which would not improve the overall ecosystem health
Asgari, Aliakbar. "Simulation of Collective Intelligence of a Multi-Species Artificial Ecosystem Based on Energy Flow". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31796.
Texto completoForrest, Robyn Elizabeth. "Simulation models for estimating productivity and trade-offs in the data-limited fisheries of New South Wales, Australia". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/3417.
Texto completoKabir, Md Imran. "Dynamics of heavy metals in urban green water infrastructures". Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/14510.
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