Дисертації з теми "Spatial Ecosystems"
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Zillio, Tommaso. "Spatial Dynamics of Ecosystems." Doctoral thesis, SISSA, 2005. http://hdl.handle.net/20.500.11767/4081.
Повний текст джерелаSandin, Leonard. "Spatial and temporal variability of stream benthic macroinvertebrates : implications for environmental assessment /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-6056-5.pdf.
Повний текст джерелаGill, Wendy Jane. "The spatial characterisation of transitional areas between plant communities : a case study from upland Britain." Thesis, University of Plymouth, 1996. http://hdl.handle.net/10026.1/2196.
Повний текст джерелаAlibegovic, Goran. "Spatial and Temporal Characterisation of Ecosystems in Landscapes Surrounding Granite Outcrops." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/2087.
Повний текст джерелаKoukoulas, Sotirios. "Analysing the spatial structure of semi natural deciduous woodlands through high resolution airborne imagery and Geographical Information Systems." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272583.
Повний текст джерелаLeach, Taylor Hepburn. "Cause and Consequences of Spatial Dynamics of Planktonic Organisms in Lake Ecosystems." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1479747973843758.
Повний текст джерелаThompson, Melissa L. "Evaluating the use of high spatial resolution imagery in characterizing sagebrush ecosystems." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594496621&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Повний текст джерелаEdwards, Grant R. "The creation and maintenance of spatial heterogeneity in plant communities : the role of plant-animal interactions." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239335.
Повний текст джерелаEngelhard, Sarah Laure. "Marine Spatial Connectivity in Theory and Conservation." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/365470.
Повний текст джерелаThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Grifffith School of Environment
Science, Environment, Engineering and Technology
Full Text
DENARO, Giovanni. "Stochastic models for phytoplankton dynamics in marine ecosystems." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/91323.
Повний текст джерелаHARRISON, Sofie, and sofieh@student ecu edu au. "The influence of seabird-derived nutrients on island ecosystems in the oligotrophic marine waters of south-western Australia." Edith Cowan University. Computing, Health And Science: School Of Natural Sciences, 2006. http://adt.ecu.edu.au/adt-public/adt-ECU2007.0010.html.
Повний текст джерелаLópez, Muñoz Ignacio Francisco. "Optimal spatial arrangements of three ecosystems: microalgae pond, anaerobic digester and aerobic wastewater treatment plant." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/139852.
Повний текст джерелаIngeniero Civil Químico
Actualmente existen diversos problemas medioambientales, dos de ellos corresponden a la futura crisis energética, debido al agotamiento de los combustibles fósiles, y a la existencia de aguas residuales con altas concentraciones de nitrógeno y carbono. Un microorganismo llamado microalga podría ser una potencial solución a estos problemas, ya que éstos consumen nitrógeno y carbono para acumular lípidos en su medio intracelular, el cual posteriormente es procesado para producir biocombustibles. Sin embargo, la producción de energía a partir de microlagas es aún muy cara, es por eso que se debe optimizar este proceso, en este trabajo se abordará la estrategia de optimización a través del acoplamiento de ecosistemas, los cuales corresponden a: Piscina de microalgas (PM), digestor anaeróbico (DA) y una planta de tratamiento de aguas (PTA). El objetivo general de esta investigación es encontrar el arreglo espacial óptimo entre ellos. Se diseñaron y calibraron modelos matemáticos simples para el ecosistema PM y PTA. La calibración se llevó a cabo usando las curvas de nitrógeno y de demanda química de oxígeno (DQO) en paralelo, con una suma de errores de 22.5% para el PM y de 38.5% para el PTA. Los parámetros obtenidos son comparables a los encontrados en la literatura. Los ecosistemas fueron acoplados a través de sus flujos de DQO y de nitrógeno, y las siguientes funciones objetivo fueron definidas: 1) Maximizar el metano producido 2) Maximizar la energía total producida y 3) Maximizar las ganacias obtenidas gracias al valor del metano y de la biomasa producida. Además, fueron consideradas restricciones medioambientales, tales como la concentración de nitrógeno y la DQO en la salida del sistema. Si lo que se maximiza es el metano, se obtienen 99.96 [mol]. El reactor anaeróbico es el más grande y recibe la alimentación más alta, el CH4 generado corresponde al 72.4% del máximo teórico. En este caso, el arreglo espacial no puede ser presentado como una cadena de etapas porque el diagrama de flujos obtenido es uno circular y por lo tanto el orden entre cada ecosistema es irrelevante para el proceso. Si la ganacia y la energía total producida son maximizadas, se obtuvo 343.6 US$ y 115.53 [kWh], respectivamente. El ecosistema de tratamiento de aguas recibe la alimentación más alta, el cual produce el mayor beneficio económicos y la mayor producción de energía. El metano producido es un 21% del máximo teórico. En ambos casos, el arraglo espacial obtenido son iguales, debido a la presencia de mínimos locales y a la similtud de las funciones objetivo. Además, es posible concluir que el primer paso del proceso debiese ser el ecosistema PTA, luego el DA y finalmente el PM. Así, se pudo cumplir el objetivo general de este trabajo. Finalmente, la metodología usada es capaz de cumplir los objetivos planteados, incluso es posible escalar el problema agregando otros ecosistemas o usarla en otras aplicaciones." "In recent years several environmental problems have come about, two of them are an energy crisis as a result of fossil fuel exhaust and the waste water created with high nitrogen and carbon concentrations. A potential solution of the aforementioned problems is contained in the properties of microalgae, which is a microorganism that can accumulate lipids in its intracellular medium. These lipids can be processed and converted into biofuel by allowing microalgae to consume nitrogen and an organic source from the medium. However, energy production from microalgae is too expensive in comparison with fossil fuel and thus there is a need to optimize this process. The strategy of optimizing by coupling ecosystems will be carried out in this work. The ecosystems that will be coupled are: Microalgae pond (MP), anaerobic digester (AD) and wastewater treatment plant (WWT). The general objective of this research is to find the optimal spatial arrangement among them through mathematical modelling. Simple mathematical models were designed and calibrated to MP and WWT ecosystem. Calibrations were carried out using nitrogen and chemical oxygen demand (COD) curves in parallel with a sum error of 22.5% in MP and 38.5% in WWT. Obtained parameters are similar to ones found in previous literature. Ecosystem were coupled through COD and nitrogen flows and the following objectives functions were defined: 1) Maximize methane produced 2) Maximize total energy produced and 3) Maximize profit due to the value of methane and microalgae biomass produced. Environmental constraints were considered, such as nitrogen and COD because they are in the output. When the methane produced was maximized it reached 99.96 [mol]. The anaerobic reactor has the biggest size, it receives the highest input flow, and CH4 generated is the 72.4% of maximum theoretical methane production. This result determined that the spatial arrangement can not be summarized by a chain of processes since the flowsheet obtained is a circular one and thus the order is irrelevant for the process. When profit and total energy produced are maximized, it was obtained 343.6 US$ and 115.53 [kWh]$ respectively. Waste water ecosystem received the biggest input flow, which produced the majority of amount of revenues and energy. Methane produced is equal to 21% of maximum theoretical. In both cases, the spatial arrangements obtained are equals due to the presence of local minima and the similarity in the objective function. These calculations allow to conclude the best order of the ecosystems: WWT, AD, and finally MP. Finally the methodology is enough to reach the objectives of this work, even it is possible to scale the system adding more than one ecosystem or using this methodology in other fields.
Hedberg, Nils. "Sea cages, seaweeds and seascapes : Causes and consequences of spatial links between aquaculture and ecosystems." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-141009.
Повний текст джерелаAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
Henry, Mary Catherine. "Characterizing fire-related spatial patterns in fire-prone ecosystems using optical and microwave remote sensing." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280006.
Повний текст джерелаZhao, Chang. "Quantifying and mapping the supply of and demand for urban ecosystem services." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6350.
Повний текст джерелаHenri, Dominic Charles. "From individuals to ecosystems : a study of the temporal and spatial variation in ecological network structure." Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/15726.
Повний текст джерелаMillington, Heidi Kathryn. "Spatial Analysis of the Impacts of Urbanisation on the Health of Ephemeral Streams in Southeast Queensland." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/367358.
Повний текст джерелаThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text
Marshall, Laura. "Statistical developments for understanding anthropogenic impacts on marine ecosystems." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3172.
Повний текст джерелаNeal, Andrew. "Soil Moisture Controls on Spatial and Temporal Patterns of Carbon Dioxide Fluxes in Drylands." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/241932.
Повний текст джерелаHarrison, Sofie A. "The influence of seabird-derived nutrients on island ecosystems in the oligotrophic marine waters of south-western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2006. https://ro.ecu.edu.au/theses/68.
Повний текст джерелаSigovini, Marco <1980>. "Multiscale dynamics of zoobenthic communities and relationships with environmental factors in the Lagoon of Venice." Doctoral thesis, Università Ca' Foscari Venezia, 2011. http://hdl.handle.net/10579/1092.
Повний текст джерелаLa tesi analizza la comunità macrozoobentonica della Laguna di Venezia. Sono stati principalmente indagati: la variabilità spaziale e interannuale della struttura della comunità; il ruolo dei fattori ambientali; le scale spaziali di variabilità della comunità, in relazione alla scala di variabilità dei fattori ambientali. Il data set analizzato è relativo a tre anni. E' stata verificata un'elevata variabilità interannuale ed eterogeneità spaziale. Descrittori di struttura multivariata e univariate sono risultati notevolmente correlati ai fattori ambientali. E' stato evidenziato un gradiente da mare verso terra in merito al numero di specie e alla composizione della comunità, in relazione ad un ecocline composito, e principalmente a ricambio idrico e salinità. Sono emersi pattern spaziali più complessi. Descrittori univariati e strutture multivariate seguono diverse scale di variabilità. I risultati hanno implicazioni per la valutazione della qualità degli ecosistemi di transizione.
Hogland, John Scott MacKenzie Mark D. "Creating spatial probability distributions for longleaf pine ecosystems across east Mississippi, Alabama, the Panhandle of Florida, and west Georgia." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/HOGLAND_JOHN_19.pdf.
Повний текст джерелаPilote, Martin. "Trends in the Exchange of CO2 and CH4 between the Atmosphere and Eastern Canadian Subarctic and Arctic Ecosystems." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33426.
Повний текст джерелаHaberstroh, Charlotte Juliane. "Geographical Information Systems (GIS) Applied to Urban Nutrient Management: Data Scarce Case Studies from Belize and Florida." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6620.
Повний текст джерелаVilmi, A. (Annika). "Assessing freshwater biodiversity:insights from different spatial contexts, taxonomic groups and response metrics." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216669.
Повний текст джерелаTiivistelmä Makeanveden ekosysteemit ovat hyvin alttiita ihmistoiminnalle. Ekosysteemissä mahdollisesti tapahtuvien muutosten havaitseminen vaatii tehokkaita vesistöjen ekologisen tilan ja luonnon monimuotoisuuden arviointi- ja seurantamenetelmiä. Näiden menetelmien toimintaperiaatteen yleisenä tausta-ajatuksena on, että biologiset yhteisöt määräytyvät paikallisten ympäristöolojen mukaan. Tietyn paikan yhteisön oletetaan siis heijastavan kyseisen paikan ympäristön tilaa. Viime aikoina tausta-ajatus paikallisten ympäristöolojen merkityksestä ainoana eliöyhteisöjä muovaavana tekijänä on kuitenkin kohdannut kritiikkiä. Kriitikot painottavat, että biologisten yhteisöjen rakenteeseen vaikuttavat monet muutkin asiat kuin paikalliset ympäristöolosuhteet ja niissä tapahtuvat ihmisperäiset muutokset. Väitöskirjassani tutkin sisävesien luonnon monimuotoisuuteen vaikuttavia tekijöitä. Olin erityisen kiinnostunut siitä, näkyykö tutkituissa biologisissa parametreissa maantieteellisessä tilassa ilmeneviä spatiaalisia säännönmukaisuuksia. Saadakseni mahdollisimman laaja-alaisen käsityksen luonnon monimuotoisuudessa esiintyvistä spatiaalisista säännönmukaisuuksista, tutkin useaa spatiaalista kontekstia, eliöryhmää ja indeksiä. Tutkimuksessa selvisi, että paikalliset ympäristöolosuhteet eivät ole ainoita luonnon monimuotoisuuteen vaikuttavia tekijöitä. Erilaiset spatiaaliset säännönmukaisuudet, todennäköisesti eliöiden levittäytymiseen liittyvien seikkojen aiheuttamina, olivat yllättävän yleisiä makeiden vesien eliöyhteisöjen rakenteessa ja niihin perustuvien indeksien arvoissa. Tutkimussysteemien spatiaalinen konteksti (alueen laajuus ja paikkojen väliset spatiaaliset suhteet) selvästi vaikutti luonnon monimuotoisuutta kuvastavien indeksien arvojen vaihteluun. Lisäksi selvisi, että eri eliöryhmät ja indeksit olivat useimmiten liitoksissa hyvin erilaisiin selittäviin muuttujiin, osoittaen, että nämä mittarit kuvastavat eri asioita. Väitöskirjassa esitetyt havainnot on tärkeää huomioida vesistöjen ekologisen tilan ja luonnon monimuotoisuuden arviointi- ja seurantamenetelmiä kehitettäessä. Spatiaalisen kontekstin merkitys olisi hyvä huomioida myös nykyisten arviointi- ja seurantamenetelmien tuottamien tulosten tulkinnassa
Jörgensen, Tove Lund. "Coral Reef Habitats and Fish Connectivity : Implications for coastal management and fishery." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-125595.
Повний текст джерелаAt the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.
Dunn, Shanna K. "Analyzing Spatial Patterns in Reefscape Ecology Via Remote Sensing, Benthic Habitat Mapping, and Morphometrics." NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/234.
Повний текст джерелаPicazo, Mota Félix. "Diversity patterns in freshwate ecosystems : new insights using water beetles at different spatial scales = Patrones de diversidad en ecosistemas acuáticos continentales : nuevas aportaciones usando coleópteros a diferentes escaleas espaciales." Doctoral thesis, Universidad de Murcia, 2016. http://hdl.handle.net/10803/369839.
Повний текст джерелаThe main goal of this thesis is to increase the existing knowledge about diversity patterns displayed by biological communities in freshwater ecosystems, the understanding on the main factors underlying them and their performance at different spatial scales, especially focusing on the particularities derived from the lotic-lentic divide. For that purpose, different approaches (taxonomic, functional and ecological), at different spatial scales (from local assemblages of Iberian southeast to whole inventories of different biogeographic regions in the Western Palaearctic), and using beetles as surrogates of aquatic biodiversity, so that, all this information can be finally useful to be implemented in future nature conservation policies. Chapters 1 and 2 deal with the contribution of standing water bodies to regional diversity of water beetles, both for the whole set of localities and for each of the habitat types established. The former is focused exclusively on the local assemblage composition, whereas the latter also tackles the way in which they are structured. Both chapters confirm the importance that these systems have not only for lentic specialist but also for a wide spectrum of facultative species. The role of natural pools in terms of total richness and endorheic lagoons close to saline habitats in terms on endemic richness is highlighted as well. Chapter 2 shows that conductivity is the most explanatory variable for differences in assemblage composition, whereas the degree of anthropogenic impact is the main responsible for the nestedness pattern detected. When fresh and saline water bodies were analyzed independently the two mentioned variables played different roles both in the assemblage composition and structure. The degree of anthropogenic stress was again the most explanatory variable for the nestedness pattern showed by the fresh water sites, whereas for saline sites was conductivity. Chapter 3 includes a functional approach and demonstrates that the species richness of the different water beetle families is significantly related to their biological and ecological trait diversities. However, there were families which displayed higher or lower biological trait diversity than expected in relation to their taxonomic diversity. These results point to the predominance of habitat filtering processes in headwater streams whereas biotic factors, such as interspecific competition, would be more relevant in a priori less stressed habitats as some lentic systems are. As a result of the detailed taxonomic study of the water beetle assemblages carried out in the previous chapters, in chapter 4 a new species for science is described: Stictonectes abellani. Such information is completed with the estimation of the potential distribution and the environmental preferences of the 3 Iberian endemic species of the genus. Finally, chapter 5 evidences, in a wider spatial scale, the existence of contrasting latitudinal patterns of alpha and gamma diversity for lotic and lentic specialist, as well as the decrease of beta diversity as latitude increases for both groups of species. Such findings prove the key role that dispersal ability, framed in the Pleistocene climate changes, plays in shaping the diversity patterns observed in the Western Palaearctic, which is finally originated by the contrasting long-term stability displayed by both kinds of habitats.
Guttal, Vishwesha. "Applications of nonequilibrium statistical physics to ecological systems." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1209696541.
Повний текст джерелаRuiz, Winston Franz Rios. "Biogeografia de bactérias da filosfera de Maytenus robusta na Mata Atlântica." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-14022011-084227/.
Повний текст джерелаBiogeography studies the distribution of organisms in relation to space and time, favoring the understanding of the mechanisms that generate and keep the diversity, speciation, extinction and dispersion of species. Among the tropical forests, the Atlantic Forest constitutes a highly diverse vegetation mosaic, in which the phyllosphere represents one of the most common habitats for microorganisms. The goal of this work was to evaluate the structure and diversity of the bacterial community from the phyllosphere of Maytenus robusta in the Carlos Botelho State Park, Ilha do Cardoso State Park and Assis Ecologic Station, São Paulo state, Brazil. The leaves were collected in two different seasons of the year, dry season and rainy season. The structure of the bacterial community was evaluated through PCR-DGGE of the 16S rRNA gene V3 region, and the diversity by sequencing of the V1-V3 region of the same gene. The similarities between the structures of the bacterial community were determined based on the presence or absence of bands detected in the gels after PCR-DGGE. The hierarchical clustering generated using the Jaccard coefficient and the UPGMA method showed the existence of distinct bacterial communities in the M. robusta phyllosphere of the sampled areas. The existence of biogeographic patterns was determined through regression analyses, using the community structure similarity data geographic distance among the sampled trees. The negative correlation observed in most of the cases provides evidence to support the hypothesis that the similarity between the bacterial communities from phyllosphere of plants of the same species decreases as the distance among trees increased, within the same biome. The spacial-temporal evaluation of the structure of the bacterial communities, performed by the NMDS analyses, showed the occurrence of spacial but not temporal effects on the structure of the bacterial communities of M. robusta phyllosphere. The taxonomic affiliation of 1,470 bacterial 16S rRNA gene clones obtained from the M. robusta phyllosphere, in different areas and seasons, as well as the multiple comparisons of libraries showed that the bacterial communities in the phyllosphere were distinct from each other, and that Proteobacteria and Acidobacteria phyla were the most frequent. Only 1% of the bacterial Operational Taxonomic Units were common among the individuals evaluated. Based on the results obtained it is possible to conclude that, in each biome, plants of same species have unique bacterial communities, suggesting the existence of endemism, high levels of speciation and low dispersal of bacterial communities in the evaluated areas.
Stempfhuber, Barbara Hildegard Josefine [Verfasser], Michael [Akademischer Betreuer] [Gutachter] Schloter, and Johannes [Gutachter] Kollmann. "Drivers for the performance of nitrifying organisms and their temporal and spatial interaction in grassland and forest ecosystems / Barbara Hildegard Josefine Stempfhuber ; Gutachter: Johannes Kollmann, Michael Schloter ; Betreuer: Michael Schloter." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1113749148/34.
Повний текст джерелаLaan, Jan Dingemans van der. "Spatio-temporal patterns in ecosystems : a bioinformatic approach = Patronen in ruimte en tijd in ecosystemen /." Utrecht : Universiteit, Fac. Biologie, 1994. http://www.gbv.de/dms/bs/toc/189735392.pdf.
Повний текст джерелаCosme, Maximilien. "Modélisation qualitative à événements discrets des dynamiques d'écosystèmes." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONG013.
Повний текст джерелаEcosystems unfold over time in response to successive events that modify their components. These events, whether random or not, are the phenomena by which ecosystems assemble and disassemble. Each sequence of states - or trajectory - is a possible history of the ecosystem. Yet, if these events, or their order, had been different, the future state could have been different. However, the order of events, due to the limits of our knowledge, is often uncertain. When this uncertainty is important, it is therefore reasonable to conceive the dynamics of the ecosystem as a set of possible trajectories. If the set of possible trajectories were known, it could be useful to know if a desirable state is attainable, and if so, by which path(s).In this thesis, we propose a modelling approach named EDEN (for Ecological Discrete-Event Networks) to answer this question. It is presented in the form of a formalism whose variables are qualitative and whose values are modified by "if-then" rules representing the events of the ecosystem. These rules are executed one by one, in a non-deterministic way and without any probability. This non-deterministic and non-probabilistic approach has therefore been called possibilistic. The dynamics are then presented in the form of a state-transition graph whose dynamic properties (such as the fact that a species can persist) can be verified.First, a brief history of dynamical modelling in ecosystem ecology is presented, with a particular focus on qualitative modelling approaches, to which EDEN belongs to. Based on the limitations of existing approaches to answer certain questions, we propose the EDEN approach and justify the relevance of its properties with simple examples.Then, the EDEN approach is illustrated on semi-arid ecosystems in East and West Africa in order to know if certain states of interest are reachable (such as the maintenance of vegetation in savanna, or soil fertility in an agroecosystem). To do this, we present and use tools that have not been used much in ecology until now, such as summary graphs and temporal logics. For a given scenario, these tools enable to define (1) the possible transitions between the states of interest, (2) the conditions under which they can occur and (3) the events responsible for these transitions. In East Africa, the EDEN approach was able to determine the long-term effects on vegetation and human activities of reduced/increased surface water availability, indicating a strong indirect influence of the latter on woody vegetation. In West Africa, using EDEN, it was possible to determine the conditions that allowed small-scale producers in southwestern Burkina Faso to develop persistent agropastoralism, as well as the events necessary to achieve such a state.Finally, we discuss the contributions of the EDEN set of models to various fields of ecology, as well as possible improvements and bridges to be built between ecology, systems biology and theoretical computer science
Barros, Ceres. "Etude de la stabilité des écosystèmes à plusieurs échelles spatiales et trophiques." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAV013/document.
Повний текст джерелаAs global change threatens ecosystems worldwide with biodiversity loss, studying ecosystem stability has never been so important. Most ecosystem stability studies have heretofore focused on single ecosystems and disturbances, usually following the behaviour of particular ecosystem properties, such as productivity and diversity indices. However, ecosystems are subjected to multiple disturbances simultaneously and at large spatial scales different ecosystems co-occur, each responding specifically to any given disturbance. Hence, the study of ecosystem stability needs to move towards approaches that can be informative at broad scales that are relevant for ecosystem management. This thesis is a step forward in this direction. Here, I used several approaches to assess how multiple global change drivers, such as climate change, extreme whether events, and land-use changes, affect ecosystem stability at landscape and larger spatial scales, and from single to multi-trophic level perspectives.I begin by highlighting the importance of considering the interactions between gradual and extreme climate changes, in conjunction with land-use changes, for the management of highly diverse landscapes, such as the European Alps. Using a spatially explicit dynamic vegetation model, I show that increasing drought frequency and intensity will likely change the trends of treeline movement expected under future gradual climate warming scenarios. I then investigated whether drought and gradual climate warming caused plant communities to shift in different ways, using n-dimensional hypervolumes to describe community states in multidimensional space. Drought effects on forest and grassland structure did not greatly change the long-term trajectories caused by gradual climate warming alone, but showed that forest communities became more unstable than grasslands in the future. However, focusing on vegetation dynamics remains limited to a single trophic level. Because trophic networks represent energy flows in an ecosystem, studying their stability to disturbances should provide more accurate information on overall ecosystem stability. Hence, I also investigated trophic network stability in European protected areas to future scenarios of land-use and climate changes. My results show that these trophic networks may be highly sensitive to climate changes, even if no land-use changes occur. Importantly, I show that considering different dispersal limitations will greatly impact network robustness, and stress the importance of accounting for these processes in ecosystem management.In my thesis, I demonstrate that ecosystem stability concepts can and should be applied at scales that are relevant for management, while embracing the multidimensional nature of ecosystems
Laan, Jan D. van der. "Spatio-temporal patterns in ecosystems : a bioinformatic approach = Patronen in ruimte en tijd in ecosystemen een bioinformatische benadering /." [S.l. : s.n.], 1994. http://www.gbv.de/dms/bs/toc/189735392.pdf.
Повний текст джерелаTurc, Hubert-Alexandre. "Contribution à l'étude de la définition et de la conception d'un écosystème clos artificiel simplifié à partir de l'opération d'oxydation par voie humide." Châtenay-Malabry, Ecole centrale de Paris, 1997. http://www.theses.fr/1997ECAP0531.
Повний текст джерелаWallhead, Philip John. "Accounting for unpredictable spatial variability in plankton ecosystem models." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/63762/.
Повний текст джерелаRackliffe, Daniel Riley. "Spatial Heterogeneity of Ecosystem Metabolism in a Shallow Wetland." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5757.
Повний текст джерелаKabaya, Kei. "Essays on Spatially Diverse Values of and Preferences in Ecosystem Services." Kyoto University, 2019. http://hdl.handle.net/2433/242700.
Повний текст джерела0048
新制・課程博士
博士(農学)
甲第21823号
農博第2336号
新制||農||1067(附属図書館)
学位論文||H31||N5195(農学部図書室)
京都大学大学院農学研究科生物資源経済学専攻
(主査)教授 栗山 浩一, 教授 伊藤 順一, 教授 梅津 千恵子
学位規則第4条第1項該当
Ferrari, Marika. "Spatial assessment of multiple ecosystem services in an Alpine region." Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/367721.
Повний текст джерелаFerrari, Marika. "Spatial assessment of multiple ecosystem services in an Alpine region." Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/2758/1/PhDThesis_MarikaFerrari.pdf.
Повний текст джерелаCarter, Christopher Michael. "Spatial and temporal dynamics of phytoplankton communities in a coastal ecosystem." Thesis, University of Canterbury. Zoology, 2004. http://hdl.handle.net/10092/4807.
Повний текст джерелаTardieu, Léa. "Integrating ecosystem services in the evaluation of transport infrastructure projects." Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0024.
Повний текст джерелаThe purpose of this thesis is to broaden the assessment process of terrestrial transport infrastructure into the field of Ecosystem Services (ES), i.e., the benefits people derive from ecosystems. Taking into account ES in an ex-ante assessment of public infrastructure projects can be of critical importance for the improvement of transportation decision-making tools, such as environmental impact assessment and cost-benefit analysis. To achieve this, we first review the major challenges to integrate the ES approach into transport infrastructure decisions. This inclusion is only possible if changes in ES, involved by the project, are explained in a spatially explicit way. We illustrate this point, in a first step, by assessing the loss of a global climate regulation service due to the soil sealing caused by a infrastructure construction, using the example of a high-speed rail in Western France.We further deepen the issue of combining direct loss of ES with indirect loss due to impacts of the infrastructure on landscape connectivity. For both direct and indirect effects we also integrate potential threshold effects on ES loss. We compare implementation options, for the same case of infrastructure project, to provide an example of how choices can be improved by mapping ES loss associated with a combination of direct and indirect impacts. Finally, we provide a test of the usefulness of the ES consideration into environmental impact assessment and cost benefit analysis in order to assess the additional information it may bring. Attention is paid to the applicable character of methods to the real legal framework within which they must be conduced. We show that this type of analysis can enlighten and provide guidance at different stages of transport project: from preliminary studies to the study of the final implementation option. For environmental impact assessment, the integration of an ES based approach opens the possibility of measuring a loss in ES supply (and its economic value) providing a means of selecting among different route option for the infrastructure. For cost-benefit analysis, since the ES loss induced by the selected route option is expressed in monetary terms, it can be integrated as a standard social cost in the analysis, permitting a more efficient control of natural capital loss. More specifically, this type of analysis can help designing appropriate environmental measures by expanding the types of impacts assessed, and provide a quantitative assessment of the cost related to the final chosen option. Then, it may help project stakeholders to apprehend the effects on a broader (ecosystem) scale instead of staying confined into project boundaries and regulatory check-lists
Bauer, Dana Marie. "Cost-effective land development with a spatially-realistic ecosystem constraint /." View online ; access limited to URI, 2005. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3206243.
Повний текст джерелаDavid, Gwendoline. "Spatio-temporal structuring of microbial communities in freshwater ecosystems." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL049.
Повний текст джерелаMicroorganisms are the most abundant and diverse forms of life on Earth and are characterized by high phylogenetic and metabolic diversities. They are thus involved in biogeochemical cycles and trophic webs, which make them key players in ecosystem functioning. To decipher the ecology of microorganisms, it is crucial to include spatial, temporal and taxonomic scales. Although several abiotic and biotic parameters have been identified as drivers of microbial community composition in aquatic ecosystems (e.g. temperature, orthophosphate concentration, predation, symbiosis), more investigations are needed to better understand how microbial community structure is shaped. However, investigating biotic interactions involving microbes is challenging because of microbial features (e.g. small size, high diversity, low cultivation efficiency). This PhD thesis aims at describing the microbial diversity inside two overlooked types of freshwater ecosystems and at identifying the factors driving microbial community composition. The first section of this thesis aims at comprehensively describing the spatial distribution (horizontal and vertical) of planktonic microbial eukaryotes in Lake Baikal (Siberia, Russia). We focus on samples collected in summer 2017 along a transect of ~600 km across the three basins of the lake, from the surface to the deepest areas (~1500 m) and from littoral to open waters. The three other sections present an eight-year investigation of the composition and temporal dynamics of microbial communities belonging to the three domains of life at the surface of five small freshwater ecosystems (located in the South West of Paris, France). Samples were collected at two different frequencies, monthly (2011-2013) and seasonally (2011-2019). The composition of planktonic communities was assessed by the sequencing of the phylogenetic marker genes 16S and 18S rRNA. In all the ecosystems studied, the microbial communities were diverse, covering all eukaryotic and prokaryotic supergroups. Moreover, they included typically marine lineages, especially in Lake Baikal, (e.g. diplonemid, MAST) which suggested that the frontiers between marine and freshwater systems may be thinner than previously thought. They also included taxa that remain enigmatic, such as bacteria of the Candidate Phyla Radiation. Multivariate analysis showed that only a low fraction of the variance can be explained by the measured physico-chemical parameters. In terms of spatial variations, there was a weak variability of communities in Lake Baikal in summer across sampling basins, but a strong stratification along the water column. Depth, which is a proxy and a summary of the variations of the environmental conditions (e.g. light) along the water column, appeared to be a major driver of community composition. The small freshwater ecosystems harbored different microbial communities despite their geographic proximity. In terms of temporal variations, two types of patterns were detected. At the intra-annual scale, global communities were characterized by a strong seasonality. However, at the Operational Taxonomic Unit level, less than 2% of the community were characterized by recurrent seasonal patterns. This suggests that ecosystems have a yearly seasonal functioning, despite the presence of some unpredictable microbial dynamics. At the inter-annual scale, microbial communities experienced an increase of dissimilarities over the eight years, indicating turnovers in community composition. Finally, the structure of the communities studied through co-occurrence network inference reflected the spatio-temporal variations previously observed. Indeed, communities were more connected at the surface of Lake Baikal compared to the bottom. Moreover, ecosystems shared similar structural properties at each season. This underlines the importance of ecological interactions in the composition of microbial community over space and time
Solé-Senan, Xavier Oriol. "Plant diversity and ecosystem services in agricultural landscapes along different spatial scales." Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/406287.
Повний текст джерелаLa presente tesis tiene como objetivo dilucidar hasta qué punto la riqueza en especies y la diversidad funcional de las comunidades de flora arvense cambian a escala de campo y de paisaje. A escala de campo, el estudio se ha enfocado en el análisis del efecto de la intensificación agrícola, en cuanto a la posición en el campo y al nivel de perturbación en cada hábitat en la diversidad y funcionalidad de las comunidades de flora arvense. A escala de paisaje, hemos analizado los cambios en la diversidad a lo largo de gradientes de heterogeneidad en el paisaje, teniendo en cuenta por un lado la heterogeneidad composicional y por el otro la heterogeneidad configuracional. La aproximación basada en atributos biológicos nos ha permitido enfocar el estudio en cómo afectan los cambios en la composición florística de dichas comunidades a la provisión de los servicios ecosistémicos que los agroecosistemas aportan a otros organismos.
This thesis is aimed at disentangling the extent at which species richness and functional diversity of plant species from arable communities change at field and landscape scale. At field scale, the study was focused on the effects of agricultural intensification regarding field position and the level of disturbance at which such habitat is subjected on the diversity and functionality of arable plants community. At landscape scale, we assessed the diversity changes along gradients of landscape heterogeneity, taking into account on the one hand the surrounding compositional landscape heterogeneity and on the other hand the configurational landscape heterogeneity. The trait-based approach conducted allows us to focus on how shifts in species composition in such arable plant communities are expected to affect the delivery of the ecosystem services that these agroecosystems provide to other organisms.
Harris, Linda Rozanne. "An ecosystem-based spatial conservation plan for the South African sandy beaches." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1007920.
Повний текст джерелаOjike, Uzoma. "Combining tools and techniques for embedding an ecosystem approach in spatial planning." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11196.
Повний текст джерелаZhang, Jing. "Bayesian spatial analysis with application to the Missouri Ozark Forest ecosystem project." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/6062.
Повний текст джерелаThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 3, 2009) Vita. Includes bibliographical references.
Nolander, Carl. "Spatial and Economic Values of Ecosystem Services : The Case of Sweden's Forests." Licentiate thesis, Luleå tekniska universitet, Samhällsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67918.
Повний текст джерела