Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 53 for “"ecosystem model"”.
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Marine ecosystem model analysis using data assimilation
Numerical modelling of the marine ecosystem requires the aggregation of diverse chemical and biological species into broad categories. To avoid large bias errors it is preferable to resolve as many explicit state variables and processes as possible. The cost of this increased complexity is greater …
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An Ecosystem Model with Evolutionary Adaptive Trophic Structure
We live in an era of rapid change in ecosystems and their environ- ments, that all scales up to the global. The contemporary view is that the interactions between life and the environment are bidirectional: the environment creates life and life creates the environment. However, most ecosystem …
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Relative Role of Uncertainty for Predictions of Future Southeastern U.S. Pine Carbon Cycling
… of uncertainty, we calculated and compared ecosystem model parameter, ecosystem model process, climate model, and climate scenario uncertainty for predictions of Southeastern U.S. pine forest productivity. We applied a data assimilation using Metropolis-Hastings Markov Chain Monte Carlo to …
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Uncertainty quantification and calibration of physical models
<p>An ecosystem model is a representation of a real complex ecological system, and is usually described by sophisticated mathematical models. Terrestrial Ecosystem Model (TEM) is one of the ecosystem models, that describes the dynamics of car- bon, nitrogen, water and other vegetation related …
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Physical Control of Biological Processes in the Central Equatorial Pacific: A Data Assimilative Modeling Study
<p>A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes …
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Cross-shore exchange in the northern Benguela and the related role of upwelling filaments Annethea Auguste Muller.
… For the analyses results from a MOM-4 regional ecosystem model are combined with remote sensing and cruise data.
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Decoding divergence in marine protistan communities: from strain diversity to basin biogeography
… during the experiments to design a Darwin ecosystem model simulation, which demonstrated basin-specific biogeography of thermal optima and niche widths (Chapter 2). For seven of the twelve strains, I sequenced transcriptomes at 3-5 temperatures to assess gene expression variation. Using the …
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On the interaction of rate-induced and bifurcation-induced tipping in ecosystems
… nonlinear tipping phenomena in a bi-stable ecosystem model, defined as sudden and unexpected transitions from the herbivore-dominating equilibrium to the plant-only equilibrium, which are triggered by environmental changes represented by time-varying parameters [Scheffer et al. {\em …
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Decoding divergence in marine protistan communities: from strain diversity to basin biogeography
… during the experiments to design a Darwin ecosystem model simulation, which demonstrated basin-specific biogeography of thermal optima and niche widths (Chapter 2). For seven of the twelve strains, I sequenced transcriptomes at 3-5 temperatures to assess gene expression variation. Using the …
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Physical influences on phytoplankton ecology : models and observations
… complementary ways, working with a global ocean ecosystem model, and collecting data at sea. In the first half of the thesis, I examine the role of mesoscale physical features in shaping phytoplankton community structure and influencing rates of primary production. I compare the output of a …
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Physical influences on phytoplankton ecology : models and observations
… complementary ways, working with a global ocean ecosystem model, and collecting data at sea. In the first half of the thesis, I examine the role of mesoscale physical features in shaping phytoplankton community structure and influencing rates of primary production. I compare the output of a …
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Observations and modelling of the variability of the Solent-Southampton Water estuarine system
… and the ocean. The combination of numerical models and discrete datasets is used to describe and investigate processes of natural variability in the partially-mixed, non-turbid, macrotidal Solent-Southampton Water estuarine system (UK).<br/>The estuarine circulation and the response of wind …
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Quantitative modelling of spatial variability in the north Atlantic spring phytoplankton bloom
… bloom are investigated using a physically forced model of the annual plankton cycle in the ocean mixed layer. The model is optimised to fit survey data from the eastern North Atlantic, collected over a 1500 x 1500 km area between 39N and 54N, from April-June 1991, establishing the feasibility of …
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Addressing the impact of the EU CFP landing obligation on the northern North Sea ecosystem and Shetland fisheries in a changing climate.
Using ecosystem models, past and present dynamics of the northern North Sea were explored to estimate future impacts of the Landing Obligation (LO) and climate change. Building an Ecopath with Ecosim (EwE) model of northern North Sea (International Council for the Exploration of the Sea ICES …
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Human ecological analysis of land and forest use by the Hmong people for harmonising with the governmental reforestation program in Vietnam
… of the research is adapted from the Human Ecosystem Model (Machlis et al., 1997). For this study, both case study and survey are conducted. Three Hmong villages considered as three cases are selected based on predetermined criteria. In each of the selected villages, a mix of qualitative and …
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Modeling the Effects of Physical and Biogeochemical Processes on Phytoplankton Species and Carbon Production in the Equatorial Pacific Ocean
… multi-component lower trophic level ecosystem model that includes detailed algal physiology, such as spectrally-dependent photosynthetic processes and iron limitation on algal growth. The ecosystem model is forced by a one-year (1992) time series of spectrally-dependent light, …
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From Allies to Co-Conspirators: Unveiling the Many Faces of Solidarity in Contemporary Racial Justice Social Movements in the U.S.
… these findings, I offer the Millslowe Allyship Ecosystem Model as a practical tool for practitioners to examine and measure the effectiveness and scale of allyship practices within their movement. By bridging the gap between academic and activist perspectives on allyship, this work fosters …
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Fire regime change and the boreal forest carbon cycle from 10,000 years ago to 2100 AD
… Alaska, incorporating the paleorecord into ecosystem model experiments, and applying insights from these approaches to the development of a statistical model for predicting fire regime change. Results reveal that recent burning is unprecedented in the last 10,000 years. Fire frequency …
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Investigating Nekton Response to Changing Salinities in the Mississippi Sound: An Experimental and Statistical Approach
… used to construct salinity response curves in an ecosystem model. Secondly, field survey data were analyzed using PCA, NMDS, and a negative binomial GLM to investigate how salinity and temperature influence the abundance of blue crab, Atlantic croaker, bay anchovy, and brown and white shrimp. …
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