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Dissertations / Theses on the topic 'Nutrient cycles'

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1

Abell, Jeffrey Thomas. "Giving a damn about DOM in the subtropical North Pacific : quantifying the role of dissolved organic matter in the cycling of carbon, oxygen and nutrients in the upper ocean /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/11060.

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2

Anderson, Laurence Anthony. "The determination of Redfield ratios for use in global oceanic nutrient cycle models." [Princeton, N.J.] : Princeton University, Dept. of Geological and Geophysical Sciences, Program in Atmospheric and Oceanic Sciences, 1993. http://catalog.hathitrust.org/api/volumes/oclc/75401374.html.

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3

Crump, Byron C. "Bacterial activity and community structure in the Columbia River estuarine turbidity maxima /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/10989.

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4

Mielke, Nora. "The role of nitrogen and phosphorus in carbon and nutrient cycling of bryophyte-dominated exosystems." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231758.

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Bryophytes form an important component of northern vegetation communities. Mosses efficiently capture aerially deposited nutrients, restricting nutrient availability to the soil. Given that key ecosystem processes of northern ecosystems are nutrient-limited, understanding nutrient cycling of the moss layer is key to understanding ecosystem nutrient and C cycling in these systems. However, the role of the moss layer in regulating ecosystem-scale nutrient and C cycling, while potentially significant, is largely unknown. The aim of this thesis is to investigate the effect of the relative availabi
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5

Neu, Silke, Jörg Schaller, and E. Gert Dudel. "Silicon availability modifies nutrient use efficiency and content, C:N:P stoichiometry, and productivity of winter wheat (Triticum aestivum L.)." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-221008.

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Silicon (Si) is known as beneficial element for graminaceous plants. The importance of Si for plant functioning of cereals was recently emphasized. However, about the effect of Si availability on biomass production, grain yield, nutrient status and nutrient use efficiency for wheat (Triticum aestivum L.), as one of the most important crop plants worldwide, less is known so far. Consequently, we assessed the effect of a broad range of supply levels of amorphous SiO2 on wheat plant performance. Our results revealed that Si is readily taken up and accumulated basically in aboveground vegetative o
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6

Auguères, Anne-Sophie. "Régulation biotique des cycles biogéochimiques globaux : une approche théorique." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30290/document.

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Les activités anthropiques affectent les cycles biogéochimiques globaux, principalement par l'ajout de nutriments dans les écosystèmes. Il est donc crucial de déterminer dans quelle mesure les cycles biogéochimiques globaux peuvent être régulés. Les autotrophes peuvent réguler les réservoirs de nutriments par la consommation des ressources, mais la majorité des ressources leur sont inaccessibles à l'échelle globale. Par des modèles théoriques, nous avons cherché à évaluer la manière dont les autotrophes répondent à la fertilisation à l'échelle globale et leur capacité à réguler les concentrati
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7

Oates, Richard Hunter. "Phosphate-mineral interactions and potential consequences for nutrient cycling." Thesis, Online version of original thesis, 2008. http://hdl.handle.net/1912/2395.

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8

Neu, Silke, Jörg Schaller, and E. Gert Dudel. "Silicon availability modifies nutrient use efficiency and content, C:N:P stoichiometry, and productivity of winter wheat (Triticum aestivum L.)." Nature Publishing Group, 2016. https://tud.qucosa.de/id/qucosa%3A30213.

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Silicon (Si) is known as beneficial element for graminaceous plants. The importance of Si for plant functioning of cereals was recently emphasized. However, about the effect of Si availability on biomass production, grain yield, nutrient status and nutrient use efficiency for wheat (Triticum aestivum L.), as one of the most important crop plants worldwide, less is known so far. Consequently, we assessed the effect of a broad range of supply levels of amorphous SiO2 on wheat plant performance. Our results revealed that Si is readily taken up and accumulated basically in aboveground vegetative o
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9

Klein, Lawrence S. "An Ecosystem Dynamics Model of Monterey Bay, California." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/KleinLS2002.pdf.

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10

Murphy, Conor. "Investigation of rhizosphere priming effects for N mineralisation in contrasting soils." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=228575.

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In the context of nutrient cycling in soil, plant-mediated mineralisation of carbon (C) and nitrogen (N) is poorly understood. The broad focus of this thesis was to investigate the potential importance of plant-mediated mineralisation (i.e.priming) on C and N mineralisation in soils with contrasting crop productivities. The studies focus on two soils, which had similar chemical and physical properties but contrasting plant productivities relating to their N supply capacity. These soils were used to investigate the potential importance of priming processes in contributing to the contrasting cap
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11

Kwari, J. D. "Effects of straw burning and drying-rewetting cycles on the fertility of some soils of North-East Nigeria." Thesis, University of Aberdeen, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379809.

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The effects of straw burning and drying-rewetting cycles on nutrient availability were studied in an attempt to assess the practical importance of the yearly precropping practice by farmers of burning off excess crop residues and of the seasonal climate of North-East Nigeria. Changes in soil properties resulting from heating three soils up to 700°C and from field burning of straw on three soils were determined. Heating to 250° did not affect soil texture but increased exchangeable NH<sub>4<sup>+</sub></sup>-N, available P, Fe, Mn and phosphate adsorption. A peak of NH<sub>4<sup>+</sub></sup>-N
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12

Hardison, Amber Kay. "Interactions between macroalgae and the sediment microbial community : nutrient cycling within shallow coastal bays /." W&M ScholarWorks, 2009. http://web.vims.edu/library/Theses/Hardison09.pdf.

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13

Chuyong, George Bindeh. "Nutrient cycling in ectomycorrhizal legume-dominated forest in Korup National Park, Cameroon." Thesis, University of Stirling, 1994. http://hdl.handle.net/1893/2640.

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Patterns and rates of nutrient input to the forest floor in litterfall, throughfall and stemflow were investigated in plots of low and high abundance of ectomycorrhizal species. The aim of the study was to examine the comparative advantage of the ectomycorrhizal species in nutrient acquisition and cycling on nutrient-poor soils in Korup. Litterfall was similar in both forests with annual estimates of 9.00 and 8.33 t ha-1 yr-1 for LEM and HEM forests respectively. Litterfall distribution followed a mono-modal pattern, with peaks in the dry season in both forests and the HEM forest showing stron
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14

Ostrowski, Martin Biotechnology &amp Biomolecular Sciences Faculty of Science UNSW. "Physiological adaptation to nutrient limitation in a marine oligotrophic ultramicrobacterium Sphingopyxis alaskensis." Awarded by:University of New South Wales. School of Biotechnology and Biomolecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/27422.

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Sphingopyxis (formerly Sphingomonas) alaskensis, a numerically abundant species isolated from Alaskan waters and the North Sea represents one of the only pure cultures of a typical oligotrophic ultramicrobacterium isolated from the marine environment. In this study, physiological and molecular characterization of an extinction dilution isolate from the North Pacific indicate that it is a strain of Sphingopyxis alaskenis, extending the known geographical distribution of this strain and affirming its importance as a model marine oligotroph. Given the importance of open ocean systems in climatic
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15

Simpson, Kyle G. F. "Nutrient dynamics and nitrogen-based production in the western Canadian Arctic Ocean." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112363.

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Inclement climate conditions have made the Arctic Ocean logistically difficult to study, and thus, our historical knowledge of Arctic Ocean processes are limited. Recent observations indicate rapid and abrupt changes in climate. These changes are thought to includes rising temperatures, increase storm activity, altered freshwater balance and a notable decrease in the concentration and extent of sea ice covering the Arctic Ocean. Increasing awareness of these changing conditions and our poor knowledge of how the physical environment influences carbon fluxes, planktonic productivity and biogeoch
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16

Dam, Oscar van. "Forest filled with gaps effects of gap size on water and nutrient cycling in tropical rain forest : a study in Guyana = Bos gevuld met gaten : de effecten van de grootte kronendakopeningen op de water- en nutriëntenkringloop in tropisch regenwoud : een studie in Guyana /." Georgetown, Guyana : Tropenbos Guyana Programme, 2001. http://catalog.hathitrust.org/api/volumes/oclc/48485430.html.

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17

Human, Lucienne Ryno Daniel. "Reeds as indicators of nutrient enrichment in the East Kleinemonde Estuary." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1252.

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The release of nutrients (nitrogen and phosphorus) via land clearing, application of fertilisers, discharge of human waste and combustion of fossil fuels, is one of the most harmful effects of anthropogenic stresses on aquatic environments. This study investigated the use of reeds as indicators of nutrient input to estuaries. Small estuaries such as the oligotrophic East Kleinemonde where the research was mostly conducted are sensitive to nutrient enrichment from septic tanks, stormwater runoff and fertiliser application to lawns in close proximity to the estuary. Nutrient concentrations were
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18

Stoklas, Ulrica F. "Variation in nutrient dynamics among full-sib families of Picea mariana (Mill.) B.S.P. at two sites differing in water availability." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0004/MQ37169.pdf.

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19

Klenk, Nicole. "Controls on nutrient availability in black spruce forests of northwestern Quebec." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33012.

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The presence of mosses in black spruce forests is known to have an important impact on the availability and abundance of nutrients in this ecosystem. Mosses contribute to long-term accumulation of organic matter and storage of nutrients as well as to short-term nutrient release. In the boreal forest of northwestern Quebec, the effect of mosses on nutrient cycling was examined within the framework of a chronosequence ranging from 25 to 300 years of age. Laboratory and buried bag incubations, total nutrient digests, respirometric and root abundance measurements as well as moisture and temperatur
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20

Tobón, Marin Conrado. "Monitoring and modelling hydrological fluxes in support of nutrient cycling studies in Amazonian rain forest ecosystems." Wageningen, The Netherlands : Tropendos Foundation, 1999. http://catalog.hathitrust.org/api/volumes/oclc/43455503.html.

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21

Dessirier, Benoît, and Safeyeh Soltani. "Dynamics of internal nutrient sources in the Baltic Sea - A comparative modelling study of the Gulf of Finland." Thesis, KTH, Vattenvårdsteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96110.

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For decades the Baltic Sea has been subject to eutrophication due to heavy anthropogenic nutrient loads on the aquatic ecosystem. Quantitative projections of its effects require an understanding of its driving mechanisms, i.e., the hydrodynamics that are responsible for the physical transport and mixing and the biogeochemical nutrients pathways within the algal ecosystem and between the particulate and dissolved phases in the water and in the sediments. A simple basin-scale hydrodynamic framework is set for the Gulf of Finland to test different descriptions of the biogeochemical transformation
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22

Lindsay, Elizabeth A. "The impact of Chrysanthemoides monilifera spp. rotundata (bitou bush) on coastal ecosystem processes." Access electronically, 2004. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20041222.143610/index.html.

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23

Dassonville, Nicolas. "Impact des plantes exotiques envahissantes sur le fonctionnement des écosystèmes en Belgique." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210579.

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Les invasions biologiques sont une cause majeure de perte de biodiversité à l’échelle mondiale. L’impact direct des espèces exotiques envahissantes (EEE) sur la structure et la composition des communautés a été bien documenté. Par contre, leur impact sur le fonctionnement des écosystèmes a été comparativement moins étudié. Dans le présent travail, j’ai mesuré sur le terrain et en conditions expérimentales l’impact de 7 espèces de plantes exotiques particulièrement envahissantes en Europe sur les propriétés chimiques du sol, sur la productivité et sur le stock d’éléments minéraux dans la biomas
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Human, Lucienne Ryno Daniel. "The contribution of submerged macrophytes and macroalgae to nutrient cycling in the Great Brak Estuary." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1021102.

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An ecological reserve study by the Department of Water Affairs on the Great Brak Estuary stated that there was a need to determine how much nitrogen and phosphorus was flowing through the estuary as well as how effective the macroalgae were at removing N and P. The objective of this study was to investigate the physico-chemical characteristics in the estuary and the influence of these on the submerged macrophytes and macroalgae. A nutrient budget for the estuary was developed in order to quantify the contribution of the submerged macrophytes and macroalgae relative to other contributing source
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25

Charberet, Samuel M. "Animal-mediated terrestrial nutrient dynamics : investigating wastes, trophic transfer, and isotopic patterns." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS523.

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Certains éléments chimiques sont particulièrement importants pour les organismes. Le carbone (C), le squelette des biomolécules, l’azote (N) des protéines essentielles à toute fonction, et le phosphore (P), au cœur de l’énergie chimique de l’ATP sont si importants que la structure des écosystèmes terrestres, dépend en partie des flux de ces éléments, ainsi que de leur proportion relative, ou stœchiométrie, dans le sol. Or, les animaux se nourrissent et produisent des déchets sous forme de fèces et d’urine contenant ces mêmes éléments (C, N, P), dont le devenir dépend fortement de la quantité e
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Darrow, Brian P. "Effects of Nutrients From the Water Column on the Growth of Benthic Microalgae in Permeable Sediments." Scholar Commons, 2007. https://scholarcommons.usf.edu/etd/200.

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In some continental shelf sediments integrated benthic microalgal biomass is greater than the integrated phytoplankton biomass in the overlying water column. In addition, benthic microalgae may account for up to 10% of the primary production responsible for the coastal fishery yield of the eastern United States. A three-dimensional model of the eastern Gulf of Mexico examines the effects of water-column nutrient sources on the growth of benthic microalgae. To parameterize the exchange of nutrients across the sediment/water interface in these permeable sediments, a non-local exchange submodel w
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Haupert, Christie Lynn 1976. "Nutrient limitation dynamics of a coastal Cape Cod pond : seasonal trends in alkaline phosphatase activity." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/55335.

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Thesis (M.S.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), February 2001.<br>Includes bibliographical references (leaves 144-149).<br>A bi-weekly seasonal study was conducted in Ashumet Pond (Cape Cod, Massachusetts). The Redfield Ratio (106C:16N:1P) and alkaline phosphatase activity (APA) were utilized in tandem as nutrient deficiency indicators (NDIs) for phytoplankton. The study objective was to evaluate the limiting nutrient status of the pond throughout the growing
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Boucher, Patricia. "Base cation immobilization in the stem of some hardwoods of southern Québec." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ55039.pdf.

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Weeber, Russell C. "Nutrient addition and the use of stable isotope techniques in wetlands of the Interlake Region of Manitoba, Canada." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22825.

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This study examines the relationship between nutrient additions and algae and invertebrate productivity in a nutrient-poor wetland of the Interlake Region of Manitoba, Canada. Alfalfa hay was added to experimental enclosures in May 1992. Alfalfa additions were made in unprocessed and ground forms and consisted of three treatments: ground low, whole low, and whole high. Dissolved oxygen, surface water nutrients, algae standing crop, and invertebrate production were monitored at open marsh sites and in treatment and control enclosures during 1992 and 1993. Stable $ sp{13}$C, $ sp{15}$N and $ sp{
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Yan, Xingcheng. "Greenhouse gas emissions and nutrient retentions in reservoirs of the Seine Basin : budget and modelling." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS152.

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L'impact des barrages–réservoirs sur les émissions de GES (gaz à effet de serre, CH4: méthane, CO2: dioxyde de carbone, et N2O: protoxyde d’azote) et sur les cycles biogéochimiques du C (carbone) et des nutriments (N: azote, P: phosphore, et Si: silice) a fait l'objet d'une attention croissante depuis plusieurs années. Après un premier travail d'estimation des émissions de GES par les réservoirs mondiaux, et l’examen de leur évolution à long terme, les travaux se concentrent sur les trois principaux réservoirs du bassin de la Seine, afin de déterminer leur contribution aux émissions de GES et
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Tisserand, Romane. "The Ni biogeochemical cycle in a tropical agromining crop system." Electronic Thesis or Diss., Université de Lorraine, 2021. https://docnum.univ-lorraine.fr/ulprive/DDOC_T_2021_0115_TISSERAND.pdf.

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L'hyperaccumulation est un phénomène qui a été découvert il y a 45 ans seulement, il a fait l'objet de nombreuses recherches, en raison du comportement inhabituel des métaux dans l'écosystème et en raison du potentiel de solutions fondées sur la nature qui en découle. La description du cycle biogéochimique du Ni des plantes hyperaccumulatrices est nécessaire pour élucider leur rôle écologique dans leur environnement naturel, mais aussi pour comprendre leur comportement potentiel dans des cultures tropicales d’agromine. L'exploitation agricole et l'exportation de la biomasse riche en Ni interro
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Popendorf, Kimberly J. (Kimberly Julia). "Marine microbial intact polar diacylglycerolipids and their application in the study of nutrient stress and bacterial production." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/79293.

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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), February 2013.<br>"February 2013." Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Intact polar diacylglycerolipids (IP-DAGs) were used to study microbial dynamics in the surface ocean. IP-DAGs from surface ocean seawater were quantified using high performance liquid chromatography-mass spectrometry (HPLC-MS), after first developing a sensitive, high throughput molecular ion
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Noble, Abigail Emery. "Influences on the oceanic biogeochemical cycling of the hybrid-type metals, cobalt, iron, and manganese." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70779.

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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Trace metal cycling is one of many processes that influence ocean ecosystem dynamics. Cobalt, iron, and manganese are redox active trace metal micro-nutrients with oceanic distributions that are influenced by both biological and abiotic sources and sinks. Their open ocean concentrations range from picomolar to nanomolar,
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Lequy, Emeline. "Dépôts atmosphériques particulaires sur les écosystèmes forestiers de la moitié Nord de la France : influence sur les cycles biogéochimiques." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0277/document.

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Quantifier la totalité des apports atmosphériques, notamment particulaires, est nécessaire pour mieux comprendre les cycles biogéochimiques en vue d'une gestion durable des écosystèmes forestiers. En effet, l'intensification des récoltes de bois-énergie induit une pression nutritive supplémentaire sur les forêts. Le but de ce travail est de combler les lacunes concernant le dépôt atmosphérique particulaire (taux de dépôt, composition minéralogique et chimique), ainsi que d'étudier son influence sur les cycles biogéochimiques forestiers. Pour ce faire, un échantillonnage de 2 ans a été mis en p
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Bringhurst, Kelly. "The effect of land-use on nutrient cycles of tropical streams on the Osa peninsula, Costa Rica : a paired catchment approach to investigate current conditions and projected changes." Thesis, University of Ulster, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553867.

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The effect of land-use on nutrient cycles of tropical streams on the Osa Peninsula, Costa Rica: a paired catchment approach to investigate current conditions and projected changes. Kelly N. Bringhurst Abstract This study is concerned with potential environmental degradation of soils, rivers and coastal regions of the Osa Peninsula, Costa Rica due to deforestation. A paired, small-catchment approach to the study of environmental pressures on nutrient transfer and aquatic enrichment was used with one catchment that had been cleared for pasture (CN9) and the second primarily undisturbed tropical
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Panassa, Essowe [Verfasser], Judith [Akademischer Betreuer] Hauck, Dieter A. [Gutachter] Wolf-Gladrow, and Birgit [Gutachter] Schneider. "Role of Mixed Layer Depth and Subduction Processes for the Southern Ocean Carbon and Nutrient Cycles / Essowe Panassa ; Gutachter: Dieter A. Wolf-Gladrow, Birgit Schneider ; Betreuer: Judith Hauck." Bremen : Staats- und Universitätsbibliothek Bremen, 2018. http://d-nb.info/1160670463/34.

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Abe, Hitofumi. "Forest management impacts on growth, diversity and nutrient cycling of lowland tropical rainforest and plantations, Papua New Guinea." University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0098.

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[Truncated abstract] Globally, tropical rainforests are noted for their high biodiversity and key roles in carbon storage and influence on climate. Nevertheless, tropical deforestation in many parts of the world continues at an alarming rate. In Papua New Guinea (PNG), tropical rainforest is relatively well maintained, with about 70 % of the land area still covered by primary forest. However, PNG's native forests are coming under increasing pressure, particularly from selective logging for high quality timber. While the forests of PNG, and more broadly the entire New Guinea Island, are recogni
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Andrisoa, Aladin Danoary. "Ecological impacts of groundwater discharge to Mediterranean coastal lagoons." Thesis, Aix-Marseille, 2019. http://theses.univ-amu.fr.lama.univ-amu.fr/190326_ANDRISOA_564o889xp122jxhof868gdfl_TH.pdf.

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Bien que l’importance des eaux souterraines et des eaux porales (recirculation) en tant que voie d’apports de nutriments vers les systèmes côtiers soit de plus en plus reconnue, il y a encore peu d’information sur leur réel rôle écologique. Cette thèse vise à évaluer l’impact des flux d’eaux souterraines et du processus de recirculation au sein du sédiment sur le fonctionnement des écosystèmes lagunaires côtiers et sur leur vulnérabilité face aux impacts anthropiques et climatiques. Deux lagunes contrastées de la côte méditerranéenne française ont été étudiées (Etangs de La Palme et Salses-Leu
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Becker, Joscha Nico Verfasser], Yakov [Akademischer Betreuer] [Kuzyakov, Michaela [Gutachter] Dippold, Daniela [Gutachter] Sauer, and Sandra [Gutachter] Spielvogel. "Carbon and nutrient cycles depending on climate and land use along the elevation gradient of Mount Kilimanjaro / Joscha Nico Becker ; Gutachter: Michaela Dippold, Daniela Sauer, Sandra Spielvogel ; Betreuer: Yakov Kuzyakov." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://d-nb.info/1142001520/34.

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Bélanger, Nicolas 1971. "Investigating the long-term influence of atmospheric acid deposition and forest disturbance on soil chemistry and cation nutrient supplies in a forested ecosystem of southern Quebec." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36542.

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The objective of this thesis was to validate the dynamic model SAFE (Soil Acidification in Forested Ecosystems) in a small deciduous watershed of southern Quebec. SAFE could then be used to: (1) identify which processes are governing acidification, and (2) assess the rates of acidification according to various forest conditions.<br>Soil and soil solution chemistry between unburned and burned zones following fire disturbance seventy-five years ago was examined within the watershed. Results showed two major, statistically significant, differences: (1) higher base status, and (2) lower soil solut
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Menoyo, Molins Alexandra. "Nutrient availability regulates cell cycle through a Pho85 CDK-dependent control of Cln3 cyclin stability." Doctoral thesis, Universitat Internacional de Catalunya, 2012. http://hdl.handle.net/10803/101414.

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Cell cycle control by trophic factors has a key role in regulation of cell proliferation in all organisms. Nutrients are one of these important factors needed by cells to reproduce, so very well regulated mechanisms must exist that connect nutrient availability to cell cycle. Hence the importance on studying how exactly nutrient-dependent signaling pathways work. Cln3, the most upstream G1 cyclin in Saccharomyces cerevisiae, is one well demonstrated common effector of multiple nutrient-dependent signaling pathways. Moreover, its role in cell cycle is crucial. So it is a good candidate to regu
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Sergi, Sara. "Nutrient input from seamounts and hydrothermal vents in the Southern Ocean : impacts on the pelagic ecosystems and implications for conservation." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS508.

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Les processus bottom-up contôlent une portion importante de la variabilité des écosystèmes marins. Dans l'océan Austral, des contrastes intenses dans la distribution des écosystèmes pélagiques sont génerés par la limitation de la production primaire par le fer et la Courant Circumpolaire Antarctique. Les efflorescences massives en phytoplancton en aval des îles entretiennent des vastes réseaux trophiques. En comparaison, l'impact des sources profondes de nutriments sur la production pélagique semble négligeable. Les programmes de conservation dans la Courant Circumpolaire Antarctique vont
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43

Gillett, David James. "Effects of habitat quality on secondary production in shallow estuarine waters and the consequences for the benthic-pelagic food web." W&M ScholarWorks, 2010. http://www.vims.edu/library/Theses/Gillett10.pdf.

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44

Saunders, Darla L. "Nitrogen retention in freshwater ecosystems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq64444.pdf.

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45

Liu, Shibin Verfasser], Yakov [Akademischer Betreuer] [Kuzyakov, Michaela [Gutachter] Dippold, Sandra [Gutachter] Spielvogel, Bruno [Gutachter] Glaser, and Christoph [Gutachter] Leuschner. "Tibetan pasture degradation under the impact of global change: Consequences for carbon and nutrient cycles and recovery strategies / Shibin Liu ; Gutachter: Michaela Dippold, Sandra Spielvogel, Bruno Glaser, Christoph Leuschner ; Betreuer: Yakov Kuzyakov." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://d-nb.info/113738008X/34.

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46

Mestelan, Silvia A. "Impact of long-term no till and plow till on soil properties and soil nutrient cycling." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1199221756.

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47

Le, Noë Julia. "Biogeochemical functioning and trajectories of French territorial agricultural systems : carbon, nitrogen and phosphorus fluxes (1852-2014)." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS159.

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Cette thèse décrit les systèmes de production agricole en termes de flux biogéochimiques d’azote (N), de phosphore (P) et de carbone (C) dans les territoires français de 1852 à 2014 suivant une approche socio-écologique qui permet d’appréhender les logiques qui les gouvernent. Les résultats obtenus mettent en lumière à l’échelle des territoires français le lien systémique entre structures de production, bilans N et P et variations des stocks de C organique dans les sols agricoles. Les systèmes agricoles intensifs et spécialisés engendrent les pertes environnementales et les consommations de re
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48

Le, Noë Julia. "Biogeochemical functioning and trajectories of French territorial agricultural systems : carbon, nitrogen and phosphorus fluxes (1852-2014)." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS159/document.

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Abstract:
Cette thèse décrit les systèmes de production agricole en termes de flux biogéochimiques d’azote (N), de phosphore (P) et de carbone (C) dans les territoires français de 1852 à 2014 suivant une approche socio-écologique qui permet d’appréhender les logiques qui les gouvernent. Les résultats obtenus mettent en lumière à l’échelle des territoires français le lien systémique entre structures de production, bilans N et P et variations des stocks de C organique dans les sols agricoles. Les systèmes agricoles intensifs et spécialisés engendrent les pertes environnementales et les consommations de re
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Fink, Daniel Francis. "Effects of a pulsing hydroperiod on a created riparian river diversion wetland." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1167401886.

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Le, Van Khoi. "Nutrient cycle in an integrated recirculating aquaculture system." Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1916.

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Intensive marine aquaculture may cause negative impacts on the aquatic environment by causing water pollution, algae bloom and reduction in biodiversity of the surrounding aquatic environment. The nutrient-rich effluents from aquaculture activities contain nitrogen and phosphate which serve as a nutrient source for bivalve, algae and invertebrates. Seaweed and mussels have been integrated with marine species in culture systems to remove the waste from aquaculture farms. The research has explored the nutrient uptake capacities of green seaweed (Ulva lactuca) and blue mussel (Mytilus edulis) int
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