Дисертації з теми "Plant biogeochemistry"
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Arnold, Timothy. "Biogeochemistry of zinc and iron isotopes at the plant-soil interface." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501762.
Повний текст джерелаAlfonso, Amanda. "Organic nitrogen use by different plant functional types in a boreal peatland." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106594.
Повний текст джерелаLa minéralisation a longtemps semblé être le conducteur principal fournissant l'azote aux plantes. Cependant, les faibles taux de minéralisation des écosystèmes nordiques ne peuvent pas pourvoir l'apport total d'azote des plantes et il est maintenant reconnu que les plantes peuvent utiliser les formes organiques de l'azote. L'azote est souvent un nutriment limitant dans les tourbières ombrotrophes et, à la tourbière Mer Bleue, près de 80% de l'azote dans l'eau interstitielle est sous forme d'azote organique dissous. Cette étude avait pour but de déterminer si les plantes des tourbières peuvent absorber l'azote sous formes organiques et s'il y a des différences entre les types fonctionnels de plantes qui dominent la végétation des tourbières. Pour déterminer si les plantes des tourbières absorbent l'azote organique, 16 parcelles ont été choisies à Mer Bleue, où une moitié a été utilisée comme contrôle et l'autre moitié a reçu un traitement de glycine marquée isotopiquement (13C2, 15N, 98% atomes). La glycine marquée a été injecté dans la rhizosphère à une profondeur de 0-20cm. Après 72 heures, les feuilles et les racines des arbustes (C.calyculata, V. myrtilloides, L.groenlandicum), laîches (E. vaginatum) et les mousses (S. magellanicum, S.capillifolium) dans les parcelles ont été recueillies et analysées pour les plantes δ13C et δ15N. Les échantillons foliaires ont montré une absorption importante de 15N pour toutes les espèces et aucune augmentation significative de signatures δ13C. Les échantillons de racines ont montré un enrichissement plus grand en δ15N et δ13C pour les deux espèces d'arbustes et celle de laîche. Cependant, l'absorption de δ13C pour espèces de laîche n'a pas été jugée significative. Les résultats ont montré que les espèces d'arbustes ont absorbé la glycine entièrement alors que l'absorption de glycine n'a pas été importante pour les espèces de carex et de mousse, ce qui suggère que les associations mycorhiziennes des arbustes éricacées peut être le facteur déterminant dans l'absorption de l'azote organique à la tourbière Mer Bleue.
Ker, Keomany. "AM fungal contribution to sunflower (Helianthus annuus L) in phytoremediation of nickel-treated soils." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27258.
Повний текст джерелаHua, Yujie. "Changes of Soil Biogeochemistry under Native and Exotic Plants Species." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/1912.
Повний текст джерелаJuice, Stephanie. "The Environmental Microbiome In A Changing World: Microbial Processes And Biogeochemistry." ScholarWorks @ UVM, 2020. https://scholarworks.uvm.edu/graddis/1181.
Повний текст джерелаMontross, Scott Norman. "Geochemical evidence for microbially mediated subglacial mineral weathering." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/montross/MontrossS0507.pdf.
Повний текст джерелаGougherty, Steven W. "Exudation Rates and δ13C Signatures of Bottomland Tree Root Soluble Organic Carbon: Relationships to Plant and Environmental Characteristics". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1448818110.
Повний текст джерелаVan, der Merwe Margaretha Johanna. "Influence of hexose-phosphates and carbon cycling on sucrose accumulation in sugarcane spp." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1257.
Повний текст джерелаCard, Marcella. "Interactions among soil, plants, and endocrine disrupting compounds in livestock agriculture." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1311287470.
Повний текст джерелаFranklin, Oskar. "Plant and forest dynamics in response to nitrogen availability /." Uppsala : Swedish University of Agricultural Sciences, 2003. http://diss-epsilon.slu.se/archive/00000345/.
Повний текст джерелаAppendix consists of reprints of three papers and a manuscript, three of which are co-authored with others. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix.
Navarrete, Gutiérrez Dulce Montserrat. "Plant Metal Hyperaccumulation in Mexico : Agromining Perspectives." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0187.
Повний текст джерелаAgromining technology involves the recovery of strategic metals from metalliferous soils through the cultivation of metal(loid) hyperaccumulator plants. The impetus of this research was to evaluate the potential of Mexican plant resources for the future development of agromining. The main objectives were then to identify and to study some metal hyperaccumulator plant species in Mexico, and to assess the agronomy of one promising “metal crop” for agromining. We first undertook field explorations in three nickel-rich ultramafic regions of central and southern Mexico. Despite the availability of soil and climatic conditions, no nickel (Ni) hyperaccumulation was found in any of these regions. A second strategy based on plant phylogeny as a prediction tool for metal hyperaccumulation was followed. In total, ten plant metal hyperaccumulator species were identified during this research (Rubiaceae and Violaceae) in Ni-enriched soils influenced by volcanic activity in Southeastern Mexico; most of them were priorly unknown. Our studies revealed two of the strongest hypernickelophores reported so far (>4%wt Ni) and two new Ni hyperaccumulator genera (Orthion and Mayanaea). Special focus was given to the hypernickelophore tree Blepharidium guatemalense. The phloem on leaves, roots, stems and petioles of this plant are the richest in Ni suggesting an unusual re-distribution mechanism via the phloem. Different agronomic practices were tested for this plant. Synthetic fertilization strongly increased nickel uptake without any change in plant growth or biomass, whereas organic fertilization enhanced plant shoot biomass with a negligible effect on foliar Ni concentrations. A 5-year-old stand which was subsequently harvested twice per year produced the maximum Ni yield tree⁻¹ yr⁻¹, with an estimated total nickel yield of 142 kg ha⁻¹ yr⁻¹. Blepharidium guatemalense is a prime candidate for Ni agromining on the account of its valuable traits: extremely efficient Ni uptake, high biomass production, fast growth rate, and easy to reproduce
Branfireun, Marnie. "The role of decomposing plant litter in methylmercury cycling in a boreal poor fen /." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33382.
Повний текст джерелаMass losses follow the trend: Chamaedaphne calyculata >> S. angustifolium > S. fuscum. Between species differences were far more significant than differences between locations or depths, indicating that litter quality is the major control on decomposition.
McHg concentrations generally increased during decomposition, particularly near the water table: for C. calyculata up to 13000%, for the two Sphagnum mosses up to 500%, suggesting that decomposition stimulates mercury methylation or McHg scavenging.
The discovery of a high McHg substance on C. calyculata leaf surfaces (25 ng g-1) suggests that much plant MeHg data may by skewed by the presence of a biologically active 'film'.
Smith, Madelyn M. "Cometabolic Degradation of Halogenated Aliphatic Hydrocarbons by Aerobic Microorganisms Naturally Associated with Wetland Plant Roots." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1341854406.
Повний текст джерелаMosher, Stella G. M. S. "Carbon Isotope Discrimination and Nitrogen Isotope Values Indicate that Increased Relative Humidity from Fog Decreases Plant Water Use Efficiency in a Subtropical Montane Cloud Forest." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1430750042.
Повний текст джерелаGormley, Mark D. "The Influence of Hydrogeomorphology, Soil Redox Conditions, and Salinity on the Spatial Zoning of Saltgrass, Salt Rush, and Cattails in Scotts Creek Marsh, Swanton Pacific Ranch, CA." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1167.
Повний текст джерелаMatheny, Ashley Michelle. "Development of a Novel Plant-Hydrodynamic Approach for Modeling of Forest Transpiration during Drought and Disturbance." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468595149.
Повний текст джерелаWilson, Benjamin J. "Drivers and Mechanisms of Peat Collapse in Coastal Wetlands." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3718.
Повний текст джерелаZhao, Hongwei. "A Proteomic Study of Plant Messenger RNA Cleavage and Polyadenylation Specificity Factors and the Establishment of an In Vitro Cleavage Assay System." Oxford, Ohio : Miami University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1218547019.
Повний текст джерелаGuigues, Stéphanie. "Caractérisation des interactions physico-chimiques entre le cuivre et les racines comme base de développement d'un modèle d'évaluation de la phytodisponibilité des éléments traces." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4307.
Повний текст джерелаThis study has been dedicated to the development of a new modeling approach of trace element phytoavailability, focusing on binding reactions between trace element and plant roots. This approach was used to predict copper (Cu) adsorption on wheat and tomato roots. Several analytical techniques (acid-base titrations, nuclear magnetic resonance of carbon 13, X-ray absorption spectroscopy) were used and crossed with modeling results. At first, plant root reactivity was characterized. Because plant roots are consist of cell walls and plasma membranes, the relative contribution of these two compartments in root binding properties was evaluated. The study was then focused on Cu binding reactions on roots and the effects of physico-chemical conditions (pH, ionic strength, presence of cations) on copper binding. The model has been set thanks to results on root characterization obtained and the acquisition of a set of experimental data on Cu binding. It has been shown that binding properties of wheat and tomato roots came from both cell walls and plasma membranes. Copper speciation in roots was shared, almost evenly, between cell wall pectic compounds and proteins embedded in cell walls and plasma membranes. A model, specific to plant roots, has been developed on the basis of a current model dedicated to the humic substances reactivity. The WHAM-Terrestrial Higher Plants model presented in this study is a first step towards a new tool for assessing the availability of trace elements for plants
Tang, Guoping. "An examination of vegetation modeling-related issues and the variation and climate sensitivity of vegetation and hydrology in China." Thesis, Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2008. http://hdl.handle.net/1794/8543.
Повний текст джерелаTypescript. Includes vita and abstract. Includes bibliographical references (leaves 128-156). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
Van, de Water Peter Kent. "δ¹³C and stomatal density variability in modern and fossil leaves of key plants in the western United States". Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/289058.
Повний текст джерелаNaude, Minette. "Fynbos riparian biogeochemistry and invasive Australian acacias." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20325.
Повний текст джерелаENGLISH ABSTRACT: Riparian ecotones, transitional areas between upland terrestrial communities and aquatic ecosystems, are very dynamic and complex ecosystems with intrinsic ecological properties differing in spatial structure, function and temporal dynamics. Riparian habitats along rivers of the Mediterranean south-western Cape are sensitive to environmental change and particularly vulnerable to invasion by invasive alien plants (IAPs), especially nitrogen-fixing Acacia spp., and yet relatively little work has focused on how riparian ecosystems in this region respond to such stressors. The important roles that intact riparian vegetation play in maintaining ecosystem integrity and services have been increasingly highlighted as we acknowledge the degradation of these habitats. While the Working for Water (WfW) programme has been shown to be very successful in eradicating IAPs in riparian zones in the short-term, the extent to which riparian ecosystems recover following alien clearing activities remains poorly understood. The results presented in this study addressed several different aspects of riparian structure and function and acts as a steppingstone for guiding future research and management in riparian zones by adding to the evaluation of the success of clearing initiatives and restoration thereof. The aim of this study was to assess plant functional type (PFT) cover, soil physical and chemical properties, and selected biogeochemical processes in natural, Acacia- invaded and cleared riparian ecotones and associated non-riparian upland fynbos. Fieldwork was performed in mountain and foothill sections of six perennial river systems within the south-western Cape. Eleven sites of three categories were chosen: four natural sites (uninvaded); four moderate to highly invaded sites (predominantly A. mearnsii); and three cleared sites (a formerly invaded site that had been cleared more than 7 years prior to the study). Within each site, four to five replicate plots were established along each of three geomorphological zones (wet bank, dry bank, and upland fynbos). Seasonal soil samples were collected for a period of one year. Results from this study showed that PFT cover and composition, soil physical and chemical properties and rates of nitrogen (N) and phosphorus (P) mineralization differed amongst invasion status, between geomorphological zones and across seasons. Regarding most soil physical and chemical properties and indices N and P cycling, river floodplains (dry banks) were very similar to terrestrial uplands. Acacia spp. changes soil properties and affects plant functional attributes by i) enriching the system with N; ii) enhancing litter inputs; iii) altering soil physical properties; iv) changing the composition and reducing the cover of PFT; and v) enhancing P mineralization rates. Although measured soil physical and chemical properties and N and P mineralization rates were reduced to levels that were similar to or resembled the situation at natural areas, available inorganic N remained two times higher after more than seven years of clearance. Furthermore, cleared areas were characterized by sparse woody cover and a high cover of alien grasses. Correlations between soil silt and clay content and several soil properties measured in this and other studies indicates important linkages between soil texture and resource availability. Clearing Acacia spp. may initiate restoration of invaded riparian ecosystems, but changes in ecosystem function (e.g. elevated soil N availability) as a result of invasion may necessitate active restoration following the removal of the alien species. Active restoration under such conditions would be required to facilitate the restoration of cleared riparian communities. However, we still lack the mechanistic understanding around fynbos riparian recovery after clearing, as the success of restoration may depend on complex interaction and feedback cycles between plants and their physical environment. A greater comprehensive understanding of fynbos riparian ecological processes will not only improve the effectiveness of restoration initiatives by integrating science and management, but also advance the field of riparian ecology.
AFRIKAANSE OPSOMMING: Rivier oewerwal-areas, oorgang gebiede tussen aangrensende terrestriële gemeenskappe en akwatiese ekosisteme, is baie dinamiese en komplekse ekosisteme met intrinsieke ekologiese eienskappe wat verskil in struktuur, funksie (bv. biogeochemie siklusse) en temporale dinamika. Oewerhabitatte langs riviere van die Mediterreense suid-wes Kaap is sensitief vir omgewingsveranderinge en kwesbaar vir indringing deur uitheemse plante (bekend as “invasive alien plants” (IAPs)), veral stikstof-fiksering Acacia spp., en relatief min werk het nog gefokus op hoe ekosisteme in die streek reageer op sulke veranderinge in die omgewing. Die belangrike rol wat gesonde oewerwal plantegroei speel in die handhawing van ekosisteemdienste- en integriteit, is al hoe meer uitgelig soos ons die agteruitgang van hierdie habitat in ag neem. Terwyl die Werk vir Water (WvW)-program al dat baie suksesvol was in die uitwissing van IAPs in oewersones in die kort termyn, is die mate waarin oewer-ekostelsels herstel na skoonmaakaksies swak verstaan. Fynbos oewerwal-areas is grootliks ingeneem deur houtagtige IAPs, veral stikstof fiksering Acacia spp. (soos Acacia mearnsii). Die resultate wat in hierdie studie aangebied is, het verskillende aspekte van oewer- struktuur en funksie aangespreek en dien as middel vir toekomstige navorsing en bestuur van oewerwal ekosisteme deur by te dra tot die evaluering van die sukses van skoonmaak inisiatiewe en die herstelproses daarvan. Die doel van hierdie projek was om die moontlikhede vir herstel van fynbos owerwal-ekostelsels te evalueer deur middel van verskeie grond- fisiese en chemiese eienskappe; plant funksionele groep dekking (genoem ‘plant functional types’ (PFT)); en geselekteerde grond biogeochemie prosesse in natuurlike, Acacia- aangetaste, en skoongemaakte rivierstelsels en nabygeleë terrestriese areas te vergelyk. Veldwerk is gedoen in bergstroom en voetheuwel rivierseksies van ses standhoudende rivierstelsels in Suid-wes Kaap, Suid Afrika. Van uit hierdie geselekteerde rivierstelsels is elf studie areas van drie kategorieë (of indringing status) gekies: vier natuurlike areas (nie aangetas); vier gematig- tot hoogs aangetaste areas (hoofsaaklik A. meanrsii); en drie skoongemaakte areas (rivieroewers wat meer as sewe jaar van te vore skoongemaak is). Binne elke studie area was vier tot vyf soortgelyke persele gevestig by elke van drie breë geomorfologiese sones: naamlik nat-, droë en hoogliggende terrestriese fynbos. Seisoenale grondmonsters vir 'n tydperk van een jaar is geneem. Resultate van hierdie studie het getoon dat PFT dekking en samestelling, grond fisiese- en chemiese eienskappe en N-mineralisasie en suur fosfatase aktiwiteit verskil tussen indringing status, geomorfologiese sones en oor seisoene. Ten opsigte van meeste grond fisiese en chemiese eienskappe en indekse van stikstof (N) en fosfor (P) siklusse kom die rivier vogregimes (droë oewersones) baie ooreen met die terrestriële gebiede. Aan die anderkant is die natbanksones gekenmerk deur grondeienskappe wat baie verskil van die ander twee geomorfologiese gebiede. Die gegewens ondersteun die hipotese dat indringing deur Acacia spp. verskeie grondeienskappe verander en plante se funksionele kenmerke beïnvloed deur i) die sisteem met voedingstowwe te verryk (veral N); ii) verhoog die toevoeging van plantmateriaal; iii) verander grond fisiese eienskappe; iv) verander die samestelling en verminder die dekking van PFT; v) en verhoog P biogeochemie. Hoewel grond fisiese -en chemiese eienskappe, en indekse van N en P mineralisasie verminder is tot vlakke wat soortgelyk aan natuurlike areas, het beskikbare anorganiese N twee keer hoër gebly by skoongemaakte gebiede. Nietemin, voorheen skoongemaakte gebiede is weer-binnegeval deur eksotiese grasse en die regenerasie of hertelling van inheemse fynbos gemeenskappe is taamlik beperk, veral houtagtige oewer struike en bome. Korrelasies tussen grond slik-en klei-inhoud en verskeie grondeienskappe gemeet in hierdie en ander studies dui op belangrike skakeling tussen die grondtekstuur en voedingstof beskikbaarheid. Die opruiming van Acacia spp. mag as aansporing dien vir die herstellingsproses van rivieroewerstelsels, maar veranderinge in die funksie van ekosisteme (bv. verhoogte grond N beskikbaarheid), as gevolg van indringing, mag aktiewe herstel noodsaak nadat die indringer spesies verwyder is. Aktiewe herstel onder sulke omstandighede sal verwag word om die herstel van skoongemaak oewer gemeenskappe te fasiliteer. Ons het wel egter nog 'n gebrek aan die meganistiese begrip in verband met die herstel van fynbos oewerwal areas na opruimings-inisiatiewe, sedert die sukses van herstel kan afhang van komplekse interaksie en terugvoer siklusse tussen die plante en hul fisiese omgewing. ʼn Meer omvattende begrip van fynbos rivieroewer ekologiese prosesse sal nie net die doeltreffendheid van opruimings-inisiatiewe deur die integrasie van wetenskaplike navorsing en bestuur verbeter nie, maar ook vooraf die gebied van rivieroewer-ekologie.
Bruckner, Monica Zanzola. "Biogeochemistry and hydrology of three alpine proglacial environments resulting from glacier retreat." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/bruckner/BrucknerM1208.pdf.
Повний текст джерелаPedicino, Lisa Christine 1973. "Carbon isotopic variations in 7 southwestern United States plants from herbarium collections of the last 150 years." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/291639.
Повний текст джерелаKocha, Jahnavi. "A Spatial and Temporal Analysis of Uranium Concentrations at the Abandoned New Hope Method Mine in the Mojave Desert." Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/cmc_theses/2237.
Повний текст джерелаÖquist, Mats. "Northern peatland carbon biogeochemistry : the influence of vascular plants and edaphic factors on carbon dioxide and methane exchange /." Linköping : Univ, 2001. http://www.bibl.liu.se/liupubl/disp/disp2001/tek729s.pdf.
Повний текст джерелаKhatiwada, Raju. "Speciation of phosphorus in reduced tillage systems: placement and source effect." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/9973.
Повний текст джерелаDepartment of Agronomy
Ganga M. Hettiarachchi
Phosphorus (P) management in reduced tillage systems has been a great concern for farmers. Conclusive results for benefits of deep banding of P fertilizers for plant yield in reduced tillage system are still lacking. Knowledge of the dominant solid P species present in soil following application of P fertilizers and linking that to potential P availability would help us to design better P management practices. The objectives of this research were to understand the influence of placement (broadcast- vs. deep band-P or deep placed-P), fertilizer source (granular- versus liquid-P), and time on reaction products of P. Greenhouse and field based experiments were conducted to study P behavior in soils. Soil pH, resin extractable P, total P, and speciation of P were determined at different distances from the point of fertilizer application at 5 weeks (greenhouse and field) and 6 months (field) after P application (at rate 75 kg/ha) to a soil system that was under long-term reduced tillage. X-ray absorption near edge structure spectroscopy technique was used to speciate reaction products of fertilizer P in the soil. The reaction products of P formed upon addition of P fertilizers to soils were found to be influenced by soil pH, P placement methods, and P sources. Acidic pH (below~5.8) tended to favor formation of Fe-P and Al-P like forms whereas slightly acidic near neutral pH soils favored formation of Ca-P like forms. Scanning electron microscope with energy dispersive X-ray analysis of applied fertilizer granules at 5-wk showed enrichment of Al, Fe and Ca in granule- indicating these elements begin to react with applied P even before granules dissolve completely. The availability of an applied P fertilizer was found to be enhanced as a result of the deep banding as compared to the surface broadcasting or deep placed methods. Deep banded liquid MAP was found to be in more adsorbed P like forms and resulted greater resin extractable P both at 5 wk and 6 month after application. Deep banding of liquid MAP would most likely result both agronomically and environmentally efficient solution for no-till farmers.
Jackson, Leland J. (Leland Joseph). "Rooted aquatic macrophytes and the cycling of littoral zone metals." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39449.
Повний текст джерелаVetter, Alexandra [Verfasser], and Brian [Akademischer Betreuer] Horsfield. "The influence of geothermal plants on the biogeochemistry of the microbial ecosystems in aquifers / Alexandra Vetter. Betreuer: Brian Horsfield." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2012. http://d-nb.info/1028912900/34.
Повний текст джерелаPerlatti, Fabio. "Trace metals biogeochemistry in soils and plants affected by mining waste rocks: consequences to ecosystem and options for restoration." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14753.
Повний текст джерелаA extraÃÃo e beneficiamento de minerais metÃlicos geram grandes quantidades de rejeitos que se nÃo dispostos adequadamente, podem ser fontes de contaminaÃÃo e drenagem Ãcida; pelo contato de sulfetos com Ãgua e oxigÃnio; ocasionando diminuiÃÃo no pH e aumento na mobilidade dos metais no solo. O diagnÃstico do comportamento biogeoquÃmico de rejeitos pode fornecer informaÃÃes valiosas para que se possa dispor e controlar adequadamente os efeitos adversos causados por esse tipo de material, bem como subsidiar a adoÃÃo de medidas de controle e mitigaÃÃo mais eficientes. Esse estudo teve como objetivo geral, diagnosticar os impactos causados pela disposiÃÃo de rejeitos em uma mina de cobre (Cu) abandonada, bem como propor alternativas para mitigar os impactos e restaurar a qualidade ambiental do local, baseado na hipÃtese de que esses rejeitos podem contaminar o solo da regiÃo com os elementos traÃo presentes nos minerais, alÃm de gerar drenagem Ãcida, dada a presenÃa de sulfetos expostos Ãs condiÃÃes atmosfÃricas, impedindo a regeneraÃÃo natural do ecossistema. O capÃtulo 1 traz uma introduÃÃo ao tema, bem como uma revisÃo bibliogrÃfica sobre o assunto. O capÃtulo 2 faz um diagnÃstico geral da Ãrea, avaliando-se os teores de diversos elementos traÃo nos rejeitos, solos e plantas. No capÃtulo 3 foram aprofundados os estudos sobre o comportamento geoquÃmico dos rejeitos com foco na geraÃÃo de drenagem Ãcida, alÃm de um estudo detalhado do comportamento do Cu no solo, atravÃs da extraÃÃo sequencial. O capÃtulo 4 detalha os teores de metais nos tecidos vegetais das plantas, avalia a aptidÃo do uso dessas espÃcies para a fitoremediaÃÃo, bem como apresenta dados das alteraÃÃes que ocorrem na rizosfera. O capÃtulo 5 aprofunda-se nas alteraÃÃes que ocorrem na rizosfera das plantas e as consequÃncias na mobilidade e ecotoxicidade do Cu, via extraÃÃo sequencial, e por fim, o capÃtulo 6 apresenta um estudo experimental com a utilizaÃÃo de tecnosolos, para imobilizar o excesso de Cu lÃbil no solo. Os resultados indicam que o principal impacto à causado pelo excesso de Cu que ainda persiste nos rejeitos e que, por processos de oxidaÃÃo e dissoluÃÃo, translocam grandes quantidade do metal para o solo. A geraÃÃo de drenagem Ãcida foi descartada; dada a aÃÃo tamponante gerada pela dissoluÃÃo dos carbonatos, minimizando os efeitos negativos da oxidaÃÃo dos sulfetos. A extraÃÃo sequencial mostrou que o Cu no solo està associado principalmente aos carbonatos e Ãxidos de Fe amorfos. O ciclo geoquÃmico entre a dissoluÃÃo dos carbonatos e oxidaÃÃo dos sulfetos parece ser o principal mecanismo de liberaÃÃo e adsorÃÃo do Cu no solo. Jà as plantas estudadas, nÃo foram consideradas hiperacumuladoras, entretanto, foram observados elevados teores de metal em suas raÃzes, indicando que a estratÃgia de sobrevivÃncia dessas plantas consiste na imobilizaÃÃo do metal nas raÃzes/rizosfera. A extraÃÃo sequencial na rizosfera mostrou que a presenÃa das plantas altera as caracterÃsticas do solo sob sua influÃncia, e consequentemente o comportamento biogeoquÃmico do Cu. Jà os tecnosolos demostraram grande capacidade em imobilizar Cu. Os quatro tecnosolos elaborados imobilizaram mais de 85% do Cu, sendo a maior parte retida na fraÃÃo residual, que representa a fraÃÃo onde o cobre fica adsorvido mais fortemente, demostrando que os tecnosolos despontam como uma excelente alternativa na remediaÃÃo de solos contaminados por metais.
The extraction and processing of metallic minerals generate large amounts of waste which, if not disposed of properly, may be sources of contamination and acid mine drainage; by contact of sulphides with water and oxygen; causing a decrease in pH and an increase in the mobility of metals in the soil. The diagnosis of biogeochemical behaviour of wastes can provide valuable information to discard and control the adverse effects of this kind of material, as well to support the adoption of more efficient measures of control and mitigation. This study had as general objective diagnose the impacts of waste disposal in an abandoned copper mine (Cu), as well to propose alternatives to mitigate the impacts and restore the environmental quality of the site, based on the hypothesis that such wastes can contaminate the soil with trace elements contained in minerals, and generate acid mine drainage, given the presence of sulphides exposed to weather conditions, hindering the natural regeneration of the ecosystem. The Chapter 1 provides an introduction to the theme, as well as a literature review. Chapter 2 presents a general diagnosis from the area, assessing the levels of several trace elements in rock wastes, soils and native plant species. In chapter 3, a thorough study on the geochemical behaviour of wastes, with focus on the generation of acid drainage were done, plus a detailed study about Cu behaviour in soils, through a chemical sequential extraction. Chapter 4 details the content of metals in above-ground tissues from plants that naturally grow on the wastes, assess the ability of these plants to be used in phytoremediation and show data about the changes that occur in the rhizosphere. Chapter 5 provides through a comparative study by sequential extraction in the rhizosphere and bulk soils; details about the changes that occur in the rhizosphere of plants and their consequences for Cu mobility and ecotoxicity, and finally, the chapter 6 presents an experimental study with the use of technosols, as way to immobilize the excess of labile copper in soil solution. Based on the results, can be concluded that the major impact is caused by the excess of Cu which still persists in the waste rocks and, through oxidation and dissolution processes, translocate large amount of metal into soil. The acid mine drainage was discarded given the buffering action generated by dissolution of carbonates, minimizing the negative effects of the oxidation of sulphides. The sequential extraction showed that the Cu concentration in soil is associated mainly with carbonates and amorphous iron oxides. The geochemical cycle between the dissolution of carbonates and oxidation of sulphides appears to be the main control mechanism of release and adsorption of Cu in soil. Regarding the plants, was concluded that they cannot be considered as Cu hyperaccumulators, however, high levels of metal were observed in roots, indicating that the survival strategy of these plants consists in immobilize metal in roots/rhizosphere. The sequential extraction in the rhizosphere showed that the presence of plants alter various soil characteristics under its influence, and also the geochemical behaviour of Cu. The technosols showed great ability to immobilize Cu. The four technosols elaborated in this study can immobilize more than 85% of Cu in solution, with the largest portion retained in the residual fraction, where Cu is adsorbed strongly, demonstrating that technosols emerge as an excellent alternative to remediate soils contaminated by metals.
Biggs, Thomas Howard 1949. "Fire frequency, nutrient concentrations and distributions, and δ¹³C of soil organic matter and plants in a southeastern Arizona grassland". Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282517.
Повний текст джерелаLaubscher, Sydney. "MANGANESE UPTAKE IN RED MAPLE TREES IN RESPONSE TO MINERAL DISSOLUTION RATES IN SOIL." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1574431912056187.
Повний текст джерелаRoyer, Sarah-Jeanne. "Links Between Dimethylated Sulfur and Phytoplankton Photophysiology in the Surface Ocean Geographical Paterns and Short-Term Variability = Relación entre el Dimetilsulfuro y la Fotofsiología del Fitoplancton en la Superfcie del Océano. Patrones Geográfcos y Variabilidad a Corto Plazo." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/336378.
Повний текст джерелаEl dimetilsulfur (DMS) i el seu precursor algal dimetilsulfoniopropionat (DMSP) són part fonamental del cicle del sofre als oceans i l’atmosfera. El DMS és el compost volàtil de sofre més abundant a l’oceà superficial, que n’emet a l’atmosfera una quantitat aproximada de 28 Tg S l’any. Això representa la principal font natural de sofre a la troposfera, i aproximadament un terç de l’emissió global de sofre, incloent-hi l’antropogènica. El cicle del DMS ha estat objecte de centenars d’estudis en els darrers 27 anys, motivats sobretot per la hipòtesi CLAW que proposava que el DMS és la principal font de nuclis de condensació de núvols sobre els oceans i, d’aquesta manera, ajuda a regular la quantitat de radiació solar que arriba a la superfície de la Terra i, de retruc, el clima. Aquesta hipòtesi, avui vista com a simplista, no s’ha arribat a provar totalment, sobretot perquè la relació entre radiació solar i concentració i emissió de DMS és complexa i hi intervenen múltiples factors. Tant la concentració del DMS com la del DMSP (que referim conjuntament com a DMS(P)) varien força en l’oceà superficial com a resultat de processos que van de la biosíntesi del DMSP a la ventilació del DMS. Aquests processos, a la vegada, responen a factors i actors físics, químics i biològics, la importància relativa dels quals varia entre biomes i configuracions de l’ecosistema pelàgic. Com a conseqüència, predir la distribució del DMS a escala global demana un coneixement profund de tots els processos implicats, a totes les escales temporals i espacials. L’objectiu general de la tesi és contribuir a conèixer millor els factors físics, químics i biològics que governen el cicle dels DMS(P) en aigües polars, subtropicals i tropicals a escales temporals molt diverses. El treball combina una base de dades extensa de mesures de DMS obtingudes a baixa i alta freqüència, en regions diverses, a través de gradients ambientals, i d’escales de temps que van des dels minuts fins a les estacions de l’any. A més curt termini (minuts a hores), l’exposició a la llum UV sembla jugar un paper important en la resposta fisiològica del fitoplàncton i la subseqüent producció de DMS(P). La radiació solar també dicta el ritme de variació de la concentració de DMS en cicles dia-nit, en què el DMS es mostra sorprenentment acoblat amb els rellotges fotobiològics. Tanmateix, malgrat que la producció biològical bruta de DMS generalment augmenta amb l’exposició a la llum, la concentració depèn de l’efecte net d’aquesta producció amb les pèrdues per fotòlisi, consum microbià i ventilació. Al capdavall, no sembla que hom pugui definir un patró d’oscil·lació dia-nit únic per al DMS a l’oceà global. L’obtenció de dades en moltes províncies oceàniques tropicals i subtropicals va confirmar que la distribució del DMS s’explica millor amb factors abiòtics tals com la radiació solar, la barreja vertical, l’absorció de la llum per la matèria orgànica, i també per factors de fisiologia de fitoplàncton, com l’eficiència del fotosistema II, més que amb els indicadors d’abundància i activitat general del plàncton. El treball mostra també que les inferències que hom pugui fer sobre les causes de variabilitat de la concentració del DMS depenen força de la freqüència d’observació. En una campanya de circumnavegació, les mesures fetes a baixa freqüència mostraven, per a una província donada, una amplitud de variació d’un factor de 5. En la mateixa província, les mesures d’alta freqüència mostraven una amplitud d’un factor de 96, perquè capturaven la variabilitat de mesoescala i submesoescala. L’anàlisi estadística de les dades d’alta freqüència va mostrar que les distàncies de variabilitat crítiques per al DMS eren de 15 i 50 km per aigües més costaneres i més oceàniques, respectivament. Les distàncies d’heterogeneïtat en la distribució del DMS es fan més curtes amb la latitud i com més productives són les aigües. Això té implicacions importants en el disseny de treball de camp i en els esforços de ‘mapejat’ computacional. En conjunt, la tesi aporta llum a la complexitat de les interaccions que intervenen en el cicle del DMS, i ressalta la dificultat de trobar una relació simple que permeti predir la concentració i emissió del DMS en qualsevol punt de l’oceà global a partir de variables ambientals conegudes.
Frederick, Hannah E. "A GEOCHEMICAL EVALUATION OF WEATHERING PROCESSES AND METAL UPTAKE BY VEGETATION IN COAL MINE SPOIL." Kent State University Honors College / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1494443548705579.
Повний текст джерелаChaudhry, Tariq M. "Biogeochemical characterization of metalliferous wastes and potential role of arbuscular mycorrhizae in their phytoremediation /." Campbelltown, N.S.W. : University of Western Sydney, Macarthur, Faculty of Informatics, Science and Technology, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030811.122338/index.html.
Повний текст джерелаBottoms, Richard M. "Grass-knapweed interference involves allelopathic factors associated with ecosystem mineral cycling /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3036807.
Повний текст джерелаConley, Gary D. "Examining the Cover and Composition of the Successional Vegetation Mosaic of Pre-SMCRA Mined Landscapes in Southeast Ohio." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1357751096.
Повний текст джерелаReimer, Adam. "The role of bog plants in the exchange of carbon dioxide and water between the atmosphere and the Mer Bleue peatland /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33829.
Повний текст джерелаPowell, Christina Lynn. "Biodegradation of Groundwater Pollutants (Chlorinated Hydrocarbons) in Vegetated Wetlands: Role of Aerobic Microbes Naturally Associated with Roots of Common Plants." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1289918991.
Повний текст джерелаLardy-Fontan, Sophie. "Les substances émergentes dans les écosystèmes aquatiques français : une application aux alkylphénol-polyéthoxylés et aux substances pharmaceutiques." Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13702/document.
Повний текст джерелаAlkylphenol-polyethoxylates and pharmaceutical substances belong to the class of the emerging contaminants which have been recently studied in natural environments. These compounds of very widespread use (in terms of applications as well as in terms of quantity) are introduced into the aquatic environment, via the wastewater treatment plants, mainly, and are likely to generate toxic effects on the living organisms in these systems. The first part of this work consisted in the development and validation of various methodologies of sampling (grab sampling and integrative sampling (POCIS)), of various protocols of extraction (SPE, microwaves assisted extraction) and of analysis (LC/MS, LC/MS/MS), necessary for a reliable quantification of alkylphenol-polyethoxylates and pharmaceutical substances in the various compartments of aquatic systems (phases dissolved, particulate and sedimentary, biological organisms). Then, an assessment of the contamination of numerous aquatic systems (the catchment area of the Seine estuary, the Garonne and the Gironde, the bay of Vilaine, the bay of Authie, the Adour, the Mediterranean coast of Marseilles) was undertaken. A generalized contamination by these compounds was highlighted for all the studied sites. The measured concentrations appear to be extremely variable according to the class of molecule considered, the sites and time with concentrations ranging from the ng.l-1 to tens of µg.l-1 for the dissolved phases and from tens of ng.g-1 to tens of µg.g-1 for the solid phases (several hundreds of µg.g-1 in the clarification sludge). These studies also made it possible to document the presence and the fate of these molecules in the French wastewater treatment plant and made it possible to evaluate their effectiveness to remove the studied compounds. Lastly, this work also made it possible to highlight phenomena of partition between the dissolved phases and the solid phases as well as phenomena of transfers through the biological organisms
Harlay, Jérôme. "Biogeochemical study of coccolithophorid blooms in the context of climate change." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210352.
Повний текст джерелаThe first aspect of this work was to study the response of these organisms to artificially modified CO2 concentrations representative of the conditions occurring in the past (glacial) and those expected by the end of the century (2100). Two different levels were examined: the continuous monospecific cultures (chemostats) allowed us to work at the cellular level while the mesocosms gave light to the mechanisms taking place in an isolated fraction of the natural community. The second aspect of this work consisted of field studies carried out during four cruises (2002, 2003, 2004 and 2006) in the northern Bay of Biscay, where the occurrence of E. huxleyi blooms were observed in late spring and early summer. We describe the vertical profiles of biogeochemical variables (nutrients, chlorophyll-a, dissolved inorganic chemistry, particulate carbon, transparent exopolymer particles (TEP)) and study processes such as primary production, calcification and bacterial production. The properties of these blooms are compared with those reported in the literature and enriched with original measurements such as the abundance and concentration of TEP that could play an important role in carbon export to the deep ocean, modifying the properties of the settling ballasted aggregates.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Wang, Lixin. "Soil biogeochemistry, aridity and plant adaptation responses in southern Africa savannas." 2008. http://wwwlib.umi.com/dissertations/fullcit/3362902.
Повний текст джерелаKantola, Ilsa Beth. "Biogeochemistry of Woody Plant Invasion: Phosphorus Cycling and Microbial Community Composition." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11030.
Повний текст джерела"Denitrification in Accidental Urban Wetlands: Exploring the Roles of Water Flows and Plant Patches." Doctoral diss., 2016. http://hdl.handle.net/2286/R.I.40731.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Biology 2016
Prater, Margaret Rose. "Ecosystem consequences of post-fire invasive species in the Great Basin Desert /." 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3223695.
Повний текст джерелаSource: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3556. Adviser: Evan DeLucia. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.
Sutton-Grier, Ariana E. "The Role of Plant Functional Diversity and Soil Amendments in Regulating Plant Biomass and Soil Biogeochemistry in Restored Wetland Ecosystems in the North Carolina Piedmont." Diss., 2008. http://hdl.handle.net/10161/620.
Повний текст джерелаWillis, Cylette Raucene. "Intervarietal differences of methane emission related to plant parameters in irrigated rice cultivation." Thesis, 1995. http://hdl.handle.net/1911/16898.
Повний текст джерелаPrager, Case Mahone. "Plant diversity, physiology, and function in the face of global change." Thesis, 2017. https://doi.org/10.7916/D8K361M3.
Повний текст джерелаSorensen, Patrick. "Effects of winter snowpack on microbial activity, community composition, and plant-microbe interactions in mixed-hardwood temperate forests." Thesis, 2016. https://hdl.handle.net/2144/19576.
Повний текст джерелаDeMeester, Julie E. "FEEDBACKS of NITROGEN CYCLING and INVASION with the NON-NATIVE PLANT, MICROSTEGIUM VIMINEUM, in RIPARIAN WETLANDS." Diss., 2009. http://hdl.handle.net/10161/1129.
Повний текст джерелаInvasive species are rapidly expanding in riparian wetlands while concurrently anthropogenic causes are increasing nitrogen (N) into these ecosystems.
To learn how
Last, we disturbed a floodplain similar to wetland restoration disturbance and tracked available N. We also established a native community of plants with and without
Dissertation