Dissertations / Theses on the topic 'Soil plant interactions'
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Kraus, Tamara Esther Caroline. "Tannins and nutrient dynamics in forest soils : plant-litter-soil interactions /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
Full textSørensen, L. I. (Louise Ilum). "Grazing, disturbance and plant soil interactions in northern grasslands." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514291395.
Full textBonnett, Samuel A. F. "Biogeochemical implications of plant-soil interactions in peatland ecosystems." Thesis, Bangor University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428831.
Full textBergmann, Joana [Verfasser]. "Root traits and their effect in plant-soil interactions / Joana Bergmann." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1159900531/34.
Full textHänninen, Kaarina. "Tree-cover crop interactions : birch growth, competition and soil properties /." Oulu : Oulun Yliopisto, 2002. http://herkules.oulu.fi/isbn9514267184.
Full textCard, 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.
Full textMonteil, Oscar Vazquez. "Wastewater irrigation of crops : the influence of nitrogen on soil-plant interactions." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303449.
Full textMacpherson, Stuart Alexander. "Interactions between lead and phosphate : soil chemistry, plant uptake and ecological implications." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294125.
Full textAl-Turki, Ahmad I. "Myrosinase activity in soil and impact of Brassica on plant-microbe interactions /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486394475979013.
Full textNavarro, Patricia D. "Entomopathogenic Nematodes: Their Interactions with Plant Pathogens and Insecticides in the Soil." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265815.
Full textPrill, Nadine. "Effects of environmental change on plant performance and plant-herbivore interactions." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:c58761e9-666c-4b7d-a78a-d70de7f253d4.
Full textSteer, Jonathan. "Influences of plant growth and root material on soil microbial community dynamics." Thesis, University of East London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298081.
Full textBatten, Katharine Margaret. "Plant invasion and the soil microbial community : interactions and implications for native plant performance and ecosystem function /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Full textEmam, Taraneh Megan. "The Role of Soil Biota, Abiotic Stress, and Provenance in Plant Interactions and Restoration." Thesis, University of California, Davis, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3706585.
Full textIn this dissertation, I asked how soil biota, abiotic stress, and plant provenance influence plant communities and interactions between plants. Soil biota can have positive or negative effects on individual plants, and also influence the diversity and productivity of plant communities through their net effects on individuals and by mediating plant-plant interactions. However, the level of abiotic stress experienced by plants is likely to drive plant responses to soil mutualists and antagonists. Additionally, plant provenance (e.g. population origin) can influence responses to abiotic soil conditions as well as to soil organisms. Understanding how these three interacting components shape plant interactions may improve success of restoration and invasive plant management. During restoration, the goal is typically to create conditions conducive to native plant reestablishment. However, amelioration of disturbed areas by reducing abiotic stress or by adding beneficial soil organisms may unintentionally increase colonization and growth of non-native plants. Using the applied context of mine restoration, I examined how soil biota, abiotic stress, and plant provenance affected plant communities and interactions in four studies.
In Chapter 1, I found that both a native grass (Bouteloua gracilis ) and an invasive grass (Bromus tectorum) responded positively to soil biota when grown alone in the greenhouse. However, when grown together, the presence of soil biota increased the competitive ability of Bromus, while the removal of soil biota increased competition by Bouteloua. Results supported the hypothesis that invasive species such as Bromus often have positive responses to soil biota in the invaded range, but I also found that Bromus response to soil biota removal varied considerably by site.
In Chapters 2 and 3, I examined how methods used during restoration (application of stockpiled soil and inoculation with soil biota) affected native and non-native plant growth in field plots. I found that native plant biomass and non-native plant biomass both tended to increase when soil abiotic stress was ameliorated through the addition of deeper stockpiled soil. In addition, both native and non-native grasses responded positively to the use of local soil an as inoculant, while non-native forbs responded negatively to local soil inoculum. However, native plants only received significant benefits from inoculation when targeted application to native seedling transplants was used. Commercial mycorrhizal fungal inoculum did not affect plant growth. In studies of both stockpiled soil addition and soil inoculation, year was an important factor in determining plant responses. Variation in effects by year may reflect differences in precipitation timing or amount, or changes associated with plant and soil biota growth over time.
In Chapter 4, I used a greenhouse experiment to examine how one type of soil biota, arbuscular mycorrhizal fungi (AMF), influenced plant-plant interactions. I also manipulated abiotic stress (soil phosphorus availability) and plant provenance (stress-tolerant ecotype versus competitive ecotype) to assess whether these factors influenced AMF-mediated interactions among plants. I found that allowing or denying AMF hyphal access between neighboring pots altered plant reproduction. Inflorescence production was substantially decreased when hyphal access was allowed between two stress-tolerant plants. In addition, when hyphal access was permitted from a stress-tolerant plant to a competitive plant, the competitive plant flowered slightly sooner, whereas allowing hyphal access between two stress-tolerant plants led to slightly slower flowering. These results did not appear to be driven by abiotic stress or plant nutrition. It is possible that AMF transmission of infochemicals may play a role in regulating plant phenology and reproduction; however, further research in this area is needed.
Dehlin, Helena. "Ecosystem functioning and plant-soil interactions in forests : influences of quality and diversity of resources /." Umeå : Dept. of Forest Vegetation Ecology, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200679.pdf.
Full textRobinson, Lynne Allison. "Impacts of interactions with soil organisms on the metabolome of ragwort (Senecio jacobaea L.)." Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/44738/.
Full textAyres, Edward. "Impacts of rising atmospheric COâ‚‚ concentrations on plant-soil-microbial interactions in forest ecosystems." Thesis, Lancaster University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421605.
Full textCunha, Felisberta Maria Jesus. "The influence of extracts of Ascophvllum nodosum on plant and soil-borne pathogen interactions." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2348.
Full textDi, Palo Francesca. "Plant species and soil nutrient interactions along primary successions: the role of ecological stoichiometry." Thesis, Ulster University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.650087.
Full textShan, Shan. "The controls of nutrient limitation on resource allocation belowground." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1580078025127756.
Full textTurnbull, Gillian Anne. "The role of motility in Pseudomonas fluorescens and Pseudomonas putida in soil-plant-microbe interactions." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367105.
Full textFornara, Dario Arturo. "Ungulate browsing as an ecosystem process browser-plant-soil interactions in a southern African savanna /." Thesis, Connect to this title online, 2005. http://upetd.up.ac.za/thesis/available/etd-02172006-090829.
Full textMurray, Donna. "Interactions of Pseudomonas fluorescens and soil-borne oomycete plant pathogens in a biological control system." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259856.
Full textRichardson, Harriett Rose. "The role of plant-soil interactions in peatland carbon cycling at a Scottish wind farm." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5636/.
Full textMalyshev, Andrey [Verfasser], and Jürgen [Akademischer Betreuer] Kreyling. "Plant growth responses to winter climate change: from amongand within-species variation to plant-soil interactions / Andrey Malyshev. Betreuer: Jürgen Kreyling." Bayreuth : Universität Bayreuth, 2015. http://d-nb.info/1074461851/34.
Full textMiller, Phearen Kit. "Interactions Between Biochar and Compost in Organic Winter Wheat Production and Soil Quality Under Dryland Conditions." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7359.
Full textHammer, Erin L. "Effects of garlic mustard (Alliaria petiolata) on soil nutrient dynamics and microbial community function and structure." Connect to full text in OhioLINK ETD Center, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1241126072.
Full textTypescript. "Submitted as partial fulfillment of the requirements for The Master of Science Degree in Biology (Ecology-track)." "A thesis entitled"--at head of title. Bibliography: leaves 44-55.
Maisch, Markus [Verfasser]. "Rusty rice - unravelling rice plant and microbial interactions in the paddy soil iron cycle / Markus Maisch." Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1215568983/34.
Full textReynolds, Amanda Christine. "Geochemical Investigations of Mineral Weathering: Quantifying Weathering Intensity, Silicate versus Carbonate Contributions, and Soil-Plant Interactions." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194448.
Full textNessa, Ashrafun. "Soil nitrogen transformations and soil-plant interactions as influenced by biochar materials and prescribed burning in native forest ecosystems of southeast Queensland." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/414257.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text
Popp, Alexander, Niels Blaum, Stephanie Domptail, Nicole Herpel, Alexander Gröngröft, T. T. Hoffman, Norbert Jürgens, et al. "From satellite imagery to soil-plant interactions : integrating disciplines and scales in process based simulation models ; [Poster]." Universität Potsdam, 2006. http://www.uni-potsdam.de/imaf/events/ge_work0602.html.
Full textInterdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung
Workshop vom 9. - 10. Februar 2006.
Van, Zyl Albertus J. "Assessment of the possible interactions between soil and plant water status in a Vitis vinifera cv. Merlot vineyard." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96088.
Full textENGLISH ABSTRACT: Irrigation scheduling decisions are based either on the direct measurement of soil water status (SWS) or on physiological measurements like plant water status (PWS). Soil based measurements are quick and easily automated, but the plant response for a particular quantity of soil moisture varies as a complex function of evaporative demand. A plant-based approach measures the plant stress response directly, but is an integration of environmental effects as well. In contrary to soil-based methods, plant based measurements can indicate when to irrigate, but not the quantity. Pre-dawn leaf water potential (ΨPD) is determined mostly by the soil moisture level, and can serve as a measure of static water stress in plants and an index of bulk soil water availability or even as an estimate of soil water potential at the root surface. Therefore it should be possible to establish a link between SWS and PWS, but it is largely unknown how stable the link in a heterogeneous vineyard would be, and how the grapevine vegetative and reproductive response relates to this link. Plant water status plays a large role in determining vigour and yield of the plant. The levels of PWS are influenced by irrigation, but it was mostly affected by the season and vine location in the vineyard. More negative plant water potentials reduced vigour, but had a less pronounced effect on yield, while also reducing overall wine quality. Vigour variability in the vineyard was largely attributed to soil heterogeneity, which seemed to have a strong effect on SWS. SWS measurements were calibrated according to the observed variability, increasing the accuracy of measurements significantly. Soil water content values were used to establish a link between SWS and PWS. This link was determined over time using nine plots, consisting of rain-fed and irrigated regimes, in variable vigour areas. A non-linear relationship was found between ΨPD and percentage extraction of plant available water for rain-fed plots. When irrigation was applied, no correlation could be found. In this study, for Merlot in the Stellenbosch region, PWS differences affected vigour, and to a lesser extent yield, as well as wine quality. More negative plant water potentials reduced vigour more in high vigour areas than in lower vigour areas, which in turn led to unbalanced vegetative: reproductive ratios. This disturbed vine balance may have had a bigger impact on wine quality than PWS levels. Therefore a well-managed and balanced vine is able to withstand more stress, with less detrimental effects. This study also highlights the danger of limiting the assessment of soil and plant water status conditions to point measurements in vineyards with high levels of vigour variability.
AFRIKAANSE OPSOMMING: Besluite rakende die skedulering van besproeiing word gewoonlik gebaseer op die direkte meting van grondwaterstatus (GWS), of op fisiologiese metings soos byvoorbeeld plantwaterstatus (PWS). Grond gebaseerde metings is relatief vinnig en maklik om te outomatiseer, maar die plantrespons vir ʼn spesifieke grondwaterinhoud varieer as ʼn komplekse funksie van dampdruktekorte. ‘n Plantgebaseerde benadering meet die plantstresreaksie direk, maar is ʼn integrasie van omgewingstoestande. In teenstelling met grondgebaseerde metodes, kan plantgebaseerde metodes aandui wanneer om te besproei, maar nie die hoeveelhede wat besproei moet word nie. Voorsonsopkoms blaarwaterpotensiaal (ΨPD) word grootliks deur die grondwaterinhoud bepaal, en kan as ʼn maatstaf van statiese waterspanning in plante en as ʼn indeks van bulk grondwaterbeskikbaarheid dien, of selfs as ʼn benadering van die grondwaterpotensiaal by die worteloppervlak. Dit behoort dus moontlik te wees om ʼn verwantskap te bepaal tussen GWS en PWS, maar dit is grootliks onbekend hoe stabiel hierdie verwantskap sal wees in ʼn heterogene wingerd, asook hoe die wingerdstok se vegetatiewe en reproduktiewe reaksie die verwantskap kan beïnvloed. Plantwaterstatus speel ʼn groot rol in die bepaling van groeikrag en opbrengs in die wingerdstok. Die vlakke van plantwaterstatus word deur besproeiing beïnvloed, maar word skynbaar meesal deur die seisoen en wingerdstok se ligging in die wingerd bepaal. Meer negatiewe plantwaterpotensiaalvlakke het gelei tot laer groeikrag, maar het ʼn minder uitgesproke effek gehad op opbrengs, terwyl dit in die algemeen wynkwaliteit verswak het. Groeikrag variasie in die wingerd kon grootliks aan grond heterogeniteit toegeskryf word, wat skynbaar ʼn sterk invloed op grondwaterstatus gehad het. Grondwaterstatus metings is gekalibreer volgens die variasie wat waargeneem is, wat die akkuraatheid van metings beduidend verhoog het. Grondwaterinhoud waardes is gebruik om ʼn verwantskap aan te dui tussen SWS en PWS. Hierdie verwantskap is oor tyd bepaal vir nege persele, wat bestaan het uit droëland asook besproeide persele, in areas waarvan die groeikrag verskil het. ʼn Nie-liniêre verband is gevind tussen ΨPD en die persentasie onttrekking van plantbeskikbare water vir die droëland persele. Waar besproei was, kon geen verband gevind word nie. In hierdie studie, vir Merlot in die Stellenbosch area, het PWS vlakke groeikrag en tot ʼn mindere mate opbrengs en wynkwaliteit beïnvloed. Meer negatiewe plantwaterpotensiaal vlakke het groeikrag meer beïnvloed in hoër groeikrag areas as in die laer groeikrag areas, wat ook gelei het tot ongebalanseerde vegetatiewe:reproduktiewe verhoudings. Hierdie versteurde balans in die wingerdstokke kon dalk ʼn groter impak op wynkwaliteit gehad het as PWS vlakke. Daar moet dus gepoog word om goed bestuurde en gebalanseerde wingerdstokke te hê, sodat strestoestande beter weerstaan kan word met minder nadelige gevolge. Die studie beklemtoon ook die gevaar verbonde daaraan om die bepaling van grond- en plantwaterstatus te beperk tot puntmetings in wingerde met groot variasie in groeikrag.
Kervroëdan, Léa. "Plant traits and functional diversity effects on runoff and sediment retention : application to soil erosion control in temperate agricultural catchments." Thesis, Amiens, 2018. http://www.theses.fr/2018AMIE0031/document.
Full textPlant-soil processes are driven and influenced by plant functional traits in vegetation communities. Concentrated runoff and erosion constitute the main cause of soil degradation and can be managed by herbaceous vegetation creating hydraulic roughness that induces flow velocity reduction and sediment retention. Using plant trait-based approach, unlike taxonomical approach, allows to understand and characterise the direct effects of the vegetation on runoff and sediment retention. This research project aims to deepen the knowledge regarding the effects of (i) plant functional traits (chapter 1), (ii) traits' complementarity (chapter 2) and (iii) functional diversity (chapter 3) on concentrated runoff and sediment retention processes, in order to evaluate the efficiency and design of herbaceous hedges to reduce the impacts of soil erosion in loamy European agricultural catchments. The identification of the main efficient traits and traits' combinations towards hydraulic roughness increase (stem density, diameter, leaf area and density) highlighted negatively correlated traits, suggesting that a trade-off could be reached within a plant species assemblage through a complementarity effect of the traits. However, non-additive effects of plant species diversity and functional diversity were found, both driven by dominant traits in the community. The effects of traits and functional diversity on the hydraulic roughness and sediment retention constitute a new advance in the understanding of plant trait assemblage on runoff and soil erosion processes and a baseline for the design and modelling of herbaceous hedges for runoff and erosion control
Scott, Drew Austin. "ENVIRONMENTAL HETEROGENEITY EFFECTS ON DIVERSITY AND NITROUS OXIDE EMISSIONS FROM SOIL IN RESTORED PRAIRIE." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1683.
Full textHicks, Lettice Cricket. "Controls on carbon cycling in tropical soils from the Amazon to the Andes : the influence of climate, plant inputs, nutrients and soil organisms." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/23477.
Full textMoller, Leandra. "Soil yeasts, mycorrhizal fungi and biochar: their interactions and effect on wheat (Triticum aestivum L.) growth and nutrition." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20417.
Full textENGLISH ABSTRACT: In order to test the effect of different plant growth-promoting strategies on Triticum aestivum L. (wheat), we investigated the ability of biochar and a grain-associated soil yeast, to improve the growth of this crop. Our first goal was to study the effect of biochar amendments to sandy soil on the growth and nutrition of wheat in the presence of mycorrhizal fungi. This was accomplished by amending soil with 0%, 1%, 2.5%, 5% and 10% (w/w) biochar and cultivating wheat plants in these soil-biochar mixtures. After harvesting, plant growth and mycorrhizal colonization of roots were measured. In addition, we studied the nutritional physiology of these plants with regards to nitrogen (N), phosphorous (P) and potassium (K) concentrations, as well as the growth efficiencies and uptake rates of these nutrients. We found that wheat growth was improved by biochar amendments to soil, probably as a result of elevated K levels in the plant tissues supplied by the biochar amendments. The second goal of this study was to obtain a soil yeast from the rhizosphere of another monocot in the family Poaceae, i.e. Themeda triandra Forssk. (red grass), and then evaluate this isolate for its ability to improve wheat performance. Three different Cryptococcus species were isolated from the rhizosphere of wild grass, i.e. Cryptococcus zeae, Cryptococcus luteolus and Cryptococcus rajasthanensis. Since C. zeae was previously isolated from maize, an isolate representing this species was selected to be used in further experimentation. With the ultimate goal of testing the ability of this yeast to improve wheat growth, its effect on wheat germination was investigated and compared to that of two other soil yeasts, i.e. Cryptococcus podzolicus CAB 978 and Rhodotorula mucilaginosa CAB 826. These three yeasts were subsequently tested for their ability to improve wheat growth in pot cultures in a greenhouse. After one and two months of growth, the culturable yeasts present in the rhizosphere and bulk soil were enumerated. The effects of these yeasts were elucidated by measuring wheat growth in terms of dry weight, as well as root and shoot relative growth rates (RGR). Changes in wheat nutrition were evaluated by determining the concentrations, growth efficiencies and uptake rates for P, K, zinc (Zn) and iron (Fe). During this study, it was found that only C. zeae CAB 1119 and C. podzolicus CAB 978 were able to enhance seed germination. Similarly, it was shown that C. zeae CAB 1119 was able to improve wheat growth during the first and second month of cultivation, whereas C. podzolicus CAB 978 only improved growth during the first month, and R. mucilaginosa CAB 826 had no effect on growth. This improved growth could be attributed to C. zeae CAB 1119 improving the P, K, Zn and Fe growth efficiency of wheat, which positively influenced the root and shoot RGR, and subsequently wheat growth. Our final goal was to test whether C. zeae CAB 1119 could affect wheat growth and nutrition when cultivated in sandy soil, which contained natural microbial consortia and 10% (w/w) biochar. Plants treated with viable or autoclaved cells of C. zeae CAB 1119, were subsequently cultivated in soil only or soil amended with biochar. After one month, plants were harvested and growth was measured with regards to dry weight, root RGR and shoot RGR. In addition, the concentrations of P, K, Zn and Fe were analyzed for these plants, where after the growth efficiencies and uptake rates were calculated for these four nutrients. Results indicated that plants growing in soil amended with biochar, and treated with viable C. zeae CAB 1119, showed the best growth. The increased root and shoot RGR witnessed in these plants was probably due to increased concentrations of P and K in the plants. This study opens new avenues of research with regards to the bio-fertilizers of wheat.
AFRIKAANSE OPSOMMING: Die uiteindelike doel van die studie was om die effek van verskillende plantgroei bevorderende metodes op die groei van Triticum aestivum L. (koring) te ondersoek. Dus het ons die vermoë van houtskool en ‘n graan-geassosieerde grondgis getoets om die groei van dié plant te bevorder. Die eerste doel van die studie was om die effek van houtskool toedienings tot sanderige grond te evalueer. Dit is bewerkstellig deur 0%, 1%, 2.5%, 5% en 10% (w/w) van die houtskool by die sand toe te voeg en koring in die houtskool-sand mengsels te kweek. Na die verlangde groei tydperk is die koring geoes en die mikorrizale kolonisasie op en in die koring wortels bepaal. Gedurende hierdie studie is die effek van bogenoemde toedienings op die fisiologie van die plante ondersoek deur die konsentrasies, opname tempo’s, en groei ekonomie van die plante vir stikstof (N), fosfaat (P) en kalium (K) te bepaal. Ons het gevind dat die groei van koring deur die toediening van houtskool bevorder is en dit blyk dat dié effek weens die teenwoordigheid van hoë K vlakke in die plantweefsel is. Die tweede doel van ons studie was om ‘n gis vanuit die risosfeer van ‘n monokotiel wat aan die familie Poacea behoort, naamlik Themeda triandra Forssk. (rooigras) te isoleer. Die vermoë van die isolaat om die groei van koring te bevorder was daarna getoets. Drie verskillende Cryptococcus spesies was vanuit die risosfeer van rooigras geïsoleer, nl. Cryptococcus zeae, Cryptococcus luteolus en Cryptococcus rajasthanensis. Omdat C. zeae in ‘n vorige studie vanaf mielies geisoleer was, is ‘n isolaat van hierdie spesie gebruik in verdere eksperimente. Met die doel om te bepaal of dié gisspesie koringgroei kan bevorder, was die effek van C. zeae op die ontkieming van koring bestudeer en vergelyk met dié van twee ander grond giste, nl. Cryptococcus podzolicus CAB 978 en Rhodotorula mucilaginosa CAB 826. Hierdie drie giste is ook ondersoek om die groei van koring in ‘n glashuis te bevorder. Na een en twee maande se groei was die getalle van giste teenwoordig in die risosfeer en grond verder weg van die wortels bepaal. Die effek van dié giste op die groei van koring is bepaal in terme van droë gewig asook die relatiewe wortel en halm groei tempos. Veranderinge in die nutrient status van koring is ondersoek deur die konsentrasies, groei-ekonomie en tempo van opname vir P, K, sink (Zn) en yster (Fe) te bepaal. Ons het gedurende dié studie gevind dat C. zeae CAB 1119 en C. podzolicus CAB 978 die ontkieming van koring kon verbeter. Ons het ook gevind dat C. zeae CAB 1119 die groei van koring gedurende die eerste en tweede maand van groei kon bevorder, terwyl C. podzolicus CAB 978 dit net gedurende die eerste maand kon vermag en R. mucilaginosa CAB 826 geen effek gehad het nie. Die verbeterde groei kon aan C. zeae CAB 1119, wat die P, K, Zn en Fe groei effektiwiteit van die plante verbeter het, toegeskryf word. Die verbetering van groei effektiwiteit het ‘n positiewe invloed op die relatiewe groeisnelheid van die wortels en halms gehad, en dus op koringgroei. Die laaste doel van die studie was om te bepaal of C. zeae CAB 1119 die groei van koring kon bevorder wanneer die koring in sand wat natuurlike mikrobiese populasies bevat en met houtskool aangevul is, gekweek word. Plante is met lewensvatbare of nielewensvatbare selle van C. zeae CAB 1119 behandel en gekweek in sanderige grond, en/of grond waarby 10% (w/w) houtskool toegevoeg is. Die plante is na een maand geoes en die groei bepaal in terme van droë massa en die relatiewe wortel en halm groei tempos. Die konsentrasies van P, K, Zn en Fe in die plante, asook die fisiologie van die plante, nl. groei ekonomie en tempo van opname, met betrekking tot P, K, Zn en Fe is bepaal, Ons het gevind dat plante wat in die houtskool-grond mengsel gekweek is en met lewensvatbare selle van C. zeae CAB 1119 behandel is die beste groei getoon het. Die verbeterde relatiewe groei tempos van die wortels en halms was mees waarskynlik die gevolg van verhoogde P en K konsentrasies in die plante. Hierdie studie toon nuwe resultate in verband met die gebruik van biologiese alternatiewes tot kunsmis.
Barthelemy, Hélène. "Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-120191.
Full textEskelinen, A. (Anu). "Plant community dynamics in tundra: propagule availability, biotic and environmental control." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514293139.
Full textHeckenroth, Alma. "Evaluation des méthodes de phytostabilisation adaptées à la restauration écologique d'une friche industrielle incluse dans une zone protégée : cas de l’usine de l’Escalette dans la zone coeur du parc national des Calanques." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0001.
Full textOn the Escalette brownfield, included in the area of the Calanques National Park (Marseille, southeastern France), a research project combining restoration ecology and phytoremediation is carried out, in order to optimize the ecosystem functions which limit the transfers of metals and metalloids (MM) and to restore the functions of the contaminated soils. We developed an in situ characterization approach of the composition and structure of plant communities that grow on MM contaminated sites. This enabled the selection of native plants, tolerant to high concentrations of MM. In a second step, the response of two native perennial species to surface and depth heterogeneity of MM soil contamination was evaluated in-situ, regarding the soil-plant-microorganism interactions at the rhizosphere level. Finally, ecological restoration trials of native plant communities were carried out in a polluted hotspot, based on the ability of native plants to stabilize MM and the resilience dynamics of plant communities.The results indicated that a century of MM pollution pressure produced a significant correlation with plant community dynamics in terms of composition, diversity and structure. They showed that the tolerance of native plants involves symbiotic microorganism interactions. Preliminary results from ecological restoration trials confirmed the method for native plants species selection to recover a vegetation dynamic on highly polluted soils and the importance of creating favorable microsites in heterogeneous (semi-)arid environments. They contribute to the development of ecotechnologies for the restoration of contaminated soils in a Mediterranean context
Kumar, Amit [Verfasser], and Johanna [Akademischer Betreuer] Pausch. "Plant-microbial interactions in the rhizosphere : root mediated changes in microbial activity and soil organic matter turnover / Amit Kumar ; Betreuer: Johanna Pausch." Bayreuth : Universität Bayreuth, 2018. http://d-nb.info/1160301956/34.
Full textCondron, Leo M. "Chemical nature and plant availability of phosphorus present in soils under long-term fertilised irrigated pastures in Canterbury, New Zealand." Lincoln College, University of Canterbury, 1986. http://hdl.handle.net/10182/1875.
Full textSoti, Pushpa Gautam. "Influence of Soil Biogeochemical Properties on the Invasiveness of Old World Climbing Fern (Lygodium microphyllum)." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/960.
Full textXi, Nian-Xun. "Effects of patchy nitrogen inputs and soil nitrogen heterogeneity on grassland structure and function." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22542/document.
Full textGrasslands provide a variety of important ecological and economic services worldwide. Improved understanding of grassland structure and function is necessary for the development of sustainable management and maintaining the provision of multiple ecosystem services in a changing environment. However, predicting grassland structure and function is a challenge because grasslands are dynamic, heterogeneous systems. In grazed grasslands, large herbivore activities promote heterogeneity in soil nutrients via excretion, but the effects of patchy nutrient inputs and soil spatial heterogeneity on grassland structure and function remain unclear. This thesis addresses effects of spatial heterogeneity in soil nitrogen (N) for grassland ecosystem structure and function, with particular emphasis on community responses. A combination of experimental and modelling approaches are used to study impacts of a number of different patch attributes (N form, patch size, patch contrast), as well as possible interactions with rainfall regime and timing of N inputs. We find that patchy N inputs enhance within plot-plant production and biomass variability irrespective of N form, but do not modify whole-plot plant production in the short term. Nevertheless, patchy organic N promotes spatial and temporal asynchrony in plant-soil responses, with implications for longer-term grassland function. Unlike plant production, community structure responds significantly to patchy N inputs, with increased community dominance and a shift in the rank of subordinate species. Contrary to expectations, rainfall quantity does not modify heterogeneity effects on either plant production or community structure. Modelling work shows that heterogeneity effects on field-scale production vary depending on patch size and patch contrast. For a fixed total N input, field-scale grassland production responds positively to patch size, but decreases in high- versus low-patch contrast conditions. Patch size does not interact with patch contrast or timing of N inputs on grassland production. Overall, our results highlight the importance of N heterogeneity for plant and soil processes at different spatial scales, and demonstrate that heterogeneity effects vary depending on patch attributes. Biotic interactions (competition) appear to play a relatively greater role than abiotic factors (chronic rainfall changes) for heterogeneity effects. Impacts of N heterogeneity on plant and soil processes may have significant implications on plant-soil feedbacks involved with the regulation of biogeochemical cycling, and provide useful information for the development of efficient N management strategies
Wahbi, Sanâa. "Influence des cultures associées fève/blé sur le potentiel mycorhizien des sols et la structure de la microflore mycorhizosphérique : conséquences sur la productivité des agrosystèmes au Maroc." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS031.
Full textThe future of sustainable agriculture is based on an optimal management of the soil fertility and the soil physical and biological properties. The present study focused on identifying cultural practices that mimic some ecological processes (facilitation, complementarity, "plant-soil-feedback” effect) contributing to the maintenance of the soil fertility. These concepts have been empirically used in farming practices mixing plant species in cropping systems. One of the most commonly Mediterranean cropping system associates legumes to cereal in rotation or intercropping (i.e. Faba bean/ Durum wheat association). However, in order to optimize the impact of crop management on the productivity and stability of agro-ecosystems, the biological mechanisms involved must be clarified. The aim of this study is to improve our understanding of the mechanisms involved in the soil microflora plant interactions and especially the importance of mycorrhizal symbiosis in these biotic and abiotic processes. By conducting experiments in controlled and in situ conditions, our results show that intercropping stimulates the wheat growth and its mineral nutrition (N and P). We also showed that this cultural practice induces significant changes on the soil microbial functional diversity, on the fluorescent Pseudomonas functionalities, and also on the arbuscular mycorrhizal (AM) community structures. Furthermore, and in order to optimize the impact of the composition of the plant cover in intercropping, we have shown that increasing the diversity of legumes significantly improved the expected benefits on wheat growth and its mycorrhizal status. These results highlight the need to manage crop diversity in agroecosystems, in order to enhance the ecological services provided by legumes, and to consider the management of AM fungal communities in agro-ecological strategies as major component to maintain crop productivity
Jewell, Mark. "Diversité des arbres, interactions aériennes et souterraines et décomposition des feuilles mortes." Mémoire, Université de Sherbrooke, 2013. http://savoirs.usherbrooke.ca/handle/11143/75.
Full textGuigues, 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.
Full textThis 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
Abgrall, Corentin. "Réponse de la flore, de la faune du sol et de leur substrat à l'introduction d'espèces exotiques envahissantes végétales." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR056/document.
Full textInvasive alien plants are species introduced and naturalized outside of their native distribution range and which have the capacity to maintain and expand their population. Some of these species are considered to be ecosystem transformers by altering their structure, functioning as well as resident animal and plant communities. These induced alterations make some of these species undesirable through their ecological and economical impacts. The work presented in this thesis aimed at a better understanding of the impact of biological invasions by alien plants. The soil fauna, native vegetation and their substrate, as well as ecosystem functioning, were studied at different spatial scales. Two exotic alien species, invasive in Europe, were considered as biological models for this work: the black locust (Robinia pseudoacacia) and the Japanese knotweed (Reynoutria japonica). Firstly, a global meta-analysis demonstrated the positive impact that plant invasions can exert on the abundance of some groups within the soil fauna, notably primary consumers, within different types of habitats (open or closed). Then, a large-scale study on the black locust revealed the differences that can can occur in the response of forest ecosystems to invasions along a latitudinal gradient. Study sites along this gradient, distributed amog four distinct regions in western Europe, exhibit differences in climate and dominant native vegetation which can alter the impact of the black locust. A detailed study on black locust impact in Normandy demonstrated the impact of R. pseudoacacia on native plant and soil fauna communities, as well as some ecosystem functions, in comparison to two native tree species. Finally, a laboraty experiment demonstrated the impact that allelopathic compounds extracted from Japanese knotweed rhizomes can have on some organisms within the soil fauna. This study showed that some invasive alient plants can influence the soil fauna, and soil food webs, through their secondary metabolism. This thesis illustrates that simultaneous study of both aboveground and belowground ecosystem compartments at different spatial scales is of interest in the context of biological invasions
Juice, Stephanie. "The Environmental Microbiome In A Changing World: Microbial Processes And Biogeochemistry." ScholarWorks @ UVM, 2020. https://scholarworks.uvm.edu/graddis/1181.
Full textJewell, Mark. "Diversit?? des arbres, interactions a??riennes et souterraines et d??composition des feuilles mortes." Mémoire, Universit?? de Sherbrooke, 2013. http://savoirs.usherbrooke.ca/handle/11143/75.
Full textEgelkraut, Dagmar D. "Long-lasting ecological legacies of reindeer on tundra vegetation." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-142131.
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