Dissertations / Theses: 'Ecology of plant nutrition'

1

Mariot, E. J. "The nutritional ecology of Lupinus albus L. with special reference to phosphorus." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370288.

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Moorby, H. "Environmental conditions affecting acid-base changes around plant roots." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375279.

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Wan, Hon Chi Judy. "Interaction of earthworms and microorganisms on nutrient availability and crop growth." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/588.

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4

Knecht, Billberger Magnus F. "Plant growth - stoichiometry and competition : theory development in ecosystem ecology /." Uppsala : Dept. of Ecology and Environmental Research, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200624.pdf.

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Morris, Michael Roger. "The contribution of spawning pacific-salmon to nitrogen fertility and vegetation nutrition during riparian primary succession on an expansive floodplain of a large river." Diss., [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-09302008-151352/.

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Coyle, Kieran. "An investigation of the role of soil micro-organisms in phosphorus mobilisation : a report submitted to fulfil the requrements of the degree of Doctor of Philosophy." Title page, table of contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phc8814.pdf.

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Martinod, Kylie. "Importance of an invasive shrub, Lonicera maackii, in the diet of white-tailed deer: nutritional quality and browse rates." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1470059937.

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8

Kroehler, Carolyn J. "The role of acid phosphatases in the phosphorus nutrition of arctic tundra plants." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/80295.

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The acid phosphomonoesterase activity associated with two major rooting strategies in arctic tundra plants was examined: that of Eriophorum vagina tum, a dominant plant in tussock tundra ecosystems, with its predominantly non-mycorrhizal root system; and that of ectomycorrhizal roots. Eriophorum has phosphatase activity which is evenly distributed along its root surface, has a pH optimum at soil pH (3.5-4.0), and continues at substantial rates at 1 °C. Inorganic phosphorus inhibits activity only 7 to 19%. In addition, Eriophorum has phosphatase activity associated with all the "below-ground" components of its tussock growth form: dead roots, leaf sheaths, and soil. Plants with higher tissue phosphorus growing in soils with higher available phosphate in general had higher live and dead root, leaf sheath, and soil phosphatase activity in both natural and manipulated sites of higher plant productivity. Yearly and seasonal variation sometimes exceeded differences among treatments, suggesting that enzyme activity would not provide a reliable measure of plant or soil phosphorus levels. Experiments with radiolabeled inositol hexaphosphate showed that Eriophorum is able to hydrolyze and absorb inorganic phosphate from an organic phosphate source. A comparison of enzyme hydrolysis rates with inorganic phosphate assimilation rates indicates that organic phosphate hydrolysis may occur as rapidly as inorganic phosphate absorption. Inorganic phosphate released by root surface phosphatase activity could satisfy approximately 65% of the annual phosphate demand of Eriophorum. Phosphatases of two ectomycorrhizal fungi (Cenococcum geophilum and Entoloma sericeum) responded similarly to growth in axenic culture at 2 or 50 micromolar KH₂PO₄ or sodium inositol hexaphosphate: surface Vmax estimates were significantly greater for 2 micromolar- than for 50 micromolar-grown isolates. The presence of constitutive extracellular soluble phosphatase activity resulted in the appearance of inorganic phosphate in media initially supplied only with organic phosphate. The surface acid phosphatase activity of field-collected ectomycorrhizal roots of arctic Salix and Betula, however, did not respond in a consistent way to differences in soil characteristics. Activity differed more among "color types" or fungal types than among sites of different soil characteristics.
Ph. D.

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Ko, Wai-ping Ice, and 高惠冰. "The nutritional ecology of frugivorous birds in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31238683.

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Pienaar, Ryno Cuyler. "The feeding ecology of extralimital Nyala (Tragelaphus Angasii) in the Arid Mosaic thicket of the Southern Cape." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1021012.

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The nyala on Buffelsdrift Private Game Reserve were found to be mainly browsers and made little use of grass during the study period. Browse contributed 87.8 percent to the annual diet, while grass contributed 12.2 percent. Only six species formed > 5 percent of the annual diet. Of these six only three species formed > 10 percent. They are the shrubs Acacia karroo, Pappea capensis and Grewia robusta. These were followed by the shrub Portulacaria afra, the dwarf shrub Zygophyllum lichtensteinianum and the grass Cynodon dactylon all contributing between 5 - 10 percent. There were definite seasonal dietary shifts with preference to different plant species. The shift takes place between the wet seasons (winter and spring) and the dry season (summer). Herbaceous species such as Cynodon dactylon and Erharta calycina were favoured in the winter/wet season. Shrubs such as P. capensis, P. afra and dwarf shrubs such as Limeum aethiopicum and Z. lichtensteinianum were favoured during the spring/wet and summer/dry seasons. Nyala habitat use in BPGR differed significantly from expected use when taking the relative area of habitats into consideration. However nyala did not display signififcantly different habitat preferences between seasons. Male and female nyala displayed differences in foraging behaviour at the plant form, plant species and habitat scale. Males preferred a greater proportion of shrubs and females a greater proportion of dwarf shrubs. Males preferred the shrubs Pappea capensis and Portulacaria afra the most and females preferred the dwarf shrubs Limeum aethiopicum and Zygophyllum lichtensteinianum the most. Plant species site availability varied significantly between the sexes, indicating that males and females selected different feeding paths. The difference in their feeding strategy appears to be related to the selection of plants that best satisfy the nutrient requirements of each sex. These findings are in agreement with the results from earlier studies on nyala sexual dimorphism. At the habitat scale females selected more for open dwarf shrubland and males more for densely vegetated habitats. This appears to be as a result of males attempting to maximize their foraging opportunities by selecting areas that offer food in greater quantities. Nyala in BPGR appear to co-exist with kudu and eland through spatial resource partitioning. This is suggested to be due to the influence of body size-gut size relationships on forage selectivity.

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Pickens, Bradley A. "THE CONSEQUENCES OF A MANAGEMENT STRATEGY FOR THE ENDANGERED KARNER BLUE BUTTERFLY." Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1149173870.

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Sousa, Adervan Fernandes. "Mineralization of nutrients and plant growth in soils irrigated with wastewater from oil extraction." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16918.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
O grande volume de Ãgua utilizado na agricultura compromete a sua disponibilidade para o consumo humano. Diante desse problema, Ã necessÃrio avaliar a utilizaÃÃo de Ãguas residuais na produÃÃo agrÃcola, como uma opÃÃo para a conservaÃÃo dos recursos hÃdricos. Ãguas residuais oriundas de campos de petrÃleo podem ser uma boa opÃÃo para irrigaÃÃo, especialmente em regiÃes de pouca e alta variabilidade de chuvas como o Nordeste brasileiro. No entanto, Ã necessÃrio avaliar os seus efeitos no solo, como acÃmulo de nutrientes e decomposiÃÃo da matÃria orgÃnica, bem como no aspecto nutricional e no crescimento das plantas. Os objetivos deste trabalho foram: i) Avaliar as mudanÃas ocorridas nos sais solÃveis e nas fraÃÃes da matÃria orgÃnica do solo e no crescimento de plantas de girassol (Helianthus annuus L.) cv. BRS 321, cultivadas em solo de textura arenosa irrigado com Ãgua residual oriunda da extraÃÃo de petrÃleo tratada por filtragem e osmose reversa; ii) Avaliar as alteraÃÃes nutricionais do girassol (Helianthus annuus) BRS 321 irrigado com Ãgua residual da extraÃÃo de petrÃleo e os efeitos sobre a produÃÃo de biomassa e de aquÃnios; e iii) Avaliar a decomposiÃÃo dos restos culturais de girassol (Helianthus annuus) cv. BRS 321 em Ãreas irrigadas com Ãgua residual da extraÃÃo de petrÃleo. O girassol foi cultivado durante trÃs perÃodos sucessivos em Ãreas irrigadas com Ãgua residual da extraÃÃo de petrÃleo tratada por filtragem (APF) e por osmose reversa (APO) ou Ãgua subterrÃnea do aquÃfero AÃu (ACA). Ao fim de cada ciclo foram determinados os valores de pH, condutividade elÃtrica (CE), a razÃo de adsorÃÃo de sÃdio (RAS) e os teores de Na, Cl, Mg, Ca, K, HCO3-, Ag, As, B, Ba, Cd, Co, Cr3+, Hg, Ni, Pb, Zn, alÃm de C nas fraÃÃes hÃmicas. Em raÃzes, parte aÃrea e aquÃnios determinaram-se os teores de N, P, K, Ca, Mg, S e Na e avaliaram-se o crescimento e o acÃmulo de biomassa. AlÃm disso, avaliou-se a decomposiÃÃo dos resÃduos da parte aÃrea das plantas de girassol. Houve alteraÃÃes nos atributos quÃmicos do solo, em destaque o acrÃscimo de sais, que foi maior nas Ãreas irrigadas com APF, e elevaÃÃo do pH, independente do tipo de Ãgua utilizado. A elevaÃÃo da salinidade e alcalinidade do solo reduziu o crescimento e o acÃmulo de biomassa das plantas. AlÃm disso, a irrigaÃÃo proporcionou alteraÃÃes nutricionais das plantas, que refletiram no crescimento e na produÃÃo de aquÃnios do girassol e na decomposiÃÃo dos resÃduos da cultura, com efeitos positivos ou negativos, conforme o tratamento da Ãgua residual. Concluiu-se que a Ãgua residual da extraÃÃo de petrÃleo utilizada na irrigaÃÃo afeta os atributos quÃmicos do solo, bem como a composiÃÃo nutricional e o desenvolvimento das plantas, principalmente quando irrigadas com a APF. AlÃm disso, a irrigaÃÃo com Ãgua residual alterou a mineralizaÃÃo dos resÃduos vegetais do girassol, mas nÃo a de decomposiÃÃo do carbono orgÃnico nas fraÃÃes hÃmicas.
The large volume of water used in agriculture compromises its availability for human consumption. Faced with this problem, it is necessary to evaluate the use of wastewater in agricultural production as an option for the conservation of water resources. Wastewater from oil fields can be a good choice for irrigation, especially in regions of low or high rainfall variability, as in the Brazilian Northeast. However, it is necessary to evaluate its effects on the soil, such as the accumulation of nutrients and decomposition of organic matter, as well as the nutritional aspect and plant growth. The aims of this study were: i) to assess the changes that take place in the soluble salts and soil organic matter fractions, and in the growth of plants of the BRS 321 cultivar of the sunflower (Helianthus annuus L.) cultivated in soil of a sandy texture and irrigated with wastewater obtained from oil extraction and treated by filtration and reverse osmosis; ii) to assess the nutritional changes in the BRS 321cultivar of the sunflower (Helianthus annuus) irrigated with wastewater from oil extraction, and the effects on biomass and achene production; and iii) to evaluate the decomposition of plant residue from the BRS 321 cultivar of the sunflower (Helianthus annuus) in areas irrigated with wastewater from oil extraction. The sunflower was grown for three successive periods in areas irrigated with wastewater from oil extraction treated by filtering (APF) and reverse osmosis (APO), or with groundwater from the AÃu aquifer (ACA). At the end of each cycle, pH values were determined, together with electrical conductivity (EC), the sodium adsorption ratio (SAR) and the levels of Na, Cl, Mg, Ca, K, HCO3-, Ag, As, B, Ba, Cd, Co, Cr3+, Hg, Ni, Pb, Zn, and of C in the humic fractions. The concentrations of N, P, K, Ca, Mg, S and Na were determined in the roots, shoots and achenes, along with growth and the accumulation of biomass. In addition, the decomposition of shoot residue from the sunflower plants was evaluated. Changes were seen in the chemical properties of the soil, highlighting an increase in salts, which was greater in the areas irrigated with APF; a rise was also seen in pH irrespective of the type of water used. The rise in soil salinity and alkalinity reduced the growth and accumulation of plant biomass. Moreover, irrigation resulted in nutritional changes in the plants, which were reflected in the growth and production of achenes, and in the decomposition of the plant residue, having positive or negative effects according to the treatment of the wastewater. It was concluded that wastewater from oil extraction used in irrigation affects the chemical properties of the soil as well as the nutritional composition and development of the plants, especially when irrigated with APF. Furthermore, irrigation with wastewater changed the mineralisation of the sunflower plant residue, but not the decomposition of the organic carbon in the humic fractions.

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Ko, Wai-ping Ice. "The nutritional ecology of frugivorous birds in Hong Kong /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20667747.

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Brooker, Robin William. "Plant-plant and plant-environment interactions in the Arctic." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301266.

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Yates, Megan. "Dung beetles eat plants : insights into the nutritional world of Euoniticellus intermedius (Reiche) (Coleoptera: Scarabaeinae)." Bachelor's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/25597.

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Dung beetle eggs develop within the finite nutritional environment of the brood ball, which is made using maternally processed animal faeces. It is thought that microbial and gut-derived excretions constitute the major source of N and C for adult dung beetles, while developing larvae, which have retained the mouthparts of their saprophagous ancestors, digest larger particles in the brood ball and rely on symbionts present in the brood ball to provide breakdown products for their nutrition. Stable isotope analysis was used to trace the source of developing larval N and C. Nitrogen and carbon contents, as well as C: N ratios, were used to assess the nutritional quality of this finite food source and to track the changes in these values during the course of development. The main source of both larval and adult N and C was plant-derived and preferential assimilation of gut-derived excretions present in the dung did not occur. Symbionts, including fungi, did not appear to play a significant role in larval nutrition. Extensive amino acid recycling occurs during metamorphosis, indicated by the 0.53 %0 enrichment in 815N in emergent beetles. Maternal processing of bulk dung creates an enhanced nutritional environment for offspring and the maternal faecal deposit, on which the egg is positioned, provides the larvae with an initial, nutrient-rich source of food.

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Lopez, Ashley Karisa. "Power Plant, Plant-Based Nutrition Services| A Business Plan." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10639050.

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Today, obesity has become the number one concern of kids and teens. About one in three Americans are overweight or obese. This in part is due to the consumption of highly commercialized and processed foods that lack the essential nutrients in maintaining a healthy weight in addition to normal cholesterol and blood pressure levels. Studies have shown that eating habits are learned early in life and are carried on throughout the rest of their lives. As children grow older into their adolescent years, they are more aware of their eating habits and have gained more autonomy in regards to food choices.

Plant-based foods have shown to drastically improve the overall health of individuals with high cholesterol, high blood pressure, and excess weight.

Power Plant is a facility that intends offer plant-based nutritional services in the form of informative lectures, interactive workshops, one-on-one nutritional guidance by appointment, with access to peer-mentors for additional support and guidance. Power Plant will dedicate their services to the Whittier Union high school district, surrounding community colleges, and universities in the Los Angeles County area.

Power Plant’s unique program design, physician referrals and the critical need of our generations to come, are all factors that will contribute to its success in the Los Angeles County community and for years to come.

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Hendry, Ruth Juliet. "Spatial modelling in plant ecology." Thesis, University of Warwick, 1995. http://wrap.warwick.ac.uk/1126/.

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In this thesis a range of lattice based spatially explicit models of ecosystems are presented and their applicability to various ecological situations is demonstrated with emphasis on plant communities These mechanistic and individual based models which include coupled map lattices and cellular automata aim to produce ecological insights and testable results Models of both short and long term systems are developed with the former being potentially testable in the eld and the latter promoting understanding where experimentation is not feasible A range of graphical and numerical techniques were developed to investigate both plant and animal model ecosystems The starting point is a short term single species coupled map lattice which investigates popula tion structure arising from local competitive interactions The model concludes that increase of size variation with increasing density indicates the presence of competitive intraspecic asymme try This idea is applied to crop data where considerable asymmetry is identied emphasising the need for balancing crop yield and size consistency Multispecies extensions to this model focus on spatial patterning arising from biotic interac tions and various numerical techniques underline the asymmetrical relationship between long and short lived species Environmental heterogeneity is imposed on the plant species in a third version of the model via the incorporation of an explicit resource base The complex inter dependence of community and environment is highlighted and illustrated by a model of the evolution of seed sizes Through the application of cellular automata to forest and epidemiological systems the concept of memory such as age or stage structuring is shown to be vital in the generation of spatial structure in long term ecological systems Analytical investigations generate further insights and again emphasise the crucial role played by spatial extensiveness in the wide range of ecological situations considered here In conclusion lattice models are ideally suited to the study of ecosystems

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Damgaard, Christian. "Evolutionary ecology of plant-plant interactions : an empirical modelling approach /." Aarhus University Press, 2004. http://www.elib.se/library/ebook_detail.asp?id_type=ISBN&lib=DK&id=8779348750.

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Marazzi, Cristina. "Plant sulphur nutrition influencing host-plant selection and performance of insect herbivores /." Basel : [s.n.], 2003. http://edoc.unibas.ch/diss/DissB_7004.

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Mbatha, Khanyisile R. "Using nutritional quality of forage and faeces for predicting sustainable livestock and game stocking rates at Pniel Estates in Northern Cape, South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1347.

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Thesis (PhD)--University of Stellenbosch, 2010.
The aim of the study was to assess the importance of spatial and temporal variation in diet quality and abundance for determining sustainable stocking rates on commercial, communal and game ranches in a semi-arid savanna, with the ultimate goal of avoiding land degradation in the long term, to provide sustainable livelihoods in rangelands and to make policy that will help in managing the available natural resources in the rangelands. Thus, firstly the effects of grazing, fire, nitrogen and water availability on nutritional quality of grass in semi-arid savanna was assessed. Secondly, spatial and temporal variation in plant quantity and quality among management (commercial, communal and game) types and habitat types (open savanna, rocky, shrubby and pans) and stocking rates in different management types were determined. Thirdly, the quality and quantity of variation inside and outside herbivore exclosures among commercial, communal and game management and habitat types in the semi arid savanna were estimated. Fourthly, faecal profiling was used to assess the effects of different management types on diet quality in semi-arid savanna. Lastly, policy based on the results of the present study was formulated.

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Miller, Gabriel A. "Immunity, nutrition and phenotype in locust ecology." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497052.

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Swedo, Barbara L. "Plant-microbe associations controls on soil bacterial community structure and consequences for aboveground plant communities /." [Bloomington, Ind.] : Indiana University, 2008. 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:3337259.

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Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2008.
Title from PDF t.p. (viewed on Jul 28, 2009). Source: Dissertation Abstracts International, Volume: 69-12, Section: B, page: 7260. Adviser: Heather L. Reynolds.

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Body, Mélanie. "Manipulations des végétaux par les organismes endophytes : mécanismes physiologiques, signalisation et conséquences nutritionnelles chez un insecte mineur de feuilles." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4054.

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Les insectes endophytophages, tels que les insectes foreurs de tiges, les galligènes et les mineurs de feuilles, vivent et se nourrissent à l’intérieur des végétaux. L'hypothèse de l'alimentation sélective stipule que ces organismes endophytes possèdent un avantage adaptatif par rapport aux ectophages en accédant aux tissus les plus nutritifs tout en évitant les principaux composés défensifs de la plante. Ce comportement d’alimentation sélective peut être également renforcé par une manipulation de la physiologie de la plante comme cela a été démontré chez les insectes galligènes mais également suggéré chez certains insectes mineurs. Ces derniers sont en effet capables d’induire un phénotype « îles vertes » qui se manifestent par la persistance de la photosynthèse au niveau de la zone minée à l'automne alors que le reste de la feuille entre en sénescence et jaunit. L’objectif de notre étude a été d’étudier, en conditions de terrain, les capacités de manipulation du végétal dans le système Malus domestica / Phyllonorycter blancardella. Cet insecte hautement spécialisé complète l’ensemble de son développement dans une zone restreinte d’une seule feuille
Endophytophagous insects, such as stem-boring, gall-forming and leaf-mining insects, live within plant tissues and feed internally. The selective feeding hypothesis states that this life-style presumably provides adaptive advantages for the insect over other external-feeding modes by allowing access to most nutritional tissues while avoiding main plant defensive compounds. This selective feeding behavior can be reinforced by manipulating the plant physiology which has been clearly demonstrated in gallers but also suggested in leaf-miner insects due to the autumnal formation of “green islands” around mining caterpillars in yellow leaves. This study aimed to investigate, under field conditions, the ability of insects to manipulate their host-plant in the Malus domestica / Phyllonorycter blancardella biological system. This insect is highly specialized and entirely develops within a restricted area of a single leaf. We first characterized the plant-insect interface by describing larval mouthparts and leaf anatomy alterations resulting from the insect feeding activity

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Brandt, Erika. "Relating Plant Spatial Pattern, Plant Biodiversity, and Ecosystem Function to Management Practices in Experimental Restored Wetlands." Oberlin College Honors Theses / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1368092195.

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Colasanti, Ricardo Luigi. "Individual-based vegetation models in plant ecology." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327610.

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Vonlanthen, Corinne Maria. "Alpine plant communities : ecology and species richness /." [S.l.] : [s.n.], 2005. http://www.zb.unibe.ch/download/eldiss/05vonlanthen_c.pdf.

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Hodkinson, Dunmail John. "Plant dispersal : vectors and tradeoffs." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389924.

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Forup, Mikael Lytzau. "The restoration of plant pollinator interactions." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/f77be7e4-2baa-4d8e-8ffb-e261541923c5.

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Mason, Rosemary. "Analytical study of plant/environment interactions in thimbleberry and devil's club." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29535.

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The morphology, phenology and stem demography of devil's club and thimbleberry were examined to elucidate their niche utilization strategies. The study was conducted in the Kitimat River valley in west central B.C. during the 1986 and 1987 growing seasons. Thimbleberry was sampled in a girdled alder site and a nongirdled alder site, whereas devil's club was sampled in an old growth forest. The variation in the plant characters, as summarized by principal components axes, was apportioned within and among clones, between sites, years, and species. Except for the thimbleberry vegetative phenology, within-sites differences accounted for most variation and variation between-sites often exceeded that between years. Moreover, between-species differences accounted for less variation than within-species differences for morphology and phenology. The variation in plant characters was also examined in relation to canopy cover, soils and adjacent vegetation using multivariate methods. The rate of vegetative development for devil's club in 1986 increased as canopy cover decreased; other environmental measures were uncorrelated with devil's club. Both vegetative and reproductive rates of development increased with disturbance due to girdling and increasing moisture for the combined girdled and ungirdled thimbleberry data set. Similarly, morphdodcal size was greater for the combined thimbleberry data set with increasing moisture and dsturbance. Environmental correlations were reflected differently within-sites, however, with rates of development, plant size and the number of flowers decreasing with increasing moisture at the nongirdled thimbleberry site. The relationship between plant characters was also assessed. Phenology and morphology were correlated for both devil's dub and thimbleberry; stem development began earlier and was more rapid with increasing stem size. Demography and phenology were unrelated. Both species displayed different niche utilization strategies; thimbleberry being more flexible than devil's club. In contrast to devil's dub, thimbleberry is morphologically a phenologically responsive to disturbance and is mizomatous rather man stoloniterous. Stems and lateral branches also had several phonological and developmental possibilities. This flexibility imparted an advantage to thimbleberry in the fluctuating conditions of its earlier successional niche. The differing correlation structure between and within thimbleberry sites suggests that several scales of observation are necessary to clarify plant-environment relationships. Moreover, as environmental characters interact differently with plants from site to site, management must be site specific. Alder girdling may be a judicious management technique at drier sites, where thimbleberry is not as prolific under an open canopy.
Science, Faculty of
Botany, Department of
Graduate

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Swanepoel, Barbara Anna. "The vegetation ecology of Ezemvelo Nature Reserve, Bronkhorstspruit, South Africa." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-09142007-143511.

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31

Ng, Sai-chit. "Hong Kong's rhododendrons : ecology, population genetics and conservation /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21482743.

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CaraDonna, Paul James, and Paul James CaraDonna. "Temporal Ecology of a Subalpine Ecosystem: Plant Communities, Plant-Pollinator Interactions, and Climate Change." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/620860.

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Ecological systems are inherently dynamic, and a primary way in which they are dynamic is through time. Individual organisms, populations, communities, species interactions, and ecosystem functions all follow a temporal progression from the past, to the present, and into the future. This temporal progression can occur over the course of minutes, hours, days, weeks, months, years, decades, or various other timescales. In this sense, temporal dynamics are an intrinsic property of all biological systems. In fact, one of the most prominent signals of recent global climate change is the significant change in the timing of biological events for a diversity of organisms. In light of this widespread pattern, there is a renewed interest in understanding the multifaceted importance of time in ecology. In this dissertation, I investigate the temporal ecology of a subalpine ecosystem, specifically focusing on flowering plant communities and plant-pollinator interactions. I examine the temporal dynamics of this system over multiple decades in response to ongoing climate change as well as over shorter time scales within a growing season. Using a 39-year record of flowering phenology, I show that species-specific shifts in the timing of flowering in response to climate change can substantially reshape a subalpine plant community over this time period. Community phylogenetic analyses reveal that these changes are largely independent of evolutionary history. Using a laboratory experiment, I show that the timing of an important harsh abiotic event-low temperatures that cause frost damage to plants-can differentially affect flowering plant species, with implications for plant demography, community structure, and interactions with pollinators. Finally, I show that plant-pollinator interactions exhibit substantial within-season temporal turnover, and that this temporal flexibility of plant-pollinator interactions from one week to the next is consistent and predictable across years. Taken together, this dissertation provides a multifaceted investigation of the temporal ecology of plant communities and plant-pollinator interactions, revealing the important consequences of ecological timing at short-term and longer-term scales.

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Koslow, Jennifer Marie. "Mixed mating systems, pathogens, and plant community ecology." [Bloomington, Ind.] : Indiana University, 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:3232578.

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Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2006.
"Title from dissertation home page (viewed July 11, 2007)." Source: Dissertation Abstracts International, Volume: 67-08, Section: B, page: 4208. Advier: Keith Clay.

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Buckley, Yvonne Maria. "Ecology, evolution and manipulation of invasive plant populations." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271748.

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Irvine, Michael Alastair. "Pattern formation and persistence in spatial plant ecology." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/67166/.

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The main aim of the thesis is to explore the interaction between pattern and process in vegetation ecology using a variety of mathematical and statistical methods. Of particular interest is what information about the dynamics of the underlying system can be gained through a single spatial snapshot, such as an aerial photograph or satellite image. The hypotheses are related to seagrass ecology, whose growth is primarily clonal and broadly exists as a monoculture and thus makes it an ideal candidate to study these interactions. The thesis broadly concerns two forms of spatial pattern and the underlying dynamics that give rise to them. The first concerns regular pattern formation, where the pattern has a characteristic length scale. Examples are abundant in natural systems, such as mussel beds, semi-arid ecosystems as well as seagrass. The developments concerned with regular pattern formation include methods of detection in a large spatial dataset, a novel stochastic model of vegetation that produces regular pattern with plausible mechanisms, the development of a new methodology to fit regular spatial pattern data to the model and the impact as well as evolutionary mechanisms of regular patterning in the presence of disease. The second form of spatial pattern exhibited in a wide variety of sessile species is scale-free or fractal patterning. Certain scaling heuristics, such as the boundary dimension of a vegetation cluster or the power-law exponent of the patch-size distribution have been used to infer properties of the dynamics. We explore these heuristics using a variety of plausible models of vegetation growth and find the circumstances under which there is a clear relationship between the spatial heuristics and the dynamics. These are then supplemented by viewing vegetation growth as an aggregation process. A novel model of vegetation aggregation with death is produced to find the origin of the ubiquitous power-law patch-size distribution found in nature. Finally the impact of scaling on the spread of disease is explored.

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Allan, Caroline Elizabeth. "Nitrogen fixation in riverine wetland plant communities." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297033.

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Purves, Drew William. "Local spatial structure and plant population dynamics." Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251813.

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Lees, Robert. "Photosynthesis and nutrition in in vitro plants." Thesis, University of Central Lancashire, 1993. http://clok.uclan.ac.uk/20823/.

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The successful micropropagation of woody or herbaceous perennial plants is often limited by large losses which occur as plants are transferred from culture to soil. Poor photosynthetic capability may be partly responsible for losses at this stage. Results show that growth irradiance, CO 2 and carbohydrate in the growth medium are all factors which combine to affect the development of photosynthetic capability in vitro. Low capacity for the photochemical dissipation of excess light energy is primarily a result of endproduct inhibition of photosynthesis by accumulated leaf carbohydrate, and results in plants being extremely sensitive to photoinhibition. Manipulation of carbohydrate in the growth medium and growth irradiance may result in increased photosynthetic capability of plants transferred to soil, and can increase survival. This appears to be a result of increased energy supply for growth during the first few days ex vitro. Manipulation of carbohydrate in the growth medium and growth irradiance also affect growth morphology. In particular, root production in woody material can be affected, and can have a significant effect on nursery survival.

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Parker, John D. "Plant-herbivore interactions : consequences for the structure of freshwater communities and exotic plant invasions." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/9460.

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Invasive exotic species threaten native biodiversity, alter ecosystem structure and function, and annually cost over $100 billion in the US alone. Determining the ecological traits and interactions that affect invasion success are thus critical for predicting, preventing, and mitigating the negative effects of biological invasions. Native herbivores are widely assumed to facilitate exotic plant invasions by preferentially consuming native plants and avoiding exotic plants. Here, I use freshwater plant communities scattered broadly across the Southeastern U.S. to show that herbivory is an important force driving the ecology and evolution of freshwater systems. However, native consumers often preferentially consume rather than avoid exotic over native plants. Analyses of 3 terrestrial datasets showed similar patterns, with native herbivores generally preferring exotic plants. Thus, exotic plants appear defensively nave against these evolutionarily novel consumers, and exotic plants may escape their coevolved, specialist herbivores only to be preferentially consumed by the native generalist herbivores in their new ranges. In further support of this hypothesis, a meta-analysis of 71 manipulative field studies including over 100 exotic plant species and 400 native plant species from terrestrial, aquatic, and marine systems revealed that native herbivores strongly suppressed exotic plants, while exotic herbivores enhanced the abundance and species richness of exotic plants by suppressing native plants. Both outcomes are consistent with the hypothesis that prey are susceptible to evolutionarily novel consumers. Thus, native herbivores provide biotic resistance to plant invasions, but the widespread replacement of native with exotic herbivores eliminates this ecosystem service, facilitates plant invasions, and triggers an invasional meltdown. Consequently, rather than thriving because they escape their co-evolved specialist herbivores, exotic plants may thrive because their co-evolved generalist herbivores have stronger negative effects on evolutionarily nave, native plants.

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Robbins, H. J. "Effects of roadside pollutants on insect/plant interactions." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354405.

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Hindmarch, Colin. "The plant species enrichment of established grass swards." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295870.

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Stout, Jane Catherine. "The foraging ecology of bumblebees." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299266.

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Tew, Jason. "Humic and Fulvic Acids: Effects on Plant Nutrition and Growth." DigitalCommons@USU, 2005. https://digitalcommons.usu.edu/etd/6709.

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Humic substances are reported to improve plant growth and nutrient uptake, with iron the most studied nutrient. The most common forms of iron in soils are iron oxides, which are stable under aerobic conditions and unavailable for plant uptake. Iron deficient plants become chlorotic, which reduces growth and yield. To determine if humic substances can reduce iron chlorosis, five commercially available organic acids were tested on maize grown in sand columns at high pH. The dry granular humic acid from Aldrich Chemical Company applied at 84.4 g/liter of sand by volume (5% by mass) and 1 g/liter added with irrigation water, significantly reduced iron chlorosis (p

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Fonseca, Carlos Roberto Soerensen Dutra da. "Evolutionary ecology of Amazonian ant-myrmecophyte mutualisms." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296899.

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Hörnström, Eva. "Plant recolonization following dam removal : a phytometer experiment." Thesis, Umeå University, Department of Ecology and Environmental Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-27801.

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In the spring of 2007 the Kuba Dam in Nätra Stream was removed for restoration purposes, mainly to give free passage to migrating fish. This action gave an opportunity to study the effects of dam removal on organisms both on land and in water, a type of study which is in demand for planning purposes of future dam removals. This study focuses on the effects upon the vegetation along the stream where the former reservoir was situated. Willow cuttings and sunflower seeds were used as phytometers to assess the growth conditions one year after removal at three different elevation levels at four different sites along the Nätra Stream. The reaches studied were the former reservoir of Kuba Dam (Site A), the area just downstream of this former dam (Site B), further upstream in the reservoir of the existing Nyfors Dam (Site C), and even further upstream at Myreforsen, a reference area not affected by dams (Site D). Willow cuttings and sunflower seeds were planted at three different riparian levels at the sites in June and left to grow until August when growth results were collected. Many of the cuttings had died but statistically significant differences between sites could still be detected. They showed that the former reservoir shorelines in Kuba (Site A) had a plant growth significantly higher than the other regulated site. In other words, it was no longer equal to an existing reservoir but not yet similar to a free-flowing reach. The western side of the stream at this site had a higher growth than the eastern side and also higher than all the other sites. As for the three levels, the results showed a higher growth at the lowest elevation level at site A than all at the other levels and sites. This suggests that a combination of good access to sunlight and nutrients and fine-grade moist substrate results in a good growing conditions nearer the water in this former reservoir. The results for the sunflower seeds showed that the reference reach had a higher colonization success than the other sites.

Utrivningen av Kubadammen i Nätraån våren 2007 gav möjlighet att studera och följa upp hur en sådan förändring påverkar organismer på land och i vatten både uppströms och nedströms den tidigare dammen. Denna typ av undersökningar efterfrågas allt mer i och med att fler och fler dammar rivs av olika anledningar. I Kubadammens fall hade dammen förlorat sin ursprungliga roll och de fördelar som magasinet förde med sig för bland annat rekreation vägde inte längre upp dämningens negativa effekter på vattendragets ekosystem, till exempel som vandringshinder för fiskar. I denna studie har fokus lagts på vad som sker med vegetationen på stränderna längs det forna vattenmagasinet efter rivning. Med hjälp av videkvistar och solrosfrön som fytometrar undersöktes tillväxten ett år efter rivning på tre olika strandnivåer på fyra olika lokaler längs Nätraån. Dessa lokaler var Kubadammens gamla magasin (Lokal A), området direkt nedströms den före detta dammen (Lokal B), den nuvarande Nyforsdammens magasin (Lokal C) uppströms den före detta dammen, samt en referenssträcka vid Myreforsen (Lokal D) uppströms alla Nätraåns dammar och därmed ej påverkad av dämningseffekter. Videkvistarna och solrosorna planterades på tre nivåer på de olika lokalerna i juni och tilläts växa till augusti då tillväxtresultaten samlades in. Många kvistar hade dött under tiden men tillräckligt många överlevde för att det skulle gå att läsa ut statistiskt signifikanta skillnader i tillväxt. Resultaten visade att det före detta magasinet vid Kuba (Lokal A) hade en signifikant högre tillväxt än de andra lokalerna, vilket visar på att tillväxtförhållandena för vide varken liknar dem i ett befintligt magasin eller på en orörd sträcka eller nedströmssträckan, utan var betydligt mer gynnsamma. På denna lokal växte fytometrarna dessutom signifikant bättre på den västra sidan än på den östra sidan. När man ser till de tre nivåerna så växte videkvistarna i nivån närmast vattnet i det före detta magasinet vid Kuba bättre än på de övriga nivåerna på samma lokal och på de övriga lokalerna. Troligtvis beror detta på en kombination av öppenhet som ger bra tillgång till solljus, bra näringstillgång, substratets finkornighet och förmåga att hålla kvar fukt närmare vattnet. Resultaten av solrosfrönas etablering visade på att referenssträckan hade en högre etablering än övriga lokaler.

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46

Yee, Thomas William. "The Analysis of binary data in quantitative plant ecology." Thesis, University of Auckland, 1993. http://hdl.handle.net/2292/1973.

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The analysis of presence/absence data of plant species by regression analysis is the subject of this thesis. A nonparametric approach is emphasized, and methods which take into account correlations between species are also considered. In particular, generalized additive models (GAMs) are used, and these are applied to species’ responses to greenhouse scenarios and to examine multispecies interactions. Parametric models are used to estimate optimal conditions for the presence of species and to test several niche theory hypotheses. An extension of GAMs called vector GAMs is proposed, and they provide a means for proposing nonparametric versions of the following models: multivariate regression, the proportional and nonproportional odds model, the multiple logistic regression model, and bivariate binary regression models such as bivariate probit model and the bivariate logistic model. Some theoretical properties of vector GAMs are deduced from those pertaining to ordinary GAMs, and its relationship with the generalized estimating equations (GEE) approach elucidated.
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47

Milne, Judith May. "Plant community ecology of a major subtropical riverine floodplain." Thesis, University of Glasgow, 2004. http://theses.gla.ac.uk/4057/.

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This project described the vegetation of a stretch of the Parana River and investigated which natural or human-imposed factors might be controlling its characteristics, its capacity for biodiversity support and its potential to provide an economic resource. This information is of value in the planning of management strategies aiming to conserve biodiversity and develop sustainable ways in which the floodplain resources can be utilised. Central to this study were the surveys of vegetation and environmental characteristics of aquatic, terrestrial and transitional habitats of the Parana floodplain near Porto Rico. These produced extensive data sets which helped to reveal the types of vegetation-environment relationships structuring the floodplain plant communities. To complement this investigative approach, three aspects of the functioning of floodplain vegetation were chosen for closer study. These were the impacts of livestock grazing on wetland and island vegetation, competitive interactions between pairs of free-floating aquatic plant species and the role of aquatic macrophytes in contributing carbon to aquatic food webs. Three major community types were identified in the aquatic habitats of the floodplain, one which included Eichhornia azurea in mixture with several free-floating and emergent species, a second in which E. azurea was strongly dominant and a third comprised purely of submerged species. Two strongly contrasting broad vegetation communities were identified at bank and shore environments. Polygonum and Ludwigia species were important in one group and Poaceae, creepers, woody plants and ferns in the other group. Sub-groups of these communities could also be suggested, but these are less distinct. Most of the floodplain sites supported a Poaceae-creeper community type with the remaining sites supporting a community indicated by Polygonum species. The Poaceae group was comprised of a number of sub-communities in which the importance of Poaceae relative to other species varied. The aquatic vegetation communities differed structurally with contrasting community biomass, canopy height, canopy cover, species richness and stem density. They were associated with waterbodies with different water depth and pH and different sediment nitrogen and phosphorus contents. Water flow rate category and underwent light availability also differed between the sites that tended to support the different vegetation types. The two major bank and shore vegetation communities differed in canopy cover, in the soil nitrogen, phosphorus and calcium levels with which they were associated and in the steepness of the bank on which they tended to grow. Floodplain vegetation communities contrasted in species richness and differed in the soil nitrogen and calcium levels and river systems with which they were associated.

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Rumble, David Benjamin. "Unoccupied gaps in host plant resources for insect herbivores." Thesis, Lancaster University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310791.

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Cotton, Peter Angus. "The hummingbird-plant community of a lowland Amazonian rainforest." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334213.

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Stewart, Gavin. "Grazing management and plant community composition on Bodmin Moor." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2362.

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Background information, essential to a full appreciation of the research presented in the thesis, is submitted in Chapters Two, Three and Four in the form of literature reviews. Chapter Two includes a review of the geology, climate, soils, past management, vegetation history and nature conservation value of Bodmin Moor. The chapter culminates by discussing the proposed future management of grazing on Bodmin Moor. Chapter Three comprises a review of the mechanisms by which grazing affect vegetation. Particular reference is made to the effects of 7 General Introduction variation in grazing practices and interactions between grazing and other environmental variables. Chapter Four provides a review of successional processes with particular reference to the effects of grazing on upland plant community succession and the limits of current knowledge of grazing management in upland habitats. Chapter Five presents the results of phytosociological classification and explores the relationships between environmental variables and vegetation. Chapter Six examines spatial variation in the seed bank of Bodmin Moor in a range of communities at different depths. Chapter Seven presents the results of a Countryside Stewardship monitoring scheme established on Bodmin Moor North SSSI. Chapter Eight investigates the effects of variation in timing, frequency and severity of defoliation, on Molütia caerulea, along a soil moisture gradient. Chapter Nine reviews the preceeding work focusing on the overall implications of the thesis. The structure of the thesis is presented diagrammatically in Figure 1.1.

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Dissertations / Theses on the topic 'Ecology of plant nutrition'

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