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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Root herbivory in grasslands and savannas the potential role of June beetle (Phyllophaga spp.; Scarabaeidae) larvae in central Texas plant community structure /

Brumbaugh, Michael Shawn, Fowler, Norma L., Litvak, Marcy E., January 2004 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisors: Norma L. Fowler and Marcy E. Litvak. Vita. Includes bibliographical references. Available also from UMI company.
52

Analyzing patterns of woody plant richness at multiple spatial scales with modeled photosynthesis /

Swenson, Jennifer J. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2004. / Printout. Includes bibliographical references. Also available on the World Wide Web.
53

Will Nitrogen fixers benefit from rising Atmospheric CO2? The response of Podalyria Sericea to elevated CO2

Swemmer, Tony 05 July 2021 (has links)
To predict the response of communities and ecosystems to rising levels of atmospheric CO2, the response of individual plants under natural conditions needs to be determined. Podalyria sericea, a fynbos legume, was grown in a greenhouse under ambient (35 Pa) and elevated (70 Pa) CO2 partial pressure for 18 months. Growth, leaf 615N and leaf gas exchange was measured to determine whether this N2-fixer could maintain a positive growth response under conditions of high competition. Results revealed a lack of positive growth response to elevated CO2, although far more flowers were produced in the elevated treatment. Allocation patterns were slightly different, with relatively higher shoot mass for plants exposed to elevated CO2. Leaf 61 5N and N concentrations were unaffected. Photosynthetic capacity was greatly reduced and maximum rates of Rubisco carboxylation (V cmaJ and light saturated electron transport (Jniax) were lower for plants exposed to elevated CO2. Net CO2 assimilation (A) at growth CO2 was higher for the plants from the ambient treatment. Shading appears to have been an important constraint on growth response to elevated CO2, and plants which received more light had significantly more biomass in the elevated treatment. The potential effect of restricted root growth and low soil nutrient availability are discussed as additional factors which may have negated a positive growth response.
54

The use, abundance and conservation of woody species in the Batemi Valley, northwestern Tanzania /

Smith, Wynet January 1993 (has links)
No description available.
55

The Prevalence and Operational Feasibility of Utilizing Pre-commercially Thinned Pine as a Woody Biomass Energy Source

Hanzelka, Nathan Carl 22 May 2015 (has links)
The southern pine beetle (SPB) poses a significant threat to pine forests of the southeastern US. Pre-commercial thinning (PCT) is a commonly used silvicultural practice to mitigate and prevent SPB spread in young southern pine stands. Typically, PCT represents an added management cost to landowners and thinned material is not utilized for forest products. Increased demand for woody biomass energy may provide landowners and harvesting contractors an opportunity to utilize PCT residues as a woody biomass energy feedstock, which may wholly or partially offset PCT costs. However, little information is available regarding harvestable biomass quantities in PCT stands and few studies have assessed harvesting productivity and costs in very young pine stands. To develop estimates of biomass abundance in PCT candidate stands, loblolly pine (Pinus taeda) stands aging 5 to 12-years old, and enrolled in the Virginia Department of Forestry Pine Bark Beetle Prevention Program (VDOF PBBPP), were inventoried across the Piedmont and Coastal Plain regions of Virginia. To attain productivity and cost estimates of utilizing small-diameter stems for woody biomass energy, a biomass harvesting case study was then conducted on a 15-year old loblolly pine stand. Results of the inventory and case study indicate that stands at the upper age limit for the PCT program may contain harvestable quantities of biomass (39.63 green tons/acre), although high harvesting costs ($23.46/green ton) relative to regional delivered biomass prices may limit the economic feasibility of utilizing PCT biomass for energy. / Master of Science
56

An Analysis of the Ecology and Public Perception of Coarse Woody Debris in Virginia

Fuhrman, Nicholas E. 21 July 2004 (has links)
Coarse woody debris (CWD) is an important habitat component for wildlife, fish, and plants and is important in nutrient cycling and soil formation. Knowledge of the volume, distribution, and use of CWD across Virginia would be useful to forest managers modeling nutrient budgets in southeastern forests and is important to wildlife management efforts. Knowledge of the effectiveness of informational brochures and cooperative learning activities/presentations at influencing public perception of CWD is important to program design and evaluation efforts in teaching and extension. The objectives of this study were to quantify the relationship between forest cover type and CWD volume, correlate CWD volume with small mammal and bird activity, distribute information on the advantages and disadvantages of CWD using informational brochures and cooperative learning activities/presentations, and compare the effectiveness of such teaching techniques at influencing public perception of CWD. The volume and wildlife use of CWD was assessed within 12 mature second-growth stands in Virginia. Volume of CWD was measured using fixed-area plots. Use of CWD by small mammals and birds was assessed by noting bodily, foraging, or movement evidence. Pre- and post-survey instruments were used to evaluate how perceptions were altered in first year college students who either reviewed an informational brochure or participated in a cooperative learning activity/presentation. Results suggested that the management of CWD for wildlife was most needed in southeastern Virginia where CWD volumes were lowest and that the value of CWD for wildlife was best conveyed through cooperative learning activities/presentations and may be important to landowner education efforts. Results suggested that management efforts to increase CWD volumes in Virginia should focus on coniferous dominated stands where CWD volumes were lowest. Such a finding, combined with the knowledge that the value of CWD was best conveyed through presentations, suggests that landowners of coniferous woodlots could be effectively educated with presentations. Given that brochures were more effective for females than males, brochures addressing natural resource issues might be the most appropriate, cost effective method of education at events that target female audiences. Knowledge gained from this study that CWD management for wildlife would be most appropriate in western Virginia where CWD was most used by wildlife for travel and that presentations were most effective at reaching suburban participants may be important to outreach program design efforts. Regardless of academic major, presentations were more effective at generating positive attitudes toward CWD. The results of this study suggest that the choice between informational brochures and presentations for influencing public perceptions of CWD will likely be influenced by the demographics of the target audience and the relevance of the topic locally. / Master of Science
57

Coarse Woody Debris and the Carbon Balance of a Moderately Disturbed Forest

Schmid, Amy V 01 January 2015 (has links)
Landscapes are comprised of multiple ecosystems shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence, in contrast to severe disturbances that fell trees, may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (RE). However, woody debris dynamics are rarely examined following moderate disturbances that substantially increase standing dead wood stocks. We used an experimental manipulation of moderate disturbance in an upper Great Lakes forest to: 1) examine decadal changes in CWD stocks through a moderate disturbance; 2) quantify in situ CWD respiration during different stages of decay for downed and standing woody debris and; 3) estimate the annual contribution of CWD respiration to the ecosystem C balance through comparison with RE and net ecosystem production (NEP). We found that the standing dead wood mass of 24.5 Mg C ha-1 was an order of magnitude greater than downed woody debris stocks and a large source of ecosystem C flux six years following disturbance. Instantaneous in situ respiration rates from standing and downed woody debris in the earliest stages of decay were not significantly different from one another. Independently derived estimates of ecosystem CWD respiration of 1.1to 2.1 Mg C ha-1 yr-1 six years following disturbance were comparable in magnitude to NEP and 12.5 % to 23.8 % of RE, representing a substantial increase relative to pre-disturbance levels. Ecosystem respiration and NEP were stable following moderate disturbance even though ecosystem CWD respiration increased substantially, suggesting a reduction in the respiratory C contribution from other sources. We conclude that CWD is an essential component of the ecosystem C balance following a moderate forest disturbance.
58

A cidade cartão-postal no cinema de Woody Allen / The postcard city in Woody Allens cinema

Anjos, Ana Paula Bianconcini 04 February 2016 (has links)
Este trabalho examina a representação das cidades na obra de Woody Allen. No intuito de compreender a saída do cineasta patrimônio da cidade de Nova York para a Europa, retoma-se criticamente a questão da Era da Lista Negra, das runaway productions e dos blockbusters. Para analisar os filmes de Allen na Europa considera-se importante entender como a cidade de Nova York configura-se no início da carreira do diretor, notadamente, em filmes que estabelecem um contraponto entre o Brooklyn e Manhattan. Em seguida, examina-se a questão crítica fundamental do trabalho: o cartão-postal corporativo na Europa. Nesse sentido, propõe-se a análise dos cartões-postais de Barcelona, Paris e Roma. O filme Vicky Cristina Barcelona adquire centralidade nesta pesquisa por apresentar de maneira exemplar a paisagem postiça da cidade encarcerada sob intervenção corporativa. / This research examines the representation of cities in Woody Allens work. In order to understand Allens European sojourn, it discusses the Blacklist Era, the runaway production and the impact of the blockbuster productions in the industry. The work understands New York as the quintessential frame of Allens depiction of cities overseas, notably in the early films that juxtapose Brooklyn and Manhattan. Henceforth, the key critical core of this work is presented: the corporate postcard in Europe. In this sense, it proposes an analysis of the postcards of Barcelona, Paris and Rome. The film Vicky Cristina Barcelona presents in an exemplary manner the cityscape under corporate intervention.
59

Do sonho americano à forma mercadoria: uma leitura de Zelig de Woody Allen / From the American dream to the commodity-form: a reading of Woody Allen\'s Zelig

Queirós, Rosangela Aparecida de 01 October 2014 (has links)
O objetivo desta dissertação é apontar para a duplicidade narrativa a partir da qual a história Zelig (1983) é contada. Por um lado, tem-se um narrador tradicional de um documentário em voz over, no entanto, sua forma de narrar acaba por revelar aspectos deste gênero como produção dentro da Indústria Cultural. Por outro lado, tem-se outra instância narrativa, conhecida como autor implícito, que coloca elementos em cena para que o espectador consiga ter uma leitura totalizadora da obra. Ademais, o filme Zelig, como produção cultural do início dos anos 1980, revela os desdobramentos e consequências de viver segundo uma ordem social pós-moderna. Observa-se, dentre outros fatores, a forma-mercadoria dominando todas as instâncias da vida social, além da espetacularização da sociedade presente em diversos aspectos da vida moderna. / The aim of this dissertation is to point to the narrative duplicity from which the story Zelig (1983) is told. On the one hand, there is a traditional voiceover documentary narrator, however, his way of narrating ends up revealing aspects of this genre as a production within the Cultural Industry. On the other hand, there is another narrative instance, known as implied author, who adds elements in the scene so that the viewer can have a totalizing reading of the work. Furthermore, Zelig, as cultural production from the early 1980s, reveals the ramifications and consequences of living according to a post-modern social order. We observe, among other factors, the commodity-form dominating all levels of social life. Moreover, the spectacularization of this society found in many aspects of modern life.
60

A cidade cartão-postal no cinema de Woody Allen / The postcard city in Woody Allens cinema

Ana Paula Bianconcini Anjos 04 February 2016 (has links)
Este trabalho examina a representação das cidades na obra de Woody Allen. No intuito de compreender a saída do cineasta patrimônio da cidade de Nova York para a Europa, retoma-se criticamente a questão da Era da Lista Negra, das runaway productions e dos blockbusters. Para analisar os filmes de Allen na Europa considera-se importante entender como a cidade de Nova York configura-se no início da carreira do diretor, notadamente, em filmes que estabelecem um contraponto entre o Brooklyn e Manhattan. Em seguida, examina-se a questão crítica fundamental do trabalho: o cartão-postal corporativo na Europa. Nesse sentido, propõe-se a análise dos cartões-postais de Barcelona, Paris e Roma. O filme Vicky Cristina Barcelona adquire centralidade nesta pesquisa por apresentar de maneira exemplar a paisagem postiça da cidade encarcerada sob intervenção corporativa. / This research examines the representation of cities in Woody Allens work. In order to understand Allens European sojourn, it discusses the Blacklist Era, the runaway production and the impact of the blockbuster productions in the industry. The work understands New York as the quintessential frame of Allens depiction of cities overseas, notably in the early films that juxtapose Brooklyn and Manhattan. Henceforth, the key critical core of this work is presented: the corporate postcard in Europe. In this sense, it proposes an analysis of the postcards of Barcelona, Paris and Rome. The film Vicky Cristina Barcelona presents in an exemplary manner the cityscape under corporate intervention.

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