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Effects of aircraft emissions on weed species grown in the vicinity of Hartsfield International Airport, Mountain View, GeorgiaWiedl, Stephen Cass 12 1900 (has links)
No description available.
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Ozone-sulphur dioxide effects on petunia : effects of ozone and sulphur dioxide singly and in combination ON Petunia hybrida Vilm. cultivars of differing sensitivities.Elkiey, Tarek M. January 1978 (has links)
No description available.
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Ozone-sulphur dioxide effects on petunia : effects of ozone and sulphur dioxide singly and in combination ON Petunia hybrida Vilm. cultivars of differing sensitivities.Elkiey, Tarek M. January 1978 (has links)
No description available.
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Modeling the potential effects of growth reductions and changes in photosynthetic efficiency and needle retention on the stand-level growth of loblolly pine plantationsBessling, Karen D. 21 July 2010 (has links)
An existing individual tree growth and yield model (PT AEDA2) was modified study the potential effects of air pollution stress on the growth and yield of loblolly pine plantations. These modifications were based on the assumption that pollution stress on older trees could result in reductions in diameter and height growth, decreases in photosynthesis, and increased losses of older foliage, as demonstrated in some seedling studies.
One modification applied differential levels of reductions of diameter and height increments to various percentages of trees. Results indicated no sizeable losses on total volume per acre except at severe stress levels (-32 and -64 percent annual diameter and height increments on 50 and 67 percent of the trees).
Another modification consisted of developing a measure of photosynthetic potential to drive diameter and height growth in the model. This new measure was an estimate of foliage weight which was weighted by a factor of photosynthetic efficiency and needle retention for each age class of needles. Reductions of these weighting factors were applied to simulate air pollution stress. Results of this modification show that if air pollution does cause a decrease in photosynthesis and needle retention rates, the impact on over-all stand productivity is minimal. These results are not intended to be quantitative estimates of the effect of air pollution on tree growth but to identify potential areas within an existing growth and yield model where biologically-oriented processes to simulate air pollution impact can be incorporated. / Master of Science
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Assessment of air pollution impacts on vegetation in South AfricaBotha, Amanda Theophila January 1989 (has links)
Field surveys and biomonitoring network experiments were conducted in selected areas in South Africa to assess possible air pollution damage to vegetation. During field surveys, atmospheric fluoride was identified as an important pollutant that damaged vegetation in residential areas north of Cape Town. Gaseous air pollutants, including acid deposition and acidic mist, probably play a major role in the development of characteristic air pollution injury symptoms observed on pine trees in the Eastern Transvaal area.
The impact of urban air pollution in the Cape Town area was evaluated by exposing bio-indicator plants in a network of eight biomonitoring network stations from June 1985 to May 1988. Sensitive Freesia and Gladiolus cultivars were used to biomonitor atmospheric fluoride, while a green bean cultivar was used as a biomonitor of atmospheric sulphur dioxide and ozone. At one location, bio-indicator plants were simultaneously exposed in a biomonitoring network station (plant cages), open-top chambers (filtered and unfiltered), as well as in open plots. The responses of plants grown under these different conditions were compared.
During both the winter and summer seasons, ambient fluoride concentrations were estimated to be particularly high at the Loumar biomonitoring station (eastern side of Cape Town), as compared to that at the other biomonitoring stations. Elevated levels of atmospheric fluoride, as well as sulphur dioxide, appeared to prevail in the vicinity of industries located in the northern suburbs of Cape Town (Bothasig, Table View and Edgemead). Interveinal bleaching, which is characteristic of sulphur dioxide injury, was regularly observed on bean plants exposed at the Bothasig biomonitoring station and was usually determined to be significantly worse at this location than at the other biomonitoring stations. These results were confirmed by the evaluation of foliar sulphur content
Ambient pollutant concentrations appeared to be effectively reduced inside filtered open-top chambers, as exemplified by higher biomass production and lower foliar fluoride and sulphur levels in the relevant bio-indicator species, compared to that of plants grown in the open plots.
The methodology used during this research provided baseline data of the impact of air pollution on vegetation in South Africa which, in the absence of networks of sophisticated state of the art equipment, can be applied to aid in air pollution control strategies. / Ph. D.
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The effects of airborne particulates on certain soils in Arizona; and a preliminary survey of biological monitoring of oxidants in the Tucson areaBalsley, Samuel Lee, 1945- January 1974 (has links)
No description available.
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Efeito do aumento da concentração de dióxido de carbono do ar sobre a mancha foliar causada por cylindrocladium candelabrum em mudas de eucalyptus urophyllaSilva, Carlos Eduardo Oliveira da [UNESP] 11 June 2013 (has links) (PDF)
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silva_ceo_me_botfca.pdf: 992973 bytes, checksum: 0d39fa727acc22130c9ec40047fd3911 (MD5) / A concentração de CO2 na atmosfera vem aumentando significativamente desde a Revolução Industrial. Devido aos potenciais impactos da elevação do CO2 do ar sobre os diversos patossistemas, foram realizados ensaios em ambiente controlado para verificar os efeitos da elevação da concentração de CO2 do ar sobre Cylindrocladium candelabrum em folhas destacadas e mudas de Eucalyptus urophylla. Em três ensaios, folhas destacadas foram acondicionadas em bandejas plásticas com espuma umedecida, com concentração de 607 ± 86, 705 ± 105, 855 ± 152 e 1101 ± 305 μmol mol-1 de CO2 do ar, pulverizadas com conídios do patógeno (2 × 105 conídios mL-1) e mantidas a 28 ± 1,7 oC e fotoperíodo de 12 h por 21 dias. Foram avaliadas a severidade da mancha foliar e a esporulação do patógeno. Em dois ensaios com mudas de eucalipto, as mudas foram cultivadas em tubetes, mantidas em caixas plásticas contendo vermiculita no fundo e mantidas nas concentrações de 451 ± 35 (controle), 645 ± 118, 904 ± 116, 1147 ± 216 μmol mol-1 de CO2 por 30 dias para aclimatação. Após este período, as mudas foram pulverizadas com conídios do patógeno e mantidas sob as mesmas condições anteriores por seis dias. Foram avaliadas a incidência de folhas lesionadas, a severidade da mancha foliar e o número de folhas contendo esporos do patógeno. A altura das mudas, o diâmetro do caule e o peso da matéria seca da parte aérea e da raiz também foram avaliados. Nos ensaios com folhas destacadas, o aumento da concentração de CO2 do ar não teve efeito sobre a severidade da mancha foliar e esporulação do patógeno. Nas mudas, a elevação da concentração de CO2 do ar diminuiu a incidência de folhas lesionadas, a severidade da doença e o número de folhas contendo 2 esporos do patógeno quando comparados ao controle. Nas variáveis de... / The concentration of CO2 in the atmosphere has been increasing significantly since the Industrial Revolution. Because of the potential impacts of the increase in CO2 from the air on the various pathosystems, assays were carried out in a controlled environment to check the effects of elevation of the concentration of CO2 from the air on Cylindrocladium candelabrum in detached leaves and seedlings of Eucalyptus urophylla. In three trials, detached leaves were wrapped in plastic trays with foam moistened with concentration of 607 ± 86, 705 ± 105, 855 ± 152 and 1101 ± 305 μmol mol-1 CO2 from the air, sprayed with conidia of the pathogen (2 × 105 conidia ml-1) and maintained at 28 ± 1.7 oC and photoperiod of 12 h for 21 days. It was evaluated the severity of leaf spot and the sporulation of the pathogen. In both experiments with seedlings of eucalyptus, the seedlings were grown in plastic tubes, kept in plastic boxes containing vermiculite at the bottom and kept in concentrations of 451 ± 35 (control), 645 ± 118, 904 ± 116, 1147 ± 216μmol mol-1 CO2 per 30 days for acclimatization. After this period, the seedlings were sprayed with conidia of the pathogen and kept on the same conditions for six days. It was evaluated the incidence of lesioned leaves, leaf spot severity and the number of leaves containing spores of the pathogen. The height of the seedlings, the diameter of the stem and the weight of the dry matter of the aerial part and root were also evaluated. In the tests with detached leaves, the increase of CO2 concentration had no effect on the severity of leaf spot and sporulation of the pathogen. In seedlings, the elevation of CO2 concentration decreased the incidence of leaves lesioned, the severity of the disease and the number of leaves containing spores of the pathogen when compared to the control. In the... (Complete abstract click electronic access below)
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Efeito do aumento da concentração de dióxido de carbono do ar sobre a mancha foliar causada por cylindrocladium candelabrum em mudas de eucalyptus urophylla /Silva, Carlos Eduardo Oliveira da, 1987- January 2013 (has links)
Orientador: Raquel Ghini / Banca: Magali Ribeiro da Silva / Banca: Celso Garcia Auer / Resumo: A concentração de CO2 na atmosfera vem aumentando significativamente desde a Revolução Industrial. Devido aos potenciais impactos da elevação do CO2 do ar sobre os diversos patossistemas, foram realizados ensaios em ambiente controlado para verificar os efeitos da elevação da concentração de CO2 do ar sobre Cylindrocladium candelabrum em folhas destacadas e mudas de Eucalyptus urophylla. Em três ensaios, folhas destacadas foram acondicionadas em bandejas plásticas com espuma umedecida, com concentração de 607 ± 86, 705 ± 105, 855 ± 152 e 1101 ± 305 μmol mol-1 de CO2 do ar, pulverizadas com conídios do patógeno (2 × 105 conídios mL-1) e mantidas a 28 ± 1,7 oC e fotoperíodo de 12 h por 21 dias. Foram avaliadas a severidade da mancha foliar e a esporulação do patógeno. Em dois ensaios com mudas de eucalipto, as mudas foram cultivadas em tubetes, mantidas em caixas plásticas contendo vermiculita no fundo e mantidas nas concentrações de 451 ± 35 (controle), 645 ± 118, 904 ± 116, 1147 ± 216 μmol mol-1 de CO2 por 30 dias para aclimatação. Após este período, as mudas foram pulverizadas com conídios do patógeno e mantidas sob as mesmas condições anteriores por seis dias. Foram avaliadas a incidência de folhas lesionadas, a severidade da mancha foliar e o número de folhas contendo esporos do patógeno. A altura das mudas, o diâmetro do caule e o peso da matéria seca da parte aérea e da raiz também foram avaliados. Nos ensaios com folhas destacadas, o aumento da concentração de CO2 do ar não teve efeito sobre a severidade da mancha foliar e esporulação do patógeno. Nas mudas, a elevação da concentração de CO2 do ar diminuiu a incidência de folhas lesionadas, a severidade da doença e o número de folhas contendo 2 esporos do patógeno quando comparados ao controle. Nas variáveis de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The concentration of CO2 in the atmosphere has been increasing significantly since the Industrial Revolution. Because of the potential impacts of the increase in CO2 from the air on the various pathosystems, assays were carried out in a controlled environment to check the effects of elevation of the concentration of CO2 from the air on Cylindrocladium candelabrum in detached leaves and seedlings of Eucalyptus urophylla. In three trials, detached leaves were wrapped in plastic trays with foam moistened with concentration of 607 ± 86, 705 ± 105, 855 ± 152 and 1101 ± 305 μmol mol-1 CO2 from the air, sprayed with conidia of the pathogen (2 × 105 conidia ml-1) and maintained at 28 ± 1.7 oC and photoperiod of 12 h for 21 days. It was evaluated the severity of leaf spot and the sporulation of the pathogen. In both experiments with seedlings of eucalyptus, the seedlings were grown in plastic tubes, kept in plastic boxes containing vermiculite at the bottom and kept in concentrations of 451 ± 35 (control), 645 ± 118, 904 ± 116, 1147 ± 216μmol mol-1 CO2 per 30 days for acclimatization. After this period, the seedlings were sprayed with conidia of the pathogen and kept on the same conditions for six days. It was evaluated the incidence of lesioned leaves, leaf spot severity and the number of leaves containing spores of the pathogen. The height of the seedlings, the diameter of the stem and the weight of the dry matter of the aerial part and root were also evaluated. In the tests with detached leaves, the increase of CO2 concentration had no effect on the severity of leaf spot and sporulation of the pathogen. In seedlings, the elevation of CO2 concentration decreased the incidence of leaves lesioned, the severity of the disease and the number of leaves containing spores of the pathogen when compared to the control. In the... (Complete abstract click electronic access below) / Mestre
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EPR investigation of free radicals in excised and attached leaves subjected to ozone and sulphur dioxide air pollutionVaartnou, Manivalde January 1988 (has links)
The X-band EPR spectrometry system was modified to allow for the in situ monitoring of free radical changes in attached, intact plant leaves, which were caused by stress factors such as exposure to excessive photon flux density, ozone or sulphur dioxide. This was done through use of the dewar insert of the variable temperature accessory as a guide, the construction of 'T' shaped cellulose acetate holders to which leaves could be attached with adhesive tape, and modification of the gas flow system used for controlled temperature studies.
Kinetic studies of free radical formation were possible with leaves which had minimal underlying Fe⁺⁺ and Mn⁺⁺ signals. In leaves with large underlying signals a Varian software program was used to subtract overlapping signals from each other, thereby revealing the free-radical signal changes which occurred under different light regimes and stress conditions. Preliminary investigation disclosed the formation of a new signal upon prolonged exposure to far-red light and the effect of oxygen depletion upon photosynthetic Signals I and II.
Leaves subject to high photon flux density reveal an unreported free-radical signal, which decays upon exposure to microwave radiation; and concomitant damage to Photosystems I and II. Upon elimination of this signal leaves return to the undamaged state or reveal permanent damage to either photo-system, depending upon the degree of damage.
Kentucky bluegrass and perennial ryegrass leaves subject to low levels of ozone (up to 80ppb) for periods of 8 hours show no changes in free-radical signal formation. At intermediate levels of ozone (80-250ppb) a new free-radical signal was formed within 3 hours of fumigation, Signal II was decreased and Signal I decayed. These changes were reversible if fumigation was terminated. At fumigation levels exceeding 250ppb a different new irreversible free-radical signal was formed in darkness within 1.5 hours of fumigation.
Radish, Kentucky bluegrass and perennial ryegrass leaves subject to high levels of sulphur dioxide (10-500ppm) reveal the formation of Signal I upon irradiation with broad-band white or 650nm light, thereby indicating an interruption of normal electron flow from PSII to PSI. Damage to the oxygen-evolving complex and reaction centre of PSII is also revealed through changes in Signal II and the Mn⁺⁺ signal. These changes in the normal EPR signals are dose-dependent. Leaves subject to low levels of sulphur dioxide (600-2000ppb) reveal the disappearance of Signal I after 3 hours of fumigation and the formation of a new free-radical signal with parameters similar to the sulphur trioxide free-radical signal. These latter changes are partially reversible upon termination of fumigation.
After prolonged exposure to either ozone or sulphur dioxid a free-radical signal with parameters similar to the superoxid anion free-radical signal is formed in plant leaves. / Land and Food Systems, Faculty of / Graduate
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INVASIVE SPECIES AND PANNE ECOSYSTEMS: THE EFFECTS OF ATMOSPHERIC POLLUTIONNazareth, Cheryl 10 April 2008 (has links)
Pannes are rare intradunal wetlands. Though small, they are known to exhibit extremely diverse and sensitive vegetation and are home to a number of reptile and amphibian species. In the United States, pannes are known to occur only around the Great Lakes Basin and Cape Cod. At Indiana Dunes National Lakeshore, the fifteen known pannes have an unusually large variety of plant species for such a small geographic area and provide habitat for plant species found nowhere else in Indiana. However, these sensitive ecosystems have been exposed to over a century of atmospheric pollutants from the surrounding steel and coal industries. Since 1986, the native vegetation of the area is slowly being replaced by invasive species like Phragmites australis and Typha spp. This study attempts to explain the shift in vegetation. Pannes in two other locations, at a distance from the industrial complex, were used as control sites as they were not expected to be exposed to the same levels of heavy metal concentrations.
Four of the fifteen pannes at the Indiana Dunes National Lakeshore, two of the four pannes at Sleeping Bear Dunes National Lakeshore, Michigan, and two of the three pannes at Warren Dunes State Park, Michigan, were studied, resulting in a total of eight pannes. The pannnes were stratified and sampled by hydroperiod. Surface soil samples and sediments at depth, were recovered from each of the pannes considered in this study and analyzed for heavy metal, phosphorus, carbon and nitrogen content.
Results show that high levels of organic matter coupled with high nutrients and high metals, in the soil, are a combination that may be considered a risk factor for future invasion of pannes by invasive species. It appears to be difficult for the native vegetation to deal with the high metals and high nutrients which are deleterious to the native vegetation and facilitate establishment of invasive vegetation which is more tolerant to the altered geochemical conditions.
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