CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / RESUMO â Com o aumento significativo da procura e consumo por produtos ornamentais faz-se necessÃrio um aumento da produtividade dessas, o que torna necessÃrios o desenvolvimento de estudos para que esse incremento nÃo diminua a qualidade nem modifique as caracterÃsticas desejÃveis ao mercado consumidor, no que diz respeito a tÃcnicas de produÃÃo e cultivo. O mercado brasileiro de plantas ornamentais à Ãvido por novidades. Alternativa que os produtores veem procurando e com bastante frequÃncia à a inclusÃo de plantas - jà conhecidas e utilizadas em outras Ãreas - no setor da floricultura como plantas ornamentais, sendo esse o caso do mandacaru como ocorre no Projeto Tejucactos no municÃpio de TejuÃuoca. Baseado no exposto, esse trabalho foi conduzido com o objetivo de fornecer dados referentes a tÃcnicas para o cultivo das plantas ornamentais: Caladium x hortolanum cv Freida Hemple e Cereus jamacaru DC. Para o Caladium Freida Hemple utilizou-se o delineamento inteiramente casualizado seguindo um esquema fatorial 2x6 constituÃdo por prÃtica da desponta ou nÃo e de seis concentraÃÃes de AG3 (0, 250, 500, 750, 1000 e 1250 ppm) aplicadas antes do plantio dos tubÃrculos. Maiores comprimentos de raiz foram encontrados em plantas de tubÃrculos despontados e sem aplicaÃÃo de AG3; Maiores alturas de hastes foram encontradas em plantas de tubÃrculos despontados e tubÃrculos intactos tratados com AG3; Maiores nÃmeros de hastes foram encontrados em plantas de tubÃrculos intactos; Maiores comprimento e largura de folha foram encontradas em plantas de tubÃrculos intactos tratados com AG3 e tubÃrculos despontados sem AG3. Para o Cereus jamacaru DC, os tratamentos dispostos em delineamento inteiramente casualizado, constituÃram-se dos substratos 100% fibra de coco (FC) (T1), 100% casca de arroz carbonizada (CAC) (T2), 75%FC+25%CAC (T3), 50%FC+50%CAC (T4), e 25%FC+75%CAC (T5). PlÃntulas de mandacaru com idade de 118 dias foram transplantadas para os substratos e aos 125 dias apÃs o transplantio foram analisados: comprimento, nÃmero, massa fresca e seca de raiz e crescimento, massa fresca e seca da parte aÃrea. O substrato composto somente por fibra de coco apresentou melhores resultados em todas as variÃveis analisadas. / With the significant increase in demand and consumption of ornamental products is necessary to increase the productivity of these items. With the significant increase in demand and consumption of ornamental products is necessary to increase the productivity of these items. Studies are important for the "productivity increase" does not influence the quality, or modify the characteristics desirable to the consumer market, with respect to production techniques and cultivation. The Brazilian market for ornamental plants is hungry for novelties. So producers often seek to include new plants in cultivation, sometimes already known and used them, that being the case of âmandacaruâ, widely used in the Project with neme of âTejucactusâ in TejuÃuoca city in CE. Within this context, this work was carried out to provide information about techniques for the cultivation of three ornamental plants: Caladium, Sansevieria cylindrica and Cereus jamacaru. For Caladium were used a completely randomized design in a factorial 2x6 (or not practice is emerging and six concentrations of GA3 (0, 250, 500, 750, 1000 and 1250 ppm) applied before planting the tubers. Greater root lengths were found in plants, of tubers kept intact and without the application of GA3; Greater heights stems were found in plants of tubers kept intact, treated with GA3; Higher numbers of stems were found in plants of tubers kept intact; Greater length and leaf width was found plants of tubers kept intact and tubers treated with GA3 or Caladium tubers must be kept intact and treated with GA3 or apical dominance (De-eyed) should be performed without the use plant regulator. For Cereus jamacaru treatments in DIC, consisted in coconut fiber (FC) and carbonized rice chaff (CAC) substrates: 100% FC (T1), 100% CAC (T2), 75% FC +25% CAC (T3), 50% FC +50% CAC (T4), and 25% FC +75% CAC (T5). The substrate composed only of coconut fiber showed better results in all variables.

The main aim of this study was to investigate the effects of water availability and SO2 pollution, imposed separately or simultaneously, on the photosynthetic metabolism of Augea capensis Thunb., a succulent of the Namib Desert in the region of Skorpion Zinc mine, Namibia. The main driver for this investigation was the need to distinguish between the effects of water availability on plants native to a desert environment, where water availability dominates plant response, but where the possibility of anthropogenic SO2 pollution poses a new threat to the unique succulent vegetation. Fifteen measuring sites were selected in the vicinity of the mine to determine how rainfall influenced the physiological status of the vegetation. Chlorophyll a fluorescence measurements, and analysis of recorded OJlP fluorescence transients with the JIP-test, were used for this purpose. A series of laboratory experiments were also conducted on A. capensis to determine the precise physiological response that water deprivation and SO2 pollution had under controlled growth conditions. Potted plants were exposed to water deprivation or SO2 fumigation in the light or dark. Besides chlorophyll a fluorescence, photosynthetic gas exchange and Rubisco activity were also measured. Changes in fast fluorescence rise kinetics observed under field conditions suggest considerable modulation of photosystem II function by rainfall with concomitant involvement of a heat stress component as well. In both the field and laboratory experiments, one of the JIP-test parameters, the so-called performance index (PIABS), was identified as a very sensitive indicator of the physiological status of the test plants. Moreover, under laboratory conditions, a good correlation existed between the water deprivation-induced decline in CO2 assimilation rates and the decline in PIABS values. The JIP-test in general, and the PIABS in particular, shows considerable potential for application in the investigation of water availability influences on desert ecosystems. In the laboratory experiments, water deprivation caused stomatal closure but also a slight elevation in intercellular C02 concentration and inhibition of Rubisco activity, suggesting that mesophyll limitation was the dominant factor contributing to the decrease in C02 assimilation rates. Following re-watering, A. capensis showed remarkable recovery capacity. Fumigation of A. capensis with 1.2 ppm SO2 in the dark or light revealed relatively small effects on C02 assimilation. The inhibitory effects on photosynthesis were also fully reversible, indicating no permanent metabolic/structural damage. The effects on photosynthesis were more pronounced when fumigation occurred in the dark. This phenomenon might be related to diurnal differences in cellular capacity for SO2 detoxification. When long-term moderate water deprivation was combined with simultaneous SO2 fumigation, there was no additional inhibitory effect on photosynthesis. These findings suggest that water deprivation do not increase sensitivity towards SO2 pollution in A. capensis. Fumigation with SO2, singly or in combination with water deprivation also had no major effect on chloroplast ultrastructure. It appears that A. capensis is remarkably resistant to SO2 pollution even in the presence of low water availability, which is a common phenomenon in desert ecosystems. Since A, capensis seems to be highly tolerant to S02, its suitability as an indicator species for the detection of SO2 pollution effects at Skorpion Zinc mine is questionable. Because water availability dominates the physiological/biochemical response in this species, subtle SO2 pollution effects might be difficult to detect against this dominant background. The high water content of A. capensis and similar succulents might act as a substantial sink for SO2 and could convey considerable tolerance against this form of air pollution. / Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2006.

The main aim of this study was to investigate the effects of water availability and SO2 pollution, imposed separately or simultaneously, on the photosynthetic metabolism of Augea capensis Thunb., a succulent of the Namib Desert in the region of Skorpion Zinc mine, Namibia. The main driver for this investigation was the need to distinguish between the effects of water availability on plants native to a desert environment, where water availability dominates plant response, but where the possibility of anthropogenic SO2 pollution poses a new threat to the unique succulent vegetation. Fifteen measuring sites were selected in the vicinity of the mine to determine how rainfall influenced the physiological status of the vegetation. Chlorophyll a fluorescence measurements, and analysis of recorded OJlP fluorescence transients with the JIP-test, were used for this purpose. A series of laboratory experiments were also conducted on A. capensis to determine the precise physiological response that water deprivation and SO2 pollution had under controlled growth conditions. Potted plants were exposed to water deprivation or SO2 fumigation in the light or dark. Besides chlorophyll a fluorescence, photosynthetic gas exchange and Rubisco activity were also measured. Changes in fast fluorescence rise kinetics observed under field conditions suggest considerable modulation of photosystem II function by rainfall with concomitant involvement of a heat stress component as well. In both the field and laboratory experiments, one of the JIP-test parameters, the so-called performance index (PIABS), was identified as a very sensitive indicator of the physiological status of the test plants. Moreover, under laboratory conditions, a good correlation existed between the water deprivation-induced decline in CO2 assimilation rates and the decline in PIABS values. The JIP-test in general, and the PIABS in particular, shows considerable potential for application in the investigation of water availability influences on desert ecosystems. In the laboratory experiments, water deprivation caused stomatal closure but also a slight elevation in intercellular C02 concentration and inhibition of Rubisco activity, suggesting that mesophyll limitation was the dominant factor contributing to the decrease in C02 assimilation rates. Following re-watering, A. capensis showed remarkable recovery capacity. Fumigation of A. capensis with 1.2 ppm SO2 in the dark or light revealed relatively small effects on C02 assimilation. The inhibitory effects on photosynthesis were also fully reversible, indicating no permanent metabolic/structural damage. The effects on photosynthesis were more pronounced when fumigation occurred in the dark. This phenomenon might be related to diurnal differences in cellular capacity for SO2 detoxification. When long-term moderate water deprivation was combined with simultaneous SO2 fumigation, there was no additional inhibitory effect on photosynthesis. These findings suggest that water deprivation do not increase sensitivity towards SO2 pollution in A. capensis. Fumigation with SO2, singly or in combination with water deprivation also had no major effect on chloroplast ultrastructure. It appears that A. capensis is remarkably resistant to SO2 pollution even in the presence of low water availability, which is a common phenomenon in desert ecosystems. Since A, capensis seems to be highly tolerant to S02, its suitability as an indicator species for the detection of SO2 pollution effects at Skorpion Zinc mine is questionable. Because water availability dominates the physiological/biochemical response in this species, subtle SO2 pollution effects might be difficult to detect against this dominant background. The high water content of A. capensis and similar succulents might act as a substantial sink for SO2 and could convey considerable tolerance against this form of air pollution. / Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2006.

Das Ziel der Arbeit war die Entwicklung einer Begrünungsmethode für Gleisbette mit schneller Vegetationsentwicklung. Zur Begrünung wurden Sedumpflanzen verwendet, die durch den Einsatz von Bacillus subtilis, Lactobacillus und Nährsubstrat (allein und kombiniert) in verschiedenen Vegetationssystemen auf dem nährstoffarmen Standort Gleisbett etabliert werden sollten. Die Aktivität der inokulierten Mikroorganismen wurde indirekt über den Einfluss auf die Vegetationsleistung ermittelt. Der Einsatz von B. subtilis und Lactobacillus bewirkte eine signifikante Wachstumsförderung der oberirdischen Pflanzenteile. Die Anwendung von Nährsubstrat als Bodenhilfsmittel war ebenfalls für das Pflanzenwachstum besonders wirksam, sowohl allein appliziert als auch in Kombination mit den Bakterien. Darüber hinaus führte die Applikation der Bakterien und des Nährsubstrates zu einem reduzierten Trockenstress auf Geotextilmatten. Die Wahl des Substrates war entscheidend für die Wirksamkeit der Bakterieninokulation. Jedoch hatten höhere Versuchstemperaturen und pH-Werte ebenfalls eine positive Wirkung auf das Pflanzenwachstum. Diese Einflüsse waren in Kombination mit Ziegelbruchsubstrat wesentlich stärker als mit den anderen getesteten Substrattypen. Das Ziegelbruchsubstrat kombiniert mit einer Bakterien- und Nährsubstratbehandlung bewährte sich als günstiges, umweltschonendes Begrünungsverfahren von Gleisbettanlagen. / The aim of the present study was to develop and improve existing methods for the remediation of rail tracks using soil borne bacteria. Through the use of Bacillus subtilis and Lactobacillus ssp. alone and in combination with a nutrient solution three different growth substrates were tested. The substrates were brick chips, textile mats, and mineral wool mats. Brick chips were tested along railway tracks in Munich but all three substrates were tested along an artificial rail track on the experimental station at the Humboldt University-Berlin. Plants selected for remediation belong to the genus Sedum, which is relatively tolerant to dry conditions. The use of Bacillus subtilis and Lactobacillus in combination with a nutrient solution improved plant growth significantly. Plants inoculated with bacteria showed increased growth during the first three months but after four months there was no longer any significant difference between treatments. The addition of nutrient solution alone improved plant growth. Plant growth was significantly different on all three substrates, whereas brick chips were the best substrate. The results of this study indicate that the quality of the substrate is the most important factor for remediation and greening of rail tracks. Both bacteria tested had only a limited effect. High temperature and pH resulted in larger Sedum plants in the open field. Brick chips are a cheap substrate which can be used for rail track greening. The rapid growth of plants can be influenced by the application of an additional nutrient solution as well as inoculation with Lactobacillus and/or B. subtilis.

Contexte : Le commerce illégal d’espèces sauvages implique d’importants enjeux sociétaux, mais à ce jour peu d’études s’intéressent au commerce illégal de succulentes qui sont des plantes connues pour transformer l’eau en suc leur permettant ainsi de survivre dans des régions arides (ex. cactus, aloès, etc.). S’intéresser à ce commerce est d’autant plus crucial que la passion des consommateurs pour les succulentes ne cesse de croître, poussant alors certains à adopter des comportements illégaux. Le manque de contrôle de la part des autorités compétentes et l’adoption de ces comportements illégaux favorisent le développement d’un commerce illégal de succulentes. De plus, ce commerce s’est numérisé, posant donc de nouveaux enjeux liés à l’utilisation des nouvelles technologies. Ainsi, le mémoire vise à comprendre le choix des consommateurs à importer illégalement des succulentes à l’aide de plateformes numériques. Méthodologie : Les données analysées sont issues de 14 entrevues semi-dirigées menées auprès de consommateurs ayant importé au moins une fois illégalement une succulente à l’aide d’une plateforme de commerce en ligne. Durant les entrevues, plusieurs thèmes ont été abordés tels que le contexte d’achat, les connaissances des participants concernant les lois et enjeux environnementaux et leur perception vis-à-vis de leur comportement. Résultats : Les consommateurs sont initialement motivés à importer illégalement des succulentes au nom de leur passion et/ou pour des raisons économiques. Le marché illégal de succulentes en ligne représente alors une véritable opportunité pour eux de le faire, puisqu’ils considèrent que les succulentes y sont facilement accessibles, diversifiées et à des prix concurrentiels. Parallèlement, les risques de se faire appréhender par les autorités ou de se faire frauder sont perçus comme faibles. En revanche, ces derniers naviguent dans une zone grise alimentée par leur manque de connaissances concernant le processus légal ainsi que par l’asymétrie d’information du marché. Cette dernière les empêche alors de bien évaluer la source du produit et les risques associés. Face à cette incertitude, les consommateurs recourent à plusieurs justifications permettant de se persuader, mais également de convaincre autrui que leurs comportements sont acceptables. Implications : Ce mémoire fournit une meilleure compréhension du comportement illégal des consommateurs de succulentes, puisqu’il apporte à la fois des explications théoriques et empiriques afin de comprendre ce phénomène. Finalement, cette étude offre des pistes d’interventions intéressantes à l’élaboration de campagnes d’éducation et de sensibilisation visant la réduction de cette demande qui suscite d’important risques environnementaux. / Context: The Illegal wildlife trade (IWT) raises important environmental issues. However, up to now, few studies have focused on the illegal trade in succulents. Succulents correspond to a type of plant which are known for transforming water into juice, enabling them to survive in arid or semi-arid regions. Furthermore, consumers' passion for these plants is growing all the time. But this passion leads some individuals to engage in illegal behaviour. The lack of control by the competent authorities and the adoption of these illegal behaviours encourage the development of an illegal trade in succulents. What's more, this trade has gone online, raising new issues linked to the use of new technologies. This master’s thesis aims to understand consumers' choice to import succulents illegally using digital platforms. Methods: The data analyzed come from 14 semi-structured interviews conducted with succulent consumers who had illegally imported a succulent at least once using an online trading platform. During the interviews, several themes were addressed, such as the purchasing context, participants' knowledge of trade laws and environmental issues, and their perception of their behavior. Results: Consumers are initially motivated to illegally import succulents in the name of their passion and/or for economic reasons. The illegal online succulent market then represents a real opportunity for them to do it. Indeed, they consider succulents to be easily accessible, diversified and competitively priced. At the same time, the risk of being caught by the authorities or defrauded is perceived as low. However, consumers navigate in a grey zone fuelled by their lack of knowledge of the legal process and the asymmetry of market information. The latter prevents them from properly assessing the source of the product and the associated risks. Faced with this uncertainty, consumers use several justifications to persuade themselves and others that their behaviors are acceptable. Implications: This master’s thesis provides a better understanding of the illegal behaviour of passionate succulent consumers, since it offers both theoretical and empirical explanations for this phenomenon. Finally, this research offers interesting avenues of intervention for the development of education and awareness campaigns aimed at reducing this demand, which gives rise to significant environmental risks.