• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 21
  • 18
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 57
  • 19
  • 16
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 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.
41

Paprastojo kiečio (Artemisia vulgaris l.) biologinių savybių priklausomybė nuo augavietės edafinių ir klimatinių ypatumų / Artemisia vulgaris physiological-biochemical parameters depending on site edaphic and climatic factors

Vičkutė, Asta 15 June 2009 (has links)
Magistro darbe tiriama paprastojo kiečio (Artemisia vulgaris L.) biologinių savybių priklausomybė nuo tyrimo vietos edafinių ir klimatinių ypatumų. Darbo objektas – paprastasis kietis (Artemisia vulgaris L.). Darbo tikslas – nustatyti įvairias paprastojo kiečio fiziologinias charakteristikas. Darbo metodai – Tyrimai atlikti LŽŪU aplinkotyros laboratorijoje. Azoto kiekis nustatytas Kjeldalio metodu. Dirvožemio sunkiųjų metalų analizė atlikta mėginius deginant „Multiwave 3000 Synthos 3000“ ir gauto ekstrakto elementų koncentracijos nustatytos pagal standartą LST ISO 11047 (Dirvožemio kokybė), naudojant liepsnos ir elektoterminės atominės absorbcijos spektrometrinius metodus. Flavonoidų kokybinė ir kiekybinė sudėtis nustatyta efektyviosios skysčių chromatografijos metodu. Epifitinių mikroorganizmų kiekis nustatytas naudojant sojos leptono ir Salsbūro agarą. Duomenys įvertinti, panaudojant Excel ir SPSS statistines programas. Darbo rezultatai. Atlikus tyrimus įvertintos paprastojo kiečio fiziologinės savybės ir gauti tokie rezultatai: dirvožemio geležies, cinko nikelio koncentracijos buvo didžiausios 2 km atstumu nuo AB “Achema” (prie geležinkelio), 0,5 km atstumu nuo AB „Achema“ – vidutinės, mažiausios – Kačerginės; dirvožemio ir paprastojo kiečio įvairių augalo dalių azoto koncentracija išsidėsto tokia tvarka: dirvožemio < šaknų < stiebų < žiedų < lapų; tarp visų tyrimo vietų reikšmingai skyrėsi paprastojo kiečio sausoji masė. Pagal stiebus ir žiedynus A. vulgaris L... [toliau žr. visą tekstą] / Topic of the diploma (Master degree in Ecology) was evaluation of Artemisia vulgaris L.) physiological-biochemical parameters depending on site edaphic and climatic factors. Research object - Artemisia vulgaris L. Purpose of the work – evaluation of various morphophysiological-biochemical parameters of Artemisia vulgaris L. in respect of the distance from the nitrogen fertilizer factory, ommiting ammonia also in respect of heavy metal concentrations in the soil. Methods. Analyses were performed at the laboratory of Environment of University of Agriculture of Lithuania. Concentration of nitrogen was determined by Kjeldal method. For the determination of the heavy metal concentration the samples of the soil were burned by „Multiwave 3000 Synthos 3000“ and obtained extracts were analysed following protocol for the soil quality (LST ISO 11047), using method of flame and electrothermal atomic absorbtion spectrometry. The amount of epiphytic microorganisms was determined bacteria on soya agar and fungi on Salsbur medium. Data were analysed using Excel and SPSS statistical packages. Results and discussion. Concentration of the nitrogen in the soil and leaves of Artemisia vulgaris, falls in the following order: site, located in 2 km distance from the factory < site located besides the factory < Kačerginė site located in 45 km distance from the factory (as a control, „relatively clean“ site). In the sampling sites of Artemisia vulgaris concentrations of heavy metal (Pb, Cr, Ni... [to full text]
42

Dirvinio ir karčiojo kiečių biologinės charakteristikos nevienodos amoniakinės taršos vietose / Various biological parameters of Artemisia absinthum L. and Artemisia campestris L. growing in the areas effected by different level pollution by ammonia

Skėrytė, Neringa 15 June 2009 (has links)
Magistro darbe tiriama dirvinio ir karčiojo kiečių biologinės cherakteristikos nevienodos amoniakinės taršos vietose. Darbo tema: Dirvinio ir karčiojo (pelyno) kiečių biologinės charakteristikos nevienodos amoniakinės taršos vietose Darbo objektas - dirvinis kietis ir pelynas - paplitę Lietuvoje augalai, pasižymintys gausiomis vaistingomis medžiagomis - eteriniais aliejais ir flavonoidais. Darbo tikslas - nustatyti skirtingų (AB "Achema" atžvilgiu) vietų karčiojo kiečio, pelyno (Artemisia absinthum L.) ir dirvinio kiečio (Artemisia campestris L.) fiziologines-biochemines savybes. Darbo metodai - Kjeldalio metodas azoto nustatymui, atominės absorbcijos spektroskopija sunkiųjų metalų nustatymui. Salsburo ir sojos agaras mikroorganizmų auginimui. Darbo rezultatai - ištirtos tokios dviejų rūšių kiečių fiziologinės-biocheminės savybės: dirvožemio azoto ir sunkiųjų metalų koncentracija, kiečių įvairių organų masė, kiečių įvairių organų azoto koncentracija, kiečių antžeminių organų flavonoidų koncentracija, kiečių epifitinių mikroorganizmų skaičius, įvertinta kaip oro amoniakinė tarša ir dirvožemio tarša sunkiaisiais metalais reikšmingai įtakoja ištirtus kiečių fiziologinius rodiklius. Atlikti tyrimai parodė, kad dirvožemio ir abiejų rūšių augalų azoto koncentracija išsidėsto tokia tvarka: dirvožemio < stiebų < lapų < žiedų < skrotelių. Tirtos vietos pagal dirvožemio ar organų azoto koncentraciją nesiskyrė. Didžiausios dirvožemio sunkiųjų metalų koncentracijos nustatytos abiejų... [toliau žr. visą tekstą] / Topic of the master degree diploma: Various biological parameters of Artemisia absinthum L. and Artemisia campestris L. growing in the areas effected by different level pollution by ammonia. Artemisia absinthum L. and Artemisia campestris L. are common wild growing species in Lithuania. Despite these species are rich in flavonoids and essential oils till now in our country biology and biochemistry of these species have not received bigger attention. Present work aimed at evaluation of Artemisia absinthum L. and Artemisia campestris L. physiological-biochemical parameters depending on sampling site distance from the nitrogen fertilizer factory. Methods. Following physiological-biochemical parameters of these species were analysed: soil nitrogen and heavy metal concentrations, dry mass and nitrogen concentration of various organs of selected plant species, abundance of epiphytic microflora. Results. During vegetation period sampling was performed three times: in July, 2; July, 24, and September, 24. Obtained parameters were evaluated in respect of aerial ammonia pollution and heavy metal pollution of the soil. Present study showed that nitrogen concentration of the soil and various organs of both Artemisia species fell into following ascending order: soil < stems < leaves < inflorescences and fruits < rosettes. Between selected sites no differences were observed according to the soil and plant nitrogen concentration. The highest concentrations of heavy metals were observed... [to full text]
43

Ecologia de Cattleya coccinea (Lindl.) RCHB. F. e Coppensia ranifera (Lindl.) F. Barros & V.T. Rodrigues (Orchidaceae) em fragmentos de floresta ombrófila mista e propagação in vitro de Coppensia ranifera / Ecology of Cattleya coccinea (Lindl.) RCHB. F and Coppensia ranifera (Lindl.) F. Barros & V.T. Rodrigues (Orchidaceae) in mixed ombrophilos forest fragments and propagation in vitro Coppensia ranifera

Dill, Leandro 26 July 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-27T16:48:15Z No. of bitstreams: 1 PGPV16MA210.pdf: 1614873 bytes, checksum: 236bab6cf01b676397429dd551089261 (MD5) / Made available in DSpace on 2018-02-27T16:48:15Z (GMT). No. of bitstreams: 1 PGPV16MA210.pdf: 1614873 bytes, checksum: 236bab6cf01b676397429dd551089261 (MD5) Previous issue date: 2016-07-26 / Capes / Cattleya coccinea and Coppensia ranifera are epiphytic orchids, which have ornamental potential. Understanding how is the behavior of those species on their performance environments, along with in vitro culture of research is fundamental to building solid plans for the use and conservation of natural resources. We evaluated the occurrence of C. coccinea in three installments in the conservation unit complex Serra da Farofa in Urupema, SC; and C. ranifera in a forest fragment of a particular property in Brunópolis, SC. the frequencies of orchids were analyzed in vertical strata, the points chains (north, south, east and west) and correlation with height and diameter. In micropropagation C. ranifera protocorms we were used germinated in vitro longitudinally sectioned (2 mm) in medium Knudson C stationary and gelled liquid, supplemented with thidiazuron (TDZ) (0, 1, 2, 4 and 8 uM) to induce protocorm-like structures (ESP). For regeneration of plantlets was used in medium lacking growth regulators culture. For C. coccinea were recorded in 1398 orchids distributed in 258 phorophytes. Drimys angustifolia corresponded to 65.1% of phorophytes and held 72.2% of orchids. The Middle Fuste of phorophytes concentrated 68.7%, and the North face took 40.0% of orchids. The positive correlation to the height of phorophyte (r = 0.93) and diameter classes (r = 0.95) depending on the frequency of orchids, where 7.6 m center class obtained 32% of orchids and phorophytes; and 13,4cm class center obtained 30% of orchids and phorophytes. C. To ranifera frequencies of orchids were analyzed in vertical layers, positions in the chains, and correlation with height and diameter. They sampled 473 individuals of C. ranifera distributed in 72 phorophytes. Lamanonia ternata recorded 34.7% of phorophytes and took 42.5% of orchids. The Middle Fuste of phorophytes concentrated 54.8% and 40.6% north face orchids. Positive correlation was found to the height of phorophyte (r = 0.25) and negative for diametric classes (r = -0.88) depending on the frequency of orchids, where 14.4m center class obtained 17% of orchids and of phorophytes; the 17.5cm class center obtained 20% of orchids and phorophytes. The ESP formation occurs by direct route, without callus. The use of the liquid culture medium is more efficient than the medium gelled with respect to the number of ESP formed per explant. In liquid culture medium the highest percentage of formation and more ESP per explant occurs with the addition of 4 uM TDZ. It was established an efficient method for in vitro propagation C. ranifera, using thin layer technique cell (TCL), the efficiency (conversion percentage) in plantlet regeneration gelled media is higher than in the liquid medium. The data indicate colonization capacity and the importance of conservation actions of orchid species / Cattleya coccinea e Coppensia ranifera são orquídeas epífitas, que possuem potencial ornamental. Entender como se dá o comportamento dessas espécies em ambientes de sua ocorrência, juntamente com pesquisa de cultivo in vitro é fundamental para construção de planos sólidos para o uso e conservação dos recursos naturais. Avaliou-se a ocorrência de C. coccinea em três parcelas na unidade de conservação Complexo Serra da Farofa, em Urupema, SC; e de C. ranifera em um fragmento de floresta de uma propriedade particular, em Brunópolis, SC. Foram analisadas as frequências de orquídeas em estratos verticais, aos pontos cadeias (norte, sul, leste e oeste) e correlação com a altura e diâmetro. Na micropropagação de C. ranifera foram utilizados protocormos germinados in vitro seccionados longitudinalmente (2 mm) em meio Knudson C líquido estacionário e gelificado, suplementado com thidiazuron (TDZ) (0, 1, 2, 4 e 8 M) para a indução de estruturas semelhantes a protocormos (ESP). Para a regeneração de plântulas foi utilizado meio de cultura isento de fitorreguladores. Para C. coccinea foram registradas 1398 orquídeas, distribuídas em 258 forófitos. Drimys angustifolia correspondeu a 65,1% dos forófitos e sustentou 72,2% das orquídeas. O Fuste Médio dos forófitos concentrou 68,7%, e a face Norte abrigou 40,0% das orquídeas. A correlação positiva para a altura do forófito (r=0,93) e classes Diamétricas (r=0,95) em função da frequência de orquídeas, onde centro de classe 7,6m obteve 32% das orquídeas e forófitos; e o centro de classe 13,4cm obteve 30% das orquídeas e forófitos. Para C. ranifera foram analisadas as frequências de orquídeas em estratos verticais, nas posições cadeias, e correlação com a altura e diâmetro. Foram amostrados 473 indivíduos de C. ranifera, distribuídas em 72 forófitos. Lamanonia ternata registrou 34,7% dos forófitos e abrigou 42,5% das orquídeas. O Fuste Médio dos forófitos concentraram 54,8% e a face Norte 40,6% orquídeas. Foi verificado a correlação positiva para a altura do forófito (r=0,25) e negativa para classes Diamétricas (r= - 0,88) em função da frequência de orquídeas, onde centro de classe 14,4m obteve 17% das orquídeas e dos forófitos; o centro de classe 17,5cm obteve 20% das orquídeas e forófitos. A formação de ESP ocorre por via direta, sem calo. A utilização de meio de cultura líquido é mais eficiente do que o meio gelificado com relação ao número de ESP formado por explante. Em meio líquido de cultura o maior percentual de formação e o maior número de ESP por explante ocorre com a adição de 4 M de TDZ. Estabeleceu-se um método eficiente de propagação in vitro para C. ranifera, utilizando a técnica de camada fina celular (TCL), a eficiência (percentual de conversão) na regeneração de plântula em meio gelificado é maior do que em meio líquido. Os dados indicam a capacidade de colonização e a importância de ações de conservação das espécies de orquídeas
44

The impact of tree size, sun exposure and geographical position on the species richness of epiphytic lichens associated with coarse oak trees in southern Sweden / Inverkan av trädstorlek, solexponering och geografisk position på artrikedom av epifytiska lavar på grova ekar i södra Sverige

Melin, Emelie January 2018 (has links)
Felling of old trees as well as changes in land use and management of wooded pastures has led to the decline of biodiversity associated with old deciduous trees in Europe. This also applies to Sweden’s most species rich tree, the oak tree (Quercus robur), which changes with age and develops, for example, a rougher bark structure, deeper bark fissures and cavities. These give rise to several different microhabitats that favor the presence of lichens, mosses and wood-dependent organisms. To preserve the biodiversity, environmental conditions linked to a high diversity need to be identified and described, of which indicator species are a simplified way of measuring diversity. Epiphytic lichens are well-used indicators of environmental conditions because of their habitat specificity, longevity and sensitivity to air quality and humidity. In this study, the impact of regional (latitude, longitude and dominated landscape) and local (diameter and sun exposure) environmental variables on species richness and occurrence of epiphytic lichens on coarse oak trees (Quercus robur) were analyzed in meadows and pastures in southern Sweden with generalized linear models (GLM). A total number of 2346 oak trees were included in the study, of which about 47 % had presence of at least one of the studied lichen species. All environmental variables demonstrated significant effects on species richness, of which the regional had the greatest effect. Also with the species-specific analyses the same effect of the regional variables was found, while single species showed different requirements for the local factors. The results indicate that global warming may move the Swedish species composition more to the Northeast and that increased homogenization of the landscape may threaten the diversity attached to oaks. The results also demonstrate the importance of preserving a varied landscape with trees of different sizes, ages and different levels of sun exposure to accommodate a greater diversity of epiphytic species, but also other species linked to oak trees.
45

Filosfera da Mata Atlântica: isolamento e sistemática de cianobactérias, bioprospecção e caracterização da comunidade diazotrófica / Phyllosphere of the Atlantic Forest: isolation and systematic of Cyanobacteria, bioprospection and diazotrophic community characterization

Ana Paula Dini Andreote 30 January 2014 (has links)
A filosfera da Mata Atlântica é um importante nicho de colonização por micro-organismos, cuja comunidade ainda é pouco conhecida. Algumas bactérias associadas à superfície das folhas possuem habilidade de fixar nitrogênio, mineralizar substratos orgânicos e também suprir as árvores com dióxido de carbono e fatores de crescimento. Este trabalho teve como objetivo gerar informações sobre a comunidade cianobacteriana que coloniza a filosfera de algumas plantas da Mata Atlântica e investigar a comunidade diazotrófica presente nesse habitat. Um total de 40 linhagens de cianobactérias da filosfera de Merostachys neesii (bambu), Euterpe edulis (palmeira Juçara), Guapira opposita e Garcinia gardneriana foram isoladas e cultivadas. Os isolados foram caracterizados por análises morfológicas e filogenia do gene 16S RNAr. Essa abordagem permitiu a identificação de uma linhagem do gênero Nostoc, sete Desmonostoc, seis Leptolyngbya, uma Oculatella, cinco Brasilonema, uma Pleurocapsa e duas Chroococcidiopsis. Dezessete linhagens (uma Microchaetaceae, dez Nostocaceae e seis Pseudanabaenaceae) não puderam ser identificadas ao nível de gênero. Vinte e seis linhagens (24 pertencentes às ordens Nostocales e duas à Pseudanabaenales) foram caracterizadas como diazotróficas pela amplificação, sequenciamento e filogenia do gene nifH. Além disso, caracterizou-se o perfil de fixação biológica de nitrogênio da linhagem Desmonostoc sp. CENA362. Com relação ao potencial biotecnológico dessas linhagens, treze isolados foram identificados como potenciais produtores de ácido indol acético (IAA) de acordo com o teste Salkowski. Diversas linhagens apresentaram genes associados à via biossintética do inibidor de protease microviridina, sendo que três delas codificam para novas variantes. Além disso, dez linhagens foram identificadas como potenciais produtoras aeruginosina, três de cianopeptolina e três de microcistina. A comunidade bacteriana diazotrófica avaliada por pirosequenciamento do gene nifH apresentou um perfil de variação espécie-específica para Proteobacteria e uma correlação positiva entre a riqueza e a fixação biológica de nitrogênio. Neste estudo, cianobactérias que habitam a filosfera da Mata Atlântica foram isoladas estão sendo mantidas em condições de cultivo. Novos táxons foram descobertos e vários gêneros conhecidos foram descritos pela primeira vez neste hábitat, o que contribuiu para o aprimoramento da sistemática de Cyanobacteria. As linhagens em cultivo e as informações geradas sobre os seus compostos metabólitos representam uma valiosa fonte para estudos posteriores. Além disso, informações sobre a comunidade bacteriana diazotrófica da filosfera pode auxiliar no entendimento da dinâmica do nitrogênio, elemento limitante e pouco disponível na Mata Atlântica / The phyllosphere of the Atlantic Forest is an important niche for colonization by microorganisms, whose community is still little known. Some bacteria associated with leaf surfaces may possess the ability to fix nitrogen, mineralize the organic substrates and also supply the trees with carbon dioxide and growth factors. Therefore, this study aimed to generate information about cyanobacterial community that colonize the phyllosphere of some plants of the Atlantic Forest and investigated the diazotrophic community in this habitat. A total of 40 strains of Cyanobacteria from the phyllosphere of Merostachys neesii (bamboo), Euterpe edulis (Juçara palm), Garcinia gardneriana and Guapira opposita was isolated and cultivated. The isolates were characterized by morphological analyses and phylogeny of the 16S rRNA gene. This approach allowed the identification of one strain of the genus Nostoc, seven Desmonostoc, six Leptolyngbya, one Oculatella, five Brasilonema, one Pleurocapsa and two Chroococcidiopsis. Seventeen strains (one Microchaetaceae, ten Nostocaceae and six Pseudanabaenaceae) could not be identified at the genus level. Twenty-six strains (24 belonging to Nostocales and two belonging to Pseudanabaenales) were characterized as diazotrophic by amplification, sequencing and phylogeny of nifH gene. Also, it was characterized the profile of biological nitrogen fixation for the strain Desmonostoc sp. CENA362. Regarding the biotechnological potential of these strains, thirteen strains were identified as potential producers of indole acetic acid (IAA) according to Salkowski test. Several strains presented genes involved in the biosynthetic pathway of the protease inhibitor microviridin, three of them encoding putative novel variants. Moreover, ten strains were identified as potential producers of aeruginosin, three of cyanopeptolin and three of microcystin. The diazotrophic bacterial community evaluated by pyrosequencing of the nifH gene showed a profile of variation plant species-specific for Proteobacteria, and a positive correlation between richness and biological nitrogen fixation. In this study, cyanobacteria that inhabiting Brazilian Atlantic Forest phyllosphere were isolated and are been maintained in culture conditions. New taxa were discovered and several known genera were described for the first time in this habitat, which contributed to improvement of the cyanobacterial systematic. The culturable strains and the information generated about their metabolites compounds represent a valuable source for further studies. In addition, information about the diazotrophic bacterial community inhabiting the phyllosphere may help in understanding the dynamics of nitrogen, a limiting and low available element in Atlantic Forest
46

Response of the Epiphytic Algal Communities to Experimentally Elevated Nutrient Levels in Intertidal Salt Marsh Habitats

Verhulst, Stephanie 01 January 2013 (has links)
Epiphytes are organisms attached to plants and are responsible for the majority of primary productivity in many aquatic systems. While epiphytes serve as a valuable food resource to herbivores, they may prove deleterious to the host plant by competing for light and nutrients, as well as increasing sheer stress. This study evaluated the impacts of nutrient additions, nitrogen and phosphorus, on the epiphytic algal community on Spartina alterniflora over the course of two growing seasons. Three nutrient treatments (N, P, and N+P) and one control treatment were placed in a salt marsh in the Tolomato River during the growing seasons of 2011 and 2012. To assess community development, we examined biomass, ash-free dry mass (AFDM), chlorophyll-a levels, cell counts, and community diversity by algal division. The nutrient additions did not significantly alter any of the measured parameters in either sampling year. However, the sampling month did have a significant (pa, and community composition. A total of 155 infrageneric taxa were identified. Biomass tended to be dominated by diatoms and red algae, while cyanobacteria were most abundant. In both years, biomass was highest in the spring with a second smaller pulse in the fall. Conversely, chlorophyll-a levels varied between the years and did not show the same monthly patterns as AFDM. A laboratory study subjecting S. alterniflora to the same nutrient additions also found no significant effects of increased nutrients, but did observe temporal changes in biomass and chlorophyll-a levels. Overall, epiphytic growth was not influenced by nutrient additions in this study suggesting that this and other similar salt marsh systems may be resilient to anthropogenic eutrophication. Instead, other factors, such as light and herbivory, likely played a key role in determining epiphytic algal growth and community composition.
47

Plži, stromy, pH, podloží a epifytické lišejníky / Gastropods, trees, pH, subsoil and epiphytic lichens

Pelant, Filip January 2020 (has links)
Epiphytic lichens are under considerable grazing pressure due to invertebrate lichenivores, mostly gastropods. Preferences of tree-climbing gastropods affect vertical distribution of lichens, their habitat preferences and whole area of distribution. Higher grazing pressure is expected on sites with basic subsoil and sufficient sources of calcium, where the abundance of gastropods is higher. Most of researches about the topic of grazing pressure were therefore conducted on such sites, although this hypothesis has never been formally tested. Epiphytic communities are also affected by pH and other properties specific to its photophyte. Nevertheless, it is not known, if the same applies for grazing gastropods and how is the grazing pressure affected by tree species. I have addressed these questions in my thesis. I set an 80-days-long field transplantation experiment in the mixed forest of Moravský kras (South Moravia, Czech Republic). Glass fiber meshes with lichen thalli were placed on sixty trunks of three tree species (Carpinus betulus - hornbeam, Abies alba - fir, Fagus sylvatica - common beech) on both calcareous (limestone) and acidic (granodiorite) sites. Abundance and diversity of gastropods were measured. Determined grazing pressure was higher than pressure detected by other authors and was...
48

Diverzita, ekologie a metodika průzkumu lišejníků pralesovitých porostů ve střední Evropě / Diversity, ecology and methods of the research of lichens in old-growth forests in Central Europe

Malíček, Jiří January 2016 (has links)
1 Abstract Forests are the native Central European vegetation, which have dominated in the landscape for the last c. 10,000 years. Stands with an oak and hornbeam dominance occupied lower elevations before human colonization, beech and silver fir-beech forests middle elevations and spruce stands at higher elevations. Only a few remnants of forests, which can be regarded as primeval or with a minimal impact of forest management, have survived in densely populated Central Europe. Examples of the most preserved primeval forests are Rothwald (Austria), Białowieża (Poland, Belorussia), Stužica/Stuzhytsia (Slovakia, Ukraine) and Boubín (Czech Republic). Although these sites are small and isolated, they are local diversity centers for many organisms, mainly for fungi, lichens and bryophytes, refugia for numerous endangered species and some of them have their last localities there. Epiphytic and epixylic lichens are an ideal model group for studies about forests because they sensitively indicate management, continuity, heterogeneity and age of a woodland. Therefore they could help us to answer many important questions about the conservation of natural forests. This thesis comprises several different points of view on lichens in Central European forests and its aim is to join these heterogeneous fields into one...
49

Modèles et outils génériques pour mettre en place des systèmes d’assistance épiphytes / Generic models and tools to setup epiphytics assistance systems

Ginon, Blandine 15 September 2014 (has links)
Cette thèse en informatique se situe plus particulièrement dans le domaine de l’ingénierie des connaissances. Elle concerne la mise en place a posteriori de systèmes d’assistance dans des applications existantes, en adoptant une démarche générique. Afin de permettre la mise en place de systèmes d’assistance dans des applications existantes sans avoir à les redévelopper ni à accéder à leur code source, nous avons choisi d’adopter une démarche entièrement épiphyte. Nous avons proposé un processus d’adjonction d’un système d’assistance à une application-cible de manière épiphyte. Il est constitué de deux phases : la spécification et l’exécution de l’assistance. La phase de spécification de l’assistance permet à un expert, le concepteur de l’assistance, de représenter ses connaissances relatives à l’application-cible et à l’assistance qu’il souhaite mettre en place dans celle-ci. La phase d’exécution de l’assistance exploite ces connaissances pour fournir aux utilisateurs finaux l’assistance souhaitée par le concepteur. Pour permettre d’une part la spécification de l’assistance par un concepteur potentiellement non-informaticien, et d’autre part l’exécution automatique de l’assistance spécifiée, nous avons proposé un langage pivot : aLDEAS. Ce langage graphique permet de définir des systèmes d’assistance très variés sous la forme d’un ensemble de règles. Nos propositions théoriques ont été mises en oeuvre de façon opérationnelle à travers le système SEPIA, constitué de différents outils. L’éditeur d’assistance de SEPIA est destiné aux concepteurs d’assistance et met en oeuvre la phase de spécification de l’assistance. Il fournit aux concepteurs d’assistance une interface pour manipuler les éléments du langage aLDEAS, afin de définir un système d’assistance sous la forme d’un ensemble de règles aLDEAS. Les systèmes d’assistance aLDEAS peuvent ensuite être exécutés par le moteur générique d’assistance qui met en oeuvre la phase d’exécution de l’assistance. Il permet de fournir l’assistance ainsi définie aux utilisateurs finaux des applications-cibles. Pour cela, le moteur d’assistance s’appuie sur différents outils épiphytes, pour surveiller et inspecter l’application-cible, ainsi que pour réaliser les actions d’assistance pour l’utilisateur final. Bien que mettant en oeuvre des modèles génériques, le système SEPIA permet de mettre en place de l’assistance finement contextualisée et adaptée aux spécificités, d’une part de l’application-cible, et d’autre part des utilisateurs finaux. / This thesis in computer science is situated more particulary in the field of knowledge engineering. It concerns the a posteriori setup of assistance systems in existing applications, while having a generic approach. In order to setup the setup of assistance systems in existing applications without a need to redevelop it or to access its source code, we choose to have a fully epiphytic approach. We proposed a adjunction process of an assistance system to a target-application with a epiphytic manner. It is constituted of two phases: the specification and the execution of the assistance. The assistance specification phase enables an expert, the assistance designer, to represent his knowledge relative to the target-application and to the assistance that he wishes to setup. The assistance execution phase uses this knowledge to provide the target-application end-users with the assistance wished by the designer. To make possible on the one hand the assistance specification by an assistance designer potentially non-computer scientist, and one the second hand the automatic execution of the specified assistance, we propose a pivot language: aLDEAS. This graphical language makes possible the definition of very varied assistance systems, with the shape of a set of rules. Our theoretical propositions have been implemented through the SEPIA system, constituted of different tools. The SEPIA assistance editor is aimed at assistance designers, and it implemented the assistance specification phase. It provided the assistance designers with an interface to handle aLDEAS elements in order to define assistance rules. These rules can then be executed by the SEPIA generic assistance engine, which implements the assistance execution phase. It provides the target-application end-users with the specified assistance. For this purpose, the assistance engine manages different epiphytic tools, in order to monitor and inspect the target-application, and to perform the assistance actions. The models implemented through the SEPIA system are generic, but it make possible the setup of assistance systems specifically suited on the one hand to their target-application, and on the second hand to the end-users.
50

Efeitos funcionais e filogenéticos nas relações entre forófitos e epífetos vasculares

Vieira, Pedro Rates January 2012 (has links)
Os padrões de associação entre epífitos e forófitos não podem ser considerados espécie-específicos, mas as árvores que os epífitos colonizam também não são um conjunto aleatório das espécies forofíticas de um determinado local. Ao invés disso, parece haver uma preferência de certos epífitos por diferentes forófitos. No entanto, se conhece pouco sobre os fatores que determinam essa preferência. Nosso objetivo nesse trabalho é avaliar como os atributos funcionais e a filogenia dos epífitos vasculares influenciam na associação dos epífitos com os forófitos em uma Floresta Ombrófila Mista no sul do Brasil. Para isso nós (1) investigamos padrões de associação positiva e negativa entre grupos funcionais de epífitos e grupos de forófitos e como a diversidade e os atributos funcionais dos epífitos variavam em função do tamanho do forófito e (2) inferimos sobre a existência de sinal filogenético no uso de árvores hospedeiras pelos epífitos, procuramos por estrutura filogenética nas comunidades epifíticas e investigamos diferenças de composição filogenética de epífitos vasculares em diferentes clados de forófitos. Foram amostrados 70 forófitos compreendendo 15 espécies pertencentes a diversos clados e com arquiteturas e características variadas. A amostragem compreendeu 31 espécies epifíticas com os principais clados sendo Polypodiaceae, Bromeliaceae e Orchidaceae. A associação de grupos de epífitos vasculares com diferentes grupos de forófitos sugere que as características dos forófitos proporcionam ambientes contrastantes e que diferentes valores de atributos são necessários para colonizar esses ambientes. Mais especificamente espécies epifíticas com menor área específica foliar (SLA) parecem predominar em árvores maiores e maior SLA em árvores menores. Encontramos sinal filogenético na utilização dos forófitos, sugerindo que a conservação das interações com os forófitos deve ter sido importante ao longo da evolução dos epífitos. A tendência a agrupamento filogenético nas comunidades epifíticas sugere a influência de filtros ambientais representados pelas diferentes características dos forófitos estruturando as assembleias de epífitos. Clados mais basais de forófitos apresentaram composição filogenética distinta devido, sobretudo, a presença de diferentes clados de monilófitos epifíticos nessas árvores. Angiospermas epifíticas ocorreram principalmente em forófitos pertencente as eurosídeas. A preferência de epífitos por forófitos parece ser influenciada pelo surgimento de novidades morfológicas e ecofisiológicas em alguns clados, enquanto outros mantiveram o seu nicho ancestral. A composição florística das florestas quando da origem dos clados epifíticos também parece influenciar a associação entre epífitos e forófitos. Ao utilizar informações sobre os atributos e filogenia das espécies de epífitos vasculares nós podemos melhor compreender os mecanismos ecológicos e históricos que influenciam os padrões de associação entre epífitos e forófitos. / It has been shown that patterns of association between epiphytes and phorophytes can not be considered species-specific, although the trees that epiphytes colonize are not a random subset of phorophyte species in a particular location. Instead, there seems to be a preference of some epiphytes for different phorophytic species. However, little is known about the factors determining this choice. Our objective in this study is to assess how functional attributes and phylogeny of vascular epiphytes influence the association of epiphytes with the phorophytes in an Araucaria Forest in Southern Brazil. For that we (1) investigated the positive and negative association patterns between functional groups of epiphytes and groups of phorophytes and how functional diversity and functional traits of epiphytes varied with host tree size and (2) inferred about the existence of phylogenetic signal on the host trees use by epiphytes, looked for phylogenetic structure in the epiphytic communities and investigated differences in the phylogenetic composition of vascular epiphytes in different phorophyte clades. We used a sample of 70 phorophytes comprising 15 species and belonging to different clades and with different architectures and traits. The sample comprised 31 epiphytic species, the major clades being Polypodiaceae, Bromeliaceae and Orchidaceae. The combination of vascular epiphyte groups with different groups of 15 phorophytes suggests that phorophyte traits provide contrasting environments and that different trait values are needed to colonize these environments. More specifically, epiphytic species with lower specific leaf area (SLA) seem to predominate on larger trees and with higher SLA values on smaller trees. We found phylogenetic signal on the host tree use, suggesting that conservatism of the interactions with phorophytes must have been important throughout the evolution of epiphytes. The tendency to phylogenetic clustering in the epiphytic communities suggests the influence of environmental filters represented by phorophyte traits structuring epiphyte assemblages. More basal clades of phorophytes showed different phylogenetic composition mainly due to the presence of different epiphytic monilophyte clades on these trees. Epiphytic angiosperms occurred mainly on those trees belonging to eurosids. The preference of epiphytes for phorophytes seems to be influenced by morphological and ecophysiological novelties in some lineages, while other clades kept their ancestral niche. The floristic composition of forests at the origins of epiphytic lineages also appears to influence the association between epiphytes and phorophytes. By using information about the traits and phylogeny of species of vascular epiphytes we can better understand the ecological and historical mechanisms that influence the patterns of association between epiphytes and phorophytes.

Page generated in 0.0486 seconds