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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.
11

Ueber das Harz von Dammara orientalis (Manila-Copal), und, Ueber das siebenbürgische Resina Pini von Picea vulgaris (Link)

Koch, M. January 1902 (has links)
Inaugural dissertation (Ph. D.)--Universität Bern. / Includes bibliographical references.
12

Ecophysiological controls of conifer biogeographic distributions

Schmiege, Stephanie Christine January 2021 (has links)
The absence of the majority of conifers from tropical forests remains an unresolved evolutionary and biogeographic enigma. Correlations between a flattened conifer leaf morphology and tropical persistence have led to the hypothesis that shade tolerance is critical for conifer survival in these environments. Yet, little is known of the physiological mechanisms constraining conifer distributions. This dissertation, using the diversity of leaf morphologies and biogeographic distributions found among conifer families, examines this hypothesis from a physiological perspective. The first chapter examines the photosynthetic process in shade-house grown saplings of conifers coexisting in the Central Highlands of Vietnam, an area of unusual tropical conifer diversity. Pinus krempfii, a flat-leaved pine endemic to the densely-canopied tropical forests of Vietnam, demonstrates an intermediate photosynthesis between needle-leaved Pinus and flat-leaved Podocarpaceae, thus providing support for shade tolerance as an important driver of conifer success in tropical forests. In chapter two, respiratory traits are examined in adult conifers growing naturally in the Central Highlands of Vietnam. Flat-leaved conifer species are found to have lower respiration than needle-leaved species. Finally, in chapter 3, the respiratory temperature responses of members from the two largest conifer families, the Pinaceae and Podocarpaceae, are compared. Consistently lower respiration in Podocarpaceae compared to Pinaceae suggests that there are phylogenetic underpinnings to the respiratory differences between the two families. These findings correlate to the biogeographic differences between the two families, with Podocarpaceae being notably more successful in tropical forests than Pinaceae. Together, all three chapters demonstrate that lower foliar carbon fluxes and flattened leaf morphologies are characteristics of a shade tolerance strategy that is necessary for conifer persistence in tropical forests. Ultimately, this dissertation makes a unique link between conifer physiologies and their current biogeographic distributions that will pave the way for a mechanistic tackling of their future survival in a changing climate.
13

The fungal diversity of Pinaceae in Hong Kong

Yeung, Sze-yuen., 楊詩宛. January 2005 (has links)
published_or_final_version / abstract / Ecology and Biodiversity / Master / Master of Philosophy
14

Analysis of yellow "fat" deposits on Inuit boots

Edwards, Howell G.M., Stern, Ben, Burgio, L., Kite, M. January 2009 (has links)
No / Irregular residues of a yellow deposit that was assumed to be seal fat used for waterproofing were observed in the creases of the outer surface of a pair of Inuit boots from Arctic Canada. A sample of this deposit detached from one of these areas on these boots was examined initially by FT-Raman microscopy, from which interesting and rather surprising results demanded further analysis using FT-IR and GC-MS. The non-destructive Raman spectroscopic analysis yielded spectra which indicated the presence of a tree resin from the Pinaceae sp. The Raman spectra were also characteristic of a well-preserved keratotic protein and indicative of adherent skin. Subsequent FT-IR spectroscopic analysis supported the attribution of a Pinaceae resin to the yellow deposit. GC-MS analysis of the same deposits identified the presence of pimaric, sandaracopimaric, dehydroabietic and abietic acids, all indicative of an aged Pinaceae resin. These results confirmed that the Inuit people had access to tree resins which they probably used as a waterproofing agent.
15

NICHE CONSERVATISM OR DIVERGENCE: INSIGHTS INTO THE EVOLUTIONARY HISTORIES OF Pinus taeda, Pinus rigida, AND Pinus pungens

Bolte, Constance E 01 January 2017 (has links)
Environmentally related selective pressures and community interactions are well-documented drivers for niche differentiation, as natural selection acts on adaptive traits best fit for survival. Here, we investigated niche evolution between and within Pinus taeda, Pinus rigida, and Pinus pungens and sought to identify which climate variables contributed to species divergence. We also sought to describe niche differentiation across genetic groupings previously identified for P. taeda and P. rigida. Ecological niche models were produced using Maximum Entropy followed by statistical testing based on a measure of niche overlap, Schoener’s D. Both niche conservatism and niche divergence were detected, thus leading us to conclude that directional or disruptive selection drove divergence of the P. taeda lineage from its ancestor with P. rigida and P. pungens, while stabilizing selection was associated with the divergence of P. rigida and P. pungens. The latter implies that factors beyond climate are important drivers of speciation within Pinus.
16

Caractérisation moléculaire et isotopique de goudrons et résines archéologiques dérivés de conifères en contexte maritime / Molecular and isotopic characterization of archaeological softwood tars and resins in maritime context

Bailly, Lucile 08 April 2015 (has links)
De tous temps, les Pinacées ont été utilisés pour leur résine ou le goudron que l’on peut en tirer, principalement dans le domaine maritime (calfatage, protection des cordages) et pour le poissage d’amphores. Ces travaux ont été consacrés au développement de nouveaux outils moléculaires et isotopiques pour la caractérisation de tels matériaux trouvés en contexte archéologique (distinction goudron / résine, origine taxonomique et géographique, modes de fabrication). Sur la base des outils développés, il apparait que l’utilisation de goudron prévaut dans ce contexte sur celle de résine et que les Pinus, dont les espèces peuvent être partiellement discriminées, sont les principaux Pinacées utilisés. Il a aussi pu être montré que les matériaux de calfatage et d’enduits de cordages sont globalement issus d’une cuisson moins poussée que ceux utilisés dans le poissage de récipients. Une distinction des échantillons archéologiques sur la base de leur composition isotopique en D a été proposée. / Resins and tars of Pinaceae have been used in the past mainly in the maritime field (caulking, protection of the ropes) and for the waterproofing of jars and amphorae. This study was devoted to the development of new molecular and isotopic tools for the characterization of such materials found in archaeological context (discrimination between tar / resin, taxonomic and geographical origin, manufacturing methods). Based on the detailed molecular and isotopic investigation of diterpenic compounds, in particular, it appears that the use of tar prevails in this context over that of resin and that trees from the genus Pinus, which can be partially discriminated in terms of species, have been preferentially used. It could be shown that the caulking material and the tar protecting ropes result overall from a less intense heating process than the material used to waterproof containers. A distinction of the archaeological samples on the basis of their isotopic composition in D was proposed.
17

Pinus prekesiya sp. nov. From the Upper Miocene of Yunnan, Southwestern China and its Biogeographical Implications

Xing, Yaowu, Liu, Yu Sheng C., Su, Tao, Jacques, Frédéric M., Zhou, Zhekun 01 April 2010 (has links)
Pinus prekesiya Xing, Liu et Zhou sp. nov. was described as a new species on the basis of two well preserved ovulate cones from the upper Miocene of central Yunnan, southwestern China. It is the first fossil record of three dimensionally preserved Pinus ovulate cones from China. Morphological comparisons with 15 previously published Cenozoic cones and seven related extant pine species reveal that the fossil cones are identified as a new species, P. prekesiya sp. nov., which belongs to subsection Pinus of subgenus Pinus. The new species shows a combination of characters of P. kesiya and P. yunnanensis, but has a closer affinity with P. kesiya which occurs in the humid region of Yunnan and therefore suggests a more humid climate in central Yunnan during the late Miocene than today. The general cooling trend during the late Neogene and topographic change due to the dramatic Tibetan uplift might have caused a vicariant origin of P. kesiya and P. yunnanensis from the ancestral P. prekesiya.
18

‘Choicest unguents’: molecular evidence for the use of resinous plant exudates in late Roman mortuary rites in Britain

Brettell, Rhea C., Schotsmans, Eline M.J., Walton Rogers, P., Reifarth, N., Redfern, R.C., Stern, Ben, Heron, Carl P. 04 December 2014 (has links)
Yes / Resinous substances were highly prized in the ancient world for use in ritual contexts. Details gleaned from classical literature indicate that they played a significant role in Roman mortuary rites, in treatment of the body and as offerings at the tomb. Outside of Egypt, however, where research has shown that a range of plant exudates were applied as part of the mummification process, resins have rarely been identified in the burial record. This is despite considerable speculation regarding their use across the Roman Empire. Focusing on one region, we investigated organic residues from forty-nine late Roman inhumations from Britain. Using gas chromatographyemass spectrometry and the well-attested biomarker approach, terpenic compounds were characterized in fourteen of the burials analysed. These results provided direct chemical evidence for the presence of exudates from three different plant families: coniferous Pinaceae resins, Mediterranean Pistacia spp. resins (mastic/terebinth) and exotic Boswellia spp. gum-resins (frankincense/olibanum) from southern Arabia or beyond. The individuals accorded this rite had all been interred with a package of procedures more elaborate than the norm. These findings illuminate the multiplicity of roles played by resinous substances in Roman mortuary practices in acting to disguise the odour of decomposition, aiding temporary soft-tissue preservation and signifying the social status of the deceased. Nevertheless, it was their ritual function in facilitating the transition to the next world that necessitated transportation to the most remote outpost of the late Roman Empire, Britain. / R.C.B is supported by a PhD studentship from the Art and Humanities Research Council (43019R00209).
19

DETERMINAÇÃO DA ALTURA DE VOO DE ESCOLITÍDEOS EM MATA NATIVA E EM POVOAMENTO DE Pinus taeda / FLIGHT HEIGHT DETERMINATION OF SCOLYTIDS IN NATIVE MATA AND STAND OF Pinus taeda.

Machado, Leonardo Mortari 25 February 2013 (has links)
Scolytids (Curculionidae, Scolytinae) are small borer‟s beetles belonging to the order Coleoptera that develop within or under the bark of trees. In northern countries, these insects cause significant damage especially when outbreaks occur. In Brazil in general, the damage is minor when compared to the northern hemisphere. Given the importance of subfamily Scolytinae, this paper aims at providing a better understanding of the behavior of Scolytids, mainly regarding the flight height in native forest and in a stand of Pinus taeda. For the execution of this work 72 intercept flight traps (PET Santa Maria) were installed in two areas (native forest and stand of Pinus taeda) belonging to the State Foundation for Agricultural Research (FEPAGRO), located at the mouth of the hill district, in Santa Maria, Rio Grande do Sul. The traps were distributed in 12 treatments (different heights) with three repetitions each and according to the environment, with an interval of 30 meters between repetitions. The treatments correspond to heights of 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5; 6.0 meters. It was possible to capture: Hypothenemus eruditus in greater abundance at a height of 0.5 meter flight in native forest and in the range of 1 to 1.5 meters in Pinus taeda; Xyleborus saxeseni between 2 and 2.5 meters in native forest with no preference in the colonization of Pinus taeda; Microcorthylus quadridens in native forest at 2 meters; Xylosandrus retusus with no preference in both areas; Xyleborus ferrugineus to 0.5 meters in both areas; Corthylus pharax 0.5 to 1 meter in native forest; Xyleborinus gracilis and Xyleborus affinis to 0.5 meters in native forest. Therefore, it was possible to conclude that the range between 0.5 and 1.5 meters is ideal to analyze qualitatively and quantitatively the scolytids present in native forest and in the colonization of Pinus taeda. / Os escolitídeos (Curculionidae, Scolytinae) são besouros pequenos, broqueadores, pertencentes à ordem Coleoptera e se desenvolvem no interior de árvores. Em países do hemisfério norte, estes insetos causam prejuízos significativos principalmente quando ocorrem em surtos epidêmicos. No Brasil em geral, os danos causados são menores quando comparados aos do hemisfério norte. Tendo em vista a importância dos escolitídeos, este trabalho tem por objetivo proporcionar um melhor entendimento do comportamento destes, principalmente no que tange à altura de voo em mata nativa e em povoamento de Pinus taeda. Para a execução deste trabalho foram instaladas 72 armadilhas de interceptação de voo, em duas áreas (mata nativa e Pinus taeda) pertencentes à Fundação Estadual de Pesquisa Agropecuária (FEPAGRO), localizada em Santa Maria, Rio Grande do Sul. As armadilhas foram distribuídas em 12 tratamentos (diferentes alturas) com três repetições por ambiente, com um intervalo de 30 metros entre as repetições. Os tratamentos correspondem às alturas de 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 3,5; 4,0; 4,5; 5,0; 5,5 e 6,0 metros. Capturou-se: Hypothenemus eruditus em maior abundância na altura de voo de 0,5 metro na mata nativa e na faixa de 1 a 1,5 metros em Pinus taeda; Xyleborus saxeseni entre 2 e 2,5 metros na mata nativa e sem preferência no povoamento de Pinus taeda; Microcorthylus quadridens na mata nativa a 2 metros; Xylosandrus retusus sem preferência em ambas às áreas; Xyleborus ferrugineus a 0,5 metro em ambas as áreas; Corthylus pharax de 0,5 a 1 metro na mata nativa; Xyleborinus gracilis e Xyleborus affinis a 0,5 metro na mata nativa. Conclui-se, portanto que o intervalo situado entre 0,5 e 1,5 metros, é o ideal para analisar qualitativamente e quantitativamente os escolitídeos presentes na mata nativa e em Pinus taeda.
20

Biotransformations of Turpentine Constituents : Oxygenation and Esterification

Lindmark-Henriksson, Marica January 2003 (has links)
This thesis describes methods to obtain value–addedcompounds from TMP-turpentine obtained from the spruce, Piceaabies. The methodology focuses on biotransformations using twoapproaches: an oxygenation approach (i.e. oxygenation ofterpene hydrocarbons by cell cultures) and an esterificationapproach (i.e. lipase-catalysed transesterification of vinylacetate with terpene alcohols, and a further fractionation ofthe TMP-turpentine). The main constituents of the turpentine, a-pinene, b-pineneand limonene, were subjected to a P. abies suspension culture.Allylic oxidation formed the major products for α-pineneand β-pinene, which were further oxidised to theirrespective aldehyde or ketone. One of the minor products froma-pinene, cis-verbenol, was not only transformed into verbenonebut also isomerised to trans-verbenol. Limonene gavelimonene-(1,2)-epoxide as the major product. Fractionation of monoterpenes is accomplished throughphysical separation methods, chromatography and distillation,and lipase-catalysed transesterification of vinyl acetate withterpene alcohols. The esters of myrtenol and trans-pinocarveolwere separated from the more slowly reacting alcohols such asborneol and carveol by use of a combination of the Mucor mieheilipase and Candida antarctica lipase A as catalysts.Furthermore, the non-reacting tertiary terpene alcohols wereseparated from the reacting alcohols in a single step byCandida antarctica lipase A. Lipase-catalysed (Candida antarctica lipase B andPseudomonas cepacia lipase) transesterification of vinylacetate with sterically hindered secondary alcoholsunexpectedly yielded hemiacetals or hemiacetal esters. Thereaction conditions required to obtain these side products havebeen studied. <b>Keywords:</b>Picea abies, Pinaceae, Essential oilscomposition; Terpene alcohol; Hemiacetal; Hemiacetal ester,TMP-turpentine; Monoterpene; α-Pinene; β-Pinene;Limonene; Verbenol; Pinocarveol; Borneol; Myrtenol; Suspensioncell culture; Biotransformation; Lipase-catalysed; Oxidation;Allylic oxidation; Transesterification; Autoxidation;Separation.

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