Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 67-77). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 135-145). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 135-145). Also available on the Internet.

Knowing and understanding the sapwood and heartwood functions and properties are crucial in pressure-treating southern pine. It is very difficult to penetrate heartwood with chemicals. Therefore, knowing heartwood content before treatment will benefit companies in chemical consumption, treating cycles, and, foremost, cost. In this study, two different assessments were conducted in which lumber and pole heartwood/sapwood data was collected from eight treating plants across five Southeastern states. In both assessments, the data indicated some significant differences between similar products from different vendors, but there was no significant difference in heartwood content between plant locations. The results suggested that the amount of heartwood increases as the size and length of the products increase. These findings can argue that the size of raw materials that vendors use and the products they manufacture have more effect on heartwood content than plant location.

Heartwood is the dead, inner layers of wood in the tree which no longer transport water. It is usually dark in colour and has increased decay-resistance compared to the sapwood. Heartwood forms in the transition zone when the ray cells die and deposit chemical extractives in the surrounding xylem. These chemicals convey natural durability which is of value to the forest and timber industry. Despite its value the formation of heartwood is poorly understood. The objective of this PhD is to improve our understanding of heartwood formation in Sitka spruce and Scots pine, the most widely planted species in Britain. Separating heartwood and sapwood at the sawmill can increase timber value due to differences in wood properties. The amount of heartwood varies both with height within, and between trees. Empirical models were developed to describe heartwood and sapwood distribution by diameter, area and ring number 1) within any wood disc 2) with height in the standing tree using taper functions, and 3) its variation between trees. Models will be incorporated into wood quality models to optimise heartwood utilisation. According to pipe theory a certain area of sapwood sustains a volume of canopy, with redundant sapwood converted to heartwood. Sap flux was examined across the sapwood and transition zone in Sitka spruce to understand water transport in relation to heartwood formation and identify seasonal change in transport in the transition zone. Results suggest that the transition zone ceases water transport around dormancy and the amount of heartwood formed may be driven by new wood formation, maintaining sapwood depth. Heartwood formation is a seasonal process, however this has not been confirmed in Sitka spruce or Scots pine, or under UK climatic conditions. Seasonal variation in carbon dioxide and ethylene production by the transition zone were measured to identify the time of heartwood formation, which was late summer through dormancy, consistent with published literature. The role of ethylene in heartwood formation is confirmed. Heartwood formation is an active developmental process, a form of programmed cell death, and as such must be carefully regulated temporally and spatially. Regulation by phytohormones has been proposed but not confirmed. Screening for a broad range of phytohormones during the proposed season of heartwood formation identified an increase in abscisic acid and a decrease in auxin concentration in the transition zone. Abscisic acid, auxin and ethylene also regulate xylogenesis, therefore the same signals that initiate cambial dormancy may also provide the temporal regulation of heartwood formation. The results of this PhD will optimise the use of heartwood in Sitka spruce and Scots pine in the UK and contribute towards selective tree breeding for increased heartwood volume worldwide.

Le bois est un tissu plurifonctionnel permettant la conduction de la sève brute, le stockage de l’eau et des sucres ainsi que le soutien mécanique de la plante. L’arbre au cours de son développement expérimente différentes contraintes liées à son environnement et à sa taille croissante. En réponse à ces contraintes, les performances fonctionnelles du bois sont ajustées par des variations de valeurs de propriétés, elles-mêmes dépendantes du produit de la xylogénèse. Cependant les extrais chimiques déposés lors du processus de duraminisation, entraine la modification des propriétés du bois. Les propriétés du duramen sont le fruit de la xylognénése et de la duraminisation ainsi que de leurs interactions. Ce travail de thèse a donné naissance au terme ‘profil ligneux’, désignant l’ensemble des variations des propriétés du bois à différentes échelles et dans une dimension ontogénique résultant des deux processus cités précédemment. La diversité de tempéraments vis-à-vis de la lumière (héliophilie à sciaphilie) des essences tropicales suggère une diversité d’expressions du profil ligneux. La description de ces différentes expressions serait gage d’une meilleure compréhension du tempérament. Comprendre et caractériser le profil ligneux et la variation de la quantité de bois de cœur dans l’arbre, représentent également un enjeu économique puisque l’industrie du bois Guyanaise a été identifiée comme une filière d’avenir. L’analyse de la diversité du profil ligneux—par une approche ascendante, de l’échelle individuelle à l’échelle interspécifique—a prouvé son efficacité dans la discrimination du degré d’affinité à la lumière. La variation de densité est particuliérment pertinente. Néanmoins, sa pertinence réside dans (1) la combinaison du gradient radial et vertical et (2) la prise en compte du duramen qui modifie parfois, l’amplitude et la direction du gradient ainsi que la forme du profil.L’effet de la duraminisation sur la variation de densité devient alors évocateur du tempérament de l’espèce au même titre que la qualité et/ou la quantité d’extraits chimique mis en jeu. La pertinence du profil ligneux dans la caractérisation du tempérament écologique est due à son aspect intégrateur de divers processus et propriétés. En regard du changement l’allocation de croissance (i.e. du tronc vers la couronne) observée chez Dicorynia guianensis et de travaux précédents sur la croissance des arbres, un lien potentiel entre la diversité du profil ligneux et la stratégie d’allocation de la croissance pourrait exister. / Wood is a multifunctional tissue involved in sap conduction, storage of water and reserves as well as mechanical support. Tree during its development experiments various constraints due to its environment and its growing size. In response to these constraints, wood functional performances are adjusted by variations of property values, which are dependent on the xylogenesis product. However, wood properties may be modified by the deposition of chemical extractives during heartwood formation. Thus heartwood properties are the result of xylogenesis, heartwood formation and their interactions. This work gave rise to the term 'wood profile', designating all variations of wood properties at different scales and in an ontogenetic dimension, resulting from both processes described above. The diversity of shade tolerance (heliophilic to sciaphilic) strategies species suggests a diversity of wood profile expressions. The description of these different expressions could be a way to better understand plant strategies. Understanding and characterizing wood profile and variations in heartwood quantity in tree, is an economical issue since the Guyanese timber industry has been identified as a promising sector. The analysis of the diversity of wood profile—using a bottom-up approach, from the individual level to the interspecific level—proves to discriminate shade tolerance strategies efficiently. Wood specific gravity variation is especially relevant. However, its relevance is based on (1) combinations of both radial and vertical variations and (2) integration of heartwood that may impact range and direction of the gradient and shape of the profile as well. Effect of heartwood formation on wood specific gravity variations is suggestive of shade tolerance strategy as well as quality and/or quantity of chemical extractives. Relevant characterization of shade tolerance strategies by wood profile is the result of the integration of diverse processes and properties. To the view of growth allocation shift (from trunk to crown) observed in Dicorynia guianensis and of previous studies on tree growth, a potential link between wood profile diversity and growth allocation strategies may exist.

京都大学 / 新制・課程博士 / 博士(地域研究) / 甲第24721号 / 地博第313号 / 新制||地||121(附属図書館) / 京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻 / (主査)教授 竹田 晋也, 准教授 小坂 康之, 准教授 柳澤 雅之 / 学位規則第4条第1項該当 / Doctor of Area Studies / Kyoto University / DGAM

農林水産研究情報センターで作成したPDFファイルを使用している。

Wood is often perceived as a flawed material. When painted, technologically treated or sealed, in a pursuit to make it more predictable and durable, some of its most important qualities are mislaid. This project explores the aesthetic, material and constructional possibilities of wood, and suggests the possibility of a wood brutalism architecture. The project includes a written manifesto for the benefits of wood in the human habitat, proposes a CO₂ based economic strategy for our built environment and promotes massive wood buildings as our carbon savings account. To find out what a wood brutalism of today might be, the project includes an analysis of the relationship between the material concrete, Betón-brut and the zeitgeist of the 60´s and 70´s. In the application of the manifesto and Bois-brut on a case study housing project in Östberga, Stockholm, the Trellick tower has acted as a brutalist mirror reference. Vernacular timber buildings have provided clues in the search for the essence of wood.

[Truncated abstract] An investigation into the causes of heartwood and essential oil content of Australian plantation sandalwood, Santalum album was undertaken. Genetic diversity of 233 S. album, five S. austrocaledonicum and fifteen S. macgregorii trees growing in the Forest Products Commission arboretum, Kununurra WA, was assessed using nuclear and chloroplast RFLPs. Santalum spicatum was chosen as an out-group. Nuclear genetic diversity of the S. album collection was very low, with observed and expected heterozygosity levels of 0.047. This was lower than the results previously reported in the literature for trees in India, however a different technique was used. Based on allelic patterns, the collection was able to be categorised into 19 genotypes; each representing some shared genetic origin. Some groups were highly redundant with 56 trees being represented, while others were populated by just one tree. The essential oil yield and heartwood contents of trees from these genetic groups were compared. Yields were highly variable both within and between groups of trees which share a common genetic history, suggesting a significant environmental component was contributing to the observed phenotype, despite identical soil and climatic conditions. Ancestral lineages were tested using chloroplast RFLPs, although a lack of shared mutations between species made this difficult. Only one S. album tree originating from Timor was resolved using nuclear RFLPs, with the other trees being grouped with material sourced from India. There was no resolution of Indian S. album from Timorese using chloroplast RFLPs, however one S. album tree grown from Indian seed possessed a single unique mutation. The low genetic diversity of the Australian S. album collection is likely to be a combination of incomplete seed sourcing and highly restricted gene flow during the evolution of the species. Combined with information gathered on the phylogeny of the genus by other researchers, S. album is postulated to have originated from an over-sea dispersal out of northern Australia or Papua New Guinea 3 to 5 million years ago. Essential oil yield and composition was assessed for 100 S. album trees growing in the collection, ranging in age from 8 to 17 years. Oil content of heartwood ranged from 30 mg g-1 to 60 mg g-1, and the transition zone 36 mg g-1 to 90 mg g-1. Sapwood contained almost no sesquiterpene oils. Despite the highly variable total oil yields, the chemical profile of the oil did not vary, suggesting there was limited genetic diversity within this region of the genome. Strong, positive correlations existed between v sesquiterpenoids in the essential oil of S. album. ... These represent the first TPS genes to be isolated from sandalwood and will enable further elucidation of oil biosynthesis genes. This thesis compiles a three-pronged approach to understanding the underlying causes of oil yield variation in S. album. As a species for which so little is known, the research presented here provides a major leap forward for tree improvement, breeding and silviculture. Hence the best of Santalum album research is presented.