Eighty western hemlock trees, in the age range of 15 to 48 years, were selected on three Crown Zellerbach tree farms in northwestern Oregon and southwestern Washington to sample the range of variation in growth efficiency. Growth efficiency is defined as the ability of the crown to produce the maximum amount of wood in relation to its crown surface area. Selection of the trees was based on the crown index ratio (live crown length/ crown width). The objectives of the study were to estimate: 1) the range of variation in growth efficiency of individual trees, 2) how variation in growth efficiency of individual trees could be utilized to maximize volume on a unit area, and 3) the efficiency of narrow crown western hemlock trees as wood producers. Results from regression analysis showed that there was sufficient variation in growth efficiency, with a range of the standardized residuals exceeding at least ± 2.0 standard errors of the estimate for all three regression models. Based on this range it is suggested that selection of ten year basal area increment or gross stem volume for western hemlock in relation to crown surface area or sapwood basal area may be worthwhile. The significance of the variation in growth efficiency becomes apparent when the higher growth efficiency classes are selected. It is estimated that selection of the higher growth efficiency classes rather than the average may increase ten year basal area increment/hectare by 39 to 45 percent. It appears from the trees measured that there is little relationship between growth efficiency and the degree of slenderness of the crown. / Forestry, Faculty of / Unknown

Thesis (M.S.)--Oregon State University, 1993. / Typescript (photocopy). Includes bibliographical references (leaves 46-49). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1993. / Typescript (photography). Includes bibliographical references (leaves 71-75). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1971. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 75-84).

Thesis (M.F.)--Oregon State College, 1950. / Typescript. Includes bibliographical references (leaves 47-48). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1994. / Typescript (photocopy). Includes bibliographical references (leaves 85-91). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1986. / Typescript (photocopy). Includes bibliographical references (leaves 126-131). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 136-143). Also available on the World Wide Web.

The phenolic extractives from western hemlock wood (Tsuga heterophylla (Raf.) Sar.) have been examined. The total extractive content of the wood amounted to 1.5% of the dry weight. A leucoanthocyanidin and two lignans, conidendrin and hydroxymatairesinol, were isolated from the phenolic fraction by precipitation of a methanol solution into peroxide-free ether followed by separation on silicic acid-calcium sulphate chromatobars. The pigment produced by acid treatment of the isolated leucoanthocyanidin was shown by spectral studies and alkaline degradation to be a mixture of cyanidin and an unidentified anthocyanidin. The two anthocyanidins had identical Rf values in different solvents and similar ultra-violet spectra in ethanol-hydrochloric acid solution but the shift of the absorption maxima caused by addition of aluminium chloride was negligible in the case of the unknown compound and amounted to 30 mµ for cyanidin. Similar separations of the absorption maxima after complexing with aluminium ion were observed with the 3-methyl and 3-isopropyl ethers of the two anthocyanidins. The alkaline degradation products from the leucoanthocyanidin contained protocatechuic acid but no phloroglucinol. Degradation products of phloroglucinol, however, were present in the reaction mixture. These results suggested that the leucoanthocyanidin occurred in the wood in dimeric form and that alkaline degradation of this structure produced a symmetrical hexahydroxyhenzophenone derivative which split up directly into fragments identical to those obtained from phloroglucinol under the same conditions. New information on the structure of hydroxymatairesinol was obtained by comparison of the infrared spectra of the fully acetylated hydroxymatairesinol with that of the reduced compound and by neutral potassium permanganate oxidation of trimethylhydroxymatairesinol. The results obtained were in good agreement with only one of the two structures previously proposed for hydroxymatairesinol by other workers. The NMR spectra of hydroxymatairesinol and structurally related compounds were compared, but the interpretation of the spectrum of hydroxymatairesinol proved to be difficult because broad, incompletely resolved lines were obtained due to the complexity and asymmetry of the molecule. / Science, Faculty of / Chemistry, Department of / Graduate