Thesis (Ph. D.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 78-82). Also available on the World Wide Web.

No description available.

Three dilignol rhamnosides were isolated in 0.15 to 0.40% yield from the ethyl acetate solubles of a methyl alcohol extract of western red cedar (Thuja plicata Donn) leaves using silicic acid and Sephadex LH-20 pressure column chromatography. One of the three dilignol rhamnosides was characterized as l-(3'-methoxy-4'-hydroxyphenyl)-2-0-l"-[2"-hydroxy-4"-(propane-3"'-α-L-rhamnoside)phenyl]-propane-l,3 diol, using NMR and chemical degradation in conjunction with mass spectral techniques on the compound and its derivatives. The other dilignol rhamnosides were not completely characterized, but were shown to be chemically related to the dilignol identified. Based upon NMR, chemical and mass spectral data, the uncharacterized dilignol rhamnosides are speculated to contain phenylcoumaran and guaiacyl benzdioxane structures. The characterized dilignol rhamnoside represents the first reported occurrence of a free dilignol glycoside in plant tissues. The unusual α-L-rhamnose moiety of the dilignol occurs in a previously unreported linkage to the n-propyl hydroxyl group uncommon in lignin. The rhamnoside also displays the previously unreported guaiacylglycerol-catechol-β-aryl ether structure rather than the commonly observed guaiacylglycerol-guaiacyl-β-aryl ether structure. A new combustion-absorption technique was developed and validated which allows high efficiency evaluation of low activity radioactive products separated on thin layer cellulose chromatography plates. The technique was applied to an analysis of the anabolic products of an infusion feeding of U- (14)C--L-phenylalanine to western red cedar leaves. Facile imbibition of U-(14) C-L-phenylalanine occurs within ten hours. Maximum incorporation of 0.30%. and 0.40% of the available radioactivity occurs in the characterized dilignol rhamnoside, and its suspected phenylcoumaran homolog respectively, at the three to five hour period of the infusion feeding. The incorporation results indicate the participation of the dilignol rhamnosides in aromatic metabolism in the leaves of western red cedar. This feeding experiment is preliminary to future detailed biosynthetic studies in the leaf tissue. The combustion-absorption technique is limited to combustible sample weights of 7 mg. / Forestry, Faculty of / Graduate

Thujaplicins are the major components in the steam-volatile fraction of western redcedar (Thuja plicata Donn.) (WRC) heartwood extractives. They are consided to be highly toxic to fungi and are chiefly responsible for WRC heartwood decay resistance. This study proves that this traditional concept of toxicity is not completely correct. Thujaplicins are toxic to common decay fungi isolated from decayed WRC wood in living trees or wood in service, such as Poria albipelIucida Baxter. On the other hand, when a fungus such as Sporothrix sp. invades sound heartwood of living WRC, thujaplicins do not provide resistance but instead are altered by that fungus, so that their toxicity to decay fungi is destroyed. Evidence obtained in this study indicates that the mechanism of thujaplicin toxicity to common decay fungi involves the reactive keto-enolic group. As example, thujaplicin toxicity disappears if this reactive group is blocked by laboratory methylation. In living trees detoxification by Sporothrix sp. is demonstrated to involve a process of oxidative dimerization and isomerization of the thujaplicins to a new lactone compound. This compound is proven to have no toxicity to decay fungi, such as Poria albipelIucida Baxter. The dimerization and isomerization destroy the reactivity of the keto-enolic group and thus thujaplicin toxicity. Isolation, purification, and determination of the chemical structure of the new lactone compound produced from thujaplicins during Sporothrix sp. infection was carried out by chemical, chromatographic and spectroscopic methods. This naturally occurring compound has not been isolated previously and there are no previous reports in the literature about a compound with this structure. Following IUPAC rules, the compound is named as 3,3,4,7,7,8-hexamethyl-2,6-dioxa-1,5-anthracene-dione, and given the trivial name 'Thujin'. Biological experiments carried out in this study clearly show that in living WRC trees, fungal attack involves a succession of microorganisms. Three early stage attacking fungi were consistantly isolated from discolored WRC heartwood. They are identified as Sporothrix sp. KirschsteinieIIa thujina (Peck) Pomerleau & Etheridge and Phialophora sp. Biological roles of these fungi are demonstrated based upon the results of wood block bioassays and chemical analysis of wood blocks treated with the three fungal isolates. / Forestry, Faculty of / Graduate

Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western red cedar (Thuja plicata Donn) seedlings from four dormancy induction treatment(s) (DIT) (i.e. long-day dry, long-day wet, short-day dry, and short-day wet) were planted on a high available soil moisture field site in British Columbia and monitored for physiological response and morphological development over the first growing season. Stomatal conductance (gwv) and net photosynthesis (Pn) were recorded over an environmental matrix of photosynthetically active radiation (PAR) (0 - 2.2 mmol m⁻² s⁻¹ ) and vapour pressure deficit (VPD) (0 - 2.5 or 4.0 kPa) on both first year grown and fully developed second year foliage. To compare stocktypes, physiological data were collected and analyzed in the following ways: (1) replicated data at stable environmental conditions once a month, (2) physiological response to one increasing environmental variable using boundary line analysis, and (3) physiological response surface to two simultaneously changing environmental variables. For western hemlock first year needles, short-day DIT had a higher gwv response to both increasing VPD and PAR. Both short-day and moisture stressed DIT improved Pn response to PAR, and the combination had the highest response. Short-day DIT seedlings initially were smaller, shorter, had a better seedling water balance ratio and lower shoot to root ratio. Short-day second year needles showed a slightly higher gwv response to both increasing VPD and PAR as compared to long-day seedlings; however, they showed no treatment differences for Pn versus PAR. All stocktypes had similar final morphological parameter values. For western red cedar first year foliage, moisture stressed DIT seedlings had greater Pn response to increasing PAR and VPD. Also, moisture stressed seedlings gwv response to increasing VPD and PAR was higher when compared to its' non moisture stressed daylength counterpart. The long-day wet seedlings initially had a larger root and shoot system as compared to the other stocktypes. Second year foliage exhibited no treatment differences for gwv and Pn response to PAR ' and VPD. All stocktypes had similar final morphological parameter values. Attempts to test stocktypes at stable environmental conditions proved, at times, difficult. Potentially large measurement variation due to atmospheric environmental changes, and not stocktype effect, could result. Boundary line analysis, when used correctly and with sufficient data, offers a good stocktype assessment method which enables the isolation of a physiological response to one environmental variable. Three dimensional surface response technique was required to provide a clear conceptual representation of two primary environmental variables' influence on seedling physiological response. / Forestry, Faculty of / Graduate

No description available.

The present study was undertaken to examine the litter decay fungi of red cedar (Thuja piicata Donn). The fungi involved in conifer litter decay have not been examined intensively and there has been no study of red cedar litter decay. Since Thuja is often found in wet, poorly drained areas, it provided an opportunity to observe occurrence of litter decay fungi relative to slight differences in distance from a stream margin. This was determined by observing changes in the frequency of the fungi at various distances from the margin of a stream and also by observing seasonal changes in fungal populations. An ordination of the data was performed to determine if there were species associations which would characterize the relatively minor horizontal and vertical spatial changes in the sites. The sites were divided into subsites (high, middle and low with respect to the stream) and samples were taken at each subsite. Red cedar branchlets from the L and F litter layers were washed and plated on a selective medium or placed in moist chambers; all observed species were isolated and identified. Most of these were members of the Fungi Imperfecti. The frequency of occurrence of the more commonly isolated species was utilized in a Principal Components Analysis (PCA) to determine associations of subsites, layers or species. There was little distinction between the three subsites, but there was a general separation of the high subsite from the low subsite, the middle subsite showing affinities to both. The L and F layers represented a division of the litter layer which formed more distinct clusters in the ordination, especially in the Site B data. Seasonal distinction among the samples seemed to reflect the extremes of the seasons. The spring and summer samples generally grouped together, as did the fall and winter samples. Species associations reflected various combinations of the above groupings, depending on the species groups involved. Again the most distinct groups represented extremes, e.g., species prominent in dry samples, especially in the high subsite, or species prominent in moist conditions, especially in the low subsite. No single variable provided clear distinction among the various subsites, layers, seasons or species. However, the combination of all of these gave general indications as to probable fungal associations. / Science, Faculty of / Botany, Department of / Graduate

No description available.

Where timber production is the primary management objective, knowledge of the relationship between the potential productivity of candidate tree species and levels of light, heat, nutrient, moisture and aeration is necessary for species- and site-specific decision making. For example, foresters need to decide which tree species to regenerate on a particular harvested area to obtain maximum sustainable productivity. Similarily, when considering the application of silvicultural treatments such as spacing or fertilizing, foresters need to determine whether the potential productivity of a particular site warrants the cost of the treatment. We used the site index (height of dominant trees at breast height age) of western redcedar (Thuja plicata Donn. ex D. Don.) as a measure of productivity, and described the pattern of mean site index in relation to field identified soil moisure and soil nutrient regimes.

Thesis (Ph. D.)--Oregon State University, 1994. / Typescript (photocopy). Includes bibliographical references (leaves 109-125). Also available on the World Wide Web.