From samples of stained yellow cedar wood, Chamaecyparis nootkatens is (D. Don) Spach, collected at three different localities on the British Columbia coast, isolation studies consistently yielded two members of the group Fungi Imperfecti. Reinoculation of these fungi into sound wood produced black stain similar to that found in nature. In addition to these Deuteromycetes, three basidiomycetous fungi, Poria weirii Murr, Poria asiatica (Pilát) Overholts and Xeromphalina campanella (Batsch. ex Fr.) Kühner and Maire, were isolated. Of these the Poria species are believed to be first records for the host. Studies on Petri plates revealed no marked antagonism between the two Deuteromycetes and P. weirii. The two deuteromycetous fungi gave positive reactions on gallic and tannic acid agars, demonstrating the production of the enzyme extracellular oxidase. Two series of yellow cedar beams were respectively inoculated with macerated cultures of the Deuteromycetes by means of a special technique described. This technique produced exceptionally rapid and uniform fungal growth in comparison to that obtained under standard cultural conditions. Inoculated beams were subjected to weight and strength loss tests, in comparison to control beams. Weight losses of 0.17 percent and 8.40 percent respectively were noted for the two fungi. No significant difference in impact modulus of rupture values was detected between test and control for either fungus. Significance of experimental results is briefly discussed and recommendations for further study suggested. / Science, Faculty of / Botany, Department of / Zoology, Department of / Graduate

This study identified new compounds with pest control activities. The two sources of candidates that were followed here were the main heartwood extract of Alaska Yellow Cedar (AYC) constituents and several semi-synthetic counterparts. Five compounds were isolated and identified for the first time in AYC heartwood in this research: two monoterpenes, two sesquiterpenes, and one lignan. The two monoterpenes were (1S)-2-oxo-3-p-menthenol (41) and (4R)-4-hydroxy-4-isopropyl-cyclohex-1-enecarboxylic acid (63). The two sesquiterpenes were (5S,7R,10R,11R)-eudesm-4(14)-ene-11,12-diol (46) and (4R,5S,7R)-1(10)- eremohpilen-11,12-diol (59). The lignan was (1R,2S,5R,6S)-2,6-bis-(3,5- dimethoxy-4-hydroxyphenyl)-3,7-dioxabicyclo-[3.3.0]octane,(67). Structures for these compounds were confirmed on the basis of spectroscopic techniques such as 1- and 2-D NMR, high resolution MS and IR. The pest control activity studies of 15 compounds isolated or semi-synthesized from AYC heartwood were conducted at the Centers for Disease Control and Prevention (CDC). Two types of studies were conducted--short-term (24h) and residual (over 1-4 weeks) activity for application against three types of pests related to human health - nymphal I. scapularis ticks, adult X cheopis fleas and adult Ae. eagypti mosquitoes. The 24 h studies revealed that nootkatone, valencene-13-aldehyde and valencene-13-ol were the most active among the studied compounds against the three pests. They exhibited highly improved pest control activities compared to valencene. This suggests that oxidation on both positions C-2 and C-13 of the eremophilane ring structure has an important effect on the activity. For compounds where the conformation of the eremophilane bicyclic ring has been altered, the activity seemed to diminish greatly. The above mentioned three compounds can be good candidates as pest control lead compounds. The residual studies revealed that the most active compounds exhibited activity profiles that generally decreased with time. Although the long-term safety of these compounds has yet to be evaluated, the natural origin and the long history of use of these compounds suggest that they can be promising candidates. This study revealed that the three most promising compounds in the 24 h study exhibited reasonably promising behavior, which makes them even stronger as pest control candidates. / Graduation date: 2004

Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) forests of coastal British Columbia are apparently experiencing decline in a manner similar to that observed in southeastern Alaska. In this pilot study, we collect tree-ring data from live and standing dead yellow-cedar trees from four declining sites on the North Coast of British Columbia. We use this data to compare growth patterns at our sites to those of yellow-cedar trees at non-declining and declining sites in southwestern British Columbia and southeastern Alaska and, in addition, to assess the possibility of reconstructing yellow-cedar population dynamics in declining stands using dendrochronology. We found coherent growth patterns (i.e. marker years and periods of suppression) among yellow-cedar chronologies from non-declining and declining sites across a broad geographic range as well as unique growth patterns between our chronologies from declining sites and those from declining sites in nearby Alaska. Using outer-ring dates of increment cores, we were able to estimate time since death of decade- to century-old standing dead yellow-cedar trees, although the precision of the estimates was influenced by partial cambial mortality and erosion of outer rings. Our results provide baseline dendrochronological information that will be useful for planning future studies that assess growth-climate relations and reconstruct the long-term population dynamics of yellow-cedar in declining stands.