The usefulness of interspecific crosses between Sitka spruce (Picea sitchensis (Bong.) Carr.) and interior spruce (Picea glauca (Moench) Voss, Picea engelmannii Parry and their hybrids) was investigated in one coastal environment. For height growth and bud set most of the variation was at the regional and individual cross level, but very little variation was at the subregional level. The main genetic effects, male and female, accounted for a majority of the genetic variance and additive genetic effects are interpreted as the main factor in the determination of height growth and bud set. For bud set the maternal source of variation accounted for the majority of the genetic variance and a maternal influence on bud set is suggested. Some specific cross combinations were outstanding in height growth and non-additive genetic factors are considered important in these crosses. For bud break most of the variation was due to the residual error, although regions and crosses were statistically significant sources of variation. The Female*Male term was the most important genetic source of variation although bud break is not considered to have as much genetic variation as height and bud set. Large differences were found in the pattern of cold hardiness in the fall and it is considered that photoperiod plays a much larger role than previously thought, especially for interior spruce. Most of the variation was again at the regional and individual cross level. The intermediate performance of the hybrids suggests an inheritance of cold-hardiness based on additive genetic effects. Recommendations are given in the text for the use of these hybrids as well as the areas in which further research would be desireable. / Forestry, Faculty of / Graduate

This study was designed to investigate the repellent effects of pineoil on the Sitka spruce weevil (=white pine weevil), Pissodes strobi Peck, and to evaluate the utility of large scale color aerial photography for detecting weevil attacked Sitka spruce, Picea sitchensis (Bong.) Carr.. Two formulations of pineoil, BBR1 and BBR2, were field tested for their effect in protecting immature Sitka spruce from weevil attack in 36 twenty meter square plots at two locations on Vancouver Island. The pineoil formulations were applied both topically to the terminal leaders and in slow release devices hung at the apical whorl of Sitka spruce trees. The topical application of BBR1 to the leaders of all trees in the plots reduced the number of new weevil attacks to two trees compared with 24 new attacks in the control plots. None of the other pineoil treatments were found to differ significantly from the controls. An examination of the weevil attack history in the study plots showed that the average number of new weevil attacks in the pineoil treated plots were proportionately lower than the number of new attacks in the control plots. These findings suggest that applications of BBR1 to the terminal leaders of Sitka spruce trees will protect them from attack by P. strobi. Large scale color infra-red (CIR) and normal color (NC) aerial photograph stereo transparencies were evaluated for their utility in detecting weevil attacks in immature Sitka spruce stands. Four independent interpreters correctly identified an average of 38% more weeviled trees on CIR film than on NC film during a 1 minute test period. More errors were made by the interpreters with CIR film than with NC film. Interpreter errors made with CIR film were mainly due to a lack of ability to discriminate between new weevil attacks and attacks made the previous year. Errors made with NC film were due mainly to misidentifying healthy trees as new weevil attacks. These findings suggest that for the purpose of detecting weevil attacked Sitka spruce trees, CIR aerial photographs would be both faster and more accurate than NC photographs. / Forestry, Faculty of / Graduate

No description available.

No description available.

No description available.

Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [136]-145).

Tree-ring chronologies from ten mixed conifer stands in the Colorado Front Ranges and New Mexico Sangre de Cristo Mountains were used to reconstruct timing, duration, and radial growth impacts of past outbreaks of western spruce budworm, Choristoneura occidentalis Freeman. Graphical and statistical comparisons of tree-ring chronologies from host and non-host tree species, in conjunction with Forest Service records of outbreaks during the twentieth century, revealed that outbreaks were identifiable only in the host chronologies as sharply reduced growth periods. These comparisons also showed that host and non-host tree-ring chronologies were generally similar between outbreaks and that both were responding in a similar manner to climatic variation. A study of defoliation and insect population data that was available for the New Mexico stands demonstrated that host radial growth from 1978 to 1983 was highly correlated with budworm activity. The non-host chronologies from each stand were used to correct the host chronologies for climatic and other non-budworm environmental variations by a differencing procedure. The corrected chronologies were then used to estimate the dates and radial growth effects of past budworm outbreaks. Tree-ring characteristics of twentieth century documented outbreaks were used as criteria for inferring the occurrence of outbreaks in previous centuries. At least nine periods of increased budworm activity were identified in the region from 1700 to 1983. The mean duration of reduced growth periods caused by known and inferred budworm outbreaks was 12.6 years, and the mean interval between initial years of successive outbreaks was 34.9 years. The mean maximum radial growth loss was 50 percent of expected growth, and the mean periodic growth loss was 21.6 percent. There was an unusually long period of reduced budworm activity in the first few decades of the twentieth century, and since that time outbreaks have been markedly more synchronous between stands. Increased synchroneity of outbreaks in the latter half of the twentieth century suggests that areal extent of outbreaks has increased. This phenomenon may be due to changes in the age structure and species composition of forests following harvesting and fire suppression in the late nineteenth and early twentieth centuries.

No description available.

No description available.

Tree breeders worldwide have highlighted the importance of wood quality within the juvenile core in determining final timber strength. The potential for improving timber strength by estimating genetic parameters of certain wood properties of Sitka spruce (Picea sitchensis) within the outer zone of the juvenile core was investigated. Fifteen trees were sampled from each of 33 families selected from a 20 year old open pollinated progeny trial. A number of wood properties critical to wood strength were measured; namely, density, grain angle, microfibril angle and branching characteristics. Clearwood stiffness and strength along with indirect measures of stiffness using acoustics and density using Pilodyn measurements were assessed. All wood properties were moderately heritable, wood density and acoustic velocity were the most heritable traits (h2 i 0.71 and 0.67 respectively). Genetic correlations showed that wood strength and stiffness were strongly correlated with wood density (0.86 and 1.04 respectively) and microfibril angle (-0.79 and -0.62 respectively). Acoustic velocity was strongly correlated with wood stiffness (0.81) and microfibril angle (- 0.83). The ability to select trees for wood stiffness with the use of acoustics along with the moderate inheritance of this trait should enable improvements in the wood quality of Sitka spruce. Despite the unfavourable correlation between growth rate and some key wood quality traits associated with timber strength, selection of certain families would enable modest gains to be made in both growth rate and wood quality.