Digitized by Kansas Correctional Industries

Thesis (M.S.)--Oregon State University, 1970. / Typescript. Mounted photographs. Includes bibliographical references (leaves 67-73). Also available on the World Wide Web.

Thesis (M.S.) in Forestry--University of Maine, 2004. / Includes vita. Includes bibliographical references (leaves 34-39).

Thesis (Ph. D.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references (leaves 49-53). Also available on the World Wide Web.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1983. / Vita. Abstract. Includes bibliographical references (leaves 95-105). Also available via the Internet.

Geographic variation was investigated among 225 locations from five geographically disjunct regions in central Oregon. Characters included: germination speed and uniformity in two test environments differing in stratification period and incubation temperature; weight, three dimensions and three 'angles' of seeds; weight and three dimensions of wings; cone length and scale weight; the relative cover of 14 colors on the seed coat; and three sets of principal components (germination, morphology, color). The major objectives were to investigate: (1) the distribution of character variation within and among locations; (2) correlations among characters; (3) clinal relationships with several location variables (latitude, longitude, elevation, slope/aspect, soil characteristics, associated conifers); and (4) if the three major regions differed in the distribution of variation, correlations among characters, clinal relationships, and character means. In general, the major conclusions are: (1) much of the variation in all characters occurs within locations; (2) variation among locations is greater, and clines are steeper in germination than in morphological characters; (3) regions differ in several seed colors and morphological characters, and in several correlations among germination and morphological characters; (4) the Deschutes region has greater location-related variation, steeper clines, and stronger correlations between germination and morphological characters than do the two major regions farther east of the Cascade Mountain Range; (5) local aspect accounts for much of the variation in germination and morphological characters; (6) soil characteristics account for more variation in morphological than germination characters. Variation patterns are mainly interpreted as adaptive responses to the length of the growing season, which is strongly limited by summer drought in central Oregon. In general, drier locations appear to favor trees with faster and more uniform germination, and with longer, heavier seeds but shorter wings and cones. Seed colors are also correlated with several location variables. Effects of seed predators on seed size, shape and color are also considered. / Graduation date: 1989

The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

No description available.

Thesis (Ph.D.) -- University of Texas at Arlington, 2008.