Thesis (M.S.)--Oregon State University, 1996. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

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

Both transportation costs and market values of woody biomass are strongly linked to the amount of moisture in the woody biomass. Therefore, managing moisture in the woody biomass well can lead to significant advantages in the woody biomass energy business. In this study, two prediction models were developed to estimate moisture content for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and hybrid poplar (Populus spp.) woody biomass. Experimental data for the Douglas-fir model were collected over four different seasons at two different in-forest study sites in Oregon (Corvallis and Butte Falls) between December 2010 and December 2011. Three woody biomass bundles consisting of 3-meter length logs (30 to 385 mm diameter) were built each season at each study site; a total of 24 Douglas-fir bundles (1,316 to 3,621 kg weight) were built over the period. Experimental data for the hybrid poplar model were collected in two drying trials at two off-forest study sites in Oregon (Clatskanie and Boardman) between April 2011 and January 2012. Two types of woody bundles consisting of 3-meter length logs were built each trial: small (28 to 128 mm diameter, 2,268 to 5,389 kg weight) and large (75 to 230 mm diameter, 3,901 to 7,013 kg weight). A total of eight hybrid poplar bundles were built over the period. These data were used to develop linear mixed effects multiple regression models for predicting the moisture content of Douglas-fir and hybrid poplar biomass, respectively. The major factors considered in this study for predicting woody biomass moisture content change were cumulative precipitation, evapotranspiration (ET₀), and biomass piece size. The Food and Agriculture Organization (FAO) Penman-Monteith method, which requires temperature, solar radiation, wind, and relative humidity data, was used to calculate ET₀. The developed models can be easily applied to any location where historic weather data are available to calculate estimated air-drying times for Douglas-fir and hybrid poplar biomass at any time of the year. Oregon has been split into nine climate zones. Use of the model was demonstrated for four climate zones, two in which air-drying data were collected, and two in which it was not collected. Considerable differences in predicted drying times were observed between the four climate zones. / Graduation date: 2013

This study examines the influence of climate on tree-ring properties of several major tree species: Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Forbes), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and lodgepole pine (Pinus contorta var. latifolia Dougl. ex Loud.). Our three objectives were to determine how (1) tree-ring properties change along an elevation gradient, (2) short-term climatic influences are correlated with tree-ring properties, and (3) long-term climatic influence on tree-ring properties.

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 96-107). Also available on the World Wide Web.

We examined tree rings from Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) timbers in the Salt Lake Tabernacle, constructed from 1863–1867 in Salt Lake City, Utah. A seismic upgrade to the Tabernacle initiated in 2005 required the replacement of wooden timbers with steel beams. Our objectives were to 1) determine cutting dates for the timbers to identify logs that may have been salvaged from previous structures, and consequently would have greater historical significance, 2) identify the species and provenance of the timbers, and 3) develop a chronology that could extend or strengthen the existing tree-ring record for environmental and historical applications in northern Utah. We built a 162-year floating chronology from 13 cores and 15 cross-sections, crossdated visually using skeleton plots and verified statistically with COFECHA. Statistically significant (p , 0.0001) comparisons with established chronologies from northern Utah indicated that the Tabernacle chronology extends from 1702–1862. Cutting dates ranged from 1836–1863, with most in 1862 or 1863 and a smaller cluster around 1855. The broad range of cutting dates suggests that some of the timbers were used in previous structures, and that some trees were dead before they were cut. This study provides valuable information for the preservation of historical materials, and increases the sample depth of existing chronologies during the 18th and 19th Centuries.

The structuring of canopy arthropod communities was reviewed and investigated in relation to tree species diversity and its component factors, interspersion of different species and density of each tree species. Fifteen treatments of Douglas-fir (Pseudotsuga menziesii) and red alder (Alnus rubra) (various densities and proportions of each) were randomly assigned to 0.073 ha plots, replicated three-fold at each of two locations in Western Oregon: the Cascade Head Experimental Forest and the H.J. Andrews Experimental Forest. The six treatments used in this study were two densities of Douglas-fir and red alder monoculture (1000 trees/ha and 500 trees/ha), and mixtures of Douglas-fir and red alder (500 trees/ha of each) planted simultaneously or red alder planted 6 years after the Douglas-fir. Trees were initially planted in 1985-1986. The arthropod communities were sampled in the summer of 1998 by bagging and pruning branches from the mid-canopy of both tree species. Multivariate analyses distinguished the arthropod communities found on each tree species and geographical location, but not among the different diversity and density treatments. Many arthropod taxa and functional groups residing on a single tree species had significantly different abundances between locations. The most commonly encountered taxon, Adelges cooleyi Gillette (Homoptera: Adelgidae), was most abundant on Douglas-firs in the 500 trees/ha monoculture and the mixture with younger red alder, and least abundant in the mixture with both species planted simultaneously (the 1000 trees/ha Douglas-fir monoculture was intermediate). Adelgids showed no significant response to location, but did respond to combinations of location x treatment. The functional group of sap-feeders was dominated by adelgids, and showed similar treatment differences on Douglas-fir. Defoliators on red alder responded in abundance to location, treatment (most abundant in the 500 trees/ha monoculture and even-aged mixture, least abundant in the 1000 trees/ha monoculture), and location x treatment. This study demonstrated that tree species and geographical location are the primary determinants of forest arthropod community composition at this spatial scale. However, tree species diversity and density can affect the abundance of certain arthropod taxa, apparently through some combination of resource quality and plant apparency. / Graduation date: 2000

The structural integrity of fire-dependent ecosystems, such as ponderosa pine (<i>Pinus ponderosa </i> Dougl.) and Interior Douglas-fir (<i>Pseudotsuga menziesii </i> (Mirb.) Franco) biogeoclimatic zones in Interior British Columbia (BC) is changing. The problems within these ecosystems include decreased rangeland area, reduced carrying capacity and loss of biodiversity due to tree encroachment and forest ingrowth caused mainly by fire suppression. The goal of this study was to determine the effect of burning and thinning on understory vegetation of grassland and forested sites. The burning experiment took place at Dew Drop (Tranquille Ecological Reserve) located 20 km northwest of Kamloops, BC. Thinning was done at two upper grassland sites near Cache Creek, BC; Coal Mine Pasture and Gladys Lake Pasture. Species evenness and values of the Shannon-Weiner Diversity Index (H) were reduced (13 and 27%, respectively) within three years following burning (P = 0.014 and P = 0.038, respectively). Burning reduced canopy cover of shrubs on grassland sites (P = 0.005) and it reduced graminoid cover on forest sites (P = 0.014) immediately after the treatment (1999) but both functional groups had recovered by 2002. Litter depth and total canopy cover of plants were reduced in grasslands and forests immediately following burning (1999) but litter depth and canopy cover had recovered by 2002. Litter cover and litter depth beneath the tree canopy were reduced by burning (P = 0.037 and P = 0.009, respectively). Trends in the data indicate forb standing crop increased and total understory standing crop increased following burning in the grassland compared to the control. Graminoid standing crop was reduced 47% by burning in the forests (P = 0.049). Thinning reduced species richness in the first (P = 0.033) and fourth (P = 0.030) years, and H in the first year (P = 0.037) following the thinning at Coal Mine Pasture. Trends in the data suggest understory standing crop increased at Coal Mine and Gladys Lake Pastures following thinning. At both locations, thinning reduced litter depth. Therefore, burning and thinning kills trees, reduces fuel loads, and increases standing crop of the understory.

The structural integrity of fire-dependent ecosystems, such as ponderosa pine (<i>Pinus ponderosa </i> Dougl.) and Interior Douglas-fir (<i>Pseudotsuga menziesii </i> (Mirb.) Franco) biogeoclimatic zones in Interior British Columbia (BC) is changing. The problems within these ecosystems include decreased rangeland area, reduced carrying capacity and loss of biodiversity due to tree encroachment and forest ingrowth caused mainly by fire suppression. The goal of this study was to determine the effect of burning and thinning on understory vegetation of grassland and forested sites. The burning experiment took place at Dew Drop (Tranquille Ecological Reserve) located 20 km northwest of Kamloops, BC. Thinning was done at two upper grassland sites near Cache Creek, BC; Coal Mine Pasture and Gladys Lake Pasture. Species evenness and values of the Shannon-Weiner Diversity Index (H) were reduced (13 and 27%, respectively) within three years following burning (P = 0.014 and P = 0.038, respectively). Burning reduced canopy cover of shrubs on grassland sites (P = 0.005) and it reduced graminoid cover on forest sites (P = 0.014) immediately after the treatment (1999) but both functional groups had recovered by 2002. Litter depth and total canopy cover of plants were reduced in grasslands and forests immediately following burning (1999) but litter depth and canopy cover had recovered by 2002. Litter cover and litter depth beneath the tree canopy were reduced by burning (P = 0.037 and P = 0.009, respectively). Trends in the data indicate forb standing crop increased and total understory standing crop increased following burning in the grassland compared to the control. Graminoid standing crop was reduced 47% by burning in the forests (P = 0.049). Thinning reduced species richness in the first (P = 0.033) and fourth (P = 0.030) years, and H in the first year (P = 0.037) following the thinning at Coal Mine Pasture. Trends in the data suggest understory standing crop increased at Coal Mine and Gladys Lake Pastures following thinning. At both locations, thinning reduced litter depth. Therefore, burning and thinning kills trees, reduces fuel loads, and increases standing crop of the understory.

Thesis (M.S.)--Mississippi State University. Department of Forestry. / Title from title screen. Includes bibliographical references.