Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 77-82). Also available on the World Wide Web.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xiv, 182 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 113-124).

Short-rotation woody crops are becoming important supplies of hardwood fiber, but little is known about the early nutritional needs of these systems, especially on different site types. The study objectives were, on two young (ages 3-6) sweetgum plantations with contrasting soil types, to 1) determine the plant growth and foliar nutrition response to repeated nitrogen (N) fertilizer applications, 2) determine soil N supply, plant N demand, foliar N resorption, and soil and fertilizer uptake efficiencies, and 3) test a simple N supply model. In order to expand the findings to the range of sweetgum site types, the study objectives were also to 4) evaluate rapid methods for determining N mineralization potential, 5) characterize the soils of 14 sweetgum site types in the Atlantic coastal plain, and 6) review current N fertilizer prescriptions in forestry and recommend strategies for improvement. Two young sweetgum (Liquidambar styraciflua L.) plantations on a converted agricultural field and a pine cutover site in South Carolina were fertilized biannually with three rates of N fertilizer (0, 56, 112 kg N per ha). Fertilization doubled foliar biomass and leaf area on the cutover pine site in the years fertilizer was applied, and stem biomass increased 60%. Critical values, the N concentration required for 90% of optimum growth, is approximately 1.75%. Foliar N uptake increased at both sites when fertilizer was applied. Modeled annual soil N supply was within 20% of that measured on the two plantations even though monthly N supply was not accurately estimated. Potential N mineralization was accurately estimated with a 3-day incubation of rewetted soils that were previously dried, but not by hot salt extraction or anaerobic incubation. Across a spectrum of 14 sweetgum sites, the agricultural fields had lower mineralizable nitrogen (126 kg per ha) than the cutover sites (363 kg per ha). Current N fertilizer prescriptions are not sufficient for repeated fertilizer applications to fast-growing hardwood plantations, but simple models of soil N supply and an N-balance approach may improve prescriptions. / Ph. D.

Ellagitannins are plant phenolics characterized by biaryl-coupled gallic acid moieties esterified to a D-glucose core. They are widely distributed through higher plants. In the case of oaks, ellagitannin concentrations in heartwood can reach up to 10% (dry wt. basis). These secondary metabolites are not only important physiologically but also influence the economic value and quality of wood products that contain them. Efforts were made to develop and validate the methods used to quantify both soluble and insoluble ellagitannins. First, the efficiencies of the two commonly used extraction solvents, aqueous acetone and aqueous methanol were evaluated. The results showed that aqueous acetone is superior to aqueous methanol in obtaining higher vescalagin and castalagin yields. In a separate study, the method used for determining insoluble ellagitannins was found to under-estimate the contents of insoluble ellagitannins in wood products. Anhydrous methanolic HCl was found to be an excellent reagent for releasing insoluble ellagic acid and gallic acid (as methyl gallate) from biomass substrates. Optimization of both the reaction conditions and the gradient HPLC analysis has led to the development of a robust and reliable protocol. The chemical stability of the two predominant ellagitannins in oaks (vescalagin and castalagin) were evaluated in aqueous methanol and water. It was found that oxygen, pH and higher temperature (60 °C) affect their stability with higher temperature being the most prominent factor. Both vescalagin and castalagin were found unstable in methanolic solutions. Vestalagin, however, is less stable than castalagin. In the course of finding alternative models for ellagitannin biosynthesis study, both callus tissues and suspension cell cultures of white oak (Quercus alba) and sweetgum (Liquidambar styraciflua) were investigated for their possible use as models for ellagitannin biosynthesis. It was found that oak callus tissue cultures (Quercus alba) are capable of producing ellagitannins, and the production and profile of ellagitannins can be modified by adjusting the media composition. Comparison of extracts from the heartwood of Quercus alba with those from callus tissue reveals that they have similar ellagitannin profiles. Through manipulation of the media nitrogen and copper concentrations the callus tissue produced almost 3 times as much castalagin and vescalagin. Suspension cells of Quercus alba and Liquidambar styraciflua were found to be unsuitable for the study of biosynthesis of ellagitannins. These cells either did not produce any detectable level of ellagitannins or the production was unstable. Although the suspension cells could be elicited to produce ellagic acid with glycanases (Driselase), the levels of ellagic acid were too low for quantitative metabolic studies. A method using high performance liquid chromatography – mass spectrometry was developed and optimized with purified ellagitannins. Ellagitannins analyzed under the optimal conditions all provide base peaks of (M-H)- from which the molecular weights of the ellagitannins can be determined. Mild fragmentation was also achieved to give fragments characteristic of ellagitannins (loss of ellagic acid and gallic acid if present). These characteristic peaks allow for rapid identification of ellagitannins from other secondary metabolites present in the samples. Application of the HPLC/ESI-MS in the identification of monomeric ellagitannins in white oak heartwood extracts revealed that it can unambiguously identify the two monomeric ellagitannins, castalagin and vescalagin, and their degradation product, ellagic acid. The key fragmentation pathways of the ellagitannins are also described. Finally, preliminary work using proteomics to study the heartwood formation was conducted. Proteins from transition zone and sapwood were determined and resolved with two-dimensional electrophoresis. It was found that both sapwood and transition woods contain active enzyme(s) capable of catalyzing formation of ellagic acid from pentagalloylglucose. Preliminary results from the 2-D gel separation of sapwood and transition wood proteins showed more protein spots in sapwood than in transition wood, suggesting that sapwood not only had higher protein levels but also a great total number of proteins. The lower complexity of the transition wood proteome suggests that this material may be a good substrate for studying the biaryl-coupling process. / Ph. D.

Mature trees help to offset urban area problems caused by impervious pavement. Trees in paved areas remain unhealthy due to a poor root zone environment. The objective of this experiment was to test if soil under pervious concrete, with greater water and gas infiltration, would be more beneficial to existing mature trees during urban development. Root activity, root growth and soil chemistry of American sweetgum under standard concrete, pervious concrete and no concrete were measured. Soil CO2 efflux rates and soil CO2 concentrations were extremely high under both concrete treatments. Soil under standard concrete had lower oxygen concentrations than soil under pervious concrete and control treatments, particularly under wet conditions. There was no pavement effect on soil water content or soil chemistry. Under control treatment standing live root length was greater than under both concrete treatments. There were no major differences in soil conditions between impervious and pervious concrete treatments. The soil under the plots, a Ships clay, with very low permeability may have prevented soil water infiltration. Likely this overrode any potential treatment effects due to porosity of the concrete. To obtain root zone benefits out of pervious concrete, a different base soil with a higher permeability would be a better alternative.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 60-64). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / Typescript. Vita. Includes bibliographical references (leaves 121-127).

Loblolly pine (Pinus taeda) and coppiced sweetgum (Liquidambar styraciflua) seedlings were grown in competition with a native weed community using soil and seed bank collected near Appomattox, Virginia. Seedlings and weeds were exposed to CO₂ (ambient and elevated) and water (water stressed and well watered) treatments for approximately one growing season in closed top chambers. Weed growth had an effect on tree growth, but the amount of variation in tree biomass explained by weed biomass was very low. It appears that the tree seedlings benefited more from available resources than the herbaceous weeds. The influence of competition with loblolly pine and elevated CO₂ did not have an influence on total weed biomass; however, it did favor C3 weed community development regardless of water availability. This suggests that weed community composition may shift toward C₃ plants in a future elevated CO₂ atmosphere. Loblolly pine height, diameter, needle, shoot and total biomass were significantly greater in the well watered treatment than the water stressed treatment. Pine root, needle, shoot and total biomass were significantly greater in the elevated treatment than the ambient treatment. While not significant, root biomass of water stressed pine seedlings was 63% greater in the elevated CO₂ treatment than the ambient treatment. There was a significant water and CO₂ interaction for pine root:shoot ratio. Under elevated CO₂, root:shoot ratio was significantly greater in the water stressed treatment than the well watered treatment. In contrast, root:shoot ratio in the ambient treatment was nearly identical under both water treatments. These results indicate that loblolly pine will respond favorably in an elevated CO₂ atmosphere, even under dry conditions. The coppiced sweetgum seedlings responded favorably to well watered conditions with significant increases in leaf area, specific leaf area, leaf, shoot and total biomass compared to water stressed conditions. Leaf, root, shoot+stump and total biomass of sweetgum significantly increased and specific leaf area decreased under elevated CO₂ compared to ambient CO₂, but differences were smaller than previous findings. This indicates that coppicing may dampen the growth response to elevated CO₂, at least in the initial growth stage after coppicing. / Master of Science

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