Syftet med denna studie var att studera hur hybridlärken växer och utvecklas på de lite svagare markerna. För att uppnå syftet har höjdtillväxten jämförts mellan hybridlärksbestånd och tall eller granbestånd som växt på likande marker. Studien indikerar att hybridlärk har en betydligt högre höjdtillväxt än gran (27 %) och tall (37 %) även på svagare marker än vad som tidigare visats. Hybridlärkens kvalitet i form av tunnare årsringar verkar öka med sjunkande bördighet. Däremot har inget samband mellan ståndortsindex för hybridlärk och variationen i årsringsbredd inom samma träd kunnat påvisas.

Two studies were designed to test three herbicides and factors which influence their efficacy. In the first study four chemical combinations used for site preparation in southern pine, including triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid), trichloropicolinic acid), dichlorophenoxy)acetic acid] picloram (4-amino-3,5,6- and 2,4-D [(2,4- were screened for the most effective control of selected hardwoods. The chemical combinations were tested on Piedmont and Coastal Plain physiographic sites and were examined for the optimum amount of time for chemical activity between application and slash disposal (site disturbance). Efforts were also made to use target-plant and environmental data to predict chemical efficacy. A combination of triclopyr and picloram at 2 and 1 lb ai/ac, respectively, each gave the best overall control of hardwood brush. The amount of time required to obtain the optimum chemical control, presumably related to translocation, was found to be six to eight weeks after application to the foliage. Chestnut oak (Quercus prinus L.) control was successfully predicted on the bases of plant tissue and environmental data. In a second study the effect of temperature and time on the distribution of foliar-applied triclopyr, picloram, and 2,4-D were observed in red maple (Acer rubrum L.). Detection of the herbicides in the stems and roots using gas chromatography revealed that triclopyr was less affected by temperature differences; however, overall more herbicide reached the roots of red maple growing in a 21° C than those growing in a 29° C temperature. Triclopyr concentrations in the roots reached a peak much earlier than picloram or 2,4-D which did not peak until 42 days after application. / M.S.

Intensively managed forests of the Southern United States are among the most important sources of wood fiber and timber in this country. There is a great deal of concern that disturbances associated with trafficking by heavy machinery might diminish long-term soil-site productivity. However, determining the effect of harvesting disturbance and silvicultural treatments on the long-term productivity of pine plantations is difficult because, in addition to harvesting effects, growth distributions are affected by changes in climate, silviculture, and genetics. The primary objectives of this study were to determine (1) whether logging disturbances under operationally realistic circumstances affect soil quality, hydrologic function, and loblolly pine (Pinus taeda L.) productivity on wet pine flats, and (2) whether intensive forest management practices mitigate disturbance effects if they exist. Three 20-ha loblolly pine plantations located on wet pine flats in South Carolina were subjected to combinations of wet- and dry-weather harvesting and mechanical site preparations. Changes in soil-site productivity after five years were evaluated using a new rank method. The key advantage of the rank change method is that it is largely independent of the confounding factors (e.g. genetics, silvicultural practices, and climate) that affect comparisons of tree growth and soil quality between growth cycles. After five years, loblolly pine site indexes (base age 25) ranged between 13 and 33 m, and production ranged between 0.5 and 95 Mg ha-1. Soil bulk densities increased from 1.15 to as high as 1.44 g cm-3 after harvesting; by age 7 years it had decreased to approximately 1.25 g cm-3. At the sub-stand scale (0.008 ha), visually assessed soil physical and harvesting residue disturbances had little influence on relative changes in soil-site productivity after five years. Factors that specifically reflect site drainage were the most influential on changes in productivity. At the operational scale (3.3 ha), there were no differences between wet- and dry- harvested sites as long as bedding was applied as a site treatment. These results indicate that when standard site preparation is employed, fertile, wet pine flats such as these are resilient in that they recover from severe, but operationally realistic, harvesting disturbances. / Ph. D.

In the upland hardwood forests of the southern Appalachians, management tools are needed based on the characteristics of the site to quantify the site quality where no accurate maps of site quality exist. Three studies were conducted to achieve this objective. The first study tested if independent measures of forest productivity, based on vegetation and environment, in a six-county study area in the Blue Ridge Mountains in North Carolina would correlate with measures of forest productivity obtained from U.S. Forest Service Forest Inventory Analysis (FIA) data. Specific hypotheses included: FIA measures of forest productivity are related to one another; FIA measures of forest productivity are related to FIA-measured landscape parameters; and FIA measures of forest productivity are related to independent measures of forest productivity based on landscape parameters and soil characteristics. Four predictive indices of forest productivity were used; three were generated in a geographic information system (GIS). FIA measures of forest productivity were not significantly correlated to FIA measured landscape parameters. FIA site productivity classes were significantly correlated to FIA measures of site index. Independent measures of forest productivity, particularly the Moisture Regime Index (MRI) and the Forest Site Quality Index (FSQI), were significantly correlated to FIA measures of site index. Topography can be used to delineate site quality, but the addition of soil depth can prove to be useful in the estimation. The second study was designed to develop methods, based on field and digital data, to identify colluvial soils in the central Ridge and Valley of southwestern Virginia. Two hypotheses were tested. First, on the linear side slopes of the study area, where site quality is low in stands with subxeric to xeric moisture regimes, vegetation and topography can indicate colluvial soils. A second hypothesis tested if the topographic signature of colluvial soils could be identified geospatially with a digital elevation model. Results indicated that the MRI and the Terrain Shape Index predicted the presence of colluvial deposits in the study area. The basal area of yellow-poplar was positively associated with colluvial soils. A GIS-based model found the slope difference of colluvial soils to be less steep than residual soils as the size of the neighborhood increased. The final study determined if measures of site quality in the Blue Ridge Mountains of North Carolina were related to the water budget. Specifically,the hypothesis that site index could be predicted by variables that represented the inputs, usage, and supply of water was tested. A second hypothesis questioned if site quality classes could be predicted by a combination of topography and the annual water budget. Regression models predicted site index to be a function of topography, available water supply, and the annual water budget, but the accuracy was low (R2=0.11 and 0.13). A classification approach yielded better results. Incorporating the annual water budget into the FSQI increased classification accuracy of predicted site index by 50%, and decreased the number of sites misclassified by one class by 8%. Where accurate maps of site quality do not exist, the MRI, the abundance of yellow-poplar, and the modified FSQI may be used to delineate site quality for site-specific management and, ultimately, greater return on investment for the landowner. / Ph. D.

The present state of forestry post mining land uses has prompted concern among researchers, landowners, and the public. Surface mines reclaimed to forests under the provision of the Surface Mining Control and Reclamation Act (SMCRA) may not achieve site productivity levels required by the law. Anecdotal evidence suggests that many pre-law reforested mined sites are growing productive forests. The purpose of this study was to characterize these forests and the mine soils in which they are growing, and use them to benchmark forest development on mined land. Using 14 mined and 8 non-mined sites in the midwestern and eastern coalfields research to address the following objectives was undertaken: (i) characterize the development, composition, and diversity of woody species on pre-SMCRA, forested surface mined land; (ii) estimate forest and site productivity on surface mined land and determine the soil and site properties most influencing forest growth; (iii) estimate projected rotation-age timber product value; (iv) quantify current carbon sequestration pools associated with the developing woody plant biomass, the forest floor, and developing soil medium; (v) compare the diversity, forest and site productivity, commercial value, and carbon capture of reclaimed mined sites to that of regional non-mined forest systems. Species richness between non-mined and mined sites was about the same within each region with 14 to 15 tree species in the canopy. Canopy richness of eastern mined sites was less than that on midwestern mined sites (12 species compared to 17 species, respectively). Species richness of the understory and woody ground layer were similar between sites planted to pines versus hardwoods. White pine (Pinus strobus) monocultures, planted on many sites in the eastern region, caused species unevenness throughout all forest strata. Midwestern mined sites and eastern sites planted to hardwoods closely approximated non-mined sites in commercial species composition. Planted species represented the majority of canopy layer dominance and abundance (82% relative dominance and 56% relative abundance). Site productivity between non-mined sites and 12 of the 14 mined sites was similar. Regression analysis identified the five most influential soil properties affecting site quality, which included soil profile base saturation, total coarse fragments, total available water, C horizon total porosity, and soil profile electrical conductivity. These five properties explained 52 % of the variation in tree growth. Forest productivity of these mined sites was equal to or greater than that of non-mined forests, ranging between 3.3 m3ha-1yr-1 and 12.1 m3ha-1yr-1. Management activities such as planting pine and valuable hardwood species increased the stumpage value of forests on reclaimed mine sites. Rotation-age stumpage values on mined study sites ranged between $3,064 ha-1 and $19,528 ha-1 and were commonly greater than stumpage values on non-mined reference sites. After 20 to 55 years, total site carbon levels on mined study sites averaged 217 Mg ha-1, while total carbon amounts on natural sites averaged 285 Mg ha-1. The amounts of carbon captured within the plant biomass and litter layer were the same on mined and natural sites. However, the soil carbon content of mined sites averaged 39 % lower than natural soils. The amount of carbon captured across mined sites was largely a function of forest stand age. Pre-SMCRA forests growing on mined sites with productivity levels similar to non-mined sites are capable of developing forest attributes comparable to or greater than those found on non-mined land within a period of 60 years, the length of a commercial hardwood rotation. These mature forests can serve as benchmarks for forest development on mined lands being reclaimed under current state and federal regulations. / Master of Science

In an attempt to provide low-cost, low-input alternatives for regenerating pine-hardwood mixtures, this study examined several mechanisms that influence the growth of pine-hardwood stands. The Regeneration Alternatives Study is an ongoing experiment that was designed to gain biological and economical information concerning the growth and yield of loblolly pine and mixed hardwood species. Low-cost herbicide applications (stump treatment, basal stem spray, release, and soil spot release) were used to control competing vegetation during the study. The four even-aged regeneration treatments applied to loblolly pine and mixed hardwood stands of this study had a significant effect on their growth. Loblolly pine growth increased and mixed hardwood growth decreased as the intensity of herbicide treatment increased for all age classes. In general, loblolly pine was more productive with more intense treatment applications on poorer sites following a growing season harvest. Hardwood species were more productive with less intense treatment applications on higher-quality sites following a dormant season harvest for all age classes. Loblolly pine planting following clearfelling, coupled with a herbicide stump and release treatment (treatment 4), resulted in the highest yields of loblolly pine, the greatest economic returns, and the greatest level of site utilization. However, treatment 4 also resulted in the lowest yield of mixed hardwoods and the lowest level of species richness. Loblolly pine planting following clearfelling, with (treatment 3) and without (treatment 2) a hardwood stump treatment application, resulted in a more even distribution of pines and hardwoods, depending on the treatment. Treatment 3 favored loblolly pine growth, especially following a growing season harvest on poor sites. Treatment 2 favored mixed hardwood growth, especially following a dormant season harvest on good sites. There were no differences between methods of release (basal spray or soil spot herbicide application). Economically, treatments 2 and 3 did not realize a profit on returns. Pine yields, dbh, and basal area were all significantly greater following a summer season harvest as opposed to pine growth following a winter harvest with the same chemical treatments. The pine growth data indicated that less intense chemical treatments following a summer harvest can achieve the same or greater growth results than more intense chemical treatments following a winter harvest. The results of this study indicate a significant biological and economic tradeoff, depending on the level of hardwood control applied and the time of harvesting. / Master of Science

The purpose of the study was to define the characteristics of tree-length skidding on the Lower Coastal Plain of Georgia. The objectives were: 1) to document skidder performance based on speed and tire slip, 2) to determine the effects of skidding on soil physical properties, and 3) to develop recommendations to minimize the impact on soil properties while maintaining skidder performance. A Franklin 170 grapple skidder was operated in second gear under moist (19% moisture content) and wet (31% moisture content) soil conditions using 28L-26, 67x34-25, and 73x44-32 tires. One, three, nine, and 27 passes were tested. The skidder was also operated in third gear with the 73x44-32 tires under the wet soil condition. With moist soil conditions skidder speed and tire slip were not affected by tire size or the number of skidder passes. Tire size did not influence soil properties. It was recommended that skidding be dispersed to avoid making more than nine passes over any particular soil area because the research indicated that repetitive passes resulted in a cumulative decrease in non-capillary porosity and an increase in bulk density. During wet conditions, wheel slip increased, skidder speed decreased, and rut formation increased with smaller tires, an increase in the number of skidder passes, and second gear operation. Operating the skidder in third gear with the 73x44-32 tires was beneficial to skidder performance and a reduction in rutting. Recommendations were to disperse skidding to maintain productivity and minimize rutting. / Master of Science

Equations for modeling the height-age pattern of forest trees or stands are typically developed for a given species in a specified region. In order to adequately model height-age patterns, the resulting equations are often quite complex. This study addresses the question of how to increase the accuracy and precision of the prediction of height-age relationships through the use of localized equations. Although the pattern of height-age relationships of loblolly pine plantations was studied, the methodology should prove valuable for other species as well. The Schumacher logarithm of height-reciprocal of age model was fitted to data from loblolly pine plantations to attain an average guide curve. Various methods of localizing this equation to a particular stand were examined. The methods are based on empirical Bayesian, maximum likelihood, and Kalman filter theory. All of these methods employ the general concept of feedback in localizing the simple equation. The best of these various models is compared with the unadjusted model and a more complex polymorphic equation. The adjusted model compares favorably with these other two models. / Master of Science

Submitted by William Justo Figueiro (williamjf) on 2015-07-06T23:18:29Z No. of bitstreams: 1 08a.pdf: 1546104 bytes, checksum: 91947cb60bc59adc136fd46a64431582 (MD5) / Made available in DSpace on 2015-07-06T23:18:29Z (GMT). No. of bitstreams: 1 08a.pdf: 1546104 bytes, checksum: 91947cb60bc59adc136fd46a64431582 (MD5) Previous issue date: 2013-07-26 / Nenhuma / O presente trabalho teve por objetivo a proposição e teste de um modelo teórico, a fim de verificar as dimensões da confiança e seus antecedentes qualidade do site e satisfação, que afetam a lealdade e o boca a boca do consumidor online, mais especificamente a confiança na internet, confiança em terceiras partes e a confiança no site fornecedor. Para atingir os objetivos deste estudo, buscou-se identificar na literatura as relações existentes entre os construtos pesquisados. Com base nos estudos revisados foi desenvolvido um instrumento com escalas já validadas em marketing em contexto de compras online, sendo avaliado e revisado por meio de pré-teste. A técnica de coleta de dados foi realizada através de uma survey, com 270 respondentes que compraram produtos eletroeletrônicos pela internet. A técnica estatística utilizada foi Modelagem de Equações Estruturais (MEE) por meio da qual foi testado o modelo e as respectivas hipóteses. Foi verificada também a mediação dos tipos de confianças: confiança na internet, confiança no site fornecedor e confiança em terceiras partes, entre os antecedentes qualidade do site e satisfação, influenciando na lealdade e no boca a boca do consumidor online. Os resultados indicaram um bom ajustamento do modelo de acordo com o que é proposto na literatura, indicando que a qualidade do site influencia as diferentes dimensões de confiança e a satisfação, a satisfação influência mais a confiança no fornecedor e esta é a que mais influencia a lealdade. Quanto ao teste de mediação, neste foi possível constar que existe a mediação total da confiança no site fornecedor entre qualidade do site e a lealdade. Além disso, verificou-se que a confiança na internet e em terceiras partes exercem influência no comportamento de lealdade e boca a boca, mas não afetam, a confiança no site do fornecedor. / Researchers in the area of management and marketing have studied the understanding of factors such as online consumer confidence, loyalty, site quality, satisfaction and word of mouth. The present work had as objective the proposition and testing a theoretical model to verify the dimensions of trust and their antecedents which affect the loyalty and word of mouth of online consumer, more specifically the internet trust, trust in third parties and confidence in the supplier site. To achieve the objectives of this study, it sought to identify in the literature the relationship among constructs searched. On the basis of the reviewed studies, it was developed an instrument with scales already validated in the context of online shopping marketing, being evaluated and reviewed through pre-test. The data was collected through a survey with 270 respondents who bought consumer electronics products over the Internet. The statistical technique used was Structural Equation Modeling (SEM) whereby model was tested and their hypotheses. It was tested even the mediation of the types of trusts: trust on the internet, trust and confidence in third party supplier, between the background of quality of the site and satisfaction, influencing on loyalty and word of mouth of the consumer. The results indicated a good model adjustment in accordance with what is proposed in the literature, indicating that the quality of the site influences the different dimensions of trust and satisfaction, the Sat more influence trust in supplier and this is the one that influences the loyalty. As for mediation, in this test it was possible to show that there is a total of mediation confidence in supplier site between the quality of the site and loyalty. In addition, it was found that confidence in the internet and in third parties exert a certain influence on the behavior of loyalty and word of mouth, but do not affect the tust in the supplier site. The implications of these analyses, both managerial and academic are presented in this study in order to contribute to the advancement of studies in the area.

Response to fertilization is a function of the degree to which nutrients are limiting growth, the capacity of individual trees to respond to nutrient inputs, the degree to which other factors limit growth, and the possible extrinsic effects of treatment (e.g., root mortality due to fertilizer-induced soil pH effects). Recognition and examination of these factors is essential if response to fertilization is to be predictable. Over the past 25 years numerous western hemlock fertilizer trials have shown responses ranging from negative to positive with no clear trends. Theories for this erratic response include: (a) different nutritional requirements during different stages of stand development; (b) high native N availability or low supplies of other nutrients (P and S, in particular); (c) differential adverse effects of N fertilizers on surface roots, mycorrhizal populations and P nutrition; (d) a requirement for slow release N; and (e) induced water stress. The objective of this study was to develop site-specific guidelines for western hemlock fertilization decision-making for industrial use. This study reports on the first and third growing-season response to two different fertilizer treatments, and identification of possible relationships between fertilizer response and site and stand conditions.