Source: Dissertation Abstracts International, Volume: 40-02, Section: B, page: 0658. / Thesis (Ph.D.)--The Florida State University, 1978.

Source: Dissertation Abstracts International, Volume: 40-06, Section: B, page: 2588. / Thesis (Ph.D.)--The Florida State University, 1979.

In this research I explored the use of the statistical characteristics of the distribution of elevation points within a basin for predicting the rate at which at peak in rainfall at some point within the basin becomes at peak in runoff at the outlet of that basin. My research was stimulated by the desire to improve flood forecasting in ungauged basins and based on the pioneering hydrology research of Langbein, Horton and Strahler as updated by Harlin and Luo. I developed a simplified model of a basin with stream development and showed how basin factors known to affect runoff – area, slope, stream network development, and basin shape – could be represented by the statistical characteristics N (count), standard deviation, median less minimum, skewness, and kurtosis. Linear regression of average runoff accumulation rate on the statistical characteristics showed N, median less minimum, and skewness to have a significant effect with an R-squared of 83%, a residual standard error of 0.25 on 28 degrees of freedom, and an overall p-value of 2.4e-11. A model skill assessment through cross-validation yielded a mean square error of 11%. / A Dissertation submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Degree Awarded: Summer Semester, 2006. / Date of Defense: April 10, 2006. / Runoff, Basin Morphology, Hypsometric Curve, Flood Forecasting, Basin Statistical Analysis / Includes bibliographical references. / James B. Elsner, Professor Directing Dissertation; David Paradice, Outside Committee Member; Harry Cooper, Committee Member; Daniel J. Klooster, Committee Member; J. Anthony Stallins, Committee Member.

In decision problems that rely on technical or scientific data, values are often not explicitly considered, resulting in suboptimal environmental management decision-making. Yet, valuation is an integral part of the overall environmental management process. An environmental decision-making framework that places valuation at the forefront of the process is advocated. The application of values to environmental decisions should occur at every phase of analysis, not just the final weighing of decisions. Value-focused thinking will be used here to structure the problem and determine what is important. Management tasks, environmental or otherwise, cannot rely solely on objective criteria. Stakeholder input and values, and regulatory guidelines are normally considered along with relevant monitoring and modeling data output. Though formal risk management normally contains many decision tools, a unified procedure should exist to weigh evidence as well as formally integrate opinion and observation. A decision framework should be a helpful tool to bring together lines of evidence and values necessary to make important and costly decisions. If the decision-making consequences are detrimental, others can understand why a decision was made if a rationale is available. The best way to understand how a decision was made is to present the decision process from a value-focused perspective. Understanding the difference between objectives, alternatives, and criteria in a decision problem and placing value on features of interests should improve current informal environmental management decisions immensely. Though the current work will not explicitly evaluate costs and benefits, an approach that uses Bayesian Belief Networks (BBNs) and influence diagrams (IDs) is proposed. From the value-focused decision analysis, IDs will be created to weigh the evidence of the various alternative actions needed to reach items of value. An ID can be constructed once the major objectives, alternatives, and criteria are identified. The ID construction phase arranges the information determined in the decision analysis so that experts and lay people can evaluate what is important in a problem and how decisions and other factors influence it. Constructing an ID would include mapping the causal factors and decisions in a directed acyclic graph while preserving assumptions of conditional independence. The first three chapters of this thesis synthesized information from the decision analysis literature to establish an approach that will be beneficial to environmental management. The final two chapters developed examples of the approach that applies Bayesian decision networks in environmental management. Two topics in the final chapters were used to illustrate the framework's potential effectiveness: pesticide ecological risk assessment and natural resource management of Chesapeake Bay seagrass. The pesticide risk management scheme incorporated risk assessment evidence from various models to balance ecological risk management with spraying efficacy judgments. The seagrass assessment evaluated the ability of a BBN to assimilate water quality monitoring data in decision-making that reflect remedial goals. Assessing outcomes and the influences of future processes on restoration targets can be accomplished within the framework of a formal decision analysis with Bayesian networks.

Failure to design, construct and remediate waste rock and tailings storage facilities at mine sites leads to adverse environmental degradation and unforeseen financial costs. Typical closure options for these facilities include barrier or store and release covers. This thesis investigates the use of reactive in-situ covers as an alternative engineering design approach that involves mixing reagents (e.g. BauxsolTM) with waste rock to neutralise acidity and to immobilise major and minor metals. It was unknown whether this approach could be achieved at a field scale, whether the use of BauxsolTM would achieve its primary objectives, whether there would be adverse effects on the soil chemistry or whether there would be adverse ecotoxicological problems.Four 400 m2 field trials were conducted at a mine site and included a Control; Bauxsol™ (25 kg / m2) plus biosolids (15 kg / m2); Lime (2.5 kg / m2) plus biosolids (15 kg / m2) and a fourth site that was encapsulated with 0.3 m of compacted clay and 0.1 m of topsoil. The results suggest that soil chemistry can be significantly improved by mixing Bauxsol™ with the top 0.5 m of the waste rock profile i.e., creating a reactive in situ cover. This was sufficient to create a root zone up to 1.6 m deep that had pH greater than 5 and lower concentrations of metals measured using a sequential extraction procedure. Treatment of the acid mine waste with Lime did not achieve marked improvement of soil conditions in soil layers below the amended zone. The capping treatment created a topsoil layer with higher pH, but the underlying mine soil remained unimproved. Leachate pH in the Control became increasingly acidic (pH 4.57 to pH 3.95). The addition of Lime and biosolids led to an initial increase in leachate pH, compared to the Control, however this decreased over the duration of the study (pH 5.37 to pH 4.89). In the Bauxsol™ and biosolids treatment leachate pH increased to 6.92 after the first rainfall event and continued to increase over the duration of the study to pH 7.4. After 24 months metal leachate concentrations (mg / L) in the lysimeters for Al, Cd, Cu, Mn and Zn were (Control: 32.6, 5.7, 12.7, 39.3, 121.8), (Bauxsol™: 0.07, 0.02, 0.07, 0.57, 0.23) and (Lime: 2.19, 1.19, 2.33, 3.6, 28.4). No leachate was available for collection from the Clay treatment indicating that this technique was functioning in terms of minimising the infiltration of water into the mine soil.Ecotoxicological studies of major and minor metals in eucalypt leaves from the field trials and earthworm bioaccumulation studies were undertaken. The Bauxsol™, Ca(OH)2 and Clay treatments in the field trials allowed good tree growth of four eucalypt species, compared to the Control. There was no statistical difference in tree growth between the Bauxsol™, Lime or Clay treatments over the two years of monitoring. However the growth of one tree species was poor in the Bauxsol™ treatment.Laboratory bioaccumulation assessments found that there was good motility and no mortality of the earthworm species E. fetida after 28 days exposure to metal loaded BauxsolTM. The bioaccumulation of metals in E. fetida and bioaccumulation factors were below reported toxicity thresholds to cause mortality and below reported bioaccumulation factors for moderately contaminated soils, indicating that the metals bound to the Bauxsol™ reagents are mostly non-bioavailable E. fetida. Analyses of the 20 % treatment at 28 days using a sequential extraction procedure showed that > 95 % of the metals are bound within the Fe / Mn oxide fractions. However, changes occurred in metal fractionation after exposure to E. fetida for Cd, Cr and Fe, Mn. The data also showed that the exchangeable (1M MgCl2) and the Toxicity Characteristic Leaching Procedure extractant are useful as indicators of metal bioavailability to E. fetida.

A novel process using high-intensity ultrasonication (HIUS) was developed to isolate fibrils from cellulose fibers. The geometrical characteristics of the fibrils were investigated using polarized light microscopy (PLM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results show that small fibrils with diameter ranging from about thirty nanometers to several micrometers were peeled from the fibers. The degree of fibrillation of the fibers was significantly increased. The crystallinities or molecular structures of most of the cellulose materials were changed by HIUS treatment. To evaluate the fibrils degradation by HIUS, a method using AFM was modified and developed to measure the elastic modulus of single cellulose fibrils. The results indicated that it was necessary to consider the penetration of AFM tips to the cellulose fibril surfaces. In the diameter range of 150 to 300 nm, the elastic moduli of Lyocell fibrils did not have significant differences between the HIUS treatment time of 30 min and 60 min. The modulus of Lyocell fibrils with diameters from 150 to 180 nm was evaluated about 98 GPa and it decreased dramatically when the diameter was more than 180 nm. The elastic moduli of cellulose fibrils were not significantly different between isolation methods of HIUS and high-pressure homogenizer for pure cellulose fiber, between different cellulose sources of pulp fibers treated by homogenizer. The elastic modulus of fibrils from regenerated cellulose fibers was higher than that of natural fibers. The treated fiber and separated fibrils were used to reinforce poly(vinyl alcohol), poly(lactic acid), and polypropylene by film casting or compression molding. Both of the tensile modulus and strength of nano-biocomposites reinforced with treated fiber and separated fibrils were higher than those of the untreated fiber reinforced composites. The morphological characteristics of the nanocomposites were investigated with SEM, AFM, and PLM. The dispersion of fibrils was not perfect, and the adhesions between the polymer and fibrils were not good without further modification of the fibrils. The fibrils on the fibers and isolated from the fibers may be the role that the tensile modulus and strength of the treated fiber and separated fibril reinforced composites were higher than those of the untreated fiber.

The forest products industry is undergoing unprecedented change from international competition, increasing fiber costs, rising energy prices and falling product prices. Competitive businesses have the key ability to adapt quickly to change through improved knowledge. Among adaptations to change are better product development, improved process efficiency and superior product quality. This dissertation is directly related to improving the knowledge of forest products manufacturers by investigating data mining (DM) methods that improve the ability to quantify causality of sources of variation. A contemporary DM method related to decision theory is decision trees (DTs). DTs are designed for heterogeneous data and are highly resistant to irrelevant regressors. The tree structures of DTs are also easy to interpret. The research hypothesis of this dissertation is that there is no significant difference in the explanatory or predictive capabilities of multiple linear regression (MLR) models, parametric regression trees (RTs) and non-parametric quantile RTs. To test this hypothesis 1,335 statistical models are developed. Box Cox transforms of Y are considered. Models are developed for the internal bond (IB) of medium density fiberboard (MDF) and the IB (and Parallel EI) of oriented strand board (OSB) from automatically fused data of destructive test data and real-time production line sensor data. Models with good predictability of the validation data set are possible for MDF IB when using traditional MLR methods with short record lengths without Box Cox transforms. Significant regressors (α < 0.01) for MDF MLR models are related to overall pressing time and press pre-position time settings. Parametric and non-parametric RT models without Box Cox transforms outperform the predictability of MLR models. For MDF IB, process variables related to overall pressing time, press position times and core fiber moisture are significant (α < 0.01). RT models with Box Cox transforms of OSB IB improve predictability for record lengths less than 100. Significant regressors (α < 0.01) of OSB IB are related to pressing times and core layer moisture. Significant regressors (α < 0.01) of OSB Parallel EI are related to forming speed and pressing times. There is evidence from the extensive investigation of 1,335 models to support the alternative research hypothesis.

Hardwood plantations are becoming increasingly important in the United States. To date, many foresters have relied on a conifer plantation model as the basis of establishing and managing hardwood plantations. The monospecific approach suggested by the conifer plantation model does not appear to provide for the development of quality hardwood logs similar to those found in natural hardwood stands. Thus, there is interest in creating mixed species plantations to simulate natural hardwood stand development. A simulation system, CherrybarkSQ, was developed to provide a platform for investigating the impacts of mixed species management of hardwood plantations on the stem quality of cherrybark oak (Quercus pagoda). Stem wood quality was defined by the proportion of clear wood (without knots) grown over a knotty core expressed by a Clear Wood Index (CWI) value. The construction of CherrybarkSQ consisted of developing models for predicting first-order branch characteristics and the occlusion of first-order branches for a distance-dependent individual tree model. CherrybarkSQ tracks the production of the knotty-core and clear wood over time through relationships developed between crown length and branch diameter and branch diameter and the overwood needed to occlude the branches. CherrybarkSQ was used to simulate the development of four hardwood plantation designs, three cherrybark oak monoculture designs (Pure, PureThin and Pure25) and a cherrybark oak and sweetgum mixed design (Mix) over a 50-year period. Among designs with similar initial stand density (Pure, PureThin and Mix), the Mix design produced the lowest CWI, an indication of greater clear wood production. The Mix plantation design consistently out-performed the Pure and PureThin designs. The low-density Pure25 design had the lowest CWI and the largest average diameter. The results of the CherrybarkSQ simulations indicate that when initial stand density is similar, a mixed species approach to cherrybark oak plantation management produces greater amounts of clear wood. A low-density monospecific approach produces a similar proportion of overwood, but the distribution of that overwood is on a shorter branch-free bole compared to the longer branch-free bole of trees at the greater density. The impact of hardwood plantation management decisions on clear wood or stem quality production, and therefore value, offers a great opportunity for evaluating hardwood plantations. Models and evaluations like those provided by CherrybarkSQ can assist with the interpretation, management and future development and value of mixed species plantations.

The Cumberland Plateau in Tennessee currently is experiencing widespread forest parcelization and changes in species composition as a result of changes in land use and ownership. These changes can be attributed partially to industrial forest land divestiture, the lingering effects of the 1998 – 2002 Southern Pine Beetle (SPB) epidemic, and expanding development due to increasing population growth. The region has recently become a focus of debate concerning land use change, land management practices, and the effects on biodiversity. A stratified random sample of 1600 Nonindustrial Private Forest (NIPF) landowners owning 40 or more acres of forestland were surveyed obtaining a 39 percent response rate. The survey was undertaken to gain new insight on the socio-demographics of Plateau NIPF landowners and to understand their forest management objectives and intentions for future timber harvesting activities. The findings reveal almost 50 percent of respondents were retired or employed as professionals and lived on or within 60 miles of their forest land. Ninety-one percent of all respondents had either purchased or inherited their forest land, and the majority indicated they intended to pass their forest land on to their heirs. The top three nonconsumptive ownership objectives were to enjoy scenery (m = 3.98), for peacefulness (m = 3.94), and to preserve nature (m = 3.83). Timber management was ranked as only moderately important (m = 2.60). Forty-five percent of all respondents indicated that they had previously sold or harvested timber from their forest land, but only 30 percent indicated they intended to sell timber in the future. Logit regression (n = 438) and factor analysis (n = 344) were used to model the respondents’ willingness to sell timber in the future. NIPF landowners who indicated they would most likely consider a future timber sale had sold timber in the past, had a higher interest in timber production, had received forest management advice in the past, and had a higher interest in maintaining the health of their forest. Factor analysis revealed landowners most likely to consider selling timber in the future fit into three principle component groupings: 1) Improvers; 2) Investors; 3) or Legacy Owners.

As the traditional forestry Extension clientele in Tennessee changes, Extension professionals need to adapt and deliver programs in such a way as to reach the maximum audience while ensuring the educational benefit of the program and remaining within budget. The development of the Internet and associated web-based programs presents a new tool by which Extension professionals can develop and deliver educational programs to clientele. This study compared two Extension program delivery methods, web-based and traditional field-based. A series of field workshops were held and participants were surveyed. From these field workshops, a web-based program was developed and was marketed to a similar audience; these participants were also surveyed. Demographic information, learning preferences, and other measures of program preference were collected. Ninety-seven percent of participants in the field-based program and 68% of the web-based sample preferred a field program over a web-based program. If only a web-based program was made available to participants, at least 50% of each sample would be interested. Educational level was the only demographic characteristic that was significantly different between those who chose a web-based program and those who chose a field-based program. Participants with higher educational levels were more likely to choose a web-based program. Educational level was positively correlated with income level, computer ownership, and Internet access. Educational level was negatively correlated with age. Knowledge gain was significantly higher in the field-based sample. Web-based participants showed average knowledge gain of 12.2 to 28.7% whereas the knowledge gain for people attending the traditional field day program averaged 16.5 to 46.1%. Level of computer ownership was high in both samples as was the use of the computer on a regular basis. Internet access was high in both groups. The web-based sample had significantly higher levels of high-speed access. Those with high-speed connections were more likely to choose a web-based program, although both groups used the computer/Internet regularly for gathering information. Current forestry Extension clientele preferred a field-based program delivery method. Some clientele, though, preferred web-based programming and these types of programs should be offered when suitable. Using a variety of delivery methods, Extension can adapt programs to a wide range of learning styles to reach new audiences, including younger generations who are more comfortable with Internet learning.