Life Sciences Commons^™

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

Multidimensional Investigation Of Tennessee’S Urban Forest, Jillian L. Gorrell

Doctoral Dissertations

Preserving existing trees in urban areas and properly cultivating urban forest conservation and management opportunities is valuable to the ever-growing urban environment and necessary for creating optimal experiences and educational tools to meet the needs of increasing urban populations. This dissertation contains studies investigating several facets of the urban forest, including environmental effects of deforestation and urbanization, tree equity, and urban forest facility management and accessibility. Community education and outreach at arboreta about the importance of the tree canopy can help promote environmental stewardship. A digital questionnaire was electronically distributed to representatives of arboreta certified through the Tennessee Division of …

Plant Community Responses To Interactive Anthropogenic Disturbances Along A Natural-Wildland-Urban Gradient And Undergraduate Students’ Attitudes Toward Disturbances, Mali M. Hubert

Doctoral Dissertations

Anthropogenic disturbances are defined as any change caused by human activity that alters biodiversity. Wildfire and urbanization disturbances are among the most influential on the landscape because of their individual and interactive properties. Areas deemed wildland-urban interfaces (WUI; area where environment intermingles with human-built structures) are increasing near protected lands because of human population growth and movement, which often facilitates fire ignitions by humans. Houses that are adjacent to or overlap with wildland vegetation can complicate protection of urban development and wildlands from fires. The expansion of the WUI due to population growth will exacerbate fire risk, which can ultimately …

Investigation Of Interactions Between 1,3 Dialkyl Imidazolium Ionic Liquids And Lignocellulosic Polymers, Aparna Annamraju

Doctoral Dissertations

Lignocellulosic biomass is a potential energy source for fuels, chemicals and materials production in a sustainable manner. A network of covalent and non-covalent bonds between the three main polymers of biomass, i.e., cellulose, hemicellulose and lignin, results in a compact structure that is resistant to chemical and biological attacks and therefore challenging for the efficient utilization of lignocellulosic biomass. Ionic liquids (ILs) have been reported to disrupt the bonds between these polymers and dissolve biomass at temperatures below 100 ˚C. Research through the years has shown that biomass pretreatment with IL brings out the selective dissolution of biomass polymers and …

Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao

Doctoral Dissertations

Tropical forests, relative to other terrestrial ecosystems, exchange the largest amount of carbon with the atmosphere and also constitute a significant carbon sink. However, nutrient limitation, particularly of phosphorus (P), could limit growth of tropical forests and their function with the global carbon cycle. Thus, understanding root mechanisms to acquire P is necessary to representing the P cycle and corresponding interactions with plant growth. A large portion of total soil P in tropical forests occurs in organic forms, only accessible through root and microbial production of phosphatase enzymes. These phosphatase enzymes mineralize organic P into orthophosphate, the form of P …

Forest Resources For Bioenergy, Gerry Solano Avila

Doctoral Dissertations

The overall objective of this dissertation is to evaluate forest resources biomass availability for the production of bioenergy. Chapter II provides measures of the impact that the road sustainability criteria have on the supply of feedstock for forest products and bioenergy. A linear cost minimization programming is used in estimating forest biomass supply curves. Chapter III provides estimates on the changes in US timberland acreages overtime and the ability of timberland to meet conventional timber products and woody biomass demand within the conterminous United States. Chapter IV utilizes the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), a Geographic Information System …

Regeneration Of Imperiled Hardwoods In The Eastern United States, Joshua J. Granger

Doctoral Dissertations

Our ability to successfully promote forest stand health and facilitate species under the threat of extinction will hinge on our ability to identify species regeneration requirements in an ever-changing environment. In the first chapter of this dissertation, I address what is known about the nature of threatened and imperiled hardwoods in the eastern United States, and in doing so, I identify several large knowledge gaps in current potentials and methodologies for regenerating them. In my second chapter, I use recent data from the United States Forest Service, Forest Inventory and Analysis program (FIA) to quantify ash regeneration counts across FIA …

Three Essays In Forest Resource Management: Landowners’ Considerations In Ecosystem Services, Forest Certification, And Timber Supply, Nana Tian

Doctoral Dissertations

Forest ecosystems provide a wide range of timber and non-timber ecosystem services that play a vital role in supporting human health, well-being, and economy. Sustaining forest ecosystem will depend on landowners’ interest and willingness to responsibly manage forests, and provide timber and non-timber services for public benefit. Despite a substantial research in understanding how forest resources are managed by landowners, several literature gaps still exist regarding how landowners’ behavior/activities associated with sustaining the supply of ecosystem services and timber, and participating in best management practices such as forest certification. By applying methods grounded in economic and human dimension theory, this …

Benefits And Risks Of Imidacloprid-Based Management Programs For Hemlock Woolly Adelgid, Elizabeth Paige Benton

Doctoral Dissertations

Hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae), has caused widespread decline of eastern hemlock, Tsuga canadensis (L.) Carriére. This collaborative retrospective analysis with Great Smoky Mountains National Park (GRSM) provides research-based management guidance on imidacloprid treatments and nontarget risks to aquatic systems.

Imidacloprid and olefin concentrations were assessed in foliage from different diameter at breast height (DBH) size hemlocks 4 – 7 yr post-imidacloprid treatment. Imidacloprid concentrations were below the LC₅₀ [lethal concentration] for HWA, but olefin was above the LC₅₀ 4 yr post-treatment. HWA populations were suppressed, and hemlock canopies were healthy. Treatment efficacy can …

Population Dynamics And Ecophysiology Of Fraser Fir (Abies Fraseri) In The High Elevation Forests In The Southern Appalachian Mountains, Steven Douglas Kaylor

Doctoral Dissertations

Dominated by the endemic Fraser fir (Abies fraseri), the high-elevation forests of the Southern Appalachians are one of the most endangered ecosystems in the United States, and the future of these forests remains uncertain. Fraser fir is showing signs of decline in health and increased mortality throughout its range, possibly due to multiple environmental stresses.

Using twenty years of forest monitoring data, this dissertation documents change in forest structure and species composition in high-elevation red spruce-Fraser fir forests in southern Appalachia and generates predictions of future forest change. Additionally, it quantifies physiological measures of carbon fixation, storage and …

Nanoscaled Cellulose And Its Carbonaceous Material: Application And Local Structure Investigation, Yujie Meng

Doctoral Dissertations

In this dissertation, cellulose nanocrystals three-dimensional morphology, size distribution, and the crystal structure were statistically and quantitatively investigated. Lognormal distribution was identified as the most likely for cellulose nanocrystals’ size distribution. Height and width dimensions were shown to decrease toward the ends from the midpoint of individual CNCs, implying a spindle-like shape. XRD analysis of crystallite size accompanied with TEM and AFM measurements revealed that the cross-sectional dimensions of individual switchgrass CNC were either rectangular or elliptical shape, with an approximately 3~5 nm [nanometer] lateral element length range. A sponge-like carbon aerogel from microfibril cellulose with high porosity, ultra-low density, …

Development And Application Of Mass Spectrometry-Based Proteomics To Generate And Navigate The Proteomes Of The Genus Populus, Paul Edward Abraham

Doctoral Dissertations

Historically, there has been tremendous synergy between biology and analytical technology, such that one drives the development of the other. Over the past two decades, their interrelatedness has catalyzed entirely new experimental approaches and unlocked new types of biological questions, as exemplified by the advancements of the field of mass spectrometry (MS)-based proteomics. MS-based proteomics, which provides a more complete measurement of all the proteins in a cell, has revolutionized a variety of scientific fields, ranging from characterizing proteins expressed by a microorganism to tracking cancer-related biomarkers. Though MS technology has advanced significantly, the analysis of complicated proteomes, such as …

Spatial, Temporal, And Tri-Trophic Distribution Of Imidacloprid, Olefin And 5-Hydroxy And Their Effect On Hemlock Woolly Adelgid, Adelges Tsugae Annand, (Hemiptera: Adelgidae)., Carla Irene Coots

Doctoral Dissertations

Extensive mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) (HWA), has occurred throughout the eastern United States. Imidacloprid, a systemic insecticide, is used to control hemlock woolly adelgid. The metabolism of imidacloprid in eastern hemlock produces two metabolites of toxicological interest, olefin and 5-hydroxy. The objectives of this study were to 1.) determine the distribution and persistence of the metabolites in eastern hemlock in the southern Appalachians, 2.) their effect on hemlock woolly adelgid mortality, 3.) assess the tri-trophic movement of these compounds, 4.) evaluate the effects of …

Tree Growth Dynamics, Fire History, And Fire-Climate Relationships In Pine Rocklands Of The Florida Keys, U.S.A., Grant Logan Harley

Doctoral Dissertations

Pine rocklands are globally endangered, fire-maintained communities currently restricted to small habitat areas in southern Florida, Cuba, and the Bahamas. The purpose of this dissertation research was to identify the long-term ecological disturbance regimes and climatic trends responsible for the persistence of pine rocklands, and examine how human-induced changes during the 20^th century contributed to decline of these communities. This research applied techniques of dendrochronology in extreme southern Florida, in a subtropical region where tree‐ring science has never been applied, to increase the understanding of how anthropogenic and natural disturbance events have decreased the spatial distribution of South Florida …

An Evaluation Of Disturbance-Induced Nutrient Changes And Climate Responses Of Loblolly Pine Xylem, Rebecca Lynne Stratton

Doctoral Dissertations

Dendrochronological techniques are currently limited to the identification of visible fire scars. However, through the development of new dendrochemical techniques, the potential exists to provide insight into a broader array of pyric ecosystems. In addition, the ability to identify historic climate-growth responses provides a better understanding of the conditions under which historic fire regimes occurred.

This study provides the groundwork for the identification of a dendrochemical nutrient fire signature in xylem and identifies the climate-radial growth responses of loblolly pine (Pinus taeda L.) on five sites in the Piedmont of South Carolina. Changes in N, P, K, Ca, Mg, …

Multiple Responses By Cerulean Warblers To Experimental Forest Disturbance In The Appalachian Mountains, Than James Boves

Doctoral Dissertations

The Cerulean Warbler (Setophaga cerulea) is a mature forest obligate and one of the fastest declining songbird species in the United States. This decline may be related to a lack of disturbance within contemporary forests; however, the consequences of disturbance on the species have not been rigorously evaluated. Thus, we assessed multiple responses by Cerulean Warblers to a range of experimental forest disturbances across the core of their breeding range in the Appalachian Mountains. We quantified individual and population responses to these manipulations, and assessed the potential consequences of disturbance on the sexual signaling system. Male ceruleans were …

Silvicultural Considerations For The Reintroduction Of American Chestnut, Castanea Dentata, To The Forests Of The Eastern United States, Cornelia Cooper Wells Pinchot

Doctoral Dissertations

In anticipation of widespread planting of putatively blight-resistant hybrid chestnuts (Castanea spp.), it is critical to understand the silvics and competitive ability of the species. This dissertation examines preliminary growth and survival of several species and genetic crosses of chestnut grown as 1-0 high-quality nursery seedlings and planted in two study sites: Southeastern Kentucky (Daniel Boone National Forest; chapter 2), and Northeastern Connecticut (Yale-Myers Forest; chapter 4). The effects of three silvicultural treatments on the Daniel Boone National Forest (DBNF), and four silvicultural treatments on the Yale-Myers Forest (YM) were evaluated. Furthermore, the effect of initial seedling size on …

Steps Toward Butternut (Juglans Cinerea L.) Restoration, Sunshine L. Brosi

Doctoral Dissertations

Butternut (Juglans cinerea L.), a lesser-known relative of black walnut (Juglans nigra L.), is a native tree species beneficial for wildlife, valuable for timber, and part of the great diversity of species in the eastern forests of North America. Populations of butternut are being devastated by butternut canker disease, caused by the fungus Sirococcus clavigignenti-juglandacearum (V.M.G. Nair, Kostichka, & Kuntz), which is thought to be introduced to North America. The disease causes multiple branch and stem cankers that eventually girdle trees. Small population sizes, lack of sprouting, and shade intolerance exacerbates the disease and results in permanent losses of butternut …

The Effects Of Mercury Contamination On Tree, Fungal, And Soil Composition Along East Fork Poplar Creek, Anderson And Roane Counties, Tennessee, Sharon Jean-Philippe

Doctoral Dissertations

The Oak Ridge Reservation established under The Atomic Energy Commission was the site for uranium enrichment and the construction of the atomic bomb during the early 1950’s and 60’s. Unfortunately, large quantities of “heavy metals” such as mercury, uranium, technetium, plutonium and fission products that were produced were dumped into unlined landfills, settling ponds and surface streams. One such creek affected was East Fork Poplar Creek, whose head water begins at the Y-12 Facilities located on the Oak Ridge Reservation, and was once used as an industrial drainage ditch for runoff, which included mercury and other heavy metals.

The release …

Facilitating Private Forestland Management: Relating Landowners’ Experience Of Their Forestland And Their Conceptualization Of Forest Management To Their Management Behavior, Miriam L.E. Steiner Davis

Doctoral Dissertations

Privately owned forestland accounts for the majority of forested land in the US and provides numerous ecological, economic and social benefits to its owners and society at large. However, numerous issues ranging from fragmentation and parcelization, to pressure from the forest products industry, to increasing land values for development and real estate interests threaten to “unravel” the forest landscape. Active management of forestland is seen as one way to combat such threats. Active management of private forestland has been linked to numerous factors such as private forest landowners’ (PFLs’) general education level and familiarity with forest management, their goals, interests, …

Wildfire Risk Assessment And Community Wildfire Protection In The Chilhowee Mountain Area Of Blount County, East Tennessee, Piyarat Chimchome

Doctoral Dissertations

The growing Wildland Urban Interface community in the Chilhowee Mountain area of Blount County, Tennessee, like many other forested areas in the mountains and hills of East Tennessee, was identified by officials of the Tennessee Division of Forestry as being a high risk area for wildfire. The purpose of this research was to help wildfire managers better understand how to facilitate wildfire protection and mitigation in the Chilhowee Mountain area. A mail survey was sent to the 474 property owners in the communities of Campers Paradise, Happy Valley, and Top of the World. The survey contained 33 questions related to …

The Influence Of Selected Wood Characteristics And Composites Production Parameters On The Sorption Behavior Of Wood Materials, Trairat Neimsuwan

Doctoral Dissertations

The goal of this research was to investigate the influence of selected wood characteristics and composites production parameters on the sorption behavior of wood materials. A better understanding of the sorption behavior of different wood structures and types could be useful in protecting wood against wood deterioration. The differences among tree ring locations within the stem cross-section have not been explained in terms of sorption behavior. The purpose of the first task was to investigate the effect of differences among earlywood, latewood, and tree ring location within the stem crosssection on the water vapor sorption. A loblolly pine (Pinus …

Past Fire Regimes Of Table Mountain Pine (Pinus Pungens L.) Stands In The Central Appalachian Mountains, Virginia, U.S.A., Georgina Deweese

Doctoral Dissertations

Table Mountain pine is an Appalachian endemic that occurs in a patchy distribution from Georgia to Pennsylvania and is prolific at sites with a history of fire disturbance. The purpose of this dissertation was to reconstruct the fire regimes of Table Mountain pine stands in the Jefferson National Forest, Virginia. Sections from firescarred Table Mountain pines were collected at four sites to analyze fire history, while increment cores and stand composition information were collected from macroplots within each fire history site to investigate the possible influence of fires that were more ecologically severe. Results show that fire was frequent before …

Establishment, Growth, Spread, And Ecological Impacts Of Microstegium Vimineum In Central Hardwood Forests, Jordan M. Marshall

Doctoral Dissertations

Microstegium vimineum is an annual exotic grass common through the Southeastern United States. Adding M. vimineum to native plant communities may alter future forest composition through inhibiting the growth and influencing recruitment of seedlings into larger size classes, as well as significantly altering vertical structure and community richness, which may influence the distribution of insects.

The main objectives of these studies were to 1) establish how different mineral soil and litter disturbances, in combination with various forest canopy coverage, influence the establishment, growth, and spread of M. vimineum, 2) quantify effects of competition between M. vimineum and native hardwood …

An Experimental Release Of Elk Into Great Smoky Mountains National Park, Jennifer Lynn Murrow

Doctoral Dissertations

I conducted 6 years of field work to evaluate the habitat use and population dynamics of an experimental release of elk (Cervus elaphus) into Great Smoky Mountains National Park (Park). Elk exhibited relatively small home ranges (female: 10.4 km² and males: 22.4 km²) and movement distances decreased over time. I calculated survival rates (x = 0.73–0.93) and litter production rates (x = 0.73) for the population. To assess the potential for a long-term elk population, I incorporated those vital rates into the population modeling software Riskman and tested its sensitivity to any given …

The Decline Of Log House Construction In Blount County, Tennessee, John T. Morgan

Doctoral Dissertations

The log house is an important element of architectural heritage of much of the eastern United States. In some areas, such as East Tennessee, log construction was not replaced by frame construction until the late nineteenth century.

Several reasons have been presented in the literature for the decline of log house construction, but none of them had been tested empirically. This study determined to what extent the reasons given for the decline of the log house construction explain the decline of log dwelling construction in Blount County, Tennessee. The study analyzed the influence of five factors: (1) relative affluence of …