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 …

Demand For Guided Tours On The Tennessee River., Gessika Lee Guerra

Masters Theses

Knoxville, TN is a major urban center in east Tennessee. Knoxville’s urban planners recognized the need for green space and have installed free greenways and parks within the downtown area over several decades. These attractions are immensely popular and promote urban ecotourism. There is an opportunity to begin or expand guided tour services. This research will analyze the demand and willingness to pay for guided river activities – kayaking and pontoon boating – on the Tennessee River in downtown Knoxville. Primary data were collected by 1000 on site flyers connected to an online survey platform. These data were uploaded into …

Variability In Microclimate And Carbon Dynamics In Hardwood Forests Managed With The Irregular Shelterwood Reproduction Method, Melody June Mount

Masters Theses

How do forest edges compare to intact interior forests in terms of carbon dynamics, and how is the microclimate altered through the creation of forest edges? Woody plants and trees can act as a carbon sink by using live and dead tissue to store varying amounts of carbon. However, factors such as age, species, respiration rates, and death alter the amount of carbon sequestered by the forest (Gorte, 2009). Additionally, widespread forest fragmentation has resulted in 20% of forests worldwide being located within 100 meters (m) of a forest edge (Haddad et al., 2015). Despite this fragmentation, current carbon models …

Advancing Natural White Oak (Quercus Alba.) Reproduction Through A Midstory Removal, Canaan Jeffrey Dugger

Masters Theses

In recent decades, there has been an alarming decline in white oak (Quercus alba.) regeneration and recruitment occurring within eastern forests. Historically, the frequency and the intensity of anthropogenic disturbances was dynamic over the landscape. However, over just the last century a major compositional shift has occurred from this change in disturbance regimes. Eastern forests are now promoting the regeneration of mesic species that obstruct white oaks’ ability to compete successfully and establish in the upper canopy.

The majority of successful white oak regeneration and recruitment is now occurring on the average to more xeric sites. Limited studies …

A Watershed Prioritization Model For Community-Centered Riparian Forest Restoration In Tennessee, Madison Johnson

Masters Theses

Riparian forests are unique ecosystems that act as transitional areas between land and water that are a vital part of a healthy and functional stream ecosystem. Due to the rapidly changing landscape, riparian forests are increasingly threatened by urban development, agriculture, and invasive species, which contributes to a trend of degrading water quality in Tennessee. To address declining riparian forest quality in the face of land-use changes, the purpose of this study was to develop a simple watershed prioritization model that identifies areas that are highly susceptible to poor water quality, and where riparian plantings would be most beneficial. This …

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 …

Exploring Alternative Methodologies To Estimate By-Species Sawlog Volume In The Southeastern United States, Tara Skiba

Masters Theses

The Forest Inventory and Analysis (FIA) conducts Timber Products Output (TPO) studies to assess timber resource use across the United States. The TPO studies gather information through surveys of primary wood processing facilities to quantify the utilization of roundwood by geographic location, tree species, and timber product type. However, not all responding mills provide information on tree species utilized. As a result, a portion of the reported volume falls into the “unknown/unclassified” softwood or hardwood category, which account for up to 74% of total hardwood/softwood southern volumes in some cases. In addition, the detailed species in the TPO survey forms …

Evaluating Current And Future Potential Distribution Of Epiphytic Orchids In The Congo Basin With Ecological Niche Models, Michael L. Ngoh

Masters Theses

The Congo Basin Forest harbors a rich diversity of epiphytic communities, with the Orchidaceae alone making up more than 50% of all epiphytes in the region. Despite the huge diversity of epiphytes, many species, including epiphytic orchids, are at risk to a diverse array of threats. Climate change for instance poses severe threats to epiphytic orchids due to elevated temperatures, prolonged periods of droughts, as well as reduced rainfall across the Congo Basin Forest. In this study, we used ecological niche modeling and GIS techniques to identify spatial patterns of species richness, potential future climate refugia, and novel climatic suitability …

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 …

Growth, Browsing And Mortality In Mixed Oak And Pine Plantings, Heather Slayton

Masters Theses

The purpose of this project was to determine if different oak/pine arrangements elicited potential beneficial interactions that affected seedling growth, mortality and overall protection from deer browsing. Northern red oak (Quercus rubra L.) and shortleaf pine (Pinus echinata Mill.) were planted together and alone in six different planting patterns and spacings, replicated over three blocks in recent clearcuts in east Tennessee, USA. Each block consisted of two monocultures planted at a 3.0 by 3.0 meter (m) spacing and four multi-cropped treatments planted at varying spatial arrangements (0.3 m, 1.0 m, 1.5 m, and 3.0 m) from neighboring shortleaf …

Eyield: Testing The Adoption And Outcomes Of A Novel Online Growth And Yield Model, Timothy S. Kane

Masters Theses

eYield is an online growth and yield platform designed to assist landowners and land managers in making the best choices for their properties. eYield aims to strike a balance between the necessary data to run growth and yield models while remaining accessible to its landowner userbase. The results of this paper point to an encouraging amount of user interest in computer-aided forestry tools, specifically in growth and yield models like eYield. The pre- and post-surveys of eYield from respondents suggest that there is a yearning for tools like eYield and that eYield is reasonably representative of the real world. These …

Lidar Evaluation Of The Structural Complexity Of Multi-Cropped White Oak (Quercus Alba) And Pine (Pinus Spp.) Plantings In East Tennessee, Usa, Bret Alan Elgersma

Masters Theses

Structural complexity has an important influence on wildlife habitat and several other ecosystem services. Establishment of white oak (Quercus alba) intercropped with loblolly pine (Pinus taeda), shortleaf pine (Pinus echinata), or eastern white pine (Pinus strobus), in 2014 provided the opportunity to investigate effects of planting species mixtures in different spatial arrangements on structural complexity. Terrestrial LiDAR was used to evaluate the structure of each intercropped treatment and monoculture control. The measures of complexity included: 1) rumple 2) top rugosity 3) standard deviation of individual tree crown area, 4) standard deviation of …

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 …

Controlling Woody Vegetation For The Underplanting And Reintegration Of Shortleaf Pine Into Upland Hardwood Forests Of The Southeast, Max Street

Masters Theses

Shortleaf pine (Pinus echinata Mill.) has the widest distribution of any pine species in the southeastern United States. Shortleaf pine is an important softwood commercial timber species, second only to loblolly pine (Pinus taeda). The amount of shortleaf pine has diminished dramatically beginning in the early 19^th century.

The decline of shortleaf pine has been attributed to several, primarily societal factors. Old field abandonment has declined which provided optimum seed bed conditions for the establishment of shortleaf pine. The timber industry began to favor the faster-growing loblolly pine with shorter stand rotations at the expense of …

Regenerative Effects Of Patch Cut Harvests At Natchez Trace State Forest, Joshua K. Biggerstaff

Masters Theses

Patch cutting is a harvest method with very little precedent in the Central Hardwoods Region of the United States. It is defined as a small scale clearcut of 2 to 5-acres, and it is generally prescribed in order to lessen the aesthetic impact of harvesting in highly visible areas. This study examines a change in harvesting from clearcutting to patch cutting that occurred at Natchez Trace State Forest, located in west Tennessee, in the 1990s. The objective of the study was to determine the regenerative effects of the patch cuts 25-30 years later. Various patch-cut harvest units that were harvested …

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 …

From Drones To Soil Cores: Comprehensive Ecological Assessments For Enhancing Conservation Management Of Urban Forested Natural Areas, Mia T. Wavrek

Masters Theses

Urban natural areas are vegetated areas within cities that exhibit characteristics of non-urban natural areas in that they have relatively high levels of self-regulation (low or no level of management) of natural ecosystem processes and exhibit high taxonomic, genetic, and structural diversity. When these areas take the form of urban parkland, they are often managed for their social benefits to urban residents, while their ecological potential remains underutilized. Growing interest in enhancing biodiversity conservation in cities has highlighted the importance of improving the ecological planning and management of urban natural areas, particularly forested natural areas. For the variety of agencies …

Conservation Of Terrestrial Salamanders Through Hemlock Woolly Adelgid Management In Eastern Hemlock Forests Within Great Smoky Mountains National Park, Jonathan Lawrence Cox

Masters Theses

Hemlock woolly adelgid (Adelges tsugae; HWA), an invasive aphid-like arthropod, was first documented on the east coast of the United States in the 1950s. HWA is an herbivore which primarily feeds at the needle base of hemlock tree species (Pinaceae: Tsuga). With no evolutionary defenses and few biotic controls, the eastern and Carolina hemlock (Tsuga canadensis and Tsuga carolinensis) serve as the primary diet of HWA in eastern North America. The invasive pest began to spread rapidly throughout the hemlock’s range causing defoliation and death of the trees within 4 – 10 years. With the …

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 …

Motivation And Support For Regulatory Changes: A Typology Of Tennessee Wild Turkey Hunters, Cristina Elisa Maldonado

Masters Theses

Hunters form a diverse group with multiple motivations for seeking outdoor recreation experiences. A deeper understanding of hunters’ motivations may benefit wildlife managers in state agencies to cater services and regulations to meet the needs of this diverse group. To determine the motivations of wild turkey (Meleagris gallopavo) hunters in Tennessee, and their attitudes and preferences concerning turkey hunting and management, a self-administered questionnaire was developed and mailed to a sample of licensed Turkey hunters in Tennessee. A multivariate K-means cluster analysis was then applied to identify hunter typologies based on several motivation factors that were derived from …

Using Forest Inventory And Analysis Data To Support Resinous Stump Harvesting In The Coastal Southeast, Christopher Ryan King

Masters Theses

The objective of the research was to investigate the feasibility and potential opportunities for using broad-scale forest inventory data for identifying high-probability sites containing longleaf and slash pine stumps. The purpose was to assist in locating resinous stumps for today’s remaining naval stores industry. USDA Forest Service, Forest Inventory & Analysis (FIA) Phase 2 plots where longleaf and slash pine were present were observed. Plots were also limited to those which had been re-measured at least once. Variables observed include basal area, diameter, recent cutting, and past cutting. FIA’s Timber Products Output data regarding mill sourcing were assessed as well. …

Crop Tree Enhancement Of Green Ash (Fraxinus Pennsylvanica) In A West Tennessee Hardwood Bottom, John Luke Bowers

Masters Theses

Crop tree enhancement is a forest management technique undertaken to maintain, enhance, and improve the species composition, growth rate, and stem quality of stands so that management objectives may be better and more quickly accomplished. In 1996, a crop tree enhancement study involving green ash (Fraxinus pennsylvanica) in a 16-year-old, naturally regenerated, mixed-species, pole-sized, bottomland hardwood stand was initiated at Ames Plantation in West TN. Treatments included a crown-touching release, a crown-touching release plus one-time fertilizer application, and a control, applied in a randomized block design with five 25-crop tree repetitions of the three treatments. Initial crop tree …

Lignin Maximization: Analyzing The Impact Of Different Feedstocks And Feedstock Ratios Using Organosolv Fractionation, Marc Banholzer

Masters Theses

Over-exploitation of fossil fuels coupled with increasing pressure to reduce carbon emissions are prompting a transition from conventional petrochemical feedstocks to sustainable and renewable sourced carbon. The use of lignocellulosic biomass as a feedstock for integrated biorefining is of current high interest, as separation into its component parts affords process streams of cellulose, hemicellulose and lignin, each of which can serve as a starting point for the production of biobased chemicals and fuels. Given the large number of potential sources of lignocellulosic feedstocks, the biorefinery will need to adapt to the supplies available over a normal growing season. Of particular …

Vegetation Response To Canopy Disturbance And Season Of Burn During Oak Woodland And Savanna Restoration In Tennessee, Andrew Lee Vander Yacht, Seth A. Barrioz, Patrick D. Keyser, Craig A. Harper, David Buckley, David A. Buehler, Roger D. Applegate

UT Extension publication

The removal of fire’s influence on plant community succession has resulted in the near disappearance of oak woodlands and savannas from the Appalachian region. Negative trends in associated plant and wildlife species could be reversed if these communities are restored, but management has been limited by inadequate canopy disturbance, resprouting of woody plants, and a lack of empirical research. To address these issues, we evaluated herbaceous and woody vegetation response on the

Cumberland Plateau in Tennessee to 5 replicated treatments involving canopy reduction and fire-season combinations and unmanaged controls. All categories of woody vegetation except large saplings density, but resprouting …

Forage Availability And Nutritional Carrying Capacity For Cervids Following Prescribed Fire And Herbicide Applications In Young Mixed-Hardwood Forest Stands In The Cumberland Mountains, Tennessee, Jordan Scott Nanney

Masters Theses

I evaluated the influence of timber harvest combined with prescribed fire and/or herbicide in young mixed-hardwood forest on forage availability and nutritional carrying capacity (NCC) for elk (Cervus elaphus) and white-tailed deer (Odocoileus virginianus) at the North Cumberland Wildlife Management Area (WMA), July-August, 2013-15. I combined land cover data, forest management data, field management data, and forage availability data to model summer elk forage availability across the WMA.

I compared forage availability, NCC (animal days/ha) using 12 and 14% crude protein (CP) nutritional constraints, and vegetation composition among 6 young forest treatments, reclaimed surface mines (MINE), and closed-canopy mature forest …

Testing The Temporal Stability Of The Climate Response Of Tree Species At Norris Dam State Park, Tennessee, U.S.A., Allison Elizabeth Ingram

Masters Theses

Temporal stability of the climate-tree growth relationship means that over time, tree species were responding to a specific climate variable and continue to respond to that variable into the present. The stability of this response is important to test prior to attempting to reconstruct past climate. In this study, I sampled oaks (white oak = Quercus alba L. and chestnut oak = Quercus montana Willd.) and pines (Virginia pine = Pinus virginiana Mill. and shortleaf pine = Pinus echinata Mill.) growing in Norris Dam State Park in eastern Tennessee and tested the temporal stability of these species and their potential …

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 …