Environmental 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. …

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 …

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 …

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 …

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 …

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 …

Vegetation Response To Oak Savanna And Woodland Restoration In The Mid-South Usa, Andrew Lee Vander Yacht

Masters Theses

The decline and degradation of oak savanna and woodland communities throughout the Mid-South underscores the need to develop management techniques capable of their efficient and successful restoration. Therefore, my objectives for this work were to document plant community response to variations in canopy disturbance level, fire seasonality, and herbicide control of hardwood midstories. In Chapter One, I provide a thorough review of the current body of knowledge concerning open-oak communities and their restoration, with specific focus on herbaceous and woody plant response to canopy disturbance, fire, and herbicide midstory management. Chapter Two details the response of herbaceous and woody vegetation …

Bringing Biodiversity To Development: Perceptions Of Integrating Eucalyptus And Forest-Corridors Around The Serra Do Brigadeiro, Brazil, Maggie R Stevens

Masters Theses

The Atlantic Forest of south-eastern Brazil is a hot-spot for biodiversity and should be conserved. It is also at the center of the largest municipalities in Brazil and therefore has a severely fragmented landscape. Iracambi, a working farm near the Serra do Brigadeiro state park in Minas Gerais, is working for conservation in an area of intense agricultural production and expanding forestry industry. Most households in this rural area have some amount of eucalyptus on their property and consequently the director of Iracambi is developing the preliminary foundation for a forest corridor program comprised of primarily eucalyptus with the goal …

Applied Ecosystem Services In Working Forests: A Direct Market Valuation, Darin Stuart Hale

Masters Theses

Ecosystem services, or the benefits humans obtain from natural ecosystems, have long been recognized as critical to human health. Efforts have been taken by many to determine the non-market values of these services but few have offered a direct market valuation. Increasing awareness, scarcity, and regulation have fostered transactions, and markets are emerging that can allow for direct valuation and could provide landowners the opportunity to merchandise this natural capital. This paper provides a valuation and comparison, as a case study, of a traditional management scheme, including the marketing of fiber and recreational leases, and an ecosystem services management scheme, …

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 …

Comparative Ecophysiology Of American Chestnut Under Different Planting Treatments On Reclaimed Mine Sites, Christopher Ryan Miller

Masters Theses

American chestnut was once an abundant species that dominated the Eastern U.S. deciduous forests. Although this species is currently functionally extinct due to the chestnut blight, researchers are working on blight-resistant hybrids in hopes of restoring the species. As one potential vector for chestnut reintroduction and dispersal, the reclamation of mine sites are being considered. Recent research has found that reforestation efforts on these reclaimed mine sites provide productive tree growth while also complying with mine-reclamation laws. Understanding how American chestnut performs physiologically on mine sites will aid in the restoration of this species and reclamation of mine sites.

The …