Digital Commons Network^™

Competitive Interactions Between Appalachian Hardwoods And Different Groundcovers On Reclaimed Mine Sites, Adam David Klobucar

Masters Theses

Coal mining is a significant industry in Appalachia. Herbaceous groundcovers are commonly planted to reduce soil erosion and protect water quality during mine reclamation, but many groundcovers may be too competitive to be compatible with trees. The objectives of this research were to investigate the performance of trees planted within different groundcovers and to measure how different groundcovers influence resource availability, specifically soil moisture and light

Two studies were performed; one in a greenhouse and the other on 3 mine sites in east Tennessee where seedlings were planted and grown in competition with different groundcovers. Growth, biomass, leaf area, and …

Population Abundance And Genetic Structure Of Black Bears In Coastal South Carolina, John Michael Drewry

Masters Theses

Because of increasing frequency of bear sightings, vehicle collisions, and nuisance incidents in coastal South Carolina, the South Carolina Department of Natural Resources is developing a comprehensive black bear management plan. However, no reliable estimates of population abundance or density are available. I used genotypes of black bears determined from hair samples collected in Lewis Ocean Bay and Carvers Bay to estimate population abundance and density. I obtained hair samples from snares during 8 weekly sampling periods in 2008 and 2009. I used Huggins closed population models to estimate abundance and spatially explicit capture- recapture models to estimate density. Based …

Evaluating Ecological Restoration In Tennessee Hardwood Bottomland Forests, Elizabeth Anne Summers

Masters Theses

Hardwood bottomland ecosystems provide critical habitat for various wildlife among numerous ecosystem services. Since the 1800s, these forested wetlands have been logged and drained for agriculture. The federal government passed a series of legislative acts that protected wetlands and provided monetary support for restoration. The Wetlands Reserve Program (WRP) was established in 1990 with the goal of restoring ecological function in wetlands. Although several studies have measured plant and wildlife responses to WRP restorations, no standard protocol has been developed to monitor the state of ecological restoration at sites. Index of biotic integrity (IBI) models are commonly used to evaluate …

Soil Nitrogen Amendments And Insect Herbivory Alter Above-And Belowground Plant Biomass In An Old-Field Ecosystem, Jarrod Dwayne Blue

Masters Theses

Nutrient availability and herbivory can regulate primary production in ecosystems, but little is known about how, or whether, they may interact with one another. Here I investigate how nitrogen availability and insect herbivory interact to alter above- and belowground plant community biomass in an old-field ecosystem. In 2004, 36 experimental plots were established in which soil nitrogen (N) availability (at three levels) was manipulated and insect abundance (at two levels) in a completely randomized plot design. In 2009, after six years of treatment, I measured aboveground biomass and assessed root production at peak growth. Overall, I found a significant effect …

Seasonality, Variation In Species Prevalence, And Localized Disease For Ranavirus In Cades Cove (Great Smoky Mountains National Park) Amphibians, Megan Todd-Thompson

Masters Theses

World-wide amphibian declines sparked concern and encouraged investigation into potential causes beginning in the 1980’s. Infectious disease has been identified as one of the major potential contributors to amphibian declines. For example, Ranavirus has caused amphibian die-offs throughout the United States. Investigators isolated Ranavirus from dead or moribund amphibians during large-scale die-offs of amphibians in the Cades Cove area of Great Smoky Mountains National Park in 1999-2001. In 2009, after nearly a decade without follow-up monitoring, I undertook an investigation to determine if the virus persisted in the area, and if so, to assess spatial, temporal, and taxonomic patterns in …

Early Vessel Evolution And The Diversification Of Wood Function: Insights From The Malagasy Canellales, Patrick Joseph Hudson

Masters Theses

Xylem vessels have long been proposed as a key innovation for the ecological diversification of angiosperms by providing a breakthrough in hydraulic efficiency to support high rates of photosynthesis and growth. However, recent studies demonstrated that angiosperm woods with structurally ‘primitive’ vessels did not have greater whole stem hydraulic capacities as compared to vesselless angiosperms. As an alternative to the hydraulic superiority hypothesis, the heteroxylly hypothesis proposes that subtle hydraulic efficiencies of primitive vessels over tracheids enabled new directions of functional specialization in the wood. However, the functional properties of early heteroxyllous wood remain unknown. We selected the two species …

Molecular Analysis Of Guano From Bats In Bat Houses On Organic Pecan Orchards, Veronica Angelelli Brown

Masters Theses

Bats are generalist predators of night flying insects, including many crop pests. Pecan nut casebearer (Acrobasis nuxvorella), hickory shuckworm (Cydia caryana), and several stink bug species are some of the most damaging crop pests in pecan orchards. Attracting bats to agricultural areas using bats houses may reduce the numbers of these pests and, consequently, their economic impact. This study uses quantitative polymerase chain reaction (QPCR) of mitochondrial DNA found in the guano of bats living in bat houses on organic pecan orchards to document the consumption of pecan nut casebearer, hickory shuckworm, and corn earworm ( …

Plant Genotype And Environment Interact To Influence Soil Carbon And Nitrogen Dynamics, Clara Christina Pregitzer

Masters Theses

Abiotic and biotic variation has been shown to be important in regulating nutrient cycling and belowground communities in natural systems. However, genetic variation in dominant plants as a driver of rates of nutrient cycling is still poorly understood and few studies have looked at genotype interactions across multiple environments. Using Populus angustifolia and a common garden approach, we hypothesized that all three factors: tree genetic variation, environmental conditions and genetic by environment (G x E) interactions would affect soil carbon (C) storage and nitrogen (N) cycling. Replicated copies of five different reciprocally planted Populus genotypes were studied in three separate …