Other Ecology and Evolutionary Biology Commons^™

Brown People, Green Spaces: Colonial Imaginaries And The Whiteness Of Nature, Jeffrey Michael Desalu

Masters Theses

For several years, conversations about the absence of racial and ethnic diversity in ecology and evolutionary biology (EEB) and the conservation movement have been growing in scope. Critics argue that the overwhelmingly white demography of EEB departments and conservation organizations deprive both of a necessary diversity of perspective and, more importantly, deprive people of color and other minoritized groups of a voice in the study of and advocacy for their lived environments. Here, I situate the current conversations in historical context, arguing that the current lack of diversity is in part a reflection of the material and ideological bases for …

Climate-Driven Selection Results In Powerful Geographic Framework For Predicting Phenotype, Alexandra Neild

Masters Theses

Our ability to prepare for and mitigate the likely ecological and evolutionary impacts of climate change largely depends upon our ability to predict the phenotypic responses of organisms that allow them to persist, adapt, and migrate along environmental stress gradients. Using fifteen populations of cottonwoods, a dominant riparian forest tree, that are distributed along elevation gradients and represent three genetic provenances, we hypothesized and show that: 1) populations within a provenance demonstrate parallel evolutionary responses to climatic gradients associated with elevation; and 2) the evolutionary effects of elevation on bud-break phenology varied by provenance. Across all populations, we find strong …

Impacts Of Anthropogenic Change On Plant Reproduction And Fitness, Alexandra S. Faidiga

Masters Theses

Humans are altering natural systems around the globe in myriad ways. For plant species, such anthropogenic changes have resulted in increasingly fragmented populations, desynchronized interactions with mutualists, and shifted geographic ranges, among other effects. However, despite numerous examples of human impacts on plant populations, the consequences of these changes on plant reproduction remain poorly understood. In my thesis, I investigate the impacts of two forms of anthropogenic change–habitat disturbance and climate warming–on plant reproduction and fitness. I take two distinct approaches to address questions posed at local and regional scales. In Chapter I, I ask how inbreeding depression varies across …

Life History, Diet And Habitat Of The Federally Endangered Laurel Dace (Chrosomus Saylori), Shawna M. Fix

Masters Theses

Laurel Dace (Chrosomus saylori) is a small, freshwater minnow that is endemic to headwater streams on Walden Ridge, Tennessee. The species was listed as federally endangered in 2011 and the U.S. Fish and Wildlife Service Recovery Plan indicates a need for life history, diet and habitat studies. A literature review, samples of archived specimens, and a surrogate species, the Tennessee Dace (Chrosomus tennesseensis), were used to describe the life history and diet of the Laurel Dace. A total of 370 Tennessee Dace were collected from Laurel Ford Branch, a stream 8.6 km from the Laurel Dace …

Improving Aedes Mosquito Surveillance And La Crosse Virus Screening In Eastern Tennessee, Cassandra Urquhart

Masters Theses

La Crosse virus (LACV), transmitted by infected Aedes triseriatus, Ae. albopictus, and Ae. japonicus mosquitoes is the leading cause of pediatric arboviral encephalitis. Severe cases of LAC encephalitis occur in individuals 16-years-old or younger and may cause permanent neurological damage or fatality. No vaccines exist making mosquito control and disease prevention crucial to public health. Effective screening and surveillance practices are key components to these goals. While a number of standard mosquito surveillance methods exist, continuous testing and improved understanding of vector biology to determine the best ways to implement these methods is important. Additionally, the current standard …

A New Adaptive Landscape: Urbanization As A Strong Evolutionary Force, Lauren Christie Breza

Masters Theses

Urbanization is rapidly increasing as human population growth steadily grows, but there is little consensus of the ecological consequence of this population shift and almost no information of the evolutionary consequences for local biodiversity. Nearly two-thirds of the world’s population will live in city centers by 2050 with profound impacts on landscapes that can act as important agents of selection. This study aims to identify 1) the net effect of urbanization on species richness, 2) how phylogenetic diversity varies between urban and rural sites, and 3) the strength of urbanization as a selection pressure. First, a meta-analysis was conducted in …

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Plant Functional Traits Mediate Above- And Belowground Species Interactions In Ecological Communities, Courtney E. Gorman

Masters Theses

Functional plant traits provide a means whereby species identity can influence above- and belowground community interactions. To examine the role of plant functional traits in shaping ecological communities, Chapter 1 examines how the evolution of functional differences between closely related groups of endemic and non-endemic species influence associated species interactions, and Chapter 2 examines how plant functional traits can influence associated community composition.

Empirical Evaluation Of Proxies For The Acquisition Costs Of Protected Areas Suggests Care Is Needed To Deliver The Promise Of Cost-Effective Conservation, Nathan James Sutton

Masters Theses

Given limited budgets, conservation organizations need to efficiently allocate their resources for biodiversity protection. While many organizations combine socioeconomic and biological data to identify areas with the highest biological return per dollar invested, it is less clear how uncertainty in socioeconomic data affects this planning process. In Chapter 1, we show how uncertainty due to proxy choice and spatial averaging affect conservation planning by comparing average agricultural land values, a common proxy for the acquisition costs of protected areas, to a case study recent protected area investments in the Eastern US. We find this proxy explains little variation and significantly …

Evaluating Pollination Ecology Of The Endangered Pityopsis Ruthii (Small) Small (Asteraceae), Philip Anthony Moore

Masters Theses

Pityopsis ruthii (Small) Small, also known as Ruth’s golden aster, is a federally endangered herbaceous perennial, endemic to two river systems, the Hiwassee and the Ocoee, within the Cherokee National Forest, Polk County, Tennessee. There are approximately 13,000 individuals that may be at high risk of short-term extirpation (Thompson and Schwartz, 2006). Little is known of the basic reproduction and life history of P. ruthii. Clebesh and Sloan (1993), Cruzan (2001), Park (1998), and Wadl et al. (2014) found evidence that seed production and seed viability are highly variable. Clebesh and Sloan (1993) indicated that pollinator visitation was highly temporal …

Pelagic Larval Duration Links Life History Traits And Species Persistence In Darters (Percidae: Etheostomatinae), Morgan Jessica Douglas

Masters Theses

Pelagic larval duration (PLD) likely influences evolutionary processes including dispersal, genetic connectivity, and extinction in aquatic organisms. PLD has been well studied in marine systems, but very few freshwater species have been studied. Darters are a diverse group of freshwater North American fish with available information on the length of this stage from propagation efforts. There is surprising variation in the length of this stage ranging from 0 to 60 days. By compiling information from Conservations Fisheries, Inc. (Knoxville, TN) and the literature, we were able to make comparisons between the PLD of 23 species and other life history characteristics. …

Genetic Variation And Dispersal In Penstemon Hirsutus And P. Tenuiflorus, Anna Katherine Becker

Masters Theses

Studying plant-pollinator relationships essential for understanding angiosperm evolution. In the large endemic genus Penstemon (Plantaginaceae), shifts in pollination syndrome are proposed to be important for explaining taxonomic and morphological diversity (Wilson et al., 2004; Wolfe et al., 2006). However, little work has been done to determine the relationship between morphological and genetic divergence within pollination syndromes. This study utilized genetic data to explore whether divergence in corolla morphology among nine closely related, bee pollinated Penstemon species was consistent with pollinator-driven selection.

Bee pollinated species in Penstemon subsection Penstemon are often divided into two morphological groups based on inflation of the …

Mating System Biology Of The Florida Native Plant: Illicium Parviflorum, Nicholas Earl Buckley

Masters Theses

Self-incompatibility is thought to have played a profound role in the evolution of the angiosperms. However, there is little evidence of self-incompatibility systems in early diverging lineages of flowering plants. Illicium parviflorum, one such early-divergent angiosperm, is an evergreen perennial species endemic to central Florida, particularly within the Ocala National Forest. Although locally abundant, I. parviflorum is currently listed as endangered at the state level due to being under constant threat of habitat disturbance and over-harvesting. Notably, this species had been described as self-incompatible due to its low seed-set. However, low seed set may also be a result of …

Identifying The Spatial Distribution Of Three Plethodontid Salamanders In Great Smoky Mountains National Park Using Two Habitat Modeling Methods, Matthew Stephen Kookogey

Masters Theses

The main objective was to create habitat models of three plethodontid salamander species (Desmognathus conanti, D. ocoee, and Plethodon jordani) in GSMNP. To investigate the relationships between salamanders and their habitats, I used three models—logistic regression with use-availability sampling, logistic regression with case-control sampling, and Mahalanobis distance (D²)—for each species to gain a robust view of the relationships. The secondary objective was to compare the different modeling methods within and across the three species. Elevation was the dominant variable for all three species.

D² for D. conanti predicted low elevations, close proximity …

An Investigation Of Stratigraphic Evidence For An Abrupt Climatic Event 8200 Yr Bp In Valle De Las Morrenas, Costa Rica, Brian Thomas Watson

Masters Theses

Lago de las Morrenas 4 (9.498056° [degrees] N, 83.486111° [degrees] W, 3466 m elev.) is the lowest lake in a chain of glacial lakes located in the Valle de las Morrenas, a valley facing almost due north from Cerro Chirripó, the highest peak in the Cordillera de Talamanca in Costa Rica. Coarse resolution analyses of pollen, microscopic charcoal, and loss-on-ignition of a ca. 10,000 year sediment record from Lago de las Morrenas 4 was carried out to complement and extend previous research on the environmental history of the Chirripó highlands and to provide context for high-resolution sampling and analysis of …

Using Stable Isotopes To Assess Longitudinal Diet Patterns Of Black Bears (Ursus Americanus) In Great Smoky Mountains National Park, Jennapher Lynn Teunissen Van Manen

Masters Theses

Long-term diet patterns based on stable isotope analysis may be helpful to understand changes in food selection of black bears (Ursus americanus) over time and guide management programs to reduce human-bear conflicts. An enriched stable carbon isotope signature indicates an anthropogenic food source in the diet and an enriched nitrogen signature indicates a higher tropic level for a species. I examined longitudinal feeding patterns from 117 hair samples of black bears live captured in Great Smoky Mountains National Park during 1980–2001 using stable carbon and nitrogen isotope analysis from hair samples. I developed a set of a priori …

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 …

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 …