Population Biology Commons^™

Population Abundance And Growth Of Elk (Cervus Canadensis) In Western North Carolina, Jessica Braunstein

Doctoral Dissertations

In an effort to restore extirpated elk to their previous range, 52 elk were reintroduced to Great Smoky Mountains National Park (GRSM) in North Carolina during 2001 and 2002. Since their reintroduction, elk numbers have increased and their range has extended beyond GRSM boundaries. My primary research objectives included estimating population abundance, apparent survival, per capita recruitment, and population growth rate of elk in North Carolina. I used spatially explicit capture-recapture (SECR) models based on fecal DNA to identify individual elk and estimate population abundance and growth in the region. Technicians and I walked a series of transects throughout the …

Broadscale Outcome And Monitoring Assessment To Evaluate Protected Area Effectiveness In Northern Patagonia, Maria Daniela Rivarola

Doctoral Dissertations

Biomes worldwide have been affected by biodiversity loss and habitat degradation for more than a century. Protected Areas (PAs) have been established in almost every country, as they represent one of the most important tools in biodiversity conservation. Nevertheless, the relentless biodiversity loss trend has not stopped. Concern about PA effectiveness has risen, and several methods to evaluate it have been implemented over the last few decades. Nahuel Huapi National Park (NHNP) is the first PA in Argentina and one of the largest. The area is considered a biodiversity hotspot, and its conservation is essential, as unique ecological and evolutionary …

Elk Abundance, Survival, And Health In The Cumberland Mountains Of Tennessee, Katherine Kurth

Doctoral Dissertations

Managing sustainable wildlife populations requires insight into population abundance and health. Since reintroduction, elk (Cervus canadensis) at the North Cumberland Wildlife Management Area (NCWMA) in Tennessee have shown marginal population growth using low-precision abundance estimates. Limited research investigating possible population limiting factors has occurred since evaluations conducted directly after translocation. To provide information necessary for effective population management, we estimated abundance, identified survival rates, and conducted mortality and health surveillance. Precise abundance estimates of eastern elk populations are challenging to obtain using traditional capture-recapture due to invasive handling of individuals and low detection in forested landscapes. Therefore, we …

Applications Of Comparative Genomics And Data Science To Agricultural And Clinical Research, Katrina A. Schlum

Doctoral Dissertations

The advent of inexpensive, high-throughput whole genome sequencing (WGS) technologies has led to the generation of thousands of related genomes, even from a single study. Large-scale genome analysis has resulted in hypothesis-generating approaches in the fields of clinical, human and agriculture genomics. Additionally, population-level genomic sampling has resulted in a decrease in false positives in genotype-phenotype associations and an increase in understanding of the basis of disease, antibiotic and pesticide resistance. Deeper understanding of migration, genetic divergence and evolution has also been made possible due to WGS. This research applies comparative genomics, population genomics and data science approaches to whole …

Prevalence Of Rats And Rodent Borne Pathogens Across Post-Katrina New Orleans, Bruno Marco Ghersi

Doctoral Dissertations

Disasters are happening at an increasingly higher rate and intensity a trend that is expected to continue as more humans migrate to coastal urban areas. Disasters, and as importantly, disaster recovery can affect how native and pest populations will recover. My aim was to improve understanding of disease risk by evaluating the socioecological conditions that have shaped commensal rat recovery and distribution, as well as the pathogens they carry, across New Orleans after Hurricane Katrina. I first estimated relative abundance and distribution of commensal rats from rodent trapping conducted between mid-2014 and early-2017 across 96 sites in 10 areas of …

Root Stage Distributions And Their Importance In Plant-Soil Feedback Models, Tyler Poppenwimer

Doctoral Dissertations

Roots are fundamental to PSFs, being a key mediator of these feedbacks by interacting with and affecting the soil environment and soil microbial communities. However, most PSF models aggregate roots into a homogeneous component or only implicitly simulate roots via functions. Roots are not homogeneous and root traits (nutrient and water uptake, turnover rate, respiration rate, mycorrhizal colonization, etc.) vary with age, branch order, and diameter. Trait differences among a plant’s roots lead to variation in root function and roots can be disaggregated according to their function. The impact on plant growth and resource cycling of changes in the distribution …

Assessment Of Genetic And Education Recovery Plan Objectives For The Bog Turtle (Glyptemys Muhlenbergii), Cassie Marie Dresser

Doctoral Dissertations

Unprecedented declines in biodiversity are threatening the natural world as we know it. Without human intervention, two thousand species listed under the US Endangered Species Act are likely to disappear. Fortunately, these species receive federal protection and increased research effort is needed to create and satisfy the objectives outlined in the mandated Species Recovery Plan. In this dissertation, I address three conservation objectives outlined in the Recovery Plan for North America’s smallest and rarest turtle, the Bog Turtle (Glyptemys muhlenbergii): (1) investigate the potential genetic differentiation in southern portions of the species’ range, (2) investigate the genetic impacts …

Modeling Feral Hogs In Great Smoky Mountains National Park, Benjamin Anthony Levy

Doctoral Dissertations

Feral Hogs (Sus scrofa) are an invasive species that have occupied the Great Smoky Mountains National Park since the early 1900s. Recent studies have revitalized interest in the pest and have produced useful data. The Park has kept detailed records on mast abundance as well as every removal since 1980 including geographic location and disease sampling. Data obtained via Lidar includes both overstory as well as understory vegetation information. In this dissertation, three models were created and analyzed using the detailed data on vegetation, mast, and harvest history. The first model is discrete in time and space and …

Population Dynamics And Genetic Structure Of Louisiana Black Bears In The Lower Mississippi Alluvial Valley Of Louisiana, Jared Scott Laufenberg

Doctoral Dissertations

In 1992, the U.S. Fish and Wildlife Service granted the Louisiana black bear threatened status under the U.S. Endangered Species Act, listing loss and fragmentation of habitat as the primary threats. The 1995 Recovery Plan outlines recovery goals designed to meet the objective of reducing threats to the Louisiana black bear metapopulation and supporting habitat. To meet that objective, the Recovery Plan requires 1) at least 2 viable subpopulations, 1 each in the Tensas and Atchafalaya River Basins, 2) movement corridors between the 2 viable subpopulations, and 3) long-term protection of the habitat supporting each viable subpopulation and interconnecting corridors …

Biogeographical Patterns, Ecological Drivers, And Evolutionary Mechanisms Of Plant Invasions, Rafael Dudeque Zenni

Doctoral Dissertations

Understanding and predicting organisms’ responses to novel environments is a key issue for global change biology. In this dissertation, I study biogeographical patterns of plant invasions in Brazil, explore some of their ecological drivers, and disentangle the gene-level mechanisms that cause introduced organisms to become successful or failed invaders. I found that, for the invasive flora of Brazil, species were not introduced to new regions at random and that a species’ reason for introduction and continent of origin were associated. Asian ornamental and African forage plants are overrepresented, and two families (Poaceae and Fabaceae) dominate the invasive flora of Brazil. …

Regional Assessment Of The Relationships Of Conservation Practices To Northern Bobwhite And Other Priority Grassland Bird Breeding Populations, Christopher Manuel Lituma

Doctoral Dissertations

I documented populations of Northern Bobwhites (Colinus virginianus) and other priority grassland and early successional birds in the Central Hardwoods Bird Conservation Region (CHBCR), and determined whether conservation practices have been effective in positively impacting species occupancy and abundance. I designed and implemented a roadside survey by randomly locating five 15-km routes with 5-min unlimited distance point counts (30 counts/route), along secondary roads within Northern Bobwhite focal counties (n = 37) in the CHBCR. I also developed a survey to assess roadside biases for estimates of relative abundance (a), occupancy (ψ), detection probability (p), and associated …

Hybridization As A Stimulus For Adaptation To A Novel Environment, Dylan Robert Dittrich-Reed

Doctoral Dissertations

Understanding processes contributing to the origin of novelty, including ecological transitions in resource or habitat use, is fundamental to evolutionary biology. Early geneticists speculated about the sudden appearance of new species via special macromutations, epitomized by Goldschmidt’s infamous “hopeful monster”. Transgressive segregation during hybridization is a more plausible mechanism for producing “monstrous” phenotypes beyond the range of parental populations. Transgressive hybrid phenotypes can be products of epistatic interactions or additive effects of multiple recombined loci. However, the importance of hybridization in the origin of novelty is contested because we do not know how often hybridization enhances the probability of an …

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 …

Optimal Theory Applied In Integrodifference Equation Models And In A Cholera Differential Equation Model, Peng Zhong

Doctoral Dissertations

Integrodifference equations are discrete in time and continuous in space, and are used to model the spread of populations that are growing in discrete generations, or at discrete times, and dispersing spatially. We investigate optimal harvesting strategies, in order to maximize the profit and minimize the cost of harvesting. Theoretical results on the existence, uniqueness and characterization, as well as numerical results of optimized harvesting rates are obtained. The order of how the three events, growth, dispersal and harvesting, are arranged also affects the harvesting behavior.

Cholera remains a public health threat in many parts of the world and improved …

The Small Indian Mongoose (Herpestes Auropunctatus) On Adriatic Islands: Impact, Evolution, And Control, Arijana Barun

Doctoral Dissertations

ABSTRACT

One cause of declines and extinctions of island species is carnivore introduction. Four carnivores, including the small Indian mongoose (Herpestes auropunctatus), are on the IUCN’s list of 100 of the World's Worst Invasive Alien Species. My thesis summarizes global patterns of carnivore introductions and examines ecological, evolutionary, and management impacts of this mongoose. I study abundances of reptiles and amphibians on mongoose-infested and mongoose-free islands in the Adriatic Sea to determine if factors other than mongoose presence can account for abundance differences. For several reptiles and amphibians, the mongoose is implicated as causing differences. Additionally, I …

Islands, Metapopulations, And Archipelagos: Genetic Equilibrium And Non-Equilibrium Dynamics Of Structured Populations In The Context Of Conservation, Robert Graham Reynolds

Doctoral Dissertations

Understanding complex population dynamics is critical for both basic and applied ecology. Analysis of genetic data has been promoted as a way to reconstruct recent non-equilibrium processes that influence the apportioning of genetic diversity among populations of organisms. In a structured-deme context, where individual populations exist as geographically distinct units, island biogeography theory and metapopulation genetics predict that the demographic processes of extinction, colonization, and migration will affect the magnitude and rate of genetic divergence between demes. New methods have been developed to attempt to detect the influence of non-equilibrium dynamics in structured populations. I challenged two of these methods: …

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 …

Spatiotemporal Dynamics In A Lower Montane Tropical Rainforest, Robert Michael Lawton

Doctoral Dissertations

Disturbance in a forest’s canopy, whether caused by treefall, limbfall, landslide, or fire determines not only the distribution of well-lit patches at any given time, but also the ways in which the forest changes over time. In this dissertation, I use a 25 year record of treefall gap formation find a novel and highly patterned process of forest disturbance and regeneration, providing a local mechanism by examining the factors that influence the likelihood of treefall. I then develop a stochastic cellular automaton for disturbance and regeneration based on the analysis of this long term data set and illustrate the potential …

Optimal Control Of Species Augmentation Conservation Strategies, Erin Nicole Bodine

Doctoral Dissertations

Species augmentation is a method of reducing species loss via augmenting declining or threatened populations with individuals from captive-bred or stable, wild populations. In this dissertation, species augmentation is analyzed in an optimal control setting to determine the optimal augmentation strategies given various constraints and settings. In each setting, we consider the effects on both the target/endangered population and a reserve population from which the individuals translocated in the augmentation are harvested. Four different optimal control formulations are explored. The first two optimal control formulations model the underlying population dynamics with a system of ordinary differential equations. Each of these …

Evaluation Of Genetic Diversity Of Flowering Dogwood (Cornus Florida L.) In The Eastern United States Using Microsatellites., Denita Hadziabdic

Doctoral Dissertations

Flowering dogwood (Cornus florida L.) populations have experienced severe declines caused by dogwood anthracnose in the past three decades. Mortality has ranged from 48 to 98%, raising the concern that genetic diversity of this native tree has been reduced significantly. Microsatellite data were used to evaluate the level and distribution of genetic variation throughout much of the native range of the tree. In the first conducted study, we found that genetic variation in areas affected by anthracnose was as high as or higher than areas without die-offs. We found evidence of four widespread, spatially contiguous genetic clusters. However, there was …

Bat Population Dynamics: An Individual-Based Model Approach, Paula Federico

Doctoral Dissertations

Temperate zone bats are subject to serious energetic constraints due to their high surface area to volume relations, the cost of temperature regulation, the high metabolic cost of flight, and the seasonality of their resources. To my knowledge, there are no individual-based mathematical models for any bat species. The model developed here for a female bat is primarily based on life history and energetics. It describes the growth of an individual female bat using a system of differential equations modeling the dynamics of two main compartments: storage (lipids) and structure (proteins and carbohydrates). The model is parameterized for the little …

Online Atmospherics: An Investigation Of Feeling And Internet Purchase Intention, Kelly Price Rankin

Doctoral Dissertations

This study examines the online atmospheric cues of color and music and their impact upon feeling, attitude and purchase intention of consumers in the online environment. The research design was experimental and used data from a questionnaire. A pilot test of the instrument was conducted. The final questionnaire contained 39 items and a demographic section. A total of 200 questionnaires were collected. Participants were randomly assigned to one of four groups. Each group of 50 participants was exposed to a specific set of online atmospheric elements. The results indicated that Hypotheses 1, 3 and 4 were rejected while Hypotheses 2 …

Factors Related To Condom Use Among Sexually Active African American Females Using Health Belief Model Constructs And Potential Cues To Action With A Mass Communication/Interpersonal Communication Approach, Shiree Monika Southerland

Doctoral Dissertations

The primary purpose of this study was to assess the factors that relate to male condom utilization among sexually active African American college women at The University of Tennessee.

College women between the ages of 18 to 24 are the most susceptible to contracting a sexually transmitted disease (STD) as they do not perceive themselves to be at risk. It is estimated that each year 12 million new cases of STDs occur and two thirds of those infected are under the age of 25 (Hale & Trumbetta, 1996). Women are among the fastest growing groups being infected with HIV. In …