Ecology and Evolutionary Biology Commons^™

Riparian Ecosystem Response To Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality In The Great Smoky Mountains National Park, Usa, Misty Dawn Huddleston

Doctoral Dissertations

An invasive insect, hemlock woolly adelgid (HWA), has initiated widespread hemlock decline and mortality in the Great Smoky Mountains National Park (GSMNP). Riparian hemlock mortality impacts on vegetative and aquatic systems of first-order, headwater streams were evaluated. Reference sites for this study were representative of the best available conditions within the GSMNP, with initial stages of HWA presence. Impacted sites were defined as areas with over 90 percent hemlock mortality. Impacted streams had decreased canopy coverage and increased light availability. Residual red maple, yellow birch, and sweet birch capitalized on the loss of hemlock, with increases in relative basal area …

Factors Related To Nest Survival And Over-Winter Survival Of A Northern Bobwhite (Colinus Virginianus) Population In Southwest Florida, Steven Kenneth Brinkley

Masters Theses

The northern bobwhite (Colinus virginianus) is a gallinaceous upland game bird dependent on early successional grassland habitat for reproduction and survival. Bobwhite populations have been declining range-wide for nearly a half century. The habitat of Babcock-Webb Wildlife Management Area (BWWMA) in southwest Florida is mostly virgin, early successional grassland and pine flatwoods. Although BWWMA is located in the far southern end of the bobwhite range, the area is a popular public land for bobwhite hunting. The BWWMA bobwhite population has declined evidenced by a dramatic decrease in harvest over the last 20 years. The two objectives of my …

Movement Ecology Of An Intercontinental Migratory Bird During Spring Stopover, Emily Beth Cohen

Dissertations

Movement ecology is a component of nearly all aspects of animal behavior and an animal’s decision to move is likely influenced by a complex combination of exogenous and endogenous factors. Therefore, an examination of the causes and consequences of organismal movement provides a conceptual framework for understanding complex behavioral strategies. My dissertation research is focused on the movement ecology of an intercontinental migratory songbird during spring migration. I adopted experimental approaches to study the factors influencing how a songbird migrant, red-eyed vireos (Vireo olivaceus), makes decisions in unfamiliar landscapes from the initiation of spring stopover.

I simulated the …

Trace Metal Limitation And Its Role In Oxidative Stress Of Coral Algal Symbionts; Implications For Thermally Induced Coral Bleaching Events., Katrina Lynn Iglic

Electronic Thesis and Dissertation Repository

Coral bleaching, the process in which corals expel their photosynthetic symbionts (Genus Symbiodinium), is caused by high temperature and irradiance stress. The synergistic effect of each stressor is the generation of damaging reactive oxygen and nitrogen species (ROS and RNS), which are normally mitigated physiologically by antioxidant enzyme activity. Antioxidant enzymes require iron, copper, manganese and zinc in their structure and the limited nature of these trace metals in reef environments may enhance ROS production under elevated temperature and irradiance. The hypothesis tested within this thesis was that a limited availability of the trace metals Fe, Mn, Cu and …

A Long-Term Control Project For An Invasive Plant: Assessment Of Phragmites Australis Reduction And Redevelopment Of Native Vegetation In Interdunal Swales Of Sandy Neck Barrier Beach, Cape Cod, Massachusetts, Dena Tomassi

Biology Masters Theses Collection

Phragmites australis is a perennial wetland grass that is native to North America. However, salt marshes, estuaries, and other wetlands throughout the northeast USA and Canada have witnessed a dramatic range expansion and population increase of the introduced genetic variant Phragmites australis haplotype M (Saltonstall 2002), with loss of native vegetation through competitive exclusion. Within the dune system of Sandy Neck Barrier Beach, freshwater wetland swales form in low elevation areas, which harbor a diverse wetland plant community dominated by shrubs, and sedges -- and including some rare and endangered species. To conserve and protect these wetland plant associations, annual …

Controls On The Formation Of Algal Blooms In The Lower Chesapeake Bay And Its Tributaries, Ryan Eric Morse

OES Theses and Dissertations

Algal blooms occur seasonally in the Chesapeake Bay and its tributaries, and while the consequences of algal blooms have been qualitatively and quantitatively assessed, the causes of algal blooms and mechanisms of bloom initiation are still not well understood despite decades of research. In order to understand nutrient dynamics and other factors that promote the initiation of algal blooms, the Lafayette River, a tidal sub-estuary of Chesapeake Bay that experiences seasonal algal blooms, was sampled daily in the fall of 2005. Three phytoplankton blooms (Chlorophyll a concentrations exceeding twice the average of monthly measurements from 2000-2009) occurred during this period, …

Evolutionary Patterns In Deep-Sea Mollusks, Elizabeth Ellen Boyle

Graduate Doctoral Dissertations

The evolution of deep-sea fauna is poorly known. We know little about the scales of population differentiation, radiation and colonization of the deep sea. This dissertation explores evolution in the deep sea at the level of population differentiation on ocean-wide scales in a gastropod species Benthonella tenella and phylogeny of a deep-sea subfamily of protobranch bivalves, Ledellinae. While working on the phylogeny of the Ledellinae the presence of mitochondrial heteroplasmy was discovered.

Genetic variation was quantified within and among populations of deep-sea gastropod Benthonella tenella to identify the extent of population differentiation and potential mechanisms that might isolate gene pools. …

Growth Of Yeast, Saccharomyces Cerevisiae, Under Hypergravity Conditions, Sapir Vangruber

Honors Capstone Projects - All

The yeast, Saccharomyces cerevisiae, is a eukaryote and model organism that can be used to study how eukaryotic cells respond to hypergravity. In this experiment, six standard wild-type strains were used to determine a maximum gravitational force the yeast can withstand and still grow. Artificial gravity was generated using a centrifuge. Yeasts were found to maintain growth even at the highest artificial gravity tested, 2,114 g. An ordered deletion set of S. cerevisiae was then screened to identify genes that could not grow and withstand simulated hypergravity compared to growth under 1g conditions. Many of the strains that failed …

Modular Inheritance Of Color Pattern In Lake Malawi Cichlid Fishes, Jennifer Roscoe

Honors Capstone Projects - All

This study attempts to elucidate the mechanisms that underlie the evolution of pigmentation patterns among Lake Malawi cichlids. For decades researchers have sought to provide a theoretical model of cichlid speciation based on the evolution of male nuptial patterns and female preferences, yet our understanding of how color patterns change is limited. Here, we performed exploratory statistical analyses on an F₂ hybrid population to characterize the inheritance of color traits. Specifically, we sought to uncover patterns of modularity and levels of integration among color traits. Because cichlids are sexually dimorphic we did our analyses on males and females separately. …

Identification, Cloning And Fluorescent-Tagging Of Protamines Of The Flour Beetle, Tribolium Castaneum, Kristina Martimucci

Honors Capstone Projects - All

The genome of eukaryotes is associated with chromosomal proteins that fold the DNA into ordered arrangements. The most abundant of these are the histones. Four of these (H2A, H2B, H3 and H4) form the nucleosomal core around which DNA is wrapped. Other proteins can associate with chromatin and fold it into higher order structures. During spermatogenesis in many organisms the standard chromatin configuration undergoes a transition to a highly condensed form in which small, highly basic proteins called protamines replace the histones. It is thought that protamine-based chromatin is more resistant to mutational damage.

Previous work by the Renkawitz-Pohl group …

Molecular Evolution And Historical Biogeography Of New World Birds, Brian T. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation …

Phylogeography Of Three Heteromyid Taxa: Insight On The Evolution Of A North American Arid Grassland Rodent Guild, Sean A. Neiswenter

UNLV Theses, Dissertations, Professional Papers, and Capstones

Revealing how communities are shaped by abiotic and biotic factors plays a central role in biogeographic and comparative phylogeographic studies. The biogeography of North American arid grasslands is explored using nuclear and mitochondrial DNA from three groups of heteromyid rodents that are broadly sympatric in aridlands across western North America. Phylogenetic and molecular clock analyses are used to estimate the timing of divergences within each group. A general pattern of late Miocene divergence and expansion of lineages in each of the groups that is coincident with the rapid expansion of arid grasslands at the time. The initial divergence is followed …

Activation Of Amp-Activated Protein Kinase As An Early Indicator For Stress In The Lobster, Homarus Americanus, Stephanie Podolski

All Theses And Dissertations

Variations in water temperature, salinity, pH, and oxygen concentration are stressors that marine invertebrates face on a daily basis. Each of these physiological stressors creates a large cellular demand for energy. In mammals, energy metabolism is regulated by the enzyme AMP-activated protein kinase (AMPK), which is highly conserved during evolution. This project was designed to test the hypothesis that AMPK is present and activated by temperature, hypoxia, and anoxia stress in the lobster, Homarus americanus.

Animals were exposed to a rapid and progressive increase in temperature (6ºC per hour) beginning at 14 ºC. We measured lactate concentrations and AMPK …

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997). As far as we know, no previous data have been compiled regarding hormones and condition index of guppies. In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River. Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator. The condition …

New Genomic Approaches Reveal The Process Of Genome Reduction In Prochlorococcus, Zhiyi Sun

Open Access Dissertations

Small bacterial genomes are believed to be evolutionarily derived from larger genomes through massive loss of genes and are usually associated with symbiotic or pathogenic lifestyles. It is therefore intriguing that a similar phenomenon of genome reduction has been reported within a group of free-living phototrophic marine cyanobacteria Prochlorococcus. Here I have investigated the roles of natural selection and mutation rate in the process of Prochlorococcus genome size reduction. Using a data set of complete cyanobacterial genomes including 12 Prochlorococcus and a sister group of 5 marine Synechococcus, I first reconstructed the steps leading to Prochlorococcus genome reduction …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …

Phylogeography Of Northern Populations Of The Black-Tailed Rattlesnake (Crotalus Molossus Baird And Girard, 1853) With The Revalidation Of C. Ornatus Hallowell, 1854, Christopher Anderson

Open Access Theses & Dissertations

The black-tailed rattlesnake (Crotalus molossus Baird and Girard, 1853) is a wide-ranging species complex with representatives from the southwestern United States through the highlands of central and southern Mexico. The systematics of this group has received little attention and in the past six decades only two taxonomic revisions have been proposed (the transfer of C. basiliscus oaxacus to C. molossus and the elevation of C. m. estebanensis to full species). However, a recent revision of the Neotropical rattlesnakes (C. durissus and C. simus) recovered a polyphyletic C. molossus. Sequenced data were obtained from three mitochondrial genes …

Ecogeographical Distribution Of The Herpetofauna Of Indio Mountains Research Station, Hudspeth County, Texas, Ross Owen Couvillon

Open Access Theses & Dissertations

Indio Mountain Research Station (IMRS) in Trans-Pecos, Texas is dominated by Chihuahuan Desert scrub vegetation, but a complexity of plant communities exist relating to elevation, slope, and geologic formations. Surrounding the Indio Mountains are desert grasslands with various desert scrub associations. This mosaic of habitats forms a unique assemblage of amphibians and reptiles. The goal of this study was to determine if the current number of amphibians, turtles, lizards, and snakes (43 species) of IMRS was accurate and identify which biotic and abiotic factors define the distribution of these species. Records from the last approximately 25 years were used to …

The Ecology Of Disturbances And Global Change In The Montane Grasslands Of The Nilgiris, South India, Madhusudan P. Srinivasan

University of Kentucky Doctoral Dissertations

Biodiversity rich regions worldwide face threats from various global change agents. This research quantifies environmental influences on vegetation, and the impacts of exotic woody plant invasion and anthropogenic nitrogen (N) deposition in a global biodiversity hotspot. The study was conducted in the montane grasslands of the Nilgiris, Western Ghats, and outlines potential management options for this region. Specifically, I examined (1) the role of environmental factors in influencing native plant distribution and ecosystem properties, (2) the status and impact of exotic shrub (Scotch broom, henceforth broom) invasion, (3) the role of disturbances in the success of broom, (4) the role …

Floristic And Environmental Characteristics Of Sub-Boreal Peatlands Of Minnesota And Western Wisconsin, Kevin Douglas Clement

All Graduate Theses, Dissertations, and Other Capstone Projects

Peatland communities in the sub-boreal region of Minnesota and western Wisconsin were characterized by floristic composition, structure and environmental characteristics to determine the natural variation among peatland communities in the region and their shared associations with the boreal and temperate peatlands of North America. Floristic classification revealed five, distinct peatland community types, identified as Sphagnum Bogs, Herbaceous Fens, Forested Fens, Rich/Calcareous Fens and Phalaris anrundinacea dominated peatlands. Differences among sub-boreal peatlands largely reflected changes in the significant indicator and dominant plant species identified, which were found to exhibit high fidelities to a particular peatland community type. Floristic variations among sub-boreal …

Biogeographic Consequences Of Historic And Contemporary Climate Change In Boreal Forest Birds, Joel Ralston

Legacy Theses & Dissertations (2009 - 2024)

In this dissertation, I combine ecological niche models (ENMs), which can be extrapolated through time to predict historic and future changes in species distributions, with mitochondrial and nuclear genetic markers to study the biogeographic consequences of historic and contemporary climate change on boreal forest birds, and in particular Blackpoll Warbler.

Physiology And Biochemistry Of The Tropical Seagrass Thalassia Testudinum In Response To Hypersalinity Stress And Labyrinthula Sp. Infection, Stacey Marie Trevathan-Tackett

UNF Graduate Theses and Dissertations

Seagrass meadows are essential to coastal ecosystems and have experienced declines in abundance due to a series of environmental stressors including elevated salinity and incidence of disease caused by the pathogen Labyrinthula sp. This thesis evaluated the dynamics between T. testudinum and Labyrinthula concerning the impacts of short term elevated salinity stress on the early stages of infection in Thalassia testudinum (Chapter 2) as well as the presence of anti-labyrinthulid secondary metabolites produced by the tropical seagrass (Chapter 3). The results showed that short term exposure to hypersalinity alters some cellular processes but does not necessarily lead to an immediate …

Amphibian Community Similarity Between Natural Ponds And Constructed Ponds Of Multiple Types In Daniel Boone National Forest, Kentucky, Robert Daniel Denton

Online Theses and Dissertations

Amphibians are in a worldwide decline. Among the many causes for amphibian declines, habitat loss and alteration remains one of the most significant. A lack of federal protection for isolated wetlands that provide habitat for unique species has resulted in the loss of breeding habitat and unregulated mitigation practices. Ponds built for mitigation purposes often do not replicate the lost ponds in structure or ecological processes. A lack of general monitoring has produced a void in knowledge of what long-term role constructed ponds play in shaping amphibian communities. My objective was to compare amphibian communities of natural ponds and multiple …

Land Snail Species Diversity And Composition Between Different Forest Disturbance Regimes In Central And Eastern Kentucky Forests, Daniel Douglas

Online Theses and Dissertations

Land snails are cornerstone organisms that contribute to properly functioning ecosystems. However, habitat loss and destruction have led to these organisms being one of the most imperiled groups on the planet. Due to their relatively sedentary nature, land snails can be susceptible to anthropogenic disturbance and habitat fragmentation. Because of this, old-growth forests have the potential for being premiere habitat for these organisms, and snails have the potential to be good indicators of old-growth habitats. This study compared land snail species diversity and community composition in old-growth and second-growth forests in the Inner Bluegrass, Cumberland Plateau, and Pine Mountain ecoregions …

A Post-Restoration Assessment Of The Fishes And Macroinvertebrates Of Mill Branch, Knox County, Kentucky, With Emphasis On The Blackside Dace (Chrosomus Cumberlandensis), Dwayne Kevin Merrill

Online Theses and Dissertations

The first stream habitat restoration project for the federally threatened blackside dace, Chrosomus cumberlandensis (Starnes and Starnes), was initiated in fall 2005 on Mill Branch, a small headwater stream located in the Upper Cumberland River basin, Knox County, Kentucky. The lower 700 meters of Mill Branch were restored through construction of a new, stable channel with specially designed habitat features for blackside dace. In August 2009, the newly restored channel was connected to the mainstem and the old channel was eliminated. A post-restoration survey was conducted on the fishes (with emphasis on the blackside dace) and benthic macroinvertebrate communities, between …

The Conservation And Ecology Of Carnivorous Plants, David Jennings

USF Tampa Graduate Theses and Dissertations

As discussed in Chapter 1, although our understanding of the ecology and evolution of carnivorous plants has greatly improved in recent years, many fundamental questions remain unanswered. Unfortunately, at the present time, many carnivorous plants are increasingly threatened by anthropogenic activities. Indeed, over half of the carnivorous plant species assessed by the International Union for the Conservation of Nature (IUCN) are listed as `threatened', but the threats to carnivorous plants have not previously been quantified. In Chapter 2, I quantified the conservation threats to carnivorous plant taxa worldwide by searching peer-reviewed literature, and found data on the threats to 48 …

Evaluating The Effects Of Beach Nourishment On Loggerhead Sea Turtle (Caretta Caretta) Nesting In Pinellas County, Florida, Corey R. Leonard Ozan

USF Tampa Graduate Theses and Dissertations

The health of Florida's beaches are vital to the survival of loggerhead sea turtles (Caretta caretta), as nearly half of the world's loggerheads nest on the states beaches. Many of the beaches utilized by the turtles have undergone nourishment projects in hopes of combating erosion of the shoreline, protecting beachfront property, and creating more suitable beaches for tourism. Although it is argued that beach nourishment benefits sea turtles by providing more nesting habitat, the effects of the Pinellas County nourishment projects on loggerhead nesting are unknown. Beach nourishment can alter the compaction, moisture content, and temperature of the sand, all …