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University of Tennessee, Knoxville

2017

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Articles 1 - 23 of 23

Full-Text Articles in Ecology and Evolutionary Biology

Quantatative Analysis Of Microbial Abundance Within Arctic Fjord Sediments Assessed Through Direct Counting, Alex Taylor Swystun Dec 2017

Quantatative Analysis Of Microbial Abundance Within Arctic Fjord Sediments Assessed Through Direct Counting, Alex Taylor Swystun

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Microbes found in the marine sediments are responsible for the production of nearly half of the carbon dioxide found in the atmosphere (Arrigo, 2005). The fjords of Svalbard (79°N) are not considered typical marine sediments because high iron content influences unique subsurface redox chemistry. Radiotracer studies have shown that these sediments contain active bacterial sulfate-reducing communities (Finke et al., 2016). In addition to bacteria, archaeal cells within these sediments have been in aggregates encompassed by sulfate-reducing bacteria (Ravenschlag et al., 2001). These anaerobic organisms participate in mediating environmental biogeochemical cycles, including the oxidation of methane (Ravenschlag et al., 2001) and …


Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen Dec 2017

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …


Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower Dec 2017

Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower

Doctoral Dissertations

Phylogenetics is a powerful tool used for illuminating the diversity of life on Earth, their evolution and their ecology. I created a multi-gene phylogenetic tree of Cortinarius section Cortinarius and uncovered five previously overlooked species, increasing the number of species in the section from seven to twelve. All members of the clade possess both cheilocystidia and pleurocystidia and possess a pigment known as (R)-39,49-dihydroxybphenylalanine. Ancestral state reconstruction estimated that the ancestral host was most likely an angiosperm, switching hosts when encountering novel host species in new lands, and only C. violaceus associating with the Pinaceae in North America. Biogeographic analysis …


Aspects Of The Physiological And Behavioral Defense Adaptations Of The Mountain Madtom (Noturus Eleutherus), Meredith Leigh Hayes Dec 2017

Aspects Of The Physiological And Behavioral Defense Adaptations Of The Mountain Madtom (Noturus Eleutherus), Meredith Leigh Hayes

Masters Theses

Madtoms (Noturus spp.) are a highly endemic clade of miniature catfishes that faces widespread imperilment. Little is known about the ecology of these secretive fishes, and understanding the behavioral and physiological adaptations madtoms have evolved to resist pathogens and competitors is necessary for conservation.

Madtoms nest under cover and provide extensive paternal care. Attempts to rear eggs in captivity result in high mortality rates from infection, leading to questions about how wild nests resist disease. In many fishes, males produce antimicrobial substances that confer protection to eggs. To determine if guardian males deter disease in nests, Mountain Madtoms ( …


Physiological Ecology Of Four Endemic Alabama Species And The Exotic Asiatic Weatherfish, Misgurnus Anguillicaudatus (Cantor, 1842), Lindsay M. White, Mark E. Meade, Benjamin A. Staton Sep 2017

Physiological Ecology Of Four Endemic Alabama Species And The Exotic Asiatic Weatherfish, Misgurnus Anguillicaudatus (Cantor, 1842), Lindsay M. White, Mark E. Meade, Benjamin A. Staton

Southeastern Fishes Council Proceedings

The occurrence of Asiatic Weatherfish, Misgurnus anguillicaudatus, in Alabama, a state known for its rich biodiversity, has generated concern among conservation managers. The current study used respirometry techniques to investigate the effects of increasing temperature on four native southeastern fishes (one cyprinid, two percids, and one elassomid) and the non-native M. anguillicaudatus. A minimum of five individuals of each species were used, and three experimental temperatures were chosen to represent spring and summer averages of northeast Alabama streams (15, 20, and 25°C). Overall, mean standard metabolic rates (SMRs) for M. anguillicaudatus were low (97.01, 127.75, and 158.50 mg …


First Report Of A Population Of Western Blacknose Dace (Rhinichthys Obtusus) In The Brushy Creek System Of The Black Warrior River Drainage, Alabama, Eric Bauer, Malorie M. Hayes Sep 2017

First Report Of A Population Of Western Blacknose Dace (Rhinichthys Obtusus) In The Brushy Creek System Of The Black Warrior River Drainage, Alabama, Eric Bauer, Malorie M. Hayes

Southeastern Fishes Council Proceedings

Alabama is home to the southernmost populations of Rhinichthys obtusus, the Western Blacknose Dace. Within Alabama, R. obtusus is found in the Tennessee, Coosa, and Black Warrior River basins, but its presence in the Black Warrior River drainage has been limited. Until now, R. obtusus in the Black Warrior drainage has only been reported as collections of 1 to 4 specimens at a time in the Sipsey Fork drainage. Herein, we report two novel occurrences of R. obtusus in the headwaters of the Brushy Creek system in the Black Warrior River drainage including a singleton and a large population. …


Assessment Of Genetic And Education Recovery Plan Objectives For The Bog Turtle (Glyptemys Muhlenbergii), Cassie Marie Dresser Aug 2017

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 …


Conservation Decisions: Designing, Financing And Fundraising For Protected Areas, Rachel Elizabeth Fovargue Aug 2017

Conservation Decisions: Designing, Financing And Fundraising For Protected Areas, Rachel Elizabeth Fovargue

Doctoral Dissertations

Establishing protection for conservation is a complicated process that involves many critical decisions, from spatial prioritization to garnering the necessary financial support to complete a project. In my research, I address questions that inform various components of this process. First, I ask questions about protected area design using a case study of a large reef system in Australia. I find that simple design rules can facilitate the pursuit of conservation and extractive management goals. Second, I address questions about costs incurred by the financing of new protection. I establish a unique dataset of projects financed by a conservation non-profit through …


Stable Isotopes, Phylogenetics, And Experimental Data Indicate A Unique Nutritional Mode For Rickenella Fibula, A Bryophyte-Associate In The Hymenochaetales, Hailee Brynn Korotkin Aug 2017

Stable Isotopes, Phylogenetics, And Experimental Data Indicate A Unique Nutritional Mode For Rickenella Fibula, A Bryophyte-Associate In The Hymenochaetales, Hailee Brynn Korotkin

Masters Theses

Fungal-bryophyte interactions have been documented in all lineages of bryophytes, however, many of these relationships are poorly understood. The fungus Rickenella fibula is a known associate of various mosses, but results from previous studies have not yielded conclusive evidence of its relationship to mosses or its trophic mode. The Rickenella clade exhibits a wide variety of nutritional modes, including other bryophyte-associated fungi. Here, I combine a broad range of methods, using phylogenetics, stable isotope analyses, PCR assays, in vitro experiments, and genomics to determine the nutritional mode of R. fibula. First, phylogenetic analysis of a supermatrix of 28S rRNA, …


Hypericum Irazuense Kuntze Ex N. Robson In The Buenavista And Chirripó Páramos Of Costa Rica: Photographs Of Stem Cross Sections, Plants, And Study Sites, Sally P Horn, Matthew T. Kerr May 2017

Hypericum Irazuense Kuntze Ex N. Robson In The Buenavista And Chirripó Páramos Of Costa Rica: Photographs Of Stem Cross Sections, Plants, And Study Sites, Sally P Horn, Matthew T. Kerr

Geography Publications and Other Works

Hypericum irazuense Kuntze ex N. Robson is a common shrub in the high-elevation páramos that occur above treeline on the high peaks of the Cordillera de Talamanca in Costa Rica and westernmost Panama. In this report and accompanying high-resolution images we make available photographs of stem cross sections, plants, and habitats of H. irazuense in support of a recent study of the dendrochronological potential of the species (Kerr et al., forthcoming paper in Physical Geography) and other research on this plant and the páramo vegetation in which it occurs. We also include images from the Google EarthTM map …


Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards May 2017

Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards

Chancellor’s Honors Program Projects

No abstract provided.


Identifying Extinction Risk Patterns In Pollination Networks And Conservation Planning To Reduce The Cost Of Management-Necessitated Travel, Christine Elise Dumoulin May 2017

Identifying Extinction Risk Patterns In Pollination Networks And Conservation Planning To Reduce The Cost Of Management-Necessitated Travel, Christine Elise Dumoulin

Doctoral Dissertations

Extinction rates are currently far above background levels, as a result of human activity. Although conservation spending is substantial, there is a shortfall between the cost of meeting biodiversity targets and the resources available to do so. Consequently, decision-makers are faced with the task of identifying which taxonomic groups and geographical regions are of greatest concern, and prioritizing approaches with the greatest conservation benefit. In this dissertation, I develop novel approaches in both of these areas.

First, I take a stochastic, community dynamic approach to modeling extinction risk patterns in pollination networks. Despite the ecological and agricultural importance of pollination …


Systematics, Diversification, And Functional Diversity Of Russulaceae (Russulales), Brian Patrick Looney May 2017

Systematics, Diversification, And Functional Diversity Of Russulaceae (Russulales), Brian Patrick Looney

Doctoral Dissertations

The family Russulaceae is an iconic family of mushroom-forming Basidiomycetes both because of their importance as edible mushrooms in many parts of the world and their species richness in both temperate and tropical forested biomes. While much mycological research has been focused on this group, recent systematic and ecological research has failed to develop a comprehensive or cohesive organization by which to understand the evolutionary relationships, patterns of diversification, or functional importance of the group. Recently, interest in ectomycorrhizal fungi (EmF), of which Russulaceae is a key lineage, has greatly increased due to the recognition of the importance of EmF …


Biotic And Abiotic Drivers Of Plant Symbionts Determine Plant Performance, The Maintenance Of Diversity, And Response To Global Change, Jeremiah A. Henning May 2017

Biotic And Abiotic Drivers Of Plant Symbionts Determine Plant Performance, The Maintenance Of Diversity, And Response To Global Change, Jeremiah A. Henning

Doctoral Dissertations

Interactions among organisms regulate the structure and function of ecosystems and the response of ecosystems to global change. The outcome of species interactions is shaped by the partners involved in the interaction and the climate contexts of the systems in which they reside. Global change is altering the distributions of organisms as well as the climate contexts of the systems they reside within, shifting the biotic and abiotic factors shaping species interactions. Thus, predicting the response of ecosystem structure and function to global change remains unresolved. For my dissertation, I explored how the interactions among plants and their mutualistic communities …


Ecological And Evolutionary Dynamics Of Plant-Soil Feedbacks: Influences On Evolution And Range Dynamics, Michael E. Van Nuland May 2017

Ecological And Evolutionary Dynamics Of Plant-Soil Feedbacks: Influences On Evolution And Range Dynamics, Michael E. Van Nuland

Doctoral Dissertations

Plants interact with, modify, and are affected by their soil environments. Though plant-soil interactions are well known to be important and active regulators of ecosystem function and community structure, much less is known about how these interactions affect plant evolution. The primary goal of my dissertation was to examine plant-soil interactions under a range of ecological and evolutionary contexts to better understand patterns of biodiversity, ecosystem function, and whole system responses to environmental change. Taking such an eco-evolutionary perspective allows for a holistic understanding of the causes and consequences of complex abiotic and biotic interactions that link ecosystem ecology and …


Molecular Phylogenetic Studies Of The Genera Of Tribe Polygonateae (Asparagaceae: Nolinoideae): Disporopsis, Heteropolygonatum, And Polygonatum., Aaron Jennings Floden May 2017

Molecular Phylogenetic Studies Of The Genera Of Tribe Polygonateae (Asparagaceae: Nolinoideae): Disporopsis, Heteropolygonatum, And Polygonatum., Aaron Jennings Floden

Doctoral Dissertations

The Polygonateae (Asparagaceae) are a subtribe of the Nolinoideae that is redefined here to include three genera which are investigated here: Disporopsis; Heteropolygonatum, and Polygonatum. This group of genera, characterized by their axillary-flowered habit, are closely related but differ greatly in their morphology, cytology, and diversity. A molecular phylogeny is presented to show their relationships to one another and to closely related outgroups based on data from whole chloroplast genomes with low taxonomic sampling. The results show that the genera of the Polygonateae are each monophyletic, and also show that a fourth genus, Maianthemum, that was …


Trait Evolution In Spiders: Perspectives On The Evolution Of Behavioral Syndromes And Web Structures, Jennifer Marie Bosco May 2017

Trait Evolution In Spiders: Perspectives On The Evolution Of Behavioral Syndromes And Web Structures, Jennifer Marie Bosco

Doctoral Dissertations

Organisms have evolved complex behavioral, morphological and physiological traits in response to various selection pressures. These phenotypes are usually composed of many traits that may or may not be genetically or phenotypically correlated. Correlations of both types can lead to evolutionary trade-offs, which may be broken over long evolutionary time periods through such mechanisms as the decoupling of genetic linkages and the development of phenotypic plasticity. Behavioral traits associated with temperament provide an excellent system in which to evaluate underlying mechanisms of the establishment and decoupling of genetic linkages. Other traits, such as the type of web that a spider …


Using Phylogenetic Comparative Methods To Understand Diversification And Geographic Range Evolution, Kathryn Aurora Massana May 2017

Using Phylogenetic Comparative Methods To Understand Diversification And Geographic Range Evolution, Kathryn Aurora Massana

Doctoral Dissertations

Two key processes that have been modeled in a phylogenetic comparative framework are diversification and historical biogeography. Many questions arise on what process have shaped the abundance (or lack) of species we see today and what influences their survival and interconnectedness with other species. Many methods have been developed to answer these questions. Over the past several decades there has been a rise in parametric modeling and development of more adequate frameworks to answer biological questions of interest. However, many models still lack the incorporation of ecological, mainly biotic factors, which influence the evolution and ecology of species, while accounting …


Dispersal Rate Of The Asian Clam (Corbicula Fluminea): A Study With Pit Tagging, Tommy Cianciolo May 2017

Dispersal Rate Of The Asian Clam (Corbicula Fluminea): A Study With Pit Tagging, Tommy Cianciolo

Chancellor’s Honors Program Projects

No abstract provided.


Conservation Biology Of Bats: Invasive Threats, Research Effort, And Extinction Risk, Jessica Nicole Welch May 2017

Conservation Biology Of Bats: Invasive Threats, Research Effort, And Extinction Risk, Jessica Nicole Welch

Doctoral Dissertations

Global conservation for bats is needed: 15 percent of species are listed as extinct or threatened, signifying that they are at a high risk of extinction. An additional 17 percent are designated data-deficient, denoting that a threat category has not been assigned owing to insufficient knowledge on species abundance or distribution. In this dissertation, I use methods from both ecology and evolution to contribute to the study of bat conservation. Firstly, I review the impacts of biological invasion on bats, and provide examples of threats from each of four broad categories: predation, pathogens, competition, and indirect interactions. Overall, detailed accounts …


Spatially Explicit Population Estimates Of The Florida Black Bear, Jacob Michael Humm May 2017

Spatially Explicit Population Estimates Of The Florida Black Bear, Jacob Michael Humm

Masters Theses

The Florida black bear (Ursus americanus floridanus) is currently comprised of 7 isolated subpopulations: Apalachicola, Eglin, Osceola, Ocala/St. Johns, Chassahowitzka, Highlands/Glades, and Big Cypress. The last statewide assessment of Florida black bear population dynamics was conducted by Simek et al. (2005) using traditional capture-markrecapture methods. The subspecies was removed from Florida’s List of State Threatened Species in 2012 contingent upon the formulation of a management plan that would maintain viable subpopulations of black bears in suitable habitat. Accurate population estimates for each of the remaining black bear subpopulations in Florida were needed to achieve the management goals of …


Plasticity And Biotic Interactions Mediate Plant Persistence In A Changing World, Alix Ann Pfennigwerth May 2017

Plasticity And Biotic Interactions Mediate Plant Persistence In A Changing World, Alix Ann Pfennigwerth

Masters Theses

Anthropogenic global change is occurring today at a faster rate and larger scale than ever before. Understanding how plants will respond to such large-scale disturbance is critical for biodiversity conservation, yet the ecological and evolutionary mechanisms underlying these responses remain poorly understood. In this thesis, I investigated the mechanisms underlying plant response to two major drivers of global change, climate change and the widespread mortality of foundation species. First, I examined genetic and plastic plant trait responses to climatic variation using elevation gradients, which serve as space-for-time substitutions for climate change. Through field observations in three populations of the North …


Fire History Of The Appalachian Region: A Review And Synthesis, Charles W. Lafon, Adam T. Naito, Henri D. Grissino-Mayer, Sally P Horn, Thomas A. Waldrop Jan 2017

Fire History Of The Appalachian Region: A Review And Synthesis, Charles W. Lafon, Adam T. Naito, Henri D. Grissino-Mayer, Sally P Horn, Thomas A. Waldrop

Geography Publications and Other Works

The importance of fire in shaping Appalachian vegetation has become increasingly apparent over the last 25 years. This period has seen declines in oak (Quercus) and pine (Pinus) forests and other fire-dependent ecosystems, which in the near-exclusion of fire are being replaced by fire-sensitive mesophytic vegetation. These vegetation changes imply that Appalachian vegetation had developed under a history of burning before the fire-exclusion era, a possibility that has motivated investigations of Appalachian fire history using proxy evidence. Here we synthesize those investigations to obtain an up-to-date portrayal of Appalachian fire history. We organize the report by …