Life Sciences Commons^™

Assessing Red Spruce (Picea Rubens) Restoration Potential Under Current And Future Predicted Climate Change In Virginia, Christian Brown

Masters Theses, 2020-current

Global climate change threatens many species across the planet. High-elevation species, such as red spruce (Picea rubens), face significant and immediate threats from climate change. Red spruce has faced anthropogenic disturbances for over a century and is only recently beginning to regenerate across its range, making it an ideal restoration candidate. Ecological niche modeling has become a common method of identifying the suitable habitat of a species, providing vital information to land managers carrying out restoration efforts. In this study ecological niche models were used in a novel way, predicting distribution and habitat suitability separately to determine the …

Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin Schroeder

Biology ETDs

As some of the most charismatic megafauna to ever walk the earth, the physiology, morphology, growth and evolution of non-avian theropods has been studied exhaustively, yet little is understood about their roles in ecosystems as juveniles. For carnivorous megatheropods, which exceed 1,000kg in mass yet hatched from eggs of limited size, the likelihood of utilizing different prey through ontogeny was high, simply by proxy of the immense difference in size between adults and juveniles. We found these ontogenetic niche shifts, evidenced by significantly different dental microwear in Tyrannosaurids, to have excluded dinosaurian mesocarnivores from Mesozoic communities. The few dinosaurian mesocarnivores …

Effects Of Water Quality On Oyster Health On Georgia Coast, Laurel Henderson

Honors College Theses

ABSTRACT

Oysters are an economically and ecologically important shellfish species found along most coastlines. Along the Georgia coastline, oysters form extensive reefs, and are economically important as a food source. In addition, oysters perform a vital role in maintaining water quality due to their high filtration capacity in coastal waters. Oyster reefs form solid, 3-D substrate that prevent coastline erosion and provide structure for numerous other coastal species to grow, including many commercially and recreationally important species. Water quality factors, such as temperature and salinity, can influence oyster density, condition, and growth, and ultimately affect the services the reefs provide …

Making Sense Of Soil Microbiome Complexity For Plant And Ecosystem Function In A Changing World, Kendall K. Beals

Doctoral Dissertations

Soils contain the highest biodiversity on Earth. While the importance of the soil microbiome for larger-scale ecological phenomena such as nutrient and carbon cycling, plant growth and plant community dynamics is well-established, the fundamental question of the ecological and evolutionary function of this immense belowground microbial diversity for plant and ecosystem function still remains a great challenge in microbial ecology research. The objective of this dissertation is to understand how the importance of soil microbial community composition for plant and ecosystem function and how changes to soil microbial community composition from climate change-induced disturbance events, specifically fire, influence plant and …

Seasonality Of Orthohantavirus Seroprevalence In Northwest Arkansas Rodents, Amy Schexnayder

Biological Sciences Undergraduate Honors Theses

Zoonotic viruses are viruses that can be transmitted from animals to humans. Rodent species are likely to be reservoirs for zoonotic viruses, and particular rodent-borne viruses, such as orthohantaviruses, may greatly threaten human health. Orthohantaviruses are a group of rodent-borne viruses that are at risk for spillover to human populations. Many aspects of orthohantaviruses have been well-researched, yet the seasonality of orthohantaviruses has not yet been thoroughly examined, especially in the southern United States. In this study, we captured 616 rodents trapped over 5953 trap nights across 13 grassland sites in Northwest Arkansas. Rodents were trapped for two consecutive nights …

Plant Community Responses To Interactive Anthropogenic Disturbances Along A Natural-Wildland-Urban Gradient And Undergraduate Students’ Attitudes Toward Disturbances, Mali M. Hubert

Doctoral Dissertations

Anthropogenic disturbances are defined as any change caused by human activity that alters biodiversity. Wildfire and urbanization disturbances are among the most influential on the landscape because of their individual and interactive properties. Areas deemed wildland-urban interfaces (WUI; area where environment intermingles with human-built structures) are increasing near protected lands because of human population growth and movement, which often facilitates fire ignitions by humans. Houses that are adjacent to or overlap with wildland vegetation can complicate protection of urban development and wildlands from fires. The expansion of the WUI due to population growth will exacerbate fire risk, which can ultimately …

Life After Death – Does Carcass Biodiversity Scale With Carcass Body Size?, Troy Warfield

Biological Sciences Undergraduate Honors Theses

Mammals play a large role in the ecosystems where some, especially large-bodied mammals, act as ecosystem engineers. Mammal carcasses, particularly those of large body mass act as a temporary island of dense nutrients that support other organisms, including other mammal species, for an extended period. Research in this field currently focuses on the link between mammal carcass size and nutrient availably or on non-mammalian size and biodiversity, but little is available on the correlation between mammal carcass size and its influence on ecosystem biodiversity. Here we ask, does the available biomass (i.e., body size) of the carcass affect its role …

Assessing The Long-Term Effects Of Natural Disturbance-Based Silvicultural On The Avian Assemblage At The Acadian Forest Ecosystem Research Program, Carl Pohlman

Electronic Theses and Dissertations

Active forest management alters the resources available to forest-obligate species. Large-scale intensive management practices where timber production is the primary objective can lead to notable ecological changes in forest ecosystems. A key concept of ecological forestry is to design forest management activities to emulate natural disturbance regimes as a way to maintain the ecological integrity of forests. The Acadian Forest Ecosystem Research Program (AFERP) was undertaken as an experimental demonstration of management reflective of the region’s disturbance regime, which typically produces small canopy gaps. AFERP includes nine research areas assigned to three silvicultural treatments: unharvested control, small gap (expanding-group selection …

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 …

Spatiotemporal Factors Affecting The Occupancy And Phenology Of A Declining Songbird (Bachman's Sparrow - Peucaea Aestivalis) At The Western Extent Of Its Range, Liam G. Wolff

Electronic Theses and Dissertations

The Bachman’s Sparrow (Peucaea aestivalis) is a declining songbird that occurs throughout the southeastern United States. Bachman’s Sparrow is a Species of Greatest Conservation Need in Texas, but information crucial to management efforts, such as factors affecting their detectability and occupancy, is lacking. I investigated the predictors of Bachman’s Sparrow occupancy and phenology in Texas using detections from autonomous recording units coupled with site characteristics and weather data. My results indicate that Bachman’s Sparrow occupancy is associated with increasing herbaceous ground cover and decreasing basal area, distance to the nearest source population, and basal area when canopy height …

Fish Community Assembly At Multiple Spatial Scales In East Texas Streams, Jake R. Swanson

Electronic Theses and Dissertations

Stream communities are structured by environmental processes that vary in strength across different spatiotemporal scales. Therefore, revealing how stream fish communities are influenced by environmental gradients may clarify how communities respond to disturbance associated with anthropogenic change. I investigated the relative role environmental variables play in the processes that structure the taxonomic and functional diversity of stream fish communities, as well as historical trends in occurrence and local habitat associated with a species of greatest conservation need within east Texas. The results of this study indicate that stream sites with more habitat complexity and stability support a more taxonomically and …

Nitrogen Availability In Dune Systems And Its Effect On Root Fungal Endophyte Communities., Haley E. Sage

College of Arts & Sciences Senior Honors Theses

As global change persists, changes in resource availability can influence plant-microbe interactions. To understand how resource availability can influence these interactions and species diversity, I focused this research on how varying nitrogen (N) levels affect root endophyte communities in the plant species Ammophila breviligulata, an ecosystem engineer in the dune system. I analyzed the relationship between nitrogen addition and microbial community composition across 60 plots treated with three nitrogen addition levels (control, low, and high) in a long-term experimental field site in the Lake Michigan dunes. I identified Ammophila breviligulata's root endophyte community after creating a culture collection and …

Plant Neighbor Interactions Of A Native Goldenrod Impact Abundance And Composition Of Pollinator Communities, Emma P. Kruse

Chancellor’s Honors Program Projects

No abstract provided.

Sex And Starvation Influences Latrotoxin Expression In The Brown Widow Spider, Mattie Harris

Honors College Theses

Widow spiders (genus Latrodectus) are well-known for their potent venom. Seven latrotoxin proteins constitute the main components of widow spider venom. The vertebrate specific (α-latrotoxin) and insect specific (α-latroinsectotoxin) latrotoxins have been well-characterized with respect to structure and function. Regulation of latrotoxin gene expression is not well understood but sex and feeding could be factors influencing production. In this study, I used quantitative qPCR to (1) characterize the expression patterns of both the insect and vertebrate specific latrotoxins in male and female brown widow spiders (Latrodectus geometricus) to characterize sex-biased expression and to (2) study expression patterns …

Constructing The Eastern Coyote: A Temporal Analysis Of The Scientific And Social Production Of A Controversial Northeastern Canid, Kayleigh Moses

Senior Theses and Projects

Eastern coyotes (Canis latrans var) have confounded the scientific and social boundaries established by postcolonial United States. The first eastern coyote specimen on record comes from Otis, Massachusetts in 1957. At the time, this unknown and unnamed wolf-like creature sparked fear amongst human residents of the Northeastern United States. Threatened by the presence of this predator, Northeasterners launched coyote killing efforts similar to the eradication campaigns that had previously failed in the Western United States. Today, Massachusetts officials estimate that 11,500 eastern coyotes occupy the state, living amongst people and pets in every county. This abundance of eastern …

Development And Initial Validation Of The Parent And Family Engagement In Higher Education Measure, Michelle R. Mcnulty

USF Tampa Graduate Theses and Dissertations

Throughout the history of higher education in the United States, parents and family members of college students have often found themselves as obsolete to the postsecondary experience. Minimal research has been dedicated to understanding the experience of parents and family members of college students until the millennial generation began their collegiate years (Harper et al., 2012; Wartman & Savage, 2008). In consideration of a new generation of college students (i.e., Gen Z) and the ongoing impact of the COVID-19 global pandemic, it is crucial to illuminate the complexities of parent and family engagement in higher education and the needs of …

Macrophyte Abundance And Nitrate Dynamics Of Silver Bow Creek, Katelyn Reichle

Graduate Theses & Non-Theses

Butte, Montana has an extensive mining history contributing to the contamination degradation of terrestrial and aquatic systems, amongst Silver Bow Creek (SBC). The contamination of the stream and the floodplain created a toxic environment that could not support aquatic life. Although the remediation of the floodplain was successful in removing metal contamination, the recovery of the ecosystem from both the initial pollution and subsequent remediation is ongoing. SBC has also been impacted by the urbanization of Butte, leading to multidimensional ecological disruption. The stream is currently subject to nutrient loading by nitrate, nitrogen, and phosphorus. A possible effect of nutrient …

Behavioral And Physiological Effects Of Heavy Metals On Fish: A Review And Preliminary Results, Diana V. Morales

Theses and Dissertations

Pollution, specifically heavy metal pollution, in various bodies of water has been a significant issue for decades. Research has been conducted on heavy metals and their effects on the environment, larger fish species, and humans since the 1970s (Skidmore, 1964; Adeniyi et al., 2007; Adeosun et al., 2015; Bawuro et al., 2018). It is known that zinc is a neurotoxin in some species and causes harm to the environment. It is also known that it causes harm to people if it is ingested or if they are exposed to it for long periods of time (Mahurpawar, 2015; Mizuno and Kawahara, …

Connexin 43 Contributes To Phenotypic Variability Of The Mouse Skull, Elizabeth Jewlal

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine whether connexin 43 (Cx43) contributes to craniofacial phenotypic variability. Skull shape and variation were compared within and among two heterozygous mutant mouse models (G60S/+ and I130T/+) that exhibit different levels of Cx43 channel function when compared to their wildtype counterparts (~80% and ~50% reduction in function, respectively). Results indicated mutants have significant differences in skull shape compared to wildtype littermates. Similar patterns of shape difference were found in both mutants. Increased skull shape variation and a disruption in the covariation of skull structures were observed in G60S/+ mutants only. These results show …

Conservation, Comparative Genomics And Species Delimitation Of The Reindeer Lichens (Cladonia), Jordan R. Hoffman

Dissertations, Theses, and Capstone Projects

The genus Cladonia represents one of the most speciose genera of lichenized fungi, with more than 500 known species encompassing a diverse array of morphologies and habits. These lichens form keystone species in many habitats, serving a variety of ecological roles. However, despite being among of the more well studied lichens, there is much still unknown or under-studied about them. As is the case with most lichen study systems, phylogenetic study has been limited to a small number of partial loci, while adoption of next-generation sequence methods has been slow. As a consequence, there are still knowledge gaps in Cladonia …

Effects Of Experimental Malaria Infection On Migration Of Yellow-Rumped Warblers (Setophaga Coronata), Rebecca J. Howe

Electronic Thesis and Dissertation Repository

The potential of migratory animals to spread infectious diseases depends on how infection affects movement. If infection delays or slows the speed of travel, transmission to uninfected individuals may be reduced. Whether and how malaria (Plasmodium spp.) affects bird migration has received little experimental research. I captured 40 actively-migrating Yellow-rumped Warblers (Setophaga coronata) at a migration stopover site and held them in captivity. I inoculated 25 with P. cathemerium while 15 received sham inoculations. After 12 days the birds were released. Six P. cathemerium-inoculated birds (24%) developed P. cathemerium infections after inoculation. I radio-tagged all birds, …

Phylogenetic And Geographic Relationships Of Cheilostome Bryozoans In The Eastern Pacific, Hannah E. Lee

Cal Poly Humboldt theses and projects

The phylum Bryozoa is an incredibly diverse group of marine invertebrates with a widespread global distribution that is well suited for evolutionary studies but whose phylogenetic relationships are still poorly understood. Although recent studies on bryozoan taxonomies and phylogenies have increased, there is still a lack of assessment of species found at shallow water (<1 m) to intertidal depths. In this study, I aimed to expand the taxonomic sampling and assessment of the phylogenetic diversity of cheilostome bryozoans along the California coastline by utilizing mitochondrial DNA as well as inferring potential correlations between species presence and dispersal range both within and between rocky outer coast and sheltered harbor habitats. Illumina high-throughput sequencing was used to produce mitogenomes for cheilostome bryozoan samples collected off rocks from two rocky intertidal sites and off settlement panels from two harbor sites. Phylogenetic analyses generated evolutionary hypotheses of species relationships alongside geographic mapping of their distribution. This study identified 15 distinct species that represent 10 different families to form the first comprehensive phylogeny for multiple bryozoan families in California across a total range of approximately 973 km of coastline. Three genetically distinct species were found at multiple sites that are separated by a combination of rocky shores and sandy beaches, which indicates that the dispersal range of these species are not limited by geographic barriers along the coast of California. These results provide a future opportunity for further integration of this data with the phylogenies generated in this study to examine more robust evolutionary hypotheses for the phylogenetic and geographic relationships of Californian bryozoan species.

Mortality Risk Associated With Urban Land Use For Adult Eastern Diamondback Rattlesnakes (Crotalus Adamanteus), Mya Wiles

Theses, Dissertations and Capstones

Snakes have been a traditionally under-represented organism in urban ecology, but they face similar, if not greater challenges in the face of growing urban sprawl. Eastern diamondback rattlesnakes (Crotalus adamanteus, EDBs) are under consideration for listing under the Endangered Species Act due to population declines resulting from historical human persecution and habitat loss. This study used radio-telemetry data from a long-term monitoring project of adult EDBs on a developed sea island in South Carolina, USA. I reclassified a National Land Cover Dataset to reflect relative mortality risk for snakes attempting to move through the landscape. High-risk cover types …

Ephemeroptera Culturing Methods: An Analysis On Rearing And Toxcity Testing On Sensitive Early Life Stages Of Native Mayfly Taxa, Geneve Rainette Edwards

Theses, Dissertations and Capstones

Standard toxicity testing organisms are utilized for regulatory purposes and often ecological risk assessments. Ephemeroptera taxa have been reported to be more sensitive to aquatic contaminants than the standard toxicity testing organisms currently used in determining effects on aquatic ecosystems. Establishing methods for culturing native Ephemeroptera taxa will provide a more sensitive test organism to determine the toxicity of contaminants and will be more representative of the responses of native taxa. Additionally, it will provide a test organism at the most sensitive life stages. The objective of this research is to develop methods for culturing and testing of native Ephemeroptera …

Ephemeroptera Culturing Methods: Development Of Culturing And Rearing Methodology And High Sulfate Simulated Mine Effluent Toxicity Test Using Field Collected Water, Daniel Edward Brady

Theses, Dissertations and Capstones

Ephemeroptera taxa are not frequently used in toxicity testing; however, some mayfly taxa may be more sensitive to aquatic pollutants than standard test organisms used to determine anthropogenic effects on aquatic ecosystems. Additionally, some standard test organisms are not native to the Appalachian region and may not be truly reflective of the effects on native organisms. With mayflies not being the typical test organism, there is not a great deal of literature on culturing methods for this organism. For a standard acute toxicity test, there must be 80% survival within the control organisms for the test to be considered viable. …

Morphological Variation And Community Science In Orthoptera, Amy Byerly

Electronic Theses and Dissertations

Patterns of morphological divergence across species’ ranges provide insight into local adaptation and speciation. Here, we compare phenotypic divergence among 4,221 crickets from 337 populations of two related species of field cricket, Gryllus firmus and G. pennsylvanicus and their hybrids. We find that these species differ across their geographic range in key morphological traits, such as body size and ovipositor length, and we directly compare phenotype with genotype for a subset of crickets demonstrating nuclear genetic introgression, phenotypic intermediacy of hybrids, and essentially unidirectional mitochondrial introgression. We discuss how these morphological traits relate to life history differences between the species. …

Responses Of Arthropods To Fire And How Pollinators And Pollination Services Are Affected By Fire Severity, Blyssalyn V. Bieber

Electronic Theses and Dissertations

Fires impact ecosystems globally and due to climate change, there are shifts in fire regimes that impact ecological communities which provide essential ecosystem services. Focusing on arthropods, fire can influence this ubiquitous animal group in various way. We performed a comprehensive meta-analysis evaluating how fires impact differing arthropod functional groups. We found that overall, fire negatively effects community level responses for most functional groups with herbivores as the only exception showing some positive effects of fire. We also studied mixed-severity fires that burned >20 years ago and compared floral visitor communities across fire severities. We implemented a pollinator exclusion experiment …

Environmental Gradients Impact Key Leaf Traits In Riparian Trees, Amanda Malone

Electronic Theses and Dissertations

Specific leaf area (SLA) reflects a plant’s carbon investment per area and relates to generalized leaf economics spectrum growth strategies (LES). To fill gaps of knowledge about intraspecific SLA variation and why it is often inconsistent with the LES, we studied the response of two riparian tree species along the urban-rural gradient in Northeastern Colorado: an invasive, nitrogen-fixer with broad tolerances and a nitrogen-limited and shade-intolerant native. Despite these differences, the two species responded similarly, apart from the response to the urban-rural gradient, in which lower nitrogen in rural areas was associated with a more conservative strategy in the native …

Fish Communities Respond To Hydrology And Elevation In Restored Western Kentucky Wetlands, Lucas Zuklic

Murray State Theses and Dissertations

The Wetlands Reserve Program (WRP) is designed to restore wetland ecological function and wildlife benefits; however, these projects rarely monitor biological responses. The objectives of our study were to (1) identify environmental factors that were the most important in determining wetland fish community composition, (2) examine the influence of the environment on specific groups of fish (large-river fishes and Kentucky Species of Greatest Conservation Need (KY-SGCN) wetland fishes), and (3) compare fish community composition and diversity in wetlands of different condition (e.g., degraded, restored, and reference). From April 2019 to August 2020, monthly electrofishing surveys were performed in degraded …

Anthropogenic Influences On The Decline, Restoration, And Eco-Evolutionary Dynamics Of Lake Superior’S Coaster Brook Trout, Austin Johnson

Dissertations, Master's Theses and Master's Reports

The coaster brook trout is a life history variant of the brook trout (Salvelinus fontinalis) that is characterized by either lake residency or migration between stream and lake habitats. Coaster brook trout were once widespread throughout Lake Superior and its tributaries, but populations declined sharply in the late 19^th and early 20^th centuries. Historically, brook trout were a popular target of recreational and subsistence fishing in the Lake Superior basin, and it has been hypothesized that angling pressure combined with multiple forms of industrial development are what drove the coaster brook trout’s decline. In the mid …