Life Sciences Commons^™

Carbon Dioxide Emissions From Deadwood In Forests Of The Northeastern United States, Zoe Read

Electronic Theses and Dissertations

As the climate changes, understanding the sources and sinks of greenhouse gases such as carbon dioxide (CO₂) is increasingly important. However, several components of the carbon cycle within forests remain poorly understood. For example, knowledge gaps exist in our understanding of CO₂ emissions from coarse woody material (CWM; logs and stumps), including how emissions change over time, how they are influenced by environmental variables, and how they compare to soil and ecosystem-level CO₂ emissions.

To fill these knowledge gaps, we examined CO₂ emissions from CWM at three sites. We sampled 18 red spruce (Picea …

A Sky Island Perspective: New England Alpine Plant Distributions Across The Region, Andrea Tirrell

Electronic Theses and Dissertations

Alpine ecosystems around the globe are at risk due to climate change, human disturbance, and habitat loss. New England alpine zones are small and fragmented, which could make them vulnerable to global change. However, the persistence of tundra relics throughout the Holocene suggests the persistence of these communities in microclimate refugia. Assessing the near-term vulnerability of alpine plant communities is challenged by a lack of standardized, repeat surveys and long-term monitoring data, which presents a challenge for the many agencies monitoring New England’s alpine zones. Island biogeography theory predicts that alpine species richness is a function of area, but this …

Assessing The Legacy Of Erosion And Flood Control Management Efforts On The Fish Assemblages And Physical Conditions Of Yazoo Basin Bluff Hill Streams, Nicky M. Faucheux

Theses and Dissertations

The hills of Yazoo Basin have a long history of land use modification and subsequent erosion and flood control issues. In response, federal actions were taken to address these issues beginning after the Mississippi River flood of 1927. Four major flood control reservoirs were built in 1932-1957, and instream low-drop grade control structures (GCS) were installed beginning in the 1980s. The objective of my dissertation was to ascertain the long-term effects of these efforts on stream fish assemblages and channel morphology. To assess whether the reservoirs affected upstream fish assemblages as barriers to recolonization by fluvial fishes or as source …

Animal Husbandry In The 21st Century: Application Of Ecological Theory And Precision Technology To Inform Understanding Of Modern Grazing Systems, Ira Lloyd Parsons

Theses and Dissertations

Ruminant animals comprise the greatest proportion of herbivores around the world, provide essential ecosystem services and human consumable protein by consuming grass and human inedible dietary fiber. Herbivory pressure alters plant communities and species diversity, effectively making grazing animals ecosystem engineers in dynamic ecosystems. Development of advanced computer processing power coupled with biometric and ecosystem sensors may be employed in the internet of things framework to create an integrated information system designed to inform understanding of grazing system function and animal energy balance. Towards this end, I utilized Bos indicus / Bos taurus crossbred steers (n = 20) across two …

Vegetation And Nutritional Changes Over 20 Years Of White-Tailed Deer Exclusion, Gabrielle Nicole Ripa

Theses and Dissertations

Knowledge of the impacts of white-tailed deer (Odocoileus virginianus; hereafter deer) as dominant herbivores throughout the Southeastern United States of America is lacking. To address this, three paired experimental units of exclosures and controls were constructed in 2000 on three Wildlife Management Areas across Mississippi within the ecoregions of the Upper Coastal Plain, Lower Coastal Plain, and the Mississippi Alluvial Valley. Vegetation was sampled in the summers of 2000, 2005, and 2021 including vegetation structure, canopy coverage, basal area, and species composition. Additionally, in 2005 and 2021, biomass was sampled to determine potential impacts on nutritional carrying capacity. Among the …

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …

Venomic Characterization Of A Medically Relevant Rear-Fanged Snake, Conophis Lineatus (Dipsadidae: Xenodontinae), From Middle America, Tristan Schramer

All Theses

Most traditional research on snake venoms has focused on front-fanged snake families (Viperidae, Elapidae, and Atractaspididae). However, venom is now generally accepted as being a much more broadly possessed trait within snakes, including species traditionally considered harmless. Unfortunately, due to historical inertia and methodological challenges, the toxin repertoires of non-front-fanged snake families (e.g., Colubridae, Dipsadidae, and Natricidae) have been heavily neglected despite the knowledge of numerous species capable of inflicting medically relevant envenomations. Integrating proteomic data for validation, we perform a de novo assembly and analysis of the Duvernoy’s venom gland transcriptome of the Central American Road Guarder (Dipsadidae: Xenodontinae: …

Temperature Affects Nest Box Occupancy, Nest Success, And Nestling Size In A Southeastern Population Of Eastern Bluebirds (Sialia Sialis), Christopher G. Horacek

Biology Theses

Given the critical role that temperature plays in avian reproductive biology, rising temperatures as a result of global climate change will likely impact reproductive success of many bird populations. Secondary cavity nesting birds, many of which rely on artificial nest boxes to maintain population levels, may be particularly at risk because increased temperatures inside nest boxes can determine whether nest boxes are selected, reduce nest success, and/or negatively affect the growth and survival of offspring. We examined the effect of nest box color on nest box temperature and the influence of nest box temperature, nest box color, entrance orientation, and …

Taxonomic Revision And Morphometric Analysis Of Selected Anthurium (Araceae) Species From Bolivia And Peru, Daniel M. Tarazona Ocana

Theses

The genus Anthurium (Araceae) consists of around 1,200 species distributed in the Neotropics, particularly in Central and South America. The montane forests in the eastern flank of the Andes, ranging from northern Ecuador to central Bolivia; hereafter, the East Andes Gradient region, are particularly rich in terms of species diversity, and include an understudied group of Anthurium species endemic to the region. Within this group of species, some taxa are difficult to distinguish from each other mainly due to the lack of identification keys, incomplete species descriptions and unknown synonyms. In this study, a combination of traditional taxonomic techniques and …

Ecology And Evolution Of Social Information Use, Clare T. M. Doherty

Dartmouth College Ph.D Dissertations

Sociality is a strategy many animals employ to cope with their environments, enabling them to survive and reproduce more successfully than would otherwise be possible. When navigating their environments and making decisions, social individuals often use information provided by conspecifics (in the form of social cues and signals), thereby increasing the scope and reliability of the information they can gather. However, social information use may be influenced by many factors, including key differences in context across the physical and social environment. My thesis asks and answers a series of questions regarding the trade-offs in social information use across different contexts, …

Impacts Of Algal Morphology And Water Flow On Macroalgal Microplastic Capture, Cheyenne M. Adams

Honors College Theses

Microplastic pollution is a major area of concern in marine environments, especially as microplastics enter the food web. This study used pipe cleaners and two lichen species as algal mimics, and Chaetomorpha sp. and Chondrus crispus as model algal species to test the effects of morphology and biomass on microbead and foam capture. This study also utilized two different water flow methods: vortices and waves. Results suggest that water flow, as well as biomass and morphology, play a role in microplastic capture in macroalgae. For all mimics and algal species, except Cladonia lichens, turfs with increased biomass and length showed …

Ecology And Phytochemistry Of The Non-Native Plant Thlaspi Arvense (Brassicaceae) In Subalpine Meadows Of Colorado, Usa, Elsa Cousins

Doctoral Dissertations

Climate change is altering ecosystems at multiple scales. Globally, warming temperatures and increasing irregularity of precipitation will have large scale impacts on species distribution and success. Locally, understanding species response to fine scale microhabitat variation can provide key insights into population adaptation. Non-native plants represent an opportunity to investigate population level response and adaptation to relatively novel combinations of biotic and abiotic environments. Subalpine meadows are at the intersection of biotic and abiotic change, as large-scale climatic shifts alter water and temperature regimes and species range shifts become increasingly common and larger in scale. This dissertation addresses these questions of …

The Ecology And Evolution Of Species Rarity In Oaks (Quercus Spp.), Yingtong Wu

Dissertations

Rare species are susceptible to extinction due to ecological and genetic factors. Understanding the distribution, ecology, and evolution of rare species can provide useful information for effective conservation. To investigate species rarity, this dissertation focuses on a species-rich and ecologically diverse genus, Quercus (oaks). In Chapter 1, I aimed to understand how interactions between hosts and soil microbes contribute to habitat restriction in oak species. I performed a soil inoculum experiment on two pairs of sister oak species that show habitat divergence. I found that host-specific soil microbes contribute to habitat divergence and exclusion among sister species of oaks, but …

Evaluating Non-Invasive Environmental Methods For Detecting Tropical African Pangolin Species To Inform Conservation Actions, Ichu Godwill Ichu

Theses and Dissertations

Tropical African pangolin species are threatened throughout their range due to habitat loss and illegal take. Limited knowledge on distribution has rendered conservation efforts challenging. Methods commonly used for other wildlife species need to be tested for each pangolin species as each has variable ecologies requiring specific detection and monitoring techniques. This thesis evaluates the efficacy of two non-invasive environmental methods for detecting tropical African pangolin species, and consists of two complementary studies; a proof of concept study using soil sourced eDNA from a white-bellied pangolin enclosure in the Columbus Zoo, Ohio, to detect the species, and a field study …

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones

Theses and Dissertations

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …

Regional-Scale Climate-Induced Variation In Ant Physiology And Morphology, Daniel E. Murphy

Biology Theses

The biology of ectotherms such as insects is influenced by ambient thermal conditions. Ants are a ubiquitous and ecologically important group of insects and are well-established as bioindicators of thermal conditions. Ants are sensitive to the thermal extremes that vary with latitude, elevation, and land use, and these thermal gradients influence their spatial and temporal distributions. As a result, ants have evolved physiological and morphological thermal adaptations in response to the thermal environment of their habitats. These adaptations include increased physiological and morphological tolerance for temperature extremes. In Western New York (WNY), temperatures are temporally and spatially heterogeneous, changing with …

Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin

University of New Orleans Theses and Dissertations

Polyploidy, a term used to describe organisms with cells having more than two paired sets of chromosomes, is a significant driver of diversification among land plants. Over a century of research has advanced our understanding of polyploidization in some taxa, but polyploid organisms remain understudied. In this dissertation, I investigate chromosome number evolution, phylogeographic structure, genetic differentiation, and the effects of climate change on ploidy level distribution using polyploid plant systems. In the first chapter, I inferred a molecular phylogeny of Allium, an economically important genus that includes cultivated crops and ornamentals, to investigate evolutionary transitions in chromosome number …

Spring Gobbling Chronology And Turkey Habitat Use In Upstate South Carolina, Janelle Grehan

All Theses

Wild turkey (Meleagris gallopavo) is a highly popular game species harvested primarily during the reproductive season, which has driven substantial efforts to understand patterns of springtime habitat use and gobbling activity. Autonomous recording units (ARUs) have enabled researchers to collect unprecedented amounts of gobbling data, yet post hoc processing of audio data has been time-intensive due to false detection rates. Gobbling activity has been studied in the South Carolina Coastal Plain, but data for the Upstate are lacking. My objectives were to assess seasonal and weekly gobbling activity and turkey habitat use in Upstate South Carolina relative to …

The Paleoecology Of High-Elevation Bison In The Greater Yellowstone Ecosystem And Implications For Modern Bison Conservation, Darian Bouvier

Electronic Theses and Dissertations

The national mammal of the United States, the American Bison (Bison bison) was once nearly extinct. Populations have recovered to the degree that thousands roam the Great Plains today. Due to their large numbers and body size, this species has an oversized impact on the ecological communities where it lives and is considered a keystone herbivore in modern North American grasslands. This study explores the detailed, seasonally resolved, paleoecology of seven bison from the Greater Yellowstone Ecosystem during the Late Holocene through stable isotope analyses and species niche modeling. Isotopic analyses of δ¹³C, δ¹⁵N, …

Reproductive Ecology And Microbial Communities From Wood Duck Nest Boxes In Georgia And Florida, Jake Shurba

All Theses

Wood ducks (Aix sponsa) are an important game species throughout the Atlantic Flyway that was nearly extirpated by the early 20^th century due to overhunting and the loss of habitat. Wood ducks are secondary cavity-nesters that utilize artificial nest boxes and natural cavities. It is reported that the use of nest boxes is likely what led to re-establishment of the species in North America. Where boxes are numerous, overuse of boxes by multiple hens throughout a nesting season can occur and result in a buildup of bacteria, parasites and other potentially detrimental pathogens that can impact egg …

The Role Of Nest Location On The Reproductive Success Of Piping Plovers Breeding At Rockaway Beach, New York, Clara I.D. Arndtsen

Theses and Dissertations

The study’s goal was to learn what aspects of the piping plover experience affect reproductive outcomes at Rockaway Beach Endangered Species Nesting Area. Nest location was found to help predict reproductive success. Nests further from American oystercatcher nests were likely to fledge more chicks. Reproductive success was low in 2021.

Chemical And Biological Stressors Threaten Native Fish Diversity In The Spring River Subbasin Of Kansas, Alexandra King

Electronic Theses & Dissertations

Chemical pollution and nonnative species are two of the major threats facing freshwater fishes. As such, understanding how freshwater fish communities respond to pollution remediation efforts and nonnative fish introductions are primary goals of native fish conservation. Within the Spring River subbasin (SRS) of southeastern Kansas, this study examined the long-term response of riffle fish communities to decreases in heavy metal concentrations, as well as the effects of introduced Blackspotted Topminnow (Fundulus olivaceus) on native Blackstripe Topminnow (Fundulus notatus). The objectives of our research in Chapter 01 of this thesis were to quantify changes in riffle …

Effects Of Forest Restoration On The Recovery Of Dead Wood, Associated Arthropods, And Insect-Mediated Wood Decomposition, Estefania Fernandez Barrancos

Dissertations

Dead wood represents 8% of terrestrial carbon stocks and is an important source of habitat and food for decomposer and non-decomposer arthropods. However, anthropogenic disturbance reduces the amount of dead wood, putting at risk the presence of a habitat that is essential for many arthropods and other organisms that rely on it for food and shelter. Forest restoration aims to assist the recovery of ecosystems that have been damaged or destroyed and could be a means to recover both dead wood and its associated arthropod communities. This doctoral dissertation lies at the intersection of climate change, biodiversity loss and ecological …

Validation Of Pilot Protocol: Damage Scoring Of Puget Sound Mollusk Shells, Lauren Doffing

Environmental Science Undergraduate Theses

The Marine Sediment Monitoring Team at the Washington State Department of Ecology observed damage to mollusk shells while studying the benthic communities of Puget Sound. A pilot protocol was written to allow researchers to quantify the damage. Two researchers independently followed the protocol, including reference photos, for a set of samples collected in 2019 from an urban bay, East Possession Sound. Two scores were given to each specimen: highest-level damage and extent of highest-level damage. An additional score was given to bivalve species: rust/stain. The sets of scores were compared to determine if the protocol yielded similar values between the …

Diet And Nutrition Of Lemurs In The Lean Season, Santiago Cassalett

Dissertations, Theses, and Capstone Projects

Animals must navigate complex food and nutrient environments that are constantly in flux to obtain the macro and micronutrients necessary for their growth, reproduction, and survival. The nutritional needs of animals also vary over the life course, further complicating the search for adequate foods and the nutrients within them. The hypervariable and unpredictable environment of Madagascar creates a complex nutrient landscape for lemurs in particular because they are subject to large fluctuations in food availability. These fluctuations are thought to create extreme periods of nutritional stress during the dry season (known as the lean season) for lemurs. In response, lemurs …

Survivorship Of Columbian Black-Tailed Deer In A Predator-Free Environment, Grace Hope Barthelmess

Honors Projects

Future management of Columbian black tailed deer (Odocoileus hemionus columbianus) populations requires an understanding of survivorship and potential drivers of mortality. Little is currently known about the survivorship of O. h. columbianus, specifically in a predator-free environment. Analyzing the survivorship of deer in these contexts may be crucial for wildlife conservation efforts throughout the United States, as it could provide insight into how deer populations may be impacted by lack of population control by predation. Here, I present age analysis of O. h. columbianus based on the cementum annuli of the lower first molar in 489 males …

Analysis Of Water Quality And Fish Communities Of Crooked Creek, Tributary To The Allegheny River In Southwestern Pennsylvania, Katherine Stupar

Electronic Theses and Dissertations

Crooked Creek is a tributary of the Allegheny River with a drainage area of 292 square miles. It has been historically affected by mine drainage pollution. Extensive cleanup and monitoring efforts by the Commonwealth of Pennsylvania and the U.S. Army Corps of Engineers (USACE) have taken place over the last four decades. Unconventional oil extraction, or fracking, presents an emerging threat to the water quality of this stream and the health of its fish communities. Here we perform an analysis of the Crooked Creek watershed utilizing backpack electrofishing, eDNA metabarcoding, and various methods of water quality analysis. Seven sites on …

Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro

Theses and Dissertations

Fire suppression, combined with lack of forest thinning and short-rotation, monodominant management, has drastically altered the landscape in the southeastern U.S., leading to the loss of open pine ecosystems and associated avian species. Management of open pine ecosystems is a common practice; yet, there remains uncertainty regarding how vegetation structure impacts priority species. Using empirical data, I assessed changes in species abundance and associated vegetation characteristics before and after management. I also sought to identify vegetation characteristics that influence home range establishment and microhabitat selection of Bachman’s Sparrows. Priority species were negatively associated with hardwood midstory and abundance per site …

Migration Ecology Of American White Pelicans: Circannual Movement, Geographic Range, And Annual Survival, Ryo Ogawa

Theses and Dissertations

Responses of migratory birds to seasonal climate and long-term environmental changes have been a central theme of avian migration ecology. Atmospheric conditions (e.g., winds and thermals), climate, and land cover and land use (LCLU) are major factors influencing the flights of soaring birds. Soaring American White Pelicans (Pelecanus erythrorhynchos) (hereafter, AWPEs) migrate between the subtropical Gulf of Mexico (GOM) and the temperate Northern Great Plains. American White Pelicans are also economically important piscivorous birds, causing enormous damages to the commercial Channel Catfish (Ictalurus punctatus) aquaculture in the Southeastern US. My studies aimed to evaluate the effects …

The Effects Of Short-Term Sea Level Rise On Vegetation Communities In Coastal Mississippi, Brianna Michelle Andrews

Theses and Dissertations

Salt marshes are important habitats that provide many ecosystem services, but they are susceptible to the impacts of sea level rise (SLR), often resulting in emergent vegetation loss. In areas with enough sediment input, marshes can keep pace with SLR by gaining elevation or through upland migration. However, salt marshes in areas with limited sediment input, such as the Grand Bay National Estuarine Research Reserve, often cannot keep pace with sea level rise. Additionally, the rate of SLR is increasing making it more difficult for marshes to keep pace. To assess the short-term response of marsh vegetation to sea level …