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Environmental Drivers Of Vegetation Dynamics In Constructed And Natural Wetlands Of The Chihuahuan Desert, Enrique David Garcia

Open Access Theses & Dissertations

Desert wetlands are critical ecosystems that provide water, food, and habitat for many different species at different trophic levels. Additionally, they have the capacity to recharge aquifers, control floods, and purify water, among others. Unfortunately, they have been facing multiple environmental challenges due to different human activities, sometimes with disastrous consequences. There is an urgent need to better understand the structure and function of wetlands of different types and in different biomes in order to conserve, restore, and even create them so we can continue to obtain all the ecological services they provide. In this dissertation, I investigated how environmental …

Spatial And Thermal Aspects Of The Ecology Of Three Sympatric Rattlesnakes In The Montane Northern Chihuahuan Desert, Joshua James Mead

Open Access Theses & Dissertations

To understand how animals coexist on the landscape, the individual aspects of a species life history must first be understood. Animals need to find locations that provide the resources they need to survive. Movement, microhabitats, and temperature can alter such areas where animals occur. Understanding animal movements provide important information on space use and microhabitats on the landscape. Ectothermic animals must acquiesce to ambient temperatures or use behavioral modifications to alter their body temperature. The ability to maintain suitable body temperature is essential for physiological function, reproduction, and ability to avoid predation. Research on the variation in a species ecology …

Temporal Partitioning And Coexistence Among Four Sympatric Felid Species In The Northern Jaguar Reserve, Kylie Marie Rezendes

Open Access Theses & Dissertations

Coexistence among sympatric carnivores is shaped by behavioral strategies that mediate competition and mortality risk in heterogeneous landscapes. Understanding how sympatric carnivores, such as felids, use space and time in relation to one another requires models that account for both spatial and temporal overlap across landscapes. Models incorporating time-to-event probabilities provide a powerful framework for detecting behavioral dynamics across shared landscapes. This study evaluated the spatiotemporal responses of two apex predators â?? the jaguar (Panthera onca) and mountain lion (Puma concolor) - and two mesopredators - bobcat (Lynx rufus) and ocelot (Leopardus pardalis) - across five years of camera trap …

Phylogenetics And Integrative Taxonomy Of The Lang's Reed Frog Species Complex (Anura: Hyperoliidae: Hyperolius Langi), Dominic Troiani

Open Access Theses & Dissertations

The genus Hyperolius (Rapp, 1842) is the most speciose amphibian genus in sub-Saharan Africa. The genus has a complex taxonomic history because of its extensive intraspecific and interspecific morphological variation, large geographic distribution of many taxa, gaps in sampling, and the discovery of significant cryptic diversity within many species. The goal of this study is to understand the relationships and taxonomy of Hyperolius langi via an integrative taxonomic approach that combines molecular, morphological, and bioacoustics data to clarify the systematics of the geographically widespread species Hyperolius langi. Two mitochondrial (16S and cyt b) and one nuclear (RAG1) gene were used …

Coal Mining Reclamation: Lessons Learned From Tropical And Subtropical Countries, Priyaji Agung Pambudi, Suyud Warno Utomo, Roni Setyo Handoko

Journal of Environmental Science and Sustainable Development

This study addresses the persistent environmental challenges associated with coal mining in tropical and subtropical regions, where complex microclimates and ecological variability hinder effective reclamation. Despite the increasing global coal demand, comparative cross-country insights remain limited. This research fills the gap by evaluating the best practices. This study employs a qualitative methodology with a comparative case study design, uses systematic literature review to evaluate ecology based reclamation policies and implementation practices. Data were sourced from peer-reviewed journals from Scopus and the Web of Science database and institutional reports, and analyzed using McHarg’s landscape ecology theory to evaluate reclamation policies, ecological …

Methodology For Environmental Toxicology: Assessing Feeding And Rearing Strategies In Largemouth Bass (Micropterus Nigricans) Larvae, Amber Hitchins, Hannah Mcneese, Deise Cruz, Andrew Todd, Maria Sepúlveda, Tyler Hoskins

Discovery Undergraduate Interdisciplinary Research Internship

Poly- and perfluoroalkyl substances (PFAS) are an anthropogenic group of chemicals known for their persistence in the environment and their potential to bioaccumulate. PFAS can bioaccumulate in largemouth bass (Micropterus nigricans), yet the effects of exposure on bass larvae are unknown. While largemouth bass are commonly raised for aquaculture, techniques for rearing bass which enable controlled experiments at known densities, a necessity for toxicity studies, are poorly understood. Furthermore, the live prey typically used in existing approaches are not suitable for PFAS studies due to high background concentrations. The objective of this project was to assess different venues …

Assessing The Ecological Drivers And Consequences Of Partial Migration In Hudson River Striped Bass Over Three Decades, Caitlin Egan Zimmer

Biology ETDs

Climate change and shifts in human land use have caused extensive impacts to the connectivity, structure, and resilience of aquatic populations. Partial migration (PM), where only some individuals from a population migrate while the rest remain resident, can mitigate population-level responses to environmental stressors. However, little is known of the underlying mechanisms promoting variation in migration and whether these shift over time. In the Hudson River Estuary, striped bass (Morone saxatilis) are known to exhibit anadromous PM behavior. Here, I measured carbon isotopes (δ¹³C) of essential amino acids in striped bass scales to determine variation in …

Plant Reproductive Strategies Shift In Response To Restoration Using Beaver Dam Analogs, Laurel F. Martinez

Biology ETDs

As riparian communities become increasingly degraded, restoration treatments are being implemented in streams to recover ecosystem functions. In the Jemez Mountains, beaver dam analogs (BDAs) are used to restore degraded streams by connecting the floodplain and increasing the extent of anoxic soil conditions. These environmental disturbances are expected to alter how riparian plants recruit, particularly their allocation to seed-based and vegetative regeneration strategies. We investigated whether BDAs and associated changes in soil water filled pore space (WFPS) affected riparian plant recruitment. We investigated the number of flowering stems as a proxy for seed-based regeneration and rhizome length and mass as …

Using Triple Oxygen Isotopes To Investigate Water Usage In Desert Ecosystems, Cloe V. Knutson

Earth and Planetary Sciences ETDs

In arid environments, maintaining water balance can be more critical for survival than obtaining food. As droughts intensify, understanding how animals manage body water is essential. Triple oxygen isotope analysis provides a novel way to trace water sources in animals, distinguishing contributions from free water, food-derived oxygen, and atmospheric O₂. We developed an equilibration method using CO₂–H₂O oxygen exchange and measured δ^’18O and Δ^’17O values via tunable infrared laser direct spectroscopy (TILDAS). Validated against traditional fluorination methods, this technique enables streamlined analysis of whole blood and plant samples. Applied to …

Distributional Records Of Blanding’S Turtles (Emydoidea Blandingii) In Nebraska, Sam Thede, Dan Fogell, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Blanding’s Turtle (Emydoidea blandingii) is a species of concern in North America as many populations have declined across its distribution. Environmental factors associated with alteration of natural ecosystems have played a role in declines leading to many isolated populations. Most populations exist in the Great Lakes region with a number of outlying populations, such as Nebraska. Understanding the current distribution of the species will facilitate regional management strategies to protect this species into the future. In Nebraska, Blanding’s Turtles were known from 23 counties prior to this study. Herein, we report on eight new county records, five (Blaine, …

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xli. Pandinops Sahil Sp. N. From Somaliland (Scorpionidae), František Kovařík

Euscorpius

Pandinops sahil sp. n. from Somaliland is described and compared with other species of the genus, fully complemented with color photos of specimens of both sexes of the new species, as well as of their habitat. Pandinops bambii Rossi, 2017 is synonymyzed with Pandinops turieli Kovařík, 2016, syn. n. A key for the species of Pandinops and a map of the distribution of the genus are provided.

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xl. Barbaracurus Lowei Sp. N. From Ethiopia (Buthidae), František Kovařík, Hassan Sh A. Elmi

Euscorpius

Barbaracurus lowei sp. n. from Ethiopia is described and compared with other species of the genus, fully complemented with color photos of specimens of both sexes of the new species, as well as of their habitat. Included is a key for Barbaracurus and a map of the distribution of the genus in the Arabian Peninsula and the Horn of Africa.

Watching The Grass Grow: Expanding Outreach And Accessibility Of Itex-Aon, Justin Blough

Masters Projects

Science has an accessibility problem. Though results are published and the component data is archived and made publicly available, distrust in and misunderstanding of science by the lay populace remains common. This work focuses on bolstering the outreach component of the International Tundra Experiment (ITEX)—Arctic Observing Network (AON) to increase public awareness, interactivity, and ultimately, the understanding of how the science of ITEX-AON takes place. This project uses several component methods to further outreach goals of ITEX-AON. These include: documentary photography of researchers, study sites, subjects and the surrounding environments, 360-degree imaging and interactive virtual tour building, building interactive data …

Niche Conservatism And Sympatric Parallel Evolution May Help To Maintain Eight Nascent Tree Taxa Along A Sharp Elevation Gradient, Elizabeth A. Stacy, Rebecca Ostertag

Life Sciences Faculty Research

1. Patterns of niche partitioning among closely related taxa, such as those in incipient adaptive radiations, can provide clues into how niches are created, partitioned, and integrated over ecological and evolutionary time scales. Hawaiian Metrosideros is a ~3-MYO adaptive radiation of trees that dominates the Hawaiian Islands in continuous stands within islands and allows examination of niche partitioning at the early stages of adaptive radiation.
2. We monitored growth and survivorship over 2 years of seedlings derived from open-pollinated fruits of eight Metrosideros taxa distributed along the elevation gradient of Koʻolau Volcano, Oʻahu, under four combinations of light and phosphorus. We included …

Planetary Thinking: Hellbenders As Emissaries Of Appalachia, Tierra R. Curry

Critical Humanities

Hellbenders are prehistoric salamanders that have thrived in cold rivers since before the continents divided. Once found throughout Appalachian watersheds, due to exploitation and habitat degradation only a few dozen healthy populations survive. Monstrous yet fascinating, hellbenders were often reviled historically, but in recent decades they have gained iconic status and are now celebrated as charismatic indicators for clean rivers. Hellbenders are symbols of the wild because of their ancient history, elusive nature, and contribution to ecosystem resilience. The same forces that drove the decline of these amphibian sentinels have sacrificed public health in Appalachia. Their demise echoes the struggle …

The Astrobiological Figure Of Humboldt As Pioneer In The Rock Varnish Research, Jose Jordan-Soria

Homage to Alexander von Humboldt: Travels to and from Spain Throughout the Centuries / Homenaje a Alexander von Humboldt: Viajes hacia y desde España de todos los siglos

From Humboldt is particularly interesting -and little know- his description of mineral coatings on rocks 200 years ago, reported in his book Personal Narrative of Travels to the Equinoctial Regions of the New Continent during the years 1799-1804, co-written with Aimé Bonpland, for which is considerate the father of rock coating research. On June 5th 1799 set sail from A Coruña -Spain- to Cumaná -Venezuela- beginning five years of expedition. While they explored the Orinoco River system, in th eriver basin waterfalls, Humboldt observed the presence of dark coating depositions. He ascertained a manganese-rich accretion, reporting similar structures in other …

First Case Of Sexual Cannibalism In Leiurus Abdullahbayrami Yağmur, Koç & Kunt, 2009 (Scorpiones: Buthidae) From Lebanon, Rami Khashab

Euscorpius

This study presents the first report of sexual cannibalism in the medically significant scorpion Leiurus abdullahbayrami Yağmur, Koç & Kunt, 2009, that was recorded during a herpetological field trip to the semi-desert area in northern Lebanon. It broadens the understanding of sexual cannibalism in scorpions and adds a new prey item to the dietary spectrum of the scorpion.

Stream Fish Assemblage Dynamics And Barriers To Aquatic Connectivity In The Ichawaynochaway Creek Watershed, Georgia, Usa, Jake R. Duhé

LSU Master's Theses

Stream fishes in the southeastern United States are adapted to hydrological disturbances such as droughts. However, this region is projected to experience increasingly frequent and severe disturbances that will elevate water demands given increasing agricultural and urban development. Further, road-stream crossings (RSCs) are abundant features in these streams that can exacerbate drought-mediated stream fragmentation and impede movements by many aquatic organisms, including fishes, when poorly constructed. These compounding effects may adversely affect the diversity and abundances of resident stream fishes, but their interactions remain poorly understood, warranting rigorous testing of how droughts and RSCs influence stream fish dynamics. I assessed …

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xxxix. Buthus Pygmaeus Sp. N. From Somaliland (Buthidae), František Kovařík, Graeme Lowe, František Šťáhlavský, Hassan Sh A. Elmi

Euscorpius

New data are presented on the distribution of the genus Buthus Leach, 1815 in the Horn of Africa, mainly in Somaliland. B. pygmaeus sp. n. is described, fully complemented with color photographs of live and preserved specimens, as well as their habitats. In addition to the analysis of external morphology and hemispermatophors, we provide a description of the karyotype of B. pygmaeus sp. n. (2n=22). A key and distribution map of Buthus in the Horn of Africa (six species) are included

​​Site Fidelity Is Associated With The Social Experience Of Forked Fungus Beetles (Bolitotherus Cornutus), Joo Yeon Kim , '22, C. W. Wood, E. D. Brodie Iii, Vincent A. Formica

Biology Faculty Works

Consistently returning to or remaining within a specific location, a behavior known as site fidelity, is a useful metric for quantifying animal space use. When multiple individuals display similar site fidelity patterns, they are likely to interact, shaping the degree and quality of their social interactions. However, the link between the expression of site fidelity behavior and an individual’s social experience has not been thoroughly investigated. In this study we examined (1) how intrinsic individual properties (body size and sex) predicted variation in site fidelity and (2) whether site fidelity was linked to the social experience of individuals in wild …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

School of Natural Resources: Dissertations, Theses, and Student Research

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …

Bioenergy Crop Production: Implications For Grassland Bird Communities In Southwestern Nebraska, Grace E. Schuster

School of Natural Resources: Dissertations, Theses, and Student Research

Biofuel and bioenergy systems are components of most climate stabilization pathways to reduce greenhouse gas emissions and limit global warming. Currently, corn (Zea mays) is the predominant feedstock used for bioenergy production in the United States. However, widespread production of this monoculture crop has resulted in many negative environmental impacts. The most notorious impact has been the loss of grassland habitat due to agriculture expansion which has had detrimental effects on wildlife that depend on grassland habitat. One such group, grassland birds, has faced steeper, more consistent, and more widespread declines than any other avian guild. Therefore, strategies …

Mammals Of Malheur National Wildlife Refuge And Surrounding Harney County, Oregon, John E. Cornely, Leslie N. Carraway

Monographs of the Western North American Naturalist

Malheur National Wildlife Refuge (NWR), located in southeastern Oregon, is part of the National Wildlife Refuge System (NWRS) of the United States. Currently, NWRS includes more than 568 NWRs, 38 Wetland Management Districts, and 5 Marine National Monuments. Malheur NWR, like a majority of the refuges in the NWRS, was established for the conservation of migratory birds. Many of these NWRs also provide significant habitat for mammals. Malheur NWR, one of the oldest (established 1908) and largest refuges in the system, is one of those with significant habitat for mammals. In addition to the refuge, we have included Harney County, …

Bite By Bite: How Ungulate Browsing Shapes North America's Forest Future, Darius Hardalau, Vladut Stefanescu, Mindaugas Bakševičius, Michael Manton, Charles Ruffner, Gediminas Brazaitis, Georgeta Ionescu, Ovidiu Ionescu

Aspen Bibliography

Ungulate browsing represents a contemporary issue for forest development, influencing forest regeneration, composition, and management practices across the world, especially in North America. This review synthesizes findings from 101 studies conducted between 1980 and 2025 to examine patterns of herbivory damage through browsing by moose, elk, white-tailed deer, black-tailed deer, and bison. Despite regional variation, high ungulate density consistently emerges as the primary factor driving browsing intensity and ecological and economic impact, leading to decreased social acceptance of coexistence with ungulates. This review highlights the selective suppression of palatable species such as balsam fir, red oak, and white cedar, leading …

A Battle Of Armies: Massive Attack Of Natural Enemies To The True Armyworm Mythimna Unipuncta (Haworth, 1809) (Lepidoptera: Noctuidae) In Forage Crops, Armando Falcon-Brindis, Raul T. Villanueva

Insecta Mundi

Understanding the interactions between plant-host-parasitoid plays a major role in insect pest management. Farmers in the southeastern United States rely on pasture systems for cattle milk and beef production, but the benefits of parasitoids and predators on major lepidopteran pests on pasture lands are still overlooked. Here, we aimed to identify and quantify the effect of parasitism on the true armyworm Mythimna unipuncta (Haworth, 1809) (Lepidoptera: Noctuidae) attacking teff grass Eragrostis tef (Zucc.) Trotter (Poaceae) and crabgrass Digitaria sanguinalis (L.) Scop. (Poaceae) in western Kentucky. In early August of 2023, 547 larvae of M. unipuncta were collected from experimental …

In Memoriam: Donald B. Thomas, Jr., January 26, 1949–November 10, 2024, Brett C. Ratcliffe, Joseph E. Eger Jr., David Rider

Insecta Mundi

We honor the life and contributions of Donald Byron Thomas, Jr. (January 26, 1949–November 10, 2024) with a short review of his professional life followed by three appendices listing his published papers, taxa described, and patronyms.

Crayfish Microhabitats Provide A Close Association With Benthic Microbiomes To Support Cleaning Symbionts., Kyle J. Harris, John Hoverson, Matthew Becker, Matthew M. Cooke Mr

NEXUS: The Liberty Journal of Interdisciplinary Studies

Stream ecosystems promote variable microhabitats along a longitudinal gradient. These microhabitats support dynamic biotic assemblages. One such microhabitat in freshwater streams involves the external surface of crayfish. We investigated the microbiome of crayfish exoskeletons and the surrounding environment (water and substrate) in association with the presence and abundance of crayfish cleaning ectosymbionts (branchiobdellidans). These ectosymbionts actively consume the biofilm on crayfish as they live and reproduce in association with crayfish microhabitats. Sequenced microbes of the environment and crayfish were compared for dominant taxa. While the sample types (water, substrate, and crayfish) had significantly different microbiomes, there was not a significant …

Using Stomach Content Analysis To Determine The Trophic Ecology Of Omosudis Lowii, A Deep-Sea Predator In The Gulf Of Mexico, Claire De Noyo

USF Tampa Graduate Theses and Dissertations

Little is known about the feeding dynamics of deep-sea communities, despite their significant ecological importance. Deep-pelagic communities contribute to marine biodiversity and ecosystem stability while directly offsetting climate change via carbon sequestration. Omosudis lowii is an understudied, deep-sea fish found in temperate and tropical waters worldwide, including the Gulf of Mexico. Omosudis lowii have large jaws and distensible stomachs, allowing them to capture prey items larger than their body size. The present seminal study used stomach content analysis to quantitatively describe the O. lowii trophic ecology, providing baseline data regarding diet composition, feeding selectivity, and factors that impact prey selection. …

Exploiting Genomics To Advance Genetic Gain For Reproductive Traits In Sheep, Mujibur Rahman

ORBioM (Open Research BioSciences Meeting)

Poor reproductive performance has a negative impact on the profitability of sheep production systems with the number of lambs reared highlighted as a key driver of farm profitability. Nevertheless, the genetic improvement of reproductive traits in sheep has been constrained by their low heritability and pleiotropic nature. Understanding the underlying genetic architecture can improve genomic prediction estimates and enhance genetic gain.

This study will utilize large-scale genomic and phenotypic datasets to enhance genetic gain in sheep reproductive traits through four approaches: 1) to determine the effect of inbreeding depression on reproduction, 2) to identify causal variants impacting reproductive performance through …

Evolutionary Dynamics Of Artificial Agents: Exploration And Learning In Games, Brian Mintz

Dartmouth College Ph.D Dissertations

The natural world abounds with examples of complex behavior in humans and many other species. Evolutionary game theory is a powerful mathematical framework to understand the origins of many such behaviors like cooperation. Since these behaviors are often selected against initially, understanding why they are so widespread has been a longstanding question. Rather than assuming agents' rationality, like in traditional game theory, this approach studies the mutation and selection of strategies themselves. However most behavior is neither perfectly rational nor entirely determined by genetics. This dissertation works to bridge the gap between these two perspectives by analyzing models where individuals …