Ecology and Evolutionary Biology Commons^™

Effects Of Sediment Composition On Spartina Alterniflora And Juncus Roemerianus Productivity In Coastal Virginia: A Thin-Layer Sediment Placement Experiment, Caitlin Hemphill

Biological Sciences Theses & Dissertations

Climate change poses a major threat to the health of estuaries and their coastal wetland systems. The Chesapeake Bay’s coastal salt marshes are at high risk of inundation due to sea-level rise and land subsidence. Restoration techniques for maintaining coastal marsh resistance to sea-level rise are being developed and refined, with thin layer placement (TLP) emerging as a feasible solution in many areas of the United States. Despite TLPs use across the country, additional research is needed on species-specific responses, sediment types, and geographically focused studies in the lower Chesapeake Bay. My research addresses these gaps by combining both greenhouse …

Assessing Long-Term Changes In Aspen Forest Cover In Northern Yellowstone National Park Before And After Carnivore Recovery, Nicholas J. Bergeron

All Graduate Theses and Dissertations, Fall 2023 to Present

The recovery of large carnivores (wolves, bears, cougars) in Yellowstone National Park and the subsequent decline of the area's elk herd have raised key questions about ecosystem restoration—particularly for species such as aspen, which are heavily browsed by elk. Following wolf reintroduction in the mid-1990s, scientists began tracking changes in browsing intensity and height of young aspen within sampling plots, assuming reduced browsing and taller stems were signs of population recovery. However, no studies have measured whether the total area covered by aspen stands actually increased, as would be expected with broader recovery. Moreover, the potential influence of climate change …

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 …

The Island Biogeography Of Mangrove-Dwelling Vertebrates: Isolation, Specialisation, And Extinction, Jian Xiong David Tan

Biology ETDs

Mangroves are highly dynamic ecosystems that are widely distributed across the coastlines of the tropics and subtropics. Despite their low plant diversity, mangroves host a disproportionately high number of terrestrial vertebrate taxa. However, mangrove specialists — taxa that only occur in mangrove habitats — exhibit a global distribution that is incongruous with the broader background distribution patterns of mangrove-associated fauna, exhibiting higher diversity in Australia and Southeast Asia. This dissertation therefore aims to assess how the diversity and distribution of mangrove specialist fauna may have been shaped by the historical biogeography of mangroves, and the effects of mangrove specialisation on …

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 …

Nitrogen Addition Additively Boosts Climate-Driven Salsola Tragus (Russian Thistle) Invasion Into Southwestern Usa Grasslands, Melissa A. Bacigalupa

Biology ETDs

Effective management of invasive, non-native plants requires understanding key drivers of invasion, including nitrogen enrichment from atmospheric deposition and agriculture. Long-term studies are essential for capturing complex invasion dynamics yet remain uncommon. We used 22 years of observations and 14 years of nitrogen experiments to examine invasion by Salsola tragus (Russian thistle) into three semi-arid grasslands of central New Mexico. Invasion patterns varied, with rapid expansion in Chihuahuan Desert grassland and the Desert-Plains ecotone but stability in Plains grassland. Under ambient nitrogen, precipitation most strongly correlated with Russian thistle biomass and high native grass biomass was associated with Russian thistle …

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, …

Simulated Walleye Responses To Various Harvest Regulations In A Nebraska Reservoir, Mikael Ranta, Melissa Wuellner, Keith D. Koupal

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Recreational fishing provides sociological and economic benefits, and fish populations are managed by state agencies to meet angler expectations. One of the most popular species in Midwest reservoirs are walleye (Sander vitreus), and most of these fisheries have established restrictions on the number and sizes of fish harvested. Regulations are set based on population structure and dynamics and management goals, but often agencies have incomplete information needed to establish regulations. Predictive models can provide insight on population responses and inform managers of the tradeoffs between angler restrictions and population sustainability. Lake McConaughy, Nebraska, supports a popular walleye fishery. …

Changing Aspen Stand Structure Following Large Carnivore Restoration In Yellowstone, Luke E. Painter, Robert L. Beschta, William J. Ripple

Aspen Bibliography

Restoration of large carnivores in northern Yellowstone National Park in the late 20th century resulted in a sustained reduction of Rocky Mountain elk (Cervus canadensis) and their herbivory, facilitating new growth of quaking aspen (Populus tremuloides) saplings. In 2020–21, we examined 87 randomly selected, previously sampled aspen stands across northern Yellowstone, combining random plots with stand-wide observations. Forty-three percent of stands contained a new cohort of small trees (5–10 cm dbh), the first documented recruitment of overstory aspen trees in northern Yellowstone since the 1940s. Both aspen saplings ( ≥2 m tall) and small trees were …

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.

Canopy Insect Communities Are Shaped By The Genes And Phenotypes Of Their Aspen Hosts, Clay J. Morrow, Jennifer Lind-Riehl, Christopher T. Cole, Kennedy Rubert-Nason, Cécile Ané, Richard L. Lindroth

Aspen Bibliography

1. Community genetics research aims to identify genetic and phenotypic mechanisms that shape communities as extended phenotypes. To date, most progress has been made identifying variation in herbivore communities associated with intraspecific variation in plants, with little focus on identifying specific genes or traits responsible for that variation. Here, we identify how extended phenotype variation of a foundation tree species, Populus tremuloides, arises from trait variation among individuals and specific genes. 2. We quantified heritability for 13 tree traits -- including phenology, defense chemistry, reproduction, and morphology -- and for 18 associated insect species (640,557 individuals). We performed genomic …

Post-Wildfire Erosion And Sedimentation: An Escalating Threat For Utah Fisheries, Colton James, Kendall Becker, Scott Hotaling, Aish Chandrasekaran, Alex Fiedler, Timothy E. Walsworth, Patrick Belmont

All Current Publications

Wildfires are a natural part of the western U.S. landscape and provide numerous benefits, including enhanced nutrient cycling and habitat rejuvenation. Utah’s fish populations evolved with wildfire as a common disturbance. However, the increasing size and severity of wildfires, combined with Utah’s heavily engineered and fragmented stream networks, pose a contemporary risk to fish populations. This fact sheet reviews wildfire impacts on erosion and Utah's watersheds and fisheries. It outlines measures we can take to prevent post-wildfire fish die-offs.

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 …

Update To: Advancing Butterfly Systematics Through Genomic Analysis, Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick Grishin

The Taxonomic Report of the International Lepidoptera Survey

In this update, we propose (type species or type localities in parentheses): Lochris Grishin, nom. nov. (Lasaia oileus Godman, 1903; Lepidoptera: Riodinidae) as a new substitute name for Locris Grishin, 2025 preoccupied by Locris Stål, 1866 (Cercopis rubra Fabricius, 1794; Hemiptera: Cercopidae), 5 new species, and 5 new subspecies: Emesis (Mandania) mandarina Grishin, sp. n. (Brazil: Santa Catarina) and Emesis (Mandania) mandela Grishin, sp. n. (Venezuela, Carabobo) in Riodinidae Grote, 1895 (1827); others in Hesperiidae Latreille, 1809: Telegonus (Rhabdoides) flavifimbro Grishin, sp. n. (Colombia), Urbanus (Urbanoides) dolus Grishin, sp. n. (Colombia: …

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 …

Aspen Impedes Wildfire Spread In Southwestern United States Landscapes, Matthew P. Harris, Jonathan D. Coop, Jared A. Balik, Jessika R. Mcfarland, Sean A. Parks, Camille S. Stevens-Rumann

Aspen Bibliography

Aspen (Populus tremuloides) forests are generally thought to impede fire spread, yet the extent of this effect is not well quantified in relation to other vegetation types. We examined the influence of aspen cover on interpolated daily fire spread rates, the relative abundance of aspen at fire perimeters versus burn interiors, and whether these relationships shifted under more fire-conducive atmospheric conditions. Our study incorporated 314 fires occurring between 2001 and 2020 in the southwestern United States and a suite of gridded vegetation, topography, and fire weather predictor variables. We found that aspen slows fire progression: as aspen cover …

Examining The Performance Of An Insect Generalist Reared On Unused Host Plants In Colorado, Maxwell J. Meyer, Kanshita Dam, Kailey G. Hicks, Emma J. Sellers, Mykaela M. Tanino-Springsteen, Jd Reigrut, Dhaval K. Vyas, Shannon M. Murphy

DU Undergraduate Research Journal Archive

Dietary generalist insects are important to ecological communities because they are commonly found in many environments and play important roles in ecosystem services like pollination and decomposition. Although dietary generalist herbivores eat a broad range of plant species, regional populations of these species may have significantly narrower or specialized diet breadths. Fall webworm (Hyphantria cunea, hereafter FW) is a dietary generalist at the species level, but we do not know if there is dietary generalism at the population level or how generalism varies across populations. In Colorado, FW larvae feed on only a few plant species, but many plant species …

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 …

Response Of Various Body Parts Of House Flies, Musca Domestica, To Sucrose, Panchalie B. Gunathunga, Merveille Muyizere, Bethia H. King

Faculty Articles, Papers, and Other Scholarship

Insects use multiple body parts, not just their mouth, to taste. Whether a particular body part has a taste function can be determined by examining the morphology or electrophysiological response of its sensilla (sense organs) or by its behavioral response. The present study investigated taste response of each of the three pairs of tarsi, tibiae, femurs, as well as the antennae and wings, in house flies, Musca domestica L. (Diptera: Muscidae). This was done by measuring the proboscis extension response (PER), and in the case of the wings, also the grooming behavior. PER is a visible precursor to consumption. The …

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 …

Scientific Note: Garden Loosestrife (Lysimachia Vulgaris, Primulaceae), An Emerging Invasive Plant Species Of Riparian Corridors In The Mid-Atlantic Region, Christopher T. Martine, Amy L. Jewitt, Claire M. Ciafre, Kaitlin G. Henry, Elizabeth H. Williams, Pj Newhart, Melody P. Sain

Faculty Journal Articles

Lysimachia vulgaris (garden loosestrife, Primulaceae) is an herbaceous perennial native to Europe that has been identified as an aggressive invasive species in parts of North America. The status of the species in the Mid-Atlantic region of the US, however, is poorly determined. Using recent field observations (from iNaturalist, iMapInvasives, and EDDMapS records) we here report localized incursions of L. vulgaris in the Susquehanna River Valley of central Pennsylvania, along with notes on its ecology, threats to native plant communities, and broader distribution in the state.

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), …