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Leveraging Mammal Mycophagy To Determine Environmental Drivers Of Truffle Diversity, Brittany Hartsock

Electronic Theses and Dissertations

Many mycorrhizal fungi are hypogeous (truffle-forming), producing underground fruiting bodies. Studying truffles is inherently challenging due to their hidden nature. However, mycophagous mammals provide a unique opportunity to study hypogeous fungi because they rely on truffles as a food source. Although several truffle species have recently been described in the southern Appalachian region, their fruiting patterns remain poorly understood. To address this, we quantified truffle richness and spore loads from 670 Peromyscus scat samples collected across 42 sites spanning an environmental gradient during 2024 in the Blue Ridge Mountains of East Tennessee. We found that truffle richness and spore abundance …

Multivariate Ecological Assessment Of Flora Of Village Karri Haider, District Tank, Kp, Numan Khan, Muhammad Azeem, Muhammad Adnan Hamza, Muhammad Aleem, Arshad Rasool, Ammara Wakeel, Sehrish Sadia

Journal of Bioresource Management

Spatial and temporal patterns of vegetation change are influenced by multiple factors, including the physical environment, land-use history, prior disturbance, and initial vegetation composition. The primary aim of this study was to understand floristic vegetation features, species diversity, and the classification of plant communities in Village Karri Haider, District Tank, Khyber Pakhtunkhwa (KP). Samples were collected from each transect using quadrats of 1 m × 1 m for herbs. Soil from three quadrats was mixed to make composite samples, and soil elements were quantified through laboratory analyses. Two surveys were conducted from July to December, 2023. In the first survey, …

Long-Term Spatiotemporal Change In Coral Reef Fish Populations And Communities In The Philippines, John Christopher Whalen

Biological Sciences Theses & Dissertations

The Visayas Region of the Philippines is a global epicenter of marine fish biodiversity. Hypotheses attribute this peak of species richness within the Coral Triangle to processes that occur at geological time scales. However, changes in biodiversity may occur on ecological time scales, allowing for the assessment of the potential impact of anthropogenic activities. Recent declines in genetic, species, and ecosystem diversity have been observed in the tropics, including the Philippines. Within the Philippines the Visayas Region is considered the epicenter of species adversity due to anthropogenic stressors such as habitat degradation, overfishing, and harvesting individuals for the aquarium trade. …

Light-Driven Zonation And Community Structure Of Aerophytic Microalgae In A Tropical Limestone Cave (Gua Tempurung, Malaysia), Wan Maznah Wan Omar, Mohammad Basri Eshak, Luthfiana Aprilianita Sari, Zulaihat Hamza Abdullahi, Yusuf Abdullahi

International Journal of Speleology

Cave ecosystems host specialized phototrophic biofilms structured primarily by light availability, yet quantitative assessments of aerophytic microalgal community organization in tropical limestone caves remain limited. This study investigated spatial variation in the structure of aerophytic microalgal communities across four ecologically distinct zones (entrance, transition, penetration, and low light) of Gua Tempurung, Malaysia. Stratified sampling was conducted during three seasonal periods. Dominant phototrophic morphospecies were identified using microscopy, and community composition was analyzed in relation to key environmental variables. Twenty-three dominant microalgal morphospecies were recorded across the cave gradient. Cyanobacteria constituted the major component of both richness and abundance, followed by …

Investigating Changes In The Stable Isotopic Composition Of Juniperus Osteosperma Over 34,000 Years Of Climatic Shifts, Lisa S. Garcia

Biology ETDs

Isotopic compositions of plants from the past provides empirical evidence for paleoclimatic shifts and plants physiologically response. This study used Neotoma paleomiddens (fossilized debris piles) collected from Death Valley National Park, which contained preserved abundant plant materials. These middens range from modern to >35,000 years and capture different climatic events in Earth history. Employing Juniperus osteosperma (Utah Juniper) leaves found in middens, I investigated variation in carbon and nitrogen stable isotopic composition. To help interpret paleomidden results, we used modern field and herbaria samples of Juniperus from a spatial gradient stretching across their geographic range. Results showed δ ¹³C …

Bio 340 Final Project: Rural Population Structure And Food Production Interact To Shape Global Undernourishment, Ava Ripanti

Biology Student Scholarship

Ava Ripanti - Environmental Biology '27

Undernourishment remains a major global public health challenge, reflecting the proportion of a population lacking sufficient dietary energy intake. While food availability is central to food security, undernourishment is also shaped by structural and socioeconomic factors such as population distribution and access to resources. Although rural populations are closely tied to agriculture, they often experience higher food insecurity due to limited infrastructure, market access, and healthcare. Prior research emphasizes that broader determinants, particularly inequality and development, are stronger predictors of undernourishment than agricultural output alone, that food insecurity exists in both rural and urban …

Assessing The Conservation Needs Of Native Texas Crayfish Species Through Distribution Analysis And Species Distribution Modeling, Elizabeth J. Croft

Biology Theses

Crayfish have essential roles in ecosystems because they are ecosystem engineers and keystone species. However, crayfish species are threatened by degradation and loss of habitats, introduction of invasive species, and high levels of endemism. Texas provides no legal protections for crayfish, despite its large number of species and endemics in the state. The overall goal of this study is to clarify the distributions of native Texas crayfish species using literature records, citizens science, and field sampling data, and highlight species in need of more conservation research. Occurrence records from all collected data were combined to visualize the distributions of species …

Can Carpobrotus Edulis Cause Significant Changes To The Soil Microbiome?, Samantha J. Cowan

Electronic Theses, Projects, and Dissertations

Invasive species cause significant damage to ecosystem biodiversity and can cost billions of dollars to restore native species (Van der Wal et al, 2008; Diagne et al., 2021).  In certain instances, even if the invasive species are removed, they can leave legacy effects on the environment that make restoration more challenging (Conser and Connor, 2008; Elgersma et al., 2011). Carpobrotus edulis is an invasive species of plant that is known to cause changes to its environment such as affecting the soil nitrogen cycle and the pH, potentially leading to persistent changes in the soil microbiome and causing native species to …

Controlled Epidemics: Examining The Effect Of Virus Density And Strain Competition In Gulf Fritillary (Dione Vanillae), Lizbeth Reyes

Biology: Student Scholarship & Creative Works

This study examines how different virus strains compete within a single host population of Dione vanillae butterflies, which is important in the study of disease ecology research. For this study, we conducted controlled experimental epidemics on passionflower plants (Passiflora caerulea) in the field. First, we infected caterpillars with one of two different virus strains from Butterfly Farms in North County (BFF004) and the City of San Diego (GRM060) and placed these caterpillars on P. caerulea plants in one of three treatments (control, BFF004, and GRM060; n=3 plants per treatment). Next, we allowed healthy butterflies in the local population to lay …

Insights On Global Rangeland Ecosystem Services Shaped By Grazing And Fertilization, Laura Yahdjian, Sofía Campana, Pedro M. Tognetti, Juan Alberti, Pamela Graff, Cecilia Molina, Elizabeth T. Borer, Eric W. Seabloom, Suzanne M. Prober, Andrew S. Macdougall, Anita C. Risch, Jodi N. Price, Sally A. Power, Isabel C. Barrio, Erika Hersch-Green, Philip A. Fay, Sumanta Bagchi, Jonathan D. Bakker, Dana Blumenthal, Elizabeth H. Boughton, Cynthia S. Brown, Miguel N. Bugalho, Marc Cadotte, Maria C. Caldeira, Jane A. Catford, Clinton Carbutt, Qingqing Chen, Scott L. Collins, Thomas W. Crowther, Carla D’Antonio, Christopher R. Dickman

Michigan Tech Publications

Rangelands are crucial to human well-being, but their ability to provide ecosystem services is threatened. We (1) quantified key ecosystem services provided by rangelands, (2) assessed short- and long-term impacts of fertilization (nutrient addition) and the exclusion of large grazing herbivores with fences (herbivore exclusion) on services, and (3) identified synergies and trade-offs among services. We measured indicators of ecosystem services and plant diversity at 79 sites across six continents in the global Nutrient Network. Short-term herbivore exclusion increased forage quantity and soil fertility, but longer-term herbivore exclusion decreased both along with plant richness and pollination. Nutrient addition improved forage …

Invasion Dynamics, Environmental Conditions, And Community Impacts Of Yellow Sweetclover (Melilotus Officinalis) Across The Northern Great Plains, Sakshi Saraf

Dissertations and Theses

Understanding how environmental conditions and invasion dynamics shape native plant Communities is critical for conserving and managing the semi-arid grasslands of the Northern Great Plains (NGP). Invasive plant species are increasingly altering ecosystem structure and function across this region, yet knowledge gaps remain regarding the drivers of invasion, their spatiotemporal dynamics, and their associations with native plant communities. This dissertation investigates three questions: (1) what environmental conditions are associated with the distribution and abundance of the invasive legume Melilotus officinalis (yellow sweetclover; MEOF), (2) how does MEOF vary across space and time under climatic conditions, and (3) how are environmental …

Bayesian Multivariate Modelling Of Lone Star (Amblyomma Americanum) Tick Life Stage Abundance And Temporal Trends To Inform Public Health Risk In Virginia, Thabo Lephoto, Henry Mwambi, Oliver Bodhlyera, Holly Gaff

Biological Sciences Faculty Publications

The increasing abundance of ticks poses a growing public health concern due to heightened human exposure to tick bites. The lone star tick (Amblyomma americanum: Ixodida: Ixodidae), a common human-biting species in the United States, has expanded its range in recent years. However, how its different life stages vary across time, habitats, and locations remains insufficiently understood. We analyzed tick abundance data collected in southeastern Virginia between 2009 and 2018, focusing on larval, nymphal, and adult life stages. A Bayesian multivariate modelling framework was used to examine seasonal patterns, habitat effects, spatial variation, and biological links between life stages. Two …

Noninvasive Monitoring Techniques: The Use Of Scat-Sourced Dna And Camera Traps To Monitor Mammalian Carnivore Species At The Ucf Arboretum, Zachary Montealegre

Honors Undergraduate Theses

The 800-acre University of Central Florida Arboretum Natural Lands functions as a conservation area, recreational space, and research site, making it essential to understand the ecological community it supports. Traditional wildlife monitoring methods such as mark-recapture and blood sampling can be effective but may stress animals or disrupt natural behaviors. To minimize these impacts, this study used non-invasive techniques, specifically scat-based DNA analysis and camera trapping, to assess carnivore species' presence. Two ecologically similar sites within the Arboretum were selected. Suspected carnivore scat was collected twice weekly over two months using both structured and opportunistic sampling. DNA was extracted, amplified, …

Mitochondrial Efficiency: Bridging Early-Life Environment And Organismal Performance, Kayla E. Lichtner

Master’s Theses

Mitochondria operate at the forefront of organismal-environmental interactions. Despite remarkable diversity in mitochondrial function both within and among species, all mitochondria serve a universal role in facilitating the flow of energy between organisms and their environment. Energetic efficiency, the way in which organisms assimilate and transform environmental substrate into physiological currency, is a major determinant of organismal performance. Although previous studies have shown that early-life environment can have lasting effects on metabolism, the underlying mechanisms driving the emergence of mitochondrial phenotypic variation remain poorly understood. Leach’s storm-petrels (Hydrobates leucorhous) provide a valuable opportunity to investigate longitudinal hypotheses of …

Vibrio In Oysters: Exploring The Impact Of Harvesting Practices, Samin Yasar

College of Graduate Studies: Theses & Dissertations

The rapid growth of oyster aquaculture in the Southeastern United States necessitates the validation of post-harvest processing strategies to mitigate the risk of Vibrio spp. infection. This study investigated the efficiency of three cooling methods - Direct Ice Burial, Indirect Ice Cooling, and Ambient Control, on the prevalence and abundance of V. cholerae, V. parahaemolyticus, and V. vulnificus in cultured oysters (Crassostrea virginica) harvested in Georgia. Additionally, the study examined the safety of two different re-submersion periods for oyster safety.

Internal temperature profiles confirmed that while Direct Ice Burial achieved the most rapid cooling (< 10° C in 7.3 ± 1.2 min), the Indirect Ice Cooling protocol successfully reached the safety threshold in 73.7 ± 17.2 min, well within the 2-hour regulatory window. Microbiological analysis (N = 270) revealed that V. …