Digital Commons Network^™

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 …

Distribution Mapping And Modeling Of The Invasive Japanese Knotweed, Jossalyn Rogalski

Masters Theses

This thesis investigates the distribution of invasive Japanese knotweed across Michigan. This plant poses significant challenges to land management due to its rapid growth, environmental impacts, and difficulty of removal once established. Using geographic information systems (GIS), remotely sensed data, and secondary environmental datasets, this research maps current infestations and analyzes key factors influencing the species’ growth and dispersal, such as soil composition, hydrology, land use, and a range of environmental variables, including climatic (annual mean temperature, temperature seasonality, annual precipitation, precipitation seasonality), elevation, vegetation and hydrological indices (NDVI, EVI, NDWI), percent tree cover, and distance to roads. Spatial analysis …

Contrasting Roles Of Downed Wood And Leaf Litter In Structuring Aphaenogaster Ants And Other Forest-Floor Arthropod Communities, Danielle E. Dolan

Great Lakes Center Masters Theses

Forest floors are dynamic and spatially heterogenous landscapes characterized by differing amounts of light, temperature, and moisture. Bounded substrates, like downed wood and leaf litter, add further complexity to this landscape. Specifically, downed wood is noted for its ability to retain a higher moisture level than the surrounding environment, and as such can serve as an ideal microhabitat for desiccation intolerant organisms (e.g., salamanders and eusocial insects). Here, I attempt to disentangle the relationship between forest floor arthropods and microhabitat selection (i.e., downed wood vs leaf litter) on a northeastern forest floor. The ant, Aphaenogaster picea, was chosen as my …

Gaining Mussel: Evaluating Reintroduction Success Of Native Freshwater Mussels In Nebraska And Eastern Wyoming, Travis A. Moore

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

Freshwater mussels are one of the most imperiled groups of organisms in North America, with over two-thirds of species considered threatened, endangered, or of special concern. These long-lived bivalves are essential to stream ecosystems, acting as filter feeders that improve water quality and as indicators of aquatic health. In Nebraska and Wyoming, native mussel populations have declined sharply due to habitat modification, pollution, and reduced connectivity. Two species of particular concern are the Plain Pocketbook Lampsilis cardium, listed as Tier I at-risk in Nebraska, and the Fatmucket Lampsilis siliquoidea, a Tier II at-risk species. In response, state agencies …

Validation Of A Real-Time Pcr Laboratory Developed Test For The Detection Of Pneumocystis Jirovecii In Bronchoalveolar Lavage Samples, Caitlyn Moon

Honors Scholar Theses

Pneumocystis jirovecii is an opportunistic, host-obligate fungal pathogen responsible for causing P. jirovecii pneumonia (PJP) in humans. PJP is treated with trimethoprim-sulfamethoxazole (TMP-SMX), a strong broad-spectrum antibiotic that carries risk of renal and hepatotoxicity. Therefore, rapid diagnosis or exclusion of PJP is crucial to ensure PJP-positive patients receive effective treatment and PJP-negative patients avoid unnecessary antibiotics. Unlike most microorganisms, P. jirovecii cannot be cultured, presenting complications for the typical methods of diagnosing fungal pathogens. Historically, the gold standard for diagnosis was direct microscopic examination with stains such as methenamine silver and calcofluor white, but this diagnostic technique requires highly skilled …

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 …

Ecological Insights And Management Implications Of The Global Migratory Connectivity Of Green Turtles, Jaime Restrepo, Dina Nisthar, Harris Wei-Khang Heng, Lily K. Bentley, Corrie Curtice, Sarah Deland, Ei Fujioka, Patrick N. Halpin, Sarah K. Poulin, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Aim

Green turtles are a widely distributed and highly migratory species; despite extensive data on their movement, there is no species-specific global synthesis on the subject. Based on three decades of published literature and building on previous global analyses, we developed a global network model of migratory connectivity for green turtles to better understand their spatial biology.

Location

Global.

Time Period

1990–2022.

Major Taxa Studied

Green Sea Turtle (Chelonia mydas).

Methods

We conducted a structured literature review extracting georeferenced information on the movement of green turtles from 1990 to 2022, aggregating this information into a single connectivity model, …

Investigating The Intra-Host Relationships Of The Microbiota At Multiple Sites, Ariel Jose Hernandez-Leyva

Arts & Sciences Graduate Student Theses and Dissertations

The human body hosts an abundance of microbial communities that, through complex and multi-faceted interactions, interface with host physiology and help govern health and disease. Many of these interactions are beneficial and help maintain host homeostasis or contribute to the metabolic capacity of the host. Some are detrimental, potentially inducing or further exacerbating disease. All are complicated by the vast diversity of microbes that comprise the microbiota at any given site. Identifying microbes or microbial functions that influence health and disease for study and potential use as biomarkers is tantalizing, though difficult. The vast diversity of potential community compositions, redundancy …

Swosu Research And Scholarly Activity Fair 2026, Swosu Office Of Sponsored Programs

SWOSU Research and Scholarly Activity Fair Programs

On behalf of the University Research and Scholarly Activity Committee (URSAC) and the Office of Sponsored Programs (OSP) at Southwestern Oklahoma State University, we are pleased to welcome you to the Thirty-Fourth SWOSU Research and Scholarly Activity Fair.

Distribution And Diversity Of Aquatic Snails (Basommatophora) In Tributary Systems Of The South Central Plains Ecoregion In Arkansas, Madison Ward, Zach R. Crain

ATU Scholars Symposium

Freshwater aquatic snails (Basommatophora) are seldom surveyed, yet they play an important part in the aquatic community. Arkansas, is one state where there have been very few snail-specific surveys, especially in the South Central Plains Ecoregion. This project investigates the distribution and diversity of freshwater aquatic snails in three previously unsampled creeks in Arkansas (Champagnolle Creek, L’Aigle Creek, Moro Creek, Chemin-A-Haut Bayou, and Derrieusseaux Creek). Sampling was conducted across various sites within each watershed, qualitative methods were used to assess snail diversity and distribution patterns. A total of 659 individuals from 8 species were observed across all five watersheds. The …

Hidden Diversity In A Clonal Endemic: Insights Into Clematis Socialis From A Population Genetics Perspective, Joanna M. Lapoint

Theses

Clematis socialis (Kral) is a rare, federally endangered perennial species restricted to a small number of fragmented populations in Alabama and Georgia. The species exhibits extensive clonality and limited sexual recruitment, characteristics that complicate expectations regarding genetic diversity and population connectivity. Despite its conservation significance, genome-wide assessments of population structure have been lacking. We used genotyping-by-sequencing (GBS) to generate a genome-wide SNP dataset for 170 individuals sampled from six natural populations. Population structure and genetic differentiation were evaluated using Bayesian clustering, analysis of molecular variance (AMOVA), pairwise FST estimates, and network-based visualization. Analyses revealed strong genetic structuring among populations and …

Ecological Studies Of Wolves On Isle Royale, Sarah R. Hoy, Rolf O. Peterson, John A. Vucetich

Ecological Studies of Wolves on Isle Royale

Annual Report 2025-2026

Functional Trait Structure In A Plant Community In Central Anatolian Steppe, Cansu Ülgen, Zeynep Ladi̇n Coşgun, Bariş Özüdoğru, Çağatay Tavşanoğlu

Turkish Journal of Botany

Exploring the trait structure of grassland plant communities enhances our understanding of how these communities will respond to climate change and disturbances such as herbivory. The trait structure of a plant community was investigated in the Central Anatolian steppe, an ecoregion with high biodiversity that has been largely unexplored in terms of plant functional ecology. Fifty plant species in the community were measured across 9 plant traits, including several leaf traits (leaf area, leaf dry matter content, specific leaf area, leaf thickness, and leaf nitrogen content), two seed traits (seed mass and seed shape), as well as the plant height …

Latest Sightings Of The Striped Hyena In North Africa: Major Threats And Conservation Actions, Abderrazak El Alami, Abderrazzak Fattah, Ilyas El Alami, Ziad El Alami

Turkish Journal of Zoology

The striped hyena (Hyaena hyaena) is widely distributed across the northern half of Africa, the Middle East, the Arabian Peninsula, and parts of Asia. However,  numerous studies indicate that this carnivore is in decline, and it is currently classified  as near threatened on the IUCN Red List of threatened species. In North  Africa, the Hyaena hyaena barbara subspecies has been extirpated from many  areas. This article summarizes data collected from observations of the striped hyena  in North Africa between 2004 and 2024. Among the 418 striped hyenas recorded in  North Africa between 2004 and 2024, 18.4% (n = 77) were …

Assessing Tree Species Diversity In Forests Using Combined Remote Sensing Data, Tufan Demi̇rel

Turkish Journal of Agriculture and Forestry

Tree species diversity (TSD) is a critical biological variable for ecosystem functioning and sustainable forest management.This study aimed to model TSD in forest ecosystems using spectral and texture metrics extracted from Sentinel-2, WorldView-3,and PlanetScope satellite imagery, and structural metrics derived from LiDAR data. Tree species data collected through field surveyswere used to calculate Shannon, Simpson, and species richness biodiversity indices. These biodiversity indicators were then related toexplanatory variables derived from remote sensing (RS) metrics. The Boruta algorithm was applied for variable selection and randomforest regression analysis was used for modeling. The results show that combining LiDAR and satellite data is …

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 …

Role Of Developmental Plasticity In Tethered Flight Performance Of The Oriental Fruit Fly, Bactrocera Dorsalis (Hendel) (Diptera: Tephritidae), Thabang P. Moropa, Steve B.S. Baleba, Christopher W. Weldon

All Peer-Reviewed Publications

This study investigated the effect of nutrition on development of wings and adult body condition of Bactrocera dorsalis (Hendel), an exotic pest of Asian origin and a species of economic importance in South Africa. Six host fruit types were used to rear B. dorsalis: mango, guava, orange, grapefruit, papaya and apple. One day after emergence, adults were used for tethered flight assessments using computerised flight mills. Additional flies were assessed in terms of wing morphology using geometric morphometrics, flight muscle mass, and lipid content. There were significant differences in the larval and pupal developmental time as well as larval and …

Aquatic Interrelations In Malika Mokeddem’S Novel N’Zid (2001), Laura C. Klein

Green Humanities: A Journal of Ecological Thought in Literature, Philosophy & the Arts

This article offers an ecological analysis of Malika Mokeddem's novel N'Zid (2001), moving beyond postcolonial and anthropocentric interpretations. It centers on the protagonist Nora's individuation, arguing this process is intrinsically linked to her evolving relationship with the aquatic environment from which she emerges. The article aims to situate N'Zid within an ecological perspective, particularly relevant in the Anthropocene, an era compelling a reassessment of humanity's place. Echoing Bruno Latour, addressing inter-relationality is essential as the stable physical framework of the Moderns becomes unstable. This view necessitates rethinking environmental issues and encourages a scientific interpretation of the novel, drawing on neurosciences, …

A Bovine Cell Line Resistant To Japanese Encephalitis Virus Entry But Permissive To Post-Entry Replication, Sang-Im Yun, Young-Min Lee

Animal, Dairy, and Veterinary Science Faculty Publications

Japanese encephalitis virus (JEV) is a mosquito-borne zoonotic orthoflavivirus that poses a significant global health threat. It causes severe neuroinflammatory disease in humans and reproductive failure in swine. Because of the broad host range and cell tropism of JEV, identifying animal cell lines resistant to infection has been a persistent challenge. In this study, we demonstrate that Madin–Darby bovine kidney (MDBK) cells are resistant to JEV infection yet remain fully permissive to viral replication when transfected with viral genomic RNA. Using immunoblotting, immunofluorescence, and flow cytometry, we show that MDBK cells, unlike the highly susceptible baby hamster kidney (BHK-21) cells …

Habitat Diversity Or Altitudinal Gradient? Which Factor Better Explains Ground Beetle (Coleoptera: Carabidae) Biodiversity? A Case Study From Davraz Mountain (Isparta, Türkiye), Ebru Ceren Fi̇dan, Ali̇ Gök

Turkish Journal of Zoology

Ground beetle (Carabidae) species diversity and spatial distribution were surveyed  across five habitat types along an elevational gradient on Davraz Mountain, a  biogeographical transition area in southwestern Türkiye. The analyses showed that  habitat heterogeneity—particularly soil moisture and texture—exerts a stronger  influence on carabid diversity than elevation. Sørensen’s and Jaccard similarity  indices showed strong faunal overlap between some sampling areas, while  multivariate principal components and canonical correspondence analyses verified  distinct environmental gradients influencing community structure. Diversity indices  indicated varying levels of species richness and evenness across sampling areas.  The data highlight the importance of fine-scaled habitat features in driving ground  beetle …

Nitrogen Dynamics And Use Efficiency In Pasture-Based Grazing Systems: A Synthesis Of Ecological And Ruminant Nutrition Perspectives, Bashiri Iddy Muzzo

Wildland Resources Student Research

Pasture-based ruminant systems link nitrogen (N) nutrition with ecosystem N cycling. Grazing ruminants convert fibrous forages into milk and meat but excrete 65 to 80% of ingested N, creating excreta hotspots that drive ammonia volatilization, nitrate leaching, and nitrous oxide (N₂O) emissions. This review synthesizes ecological and ruminant nutrition evidence on N flows, emphasizing microbial processes, biological N₂ fixation, plant diversity, and urine patch biogeochemistry, and evaluates strategies to improve N use efficiency (NUE). We examine rumen N metabolism in relation to microbial protein synthesis, urea recycling, and dietary factors including crude protein concentration, energy supply, forage …

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 …

Climate Change And Species Interactions Jointly Shape Migration Timing And Growth At A Critical Ontogenetic Transition In Juvenile Sockeye Salmon, Margaret E. Veatch

Honors Theses

Climate change is shifting the timing of biological events globally, but the mechanisms linking environmental variation to phenological changes are poorly understood in many systems, particularly those where individuals undergo ontogenetic habitat shifts. Here, I examined the join influence of climate-driven environmental variability and species interactions migration timing and body size at migration in juvenile sockeye salmon (Oncorhynchus nerka) in Lake Aleknagik, Alaska, using a multi-decadal dataset (1967–2024). Migration timing varied widely among years and was best explained by a combination of ice-out phenology, epilimnetic temperature, and fish densities in littoral habitats. Juvenile sockeye salmon migrated earlier in …

Long-Term Compositional Shifts In The Fish Community Of The Wabash River, Olivia R. Wertman

Masters Theses

There is concern about declining biodiversity in the world today and an increasing need to monitor biodiversity through collecting data and gauging changes occurring in biodiversity over time. Large river fish communities are one area of particular interest due to their sensitivity to environmental changes. One program seeking to address this is the Long-Term Survey and Assessment of Large River Fishes, LTEF, which monitors fish populations in the large rivers of Illinois. In this study, I assessed changes in the fish community of the lower 322 km of the Wabash River from 2010-2025 using annual direct current boat electrofishing surveys …

A Conserved Ethylene-Triggered Cell Death Mechanism May Underlie Hollow Stem Formation Across Plant Species, Mengxiao Yan, Weijuan Fan, Yinghui Meng, Jiamin Zhao, Wei Yang, Ziyin Xu, Yusen Gao, Haiyan Zhuang, Wuyu Zhou, Yuqin Wang, Qingjun Huang, Ling Yuan, Hongxia Wang, Jun Yang

Plant and Soil Sciences Faculty Publications

Hollow stems have independently evolved multiple times across the plant kingdom and play crucial roles in plant development and various environmental adaptations. However, the mechanisms underlying stem hollowness remain poorly understood. Water spinach (Ipomoea aquatica) is one of the few hollow-stemmed plants in the Convolvulaceae family (eudicot: asterid), and its hollow stems are essential for thriving in aquatic environments. Using histochemical staining and transcriptome analysis, we found that programmed cell death (PCD) is involved in cavity formation at water spinach shoot tips. Single-cell and spatial transcriptome analyses further revealed that ethylene and reactive oxygen species (ROS) likely drive …

First Record Of Arrhenophagus Chionaspidis Aurivillius (Hymenoptera: Encyrtidae) Parasitizing White Mango Scale In Kenya: Its Potential Distribution And Prospects In Biocontrol, Francis Obala, Abdelmutalab G.A. Azrag, Rehemah Gwokyalya, Shepard Ndlela, Ingo Grass, Georg Petschenka, Sunday Ekesi, Samira A. Mohamed

All Peer-Reviewed Publications

The white mango scale, Aulacaspis tubercularis Newstead (Hemiptera: Diaspididae), is one of the most destructive pests of mango worldwide. Its current management in most of the invaded areas largely depends on the intensive use of chemical insecticides. Biological control using parasitoids represents one of the most effective and environmentally sustainable management options. However, in Kenya, one of Africa's leading mango-producing countries, no effective parasitoid species associated with A. tubercularis had previously been recorded. This study aimed to identify encyrtid parasitoids associated with A. tubercularis in Kenya, and to assess how bioclimatic factors influence their occurrence and habitat suitability. Mango leaves …

Oligonychus Trichardti (Acari: Tetranychidae) Associated With Urochloa Grasses In Kenya: An Integrative Taxonomic Approach, Paula Espitia-Buitrago, Claudia Perea, Lavender A. Odhiambo, Rosa N. Jauregui, Frank Chidawanyika

All Peer-Reviewed Publications

Spider mites represent a significant constraint to improved forage grass adoption in East Africa, particularly affecting Urochloa cultivars that are crucial for addressing the region’s 40% livestock feed gap. This study employed an integrative taxonomic approach combining morphological and molecular analyses to identify a spider mite species infesting Urochloa interspecific grasses in Kenya. A colony of 80 spider mites was established from symptomatic Urochloa hybrid cv. Cayman plants collected from Mbita Point, Kenya, showing characteristic foliar chlorosis and necrotic spots. Morphological examination of 46 slide-mounted specimens using Hoyer’s medium revealed consistent morphotypical features characteristic of Oligonychus (Reckiella) trichardti Meyer, 1974. …

Exploring The Link Between Soil Microbes, And Land Use Through A One Health Lens, Yaw A. Antwi

Master's Theses or Doctor of Nursing Practice

The diversity of microbes within the soil plays an essential role in soil ecosystem

functioning. However, these microbes may also serve as environmental reservoirs for antibiotic resistance genes. The study examined the diversity of bacteria that are found in soil across Rural/Agricultural and Rural/Nonagricultural landscapes within some selected counties in Kansas and its associated antibiotic resistance genes taxa. A total of twenty-four soil samples was collected and analyzed using 16S rRNA gene amplicon sequencing which targeted the V3-V4 regions. Statistical analysis revealed that the alpha diversity metrics (Chao1 richness and Shannon evenness) showed no significant difference in microbial structure (p=0.693, …

Pollutant Load Reduction In Sarasota Bay, Florida (Usa): Target Development, Implementation, And Outcomes, David Tomasko, Mike Wessel, Jon Perry, Chris Anastasiou, Ryan Gandy

Gulf and Caribbean Research

Between 2006 and 2012, seagrass coverage across Sarasota Bay expanded by 1,108 ha, a 28% increase. During the subsequent years of 2012−2020, 830 ha of seagrass were lost, a 16% decline. In response to these findings, resource management efforts focused on determining the likely reason(s) why those 2 periods had such contrasting trends, to come up with strategies to reverse these losses. Based on results from the seagrass data, the 7—y period of 2006−2012 was designated a “reference period” and water quality data were compared against the subsequent 7—y designated “degraded period” of 2013−2019. Annual average chlorophyll-a (chl-a …