Physical Sciences and Mathematics Commons^™

Complexity, Polycentricity, And Climate Change: An Embedded, Multi-Level Case Study Of A Climate Meta-Network, Timothy Staub

Antioch University Dissertations & Theses

The earth is in crisis, and without urgent, systemic, and collective global action to address the emerging threat of climate change, we will continue to see catastrophic events impacting humanity, threatening our very survival in many regions of the world. Temperatures will rise, ice shelves will melt, seas will rise, crops will fail, water scarcity from drought and new weather patterns will increase and spread, wildfires will accelerate, and food and water insecurity, violence, and the largest human migration in history will ensue. These climate crises will displace over 1.2 billion people by 2050 at a rate currently exceeding 21.5 …

Evaluating Spatiotemporal Vegetation Index Variation To Detect Salt Marsh Dieback On The Georgia Coast, Emmanuella Bosompemaa Obeng

College of Graduate Studies: Theses & Dissertations

Salt marshes, essential for coastal protection and carbon sequestration, are increasingly vulnerable to dieback events, threatening ecosystem resilience and vital services. Detecting these shifts early is essential for timely intervention. However, few studies have applied Early Warning Signals (EWS) to coastal marsh systems. Most EWS research has focused on lakes, forests, or climate tipping points, with limited application to salt marsh dieback in the southeastern U.S. Site-specific, long-term spatial analyses are also lacking, as prior work often examines short time frames or single disturbance events. This study investigates the spatiotemporal patterns of salt marsh dieback on the Georgia coast from …

Identifying The Impacts Of Land Use/Land Cover Changes On Ecosystem Services From A Geospatial Perspective In Albany County, Kyaw Khaung Thant Zin

Electronic Theses & Dissertations (2024 - present)

Ecosystem services encompass the broad array of direct and indirect advantages that people derive from nature and its ecosystems. Considering accelerating environmental change and degradation, recognizing the importance of these services is more crucial than ever, as they illustrate the many ways in which healthy ecosystems sustain human life. However, these services are diminishing at a rapid and unprecedented rate, raising global concern over both the transformations taking place and their root causes. Among the leading threats, land-use change stands out as a particularly significant one, influenced by a variety of driving factors. Albany County, New York, characterized by its …

A Swirling Offering: Climate Change Impacts On Incense And Other Useful Alpine Plants Of Bhutan, Nidup Gyeltshen, Choki Gyeltshen, Sangay Dema, Suresh K. Ghimire, Natalie Konig, Robbie Hart

Research outputs 2022 to 2026

Climate change impacts on social-ecological systems —such as useful plant harvest— can be elucidated through local perceptions and ecological monitoring. To better understand how these two approaches may show convergent or divergent perspectives on a shared system, we conducted semi-structured interviews on climate change impacts on useful plants in the alpine region of Central Bhutan, contextualized with results from ecological monitoring at the same site. Participants reported 42 useful alpine plant species. Incense plants were the most frequently cited and prioritized in free-lists (three times more likely to be mentioned first), ahead of other common uses (food, medicine). Most participants …

Snag Failure And Fuel Recovery Following Stand-Replacing Fire In The Klamath Mountains, Joseph R. Nicholas

Cal Poly Humboldt theses and projects

High-severity wildfires can produce extensive patches of standing dead trees (snags), which later contribute to surface fuel loading and present a hazard as they decay and fall. In the Klamath Mountains of northwestern California and southwestern Oregon, recent increases in the occurrence of large stand-replacing wildfires have raised concerns about fuel and vegetation recovery trajectories, the likelihood of future fires, and resulting impacts to local communities. Nevertheless, the post-fire environment may offer opportunities to enhance ecological and community resilience. Estimates of snag failure and fuel loading can support land management planning and risk assessment following wildfire, though such work is …

Microbial Community Stabilization By Restored Oyster Reefs: Implications For Blue Carbon Storage, Natalie Boydstun

College of Graduate Studies: Theses & Dissertations

Coastal ecosystems provide critical carbon sequestration services, yet the microbial mechanisms underlying carbon storage remain poorly understood, particularly in non-vegetated habitats. This study investigated whether restored oyster reefs (Crassostrea virginica) enhance sediment carbon storage potential by stabilizing microbial communities and promoting efficient organic matter processing. I hypothesized that reef-mediated sediment stabilization and organic deposition would create conditions favoring microbial degradation of complex carbon compounds into stable soil organic matter, ultimately supporting anaerobic carbon storage. To test this, I compared sediment biogeochemistry, enzyme activity, and microbial community structure between three restored oyster reef sites and two unstructured control sites …

Colorado River Insights, 2025: Dancing With Deadpool, Colorado River Research Group

Books, Reports, and Studies

No abstract provided.

Spatial Analysis Of American Chestnut (Castanea Dentata) Distribution And Ecology In Kentucky’S Federal Lands, Jacob Raymond Pease

Murray State Theses and Dissertations

Anthropogenic factors have been the cause of the decline of tree species across the globe. From unsustainable logging and development to disease and improper management, threats to forests have taken their toll. The American chestnut (Castanea dentata) was once an integral basal tree species in Appalachian forests, but chestnut blight drove the species to functional extinction by the mid-1900s. The recent creation of genetically modified chestnuts gives hope for future restoration of the species throughout its historical range. Despite blight resistance, effective restoration will require optimal site selection for finding and planting chestnuts, which will maximize limited resources. …

Assessment Of The Genetic Population Structure And Extent Of Clonality In A Rare Serpentine Endemic, Lathyrus Biflorus T.W. Nelson & J.P. Nelson (Fabaceae), Using Ddrad Sequencing, Ashley Dickinson

Cal Poly Humboldt theses and projects

Lathyrus biflorus, or the two-flowered pea, is a rare herbaceous perennial restricted to a single population in Northern California. The species is considered critically imperiled but remains unprotected under state or federal endangered species acts. Despite its rarity, little is known about its life history, reproductive biology, or genetic diversity. Using genome-wide reduced representation sequencing, this study aimed to address these gaps by investigating the molecular evidence of clonality, the number and diversity of genets (unique genetic individuals which can be made up of one or many clonal units or ramets), and overall genetic health of the population. My …

Home Range, Habitat Use, And Fall Migration Of Lewis’S Woodpeckers In The Eastern Cascade Range, Oregon, Cameron Piper

Cal Poly Humboldt theses and projects

Lewis’s woodpecker (Melanerpes lewis), a burn specialist, is experiencing range-wide population declines despite increasing fire activity in the western U.S. The White River Wildlife Area in Oregon hosts the state's only year-round population, raising questions about their breeding, habitat use, and migration. In summer 2024, we tracked nine woodpeckers using telemetry to estimate home range size and overlap. Full home ranges averaged 428 ha, with 66 ha core areas, and showed evidence of growing after nesting. Home ranges overlapped extensively (Full: 91 ± 13%; Core: 63 ± 29%), though individuals had distinct areas of intense use. Males had …

An Economic And Production Analysis Of Seaweed Farms In California And The Pacific Northwest, Brian Donovan

Cal Poly Humboldt theses and projects

Since the early 2010s, the seaweed aquaculture industry has steadily expanded in the United States, with states like Alaska, Maine, Hawaii, and Connecticut leading the way in the development of this emerging sector. However, information gaps remain concerning certain aspects of the domestic seaweed aquaculture industry. The purpose of this study was to examine the status of the seaweed aquaculture industry along the West Coast of the United States; specifically in the states of California, Oregon, and Washington. Seaweed farmers in these states were invited to voluntarily complete surveys asking important production, economic, and commercial questions regarding their operations. Data …

Common Raven Habitat Selection Along The Northern California Coast, Alon Averbuj

Cal Poly Humboldt theses and projects

Nest predation by common ravens (Corvus corax) is considered one of the most significant barriers to the recovery of the population of the federally threatened western snowy plovers (Anarhyncus nivosus nivosus) in Northern California. To increase productivity of snowy plovers, conservation managers in Northern California employ three main techniques; placing symbolic fencing to deter pedestrian entrance to snowy plover nesting areas, invasive vegetation cutback, and deposition of oyster shells to increase snowy plover nest crypsis. However, little is known on how these techniques affect habitat selection of ravens in the area. I modeled habitat selection of …

Kelp Guardians Can Save The World: A Food Sovereignty Lab Report Of The Ghvtlh-K’Vsh Shu'-Srnelh-'I~ (Kelp Guardians) California Sea Grant, Delaney A. Schroeder-Echavarria

Cal Poly Humboldt theses and projects

As partners of the Ghvtlh-k’vsh Shu'-srnelh-'i~ (Kelp Guardians) California Sea Grant project, the Rou Dalagurr Food Sovereignty Lab and Traditional Ecological Knowledges Institute has actively engaged with local educators, Tribal organizations, and Tribal Nations to create youth-centered curricula, researched through a community-based participatory research lens. This is demonstrated through an innovative approach to recruiting and retaining Indigenous youth and community interest in coastal and marine ecosystems and resources by connecting with Indigenous cultural practices, Indigenous sciences, and community-based programs to encourage future careers. The Kelp Guardians project is led by the Tolowa Dee-ni’ Nation (TDN or Nation) and includes various …

Mxene-Based Materials For Enhanced Water Quality: Advances In Remediation Strategies, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Mostafa Shafiee, Lobat Tayebi, Ahmad Vaez, Atefeh Najafian, Ehsan Vafa, Sareh Mosleh-Shirazi

Electrical & Computer Engineering Faculty Publications

Two-dimensional MXenes are promising candidates for water treatment because of their large surface area (e.g., exceeding 1000 m²/g for certain structures), high electrical conductivity (e.g., >1000 S/m), hydrophilicity, and chemical stability. Their strong sorption selectivity and effective reduction capacity, exemplified by heavy metal adsorption efficiencies exceeding 95 % in several studies, coupled with facile surface modification, make them suitable for removing diverse contaminants. Applications include the removal of heavy metals (e.g., achieving >90 % removal of Pb(II)), dye removal (e.g., demonstrating >80 % removal of methylene blue), and radioactive waste elimination. Furthermore, 3D MXene architecture exhibit enhanced performance in antibacterial …

A Critical Juncture: The Convergence Of Natural Resource Management And Tribal Sovereignty, Anna Aleta Butterfield

Graduate Student Portfolios, Professional Papers, and Capstone Projects

This portfolio reflects the work I’ve done in my four years as a dual degree student, pursuing a Master of Science in Environmental Studies and a juris doctorate degree, and focuses on policies and laws surrounding natural resource management. It touches on how those policies relate to and expand or constrict the exercise of sovereignty by indigenous populations.

This piece first considers the effects of plastic on salmon populations and those indigenous groups that rely on salmon for subsistence and cultural purposes. The remaining three pieces focus on various aspects of the Confederated Salish and Kootenai Tribes - Montana Water …

Monitoring Plastic Pollution Using Bioindicators: A Global Review And Recommendations For Marine Environments, Matthew S. Savoca, Neil Angelo Abreo, Andres H. Arias, Laura Baes, Matteo Baini, Elisa Bergami, Susanne Brander, C. Anela Choy, Illaria Corsi, Bavo De Witte, Camila Domit, Sarah Dudas, Emily M. Duncan, Claudia E. Fernández, Maria Cristina Fossi, Ostin Garcés-Ordóñez, Brendan J. Godley, Daniel Gonzalez-Parades, Victoria González Carman, Bonnie M. Hamilton, Britta Denise Hardesty, Sang Hee Hong, Shirel Kahane-Rapport, Lauren M. Kashiwabara, Mariana Baptista Lacerda, Guillermo Luna-Jorquera, Clara Manno, Sarah E. Nelms, Cristina Panti, Diego J. Pérez-Venegas, Christopher K. Pham, Jennifer F. Provencher, Sara Purca, Harunur Rashid, Yasmina Rodríguez, Conrad Sparks, Chengjun Sun, Martin Thiel, Catherine Tsangaris, Robson G. Santos

Biological Sciences Faculty Publications

Monitoring the movement of plastic into marine food webs is central to understanding and mitigating the plastic pollution crisis. Bioindicators have been a component of the environmental monitoring toolkit for decades, but how, where, and which bioindicators are used in long-term monitoring programs has not yet been assessed. Moreover, these programs have yet to be synthesized and evaluated globally. Doing so is imperative if we are to learn from these pioneering programs and expand on their efforts. We reviewed global monitoring programs using bioindicators that focus on plastic pollution and found 11 worldwide that met our definition of long-term monitoring. …

Building Heat-Resilient Caribbean Reefs: Integrating Thermal Thresholds And Coral Colonies Selection In Restoration, Macarena Blanco Pimentel, Johanna Calle-Triviño, Daniel J. Barshis, Sancia E. T. Van Der Meij, Megan K. Morikawa

Biological Sciences Faculty Publications

Caribbean reefs face increasingly frequent and intense bleaching events, adding to the numerous other threats impacting these ecosystems. Addressing these challenges requires global action to reduce climate drivers, along with local efforts like reef restoration. Active restoration using thermotolerant coral colonies offers a potential strategy to alleviate these impacts; however, gaps remain in identifying context-specific temperature thresholds to guide colony selection and standardize thermotolerance assessment methods. This study addressed these gaps in two phases. First, by determining practical thresholds to differentiate species responses to heat stress; and second, by developing a framework to identify and prioritize resilient colonies for restoration. …

In The Footsteps Of Moose: Using Non-Invasive Techniques To Identify Cause-Specific Calf Mortalities And Evaluate Moose (Alces Alces) Movements Pertaining To Mineral Lick Locations On Ancestral Lands Of The Grand Portage Ojibwe, Anna B. Weesies

Electronic Theses and Dissertations

Following a sharp moose (Alces alces; mooz, Anishinaabemowin, Ojibwe language) population decline in northeastern Minnesota during the early 2000s, the Grand Portage Band of Lake Superior Chippewa initiated a long-term moose collaring effort to assess survival and mortality causes. Moose are a culturally important species to the Band, with annual subsistence hunts held on the Reservation and adjacent 1854 Ceded Territory. Continued research guides culturally appropriate management decisions aimed at bolstering calf and adult survival, helping to preserve this moose in Minnesota today and for subsequent generations. Chapter 1 identifies cause-specific calf mortality rates in this multi-predator system using minimally …

Growth, Survival, And Herbivore Browsing Preferences Of Seedlings Planted In Black Ash Stands Of Northern Michigan And Wisconsin, Seth W. Davenport

Dissertations, Master's Theses and Master's Reports

To mitigate the cascading ecosystem impacts of widespread black ash (Fraxinus nigra) mortality due to the invasive emerald ash borer (Agrilus planipennis), forested wetlands can be underplanted with seedlings of alternative species that later repopulate the vacated canopy. This study examined the survival and growth, factors influencing performance, and herbivore browsing preferences of seven non-ash species planted in northern Michigan and Wisconsin. The best performing species were river birch (Betula nigra), silver maple (Acer saccharinum), and swamp white oak (Quercus bicolor). The worst performing species was black spruce (Picea …

Bridging The Gap Between Plot-Level And Landscape-Scale Analysis For Wildfire Risk Assessment, Vanessa Leigh Niemczyk

Graduate Student Theses, Dissertations, & Professional Papers

Remote sensing technology has advanced greatly over the past couple of decades proving its ability to aid in wildfire risk assessment and improve our understanding of forest structure and fuel inventory across the landscape. While some aerial and satellite sensors perform better than others, they all have a common weakness, their reduced ability to capture understory fuels with high detail. Terrestrial laser scanning is an emerging solution due to its understory perspective. This research leverages the beneficial aspects of both terrestrial laser scanning and various aerial- or satellite-based remote sensing platforms (aerial laser scanning, digital aerial photogrammetry, and Sentinel-2) to …

Linking Empirical Data And Numerical Simulation To Characterize Dynamic Fire Behavior Associated With Interacting Firelines, Marta Sergeevna Jerebets

Graduate Student Theses, Dissertations, & Professional Papers

Understanding fuel pattern-fire process relationships is key for predicting fire behavior and effects with follow-on benefits to proactive fire management and model validation. To characterize dynamic fire behavior, this thesis leverages empirical data and numerical simulation through two complementary studies.

In the first study, longwave thermal sensors aboard unmanned aerial systems (UAS) were used to capture fine-scale fire behavior in two experimental grass burns. A novel paired design was used to quantify the effects of fuel arrangement on fire behavior with 3.66 m diameter treatments cut to a height of 0.15 m. The treatments ephemerally reduced fire rate of spread …

Investigating Non-Invasive Survey Methods And Building A Predictive Occupancy Model For Harlequin Ducks (Histrionicus Histrionicus) In Western Montana And Northern Idaho, Holli Ann Holmes

Graduate Student Theses, Dissertations, & Professional Papers

Harlequin Ducks (Histrionicus histrionicus; HADU) are an imperiled sea duck that breeds along white-water mountain streams, but challenges in surveying them have made it difficult to understand population trends in their Northern Rocky Mountain breeding population. In this study we had two objectives: (1) evaluate non-invasive survey methods for detecting HADU on their breeding grounds in Western Montana and Northern Idaho, and (2) develop an occupancy model to predict potential breeding stream use for HADU across the region. First, we assessed the efficacy of ground-based foot surveys (GBS), environmental DNA (eDNA), and camera traps to detect breeding HADU during …

Mapping Mesic Resilience In Western Rangelands: Productivity Trends, Predictors, And Targeting Frameworks, Kristopher Robert Mueller

Graduate Student Theses, Dissertations, & Professional Papers

Mesic ecosystems in riparian areas and wetlands make up only 2% of western U.S. rangelands but support 80% of wildlife during dry periods, providing vital late-season forage and refuge when surrounding uplands dry out. Yet, mesic habitats are often overlooked in landscape-scale conservation planning. This thesis addresses two key gaps: understanding how mesic productivity responds to environmental change and developing frameworks to incorporate these habitats into current conservation strategies. Using 40 years of Landsat imagery (1984–2024), we examined long-term trends in late-season mesic vegetation productivity and its relationship with drought across the sagebrush biome. From 1984 to 2004, mesic productivity …

Ecology-Driven Machine Learning For Predicting Risk Of Spread For Aquatic Invasive Species., Leif Eric Howard

Graduate Student Theses, Dissertations, & Professional Papers

Effective management of aquatic invasive species (AIS) requires predictive tools that leverage environmental and ecological data to forecast spread into uninvaded areas. However, species distribution models (SDMs) often struggle to capture key invasion processes such as dispersal, propagule pressure, and biotic interactions. This thesis integrates ecological, dispersal, and environmental predictors within a machine learning framework to enhance AIS risk prediction and model transferability across space.

In Chapter 2, 61 novel predictors were developed for 2,203 Minnesota lakes to model zebra mussel (Dreissena polymorpha) occurrence, incorporating variables related to propagule pressure (e.g., boat visitation), community composition (e.g., fish species …

North American River Otter (Lontra Canadensis) Prey Selection Of Wintering Waterbirds In A Wetland Complex, Gina Yael Culver

Cal Poly Humboldt theses and projects

Generalist predators are assumed to take a wide variety of prey throughout an annual cycle, often switching between food sources depending on availability. Prey selection is often studied by way of variables such as prey age class, body size, and various topics related to anti-predator behaviors, all variables used to measure how predators target prey. Following prior studies in coastal Northern California documenting that river otters (Lontra canadensis) had selected waterbirds as prey, we identified undigested prey items in scat to evaluate prey selection of waterbirds at the Arcata Marsh and Wildlife Sanctuary (AMWS). We compared feathers found …

Turbo Fladry Fencing To Mitigate Short-Term Agricultural Damage Caused By Wild Pigs, Michael P. Glow, Jesse A. Tussing, Johnathan G. Walls, Robert B. Hyle, Joseph M. Halseth, Nathan P. Snow, Kurt C. Vercauteren

Human–Wildlife Interactions

Wild pigs (Sus scrofa) are a destructive invasive species that damage agricultural crops in many regions of the world. Lethal techniques to reduce populations are most often used to mitigate damage, but additional techniques are also needed in conjunction with lethal tools to protect resources in some settings (e.g., where lethal control is not practical or possible to achieve population elimination). While additional tools such as deterrents or temporary fencing may provide short-term relief, few effective options are currently available because habituation by wild pigs often reduces long-term effectiveness. Turbo fladry, a type of electric fence, is an …

Advancing Sustainability In Civil Engineering Technology Through The Engineering For One Planet Framework, Dalya Ismael, Vukica M. Jovanovic, Murat Kuzlu, Charles Lowe, Lisa Bosman

Engineering Technology Faculty Publications

As global environmental challenges intensify, integrating sustainability into engineering technology education is increasingly critical. Yet, many programs lack comprehensive methods to embed sustainability principles, leaving graduates underprepared to address real-world environmental issues. Courses on sustainability often approach it in isolated or superficial contexts, unable to capture its complexity. The purpose of this study is to showcase one approach for embedding the Engineering for One Planet (EOP) framework into the Sustainable Building Practices course within the Civil Engineering Technology Department. The newly developed curriculum integrated learning outcomes from three EOP topics: Environmental Impact Assessment, Materials Selection, and Systems Thinking. Students were …

Impact Of An Herbicide Treatment In An Annual Grass Invaded Sagebrush Steppe, Jordan Dino Santia

Undergraduate Scholarship

Globally, rangelands are being threatened by invasive annual grasses (IAGs) that alter fire regimes, drive vegetation type conversion, and alter ecosystem function. This study evaluates vegetation responses to an Imazapic treatment applied in 2020 to control a population of Taeniatherum caput-medusae, an IAG, that flourished following a severe wildfire in 2013. The site, located on a Bureau of Land Management (BLM) grazing allotment east of Klamath Falls, Oregon, has been monitored annually using the Assessment, Inventory, and Monitoring (AIM) protocol since the Summer of 2022. Over this period, very little T. caput-medusae has been detected while bare ground has …

Spatiotemporal Evolution Of Surface Water Quality And Driving Factors Across Varying Levels Of Human Interference In A Major Subbasin Of The Yellow River Basin, China, Longmei Xie, Ruizhong Gao, Xixi Wang, Limin Duan, Lijing Fang, Hui Tong, Chang Yue, Tingxi Liu

Civil & Environmental Engineering Faculty Publications

Study region

The Dahei River Basin, a sub-basin of the Yellow River Basin, was selected for this study. Encompassing population centers and villages in Inner Mongolia, it supports vital ecosystems and underscores the need to address its unique challenges in water management and protection.

Study focus

This study examines surface water quality dynamics in the Dahei River Basin, a key aspect of sustainable water management. Predicting spatiotemporal variations and driving factors remains challenging. Using 2013–2023 datasets on water quality, hydrology, and meteorology, the composite pollution index (CPI), ANOVA, and generalized additive models were applied to provide insights for effective management. …

Modelling The Impacts Of Recreational Catch-And-Release Variability On Fish Stock Dynamics, Brett Crisafulli

Theses: Doctorates and Masters

Recreational fisheries often lack sufficient data for robust stock assessments, and post-release mortality (PRM) of discarded fish, particularly demersal species, poses a significant threat to sustainability. Because demersal fish often experience higher PRM (often due to barotrauma and stress), the substantial global interest in their recreational fisheries (e.g., Australia, Gulf of Mexico, Western Baltic Sea) raises conservation concerns. This study employs three distinct modelling approaches, applied to four reef-dwelling demersal species, to support effective recreational fisheries management by addressing data uncertainty, unintended consequences of management changes, and PRM effects. Specifically, this thesis (1) evaluates variability in average weights of recreationally-caught …