Digital Commons Network^™

Factors Influencing Tree Vigor And Structural Failure Along Powerline Corridors In Northern California: A Multi-Species Analysis, David Justin Dorval

Cal Poly Humboldt theses and projects

Tree failures (e.g., stem breakage, uprooting, or branch drop) can pose significant risks to public safety, particularly along powerline corridors for the risk of power outages and wildfire ignitions. In California, tree-related powerline failures have led to severe ecological and human costs in recent years. Despite extensive research on tree failure in urban environments and post-disturbance contexts, comparatively little empirical work has examined where powerlines intersect largely unmanaged stands. This study evaluates tree failure trends across multiple forest types in Northern California by examining how tree-level characteristics influence recent growth and failure occurrence in regionally dominant tree species. Specifically, the …

Can Forest Thinning Activities Be Characterized With Public Data?: Evidence From California’S Million Acre Strategy (2020-2023), Selena Rowan

Cal Poly Humboldt theses and projects

Can forest thinning activities be quantitatively described using public data? This study evaluates the feasibility of doing so using geospatial datasets and project-level documentation associated with forest operations tracked under the California Wildfire & Forest Resilience Task Force’s Million Acre Strategy (2020–2023). As fuels reduction efforts expand to address increasing wildfire risk, there is growing demand for detailed information on thinning activity characteristics and associated biomass generation to support management evaluation, biomass utilization, and life-cycle emissions modeling. However, the extent to which existing public data provide sufficient detail to support such analyses remains unclear.

This thesis analyzes forest thinning activities …

Urban Trees In The Urban Hydrology Cycle, Jorge R. Vera

Theses, Dissertations and Capstones

In urban forestry, trees provide numerous economic, ecological, and aesthetic benefits to the surrounding community. One of their key roles is intercepting stormwater runoff, reducing flooding risk, and improving water quality. Chapter 1 of this thesis characterized the ecological and economic contributions of urban trees on the Marshall University campus and provides guidance on their management and conservation in the future. Chapter 2 examined how urban tree species modify the urban hydrology cycle by altering the volume and timing of precipitation delivery. In Chapter 1, we inventoried 114 acres of Marshall University's main campus in Huntington, WV, from June 28 …

Environmental Monitoring Report: For Work To Be Performed: July 1, 2024 Through June 30, 2025, Tennessee. Department Of Environment And Conservation

Environmental Monitoring Reports

This FY2025 EMR presents results for independent projects, originally defined in TDEC’s FY2025 Environmental Monitoring Plan (EMP) and subsequently completed over the course of FY2025 period of performance.

Real-Time Immersive Wildfire Simulation: A Game Engine Approach, Jake Bova

Graduate Student Theses, Dissertations, & Professional Papers

Wildfires are growing in frequency, size, and severity, placing escalating demands on firefighting resources and putting lives, property, and ecosystems at risk. Accurate prediction of fire behavior is critical to suppression planning, evacuation decisions, and firefighter training, yet the operational models that fire managers rely upon face a persistent tradeoff. High-fidelity physics-based models capture fire–atmosphere interactions faithfully but are computationally expensive, often running far slower than real time on CPU hardware, while faster empirical models sacrifice the dynamic coupling between a fire and the wind field it generates. Furthermore, most existing tools produce abstract, two-dimensional outputs that offer limited visual …

Aquatic Invasive Species Survey And Treatment On Lake Umatilla And Lake Celilo 2024-2025 Report, Jacob Rose, Gabriel E. Campbell

Center for Lakes and Reservoirs Publications and Presentations

Flowering Rush (Butomus umbellatus) is an invasive aquatic plant in the Pacific Northwest that threatens salmon habitat. The Center for Lakes and Reservoirs staff surveyed for this and other aquatic species from 2024 and 2025 in the Columbia River in Lake Umatilla and Lake Celilo. This document summarizes their survey efforts including their protocols, data, and small-scale removal efforts.

Reinterpreting Stochastic Optimal Control Under Ecological Uncertainty: Inferring Decision Urgency From Vegetation Biomass Dynamics, Komi Mensah Agboka, Tobias Landmann, Elfatih M. Abdel-Rahman

All Peer-Reviewed Publications

Stochastic optimal control provides a rigorous framework for systems subject to uncertainty, yet its operational use in ecological crisis contexts remains limited by interpretability. We reinterpreted a stochastic control formulation in which selected parameters emerged as indicators of decision urgency rather than normative preferences. Vegetation biomass was modeled as a stochastic stock subject to nonlinear loss driven by feeding pressure (e.g., desert locust activity) and multiplicative noise, with uncertainty represented by a time-varying volatility term that integrated extreme rainfall anomalies and conflict-related disruption. Rather than prescribing an optimal policy, we inverted the closed-form solution of the control problem to infer …

Improving Human Dimensions Of Conservation Planning: Challenges And Opportunities For Sustainable Conservation Outcomes, Vivian Hulugh

Electronic Theses and Dissertations

Conservation planning is important to ensure both ecological and social benefits of natural resources, including the maintenance of functional ecosystems and stable wildlife populations as well as the provision of resources that communities rely on. Yet, the integration of the human dimensions of conservation planning remains limited in practice. This thesis examines conservation planning in South Dakota and within Joint Venture (JV) partnerships, using qualitative methods to identify challenges and opportunities for more effective and coordinated planning. In chapter one, I examine how collaboration, public participation, and the use of climate information are integrated conservation planning in South Dakota and …

A Preliminary Investigation Of Research Collaboration Through Scientific Paper Co-Authorship In The Gulf Of Mexico, Juliet Vallejo, Evelyn Roozee, Dongkyu Kim, Andrew M. Song, Christopher A. Gabler, Jasper R. De Vries, Antonia Sohns, Gordon M. Hickey, Owen Temby

School of Earth, Environmental, & Marine Sciences Faculty Publications

It is well known that publications with collaborators from external institutions increase citations. This effect scales with spatial distance. There are also many barriers to long-distance collaborations, including linguistic differences, funding constraints, and the incremental costs of remote collaboration. This paper uses the Gulf of Mexico as a case study to examine long-distance research collaboration because it consists of three countries with diverse development levels and two prominent diplomatic languages, within a singular regional ecosystem of tremendous natural and economic value. This paper uses bibliometric network analysis to examine scientific research article co-authorship in the Gulf of Mexico from 2000 …

The Conservation Value Of Silvicultural Systems For Breeding And Post-Fledging Bird Communities In Northeastern North America, Christopher Andrew Liazos

Antioch University Dissertations & Theses

Forest bird community decline in the eastern United States is partly due to the lack of early-and-late-successional forests stemming from historic land use. Silviculture can create underrepresented forest age classes and structures to support avian communities during the breeding and post-fledging periods. In southwestern New Hampshire, we conducted a case study evaluating avian conservation value indices across silvicultural systems. Our goal was to observe how avian conservation value indexes and abundance differed between recently managed and unmanaged stands. We surveyed 215 breeding and 118 post-fledging points across 22 sites using point counts and vegetation surveys. Conservation values in the breeding …

Remembering Right Relations: A Land-Centered Framework For Settler Teacher Transformation, Aimee E. De Ney

Antioch University Dissertations & Theses

Settler colonialism is based in the separation of peoples from Lands and from one another, producing ongoing harm to human and more-than-human communities as evidenced in climate collapse, racialized violence, war, and widening social inequities. These conditions are sustained by ideologies of human supremacy-specifically white, male, Christian human supremacy-that deny personhood to most humans and to all more-than-humans, while enabling the attempted erasure of Indigenous peoples and the nation-state enforcement of anti-Black and anti-Brown racism. Situated on the Lands of the Coast Salish Peoples in the Pacific Northwest of the United States, this multiparadigmatic innovation dissertation develops a Land-centered framework …

Sustainable Justice: A Critical Contemplative Approach To Sustainability In Higher Education, Jessica A. Reneau

Antioch University Dissertations & Theses

The field of sustainability studies increasingly asks students to confront ecological crises alongside considerations of power, privilege, and unequal environmental harm. This work can be emotionally challenging as well as intellectually complex. Contemplative practices, such as meditation and yoga, may offer meaningful pedagogical support, helping students cultivate the attention, reflection, and emotional capacity needed to stay engaged with justice-centered sustainability learning. Although the use of contemplative pedagogies is growing in higher education, little research has examined how these practices shape justice-orientated learning outcomes in sustainability education. This dissertation addresses that gap by exploring how both student and instructor experience contemplative …

Climate Resilience In Action: Process-Based Equity For Co-Governed, Socially Cohesive, Ecologically Integrated Democracies Through The Design And Implementation Of Nature-Based Solutions, Donna Choih

Antioch University Dissertations & Theses

Nature-based Solutions (NbS) governance and behavior have the potential to become more equitable, beginning with a closer examination of what equity entails. Governance and behavior together are the actions manifest from internal dispositions and thoughts that facilitate the process of decision-making, in this case, for equitable NbS. This critical review seeks to (1) address the gap in literature on human development and behavioral dimensions of procedural justice for NbS by further defining process-based equity (PbE), and (2) present a framework of best practices for equitable NbS. This framework, along with a complementary conceptual model, was developed using the Preferred Reporting …

Green Space: Investigation Into The Role Pocket Parks Play In Biodiversity And Human Well-Being, Jacalyn Speicher

Antioch University Dissertations & Theses

Natural communities and the birds that inhabit them are essential to the physical and emotional well-being of human residents in urban settings. The action research undertaken in this study addresses the social and environmental justice issues of equity, accessibility, and diversity afforded avian and human communities in the design of pocket parks within the urban landscape. As urbanization consumes the natural landscape, people and birds must adapt to the novel challenges of a changing environment. I studied 10 pocket parks identified in Center City, Philadelphia, Pennsylvania between January and June 2026. This time frame spanned the seasons from winter to …

Agrivoltaics Swot Analysis For Implementation In The United States, Vani Ramesh

UROP Posters

Agrivoltaics is the implementation of solar installations alongside agricultural land in order to improve the efficiency of land usage in both industries. Research in European and Asian countries developing agriculture and solar developments in tandem has indicated that implementation in the United States, including Virginia, is feasible and beneficial. The US has the highest energy use per capita in the world, with the increase of various technologies has resulted in land developments using higher energy levels than previously. While Virginia’s energy demand has increased with the addition of data centers. Increased energy demand and food security requirements have unearthed policy/political …

Data-Driven Methodologies For Mapping Cultural Heritage: The Case Of The National Coal Heritage Area, West Virginia, Usa, Hossain Mohammad Nahyan

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this dissertation was to develop a comprehensive, data-driven spatial framework for characterizing the complex cultural landscape of the National Coal Heritage Area (NCHA) in West Virginia. By transitioning away from traditional, heuristic spatial mapping, this research integrates advanced spatial statistics, machine learning, and GIS-based methodologies to objectively quantify the physical, visual, and cultural dimensions of the post-mining environment. The research is structured around three interconnected empirical studies, each addressing a specific scale of the Landscape Character Assessment (LCA) framework to support heritage conservation and sustainable spatial planning. The first paper focused on landform classification, developing an automated …

Factors Influencing Eastern Wild Turkey (Meleagris Gallopavo Silvestris) Productivity And Nesting Chronology In West Virginia, Kirstin Palumbo

Graduate Theses, Dissertations, and Problem Reports (ETD)

Identifying drivers of variation in the timing of breeding behaviors, such as courtship activities and nesting chronology, is important for the effective management of avian species. Likewise, productivity is an important component of game bird population dynamics and can be broken up into multiple components such as the probability of nesting, clutch size, and nest success. One species that experiences a relatively long reproductive season is the Eastern wild turkey (Meleagris gallopavo silvestris). Contemporary research in the southeastern United States has raised concerns regarding declines in both wild turkey populations and overall productivity. West Virginia, however, is unique …

Does Diverse Seeding Adoption Reduce Production Costs? The Case Of Diverse Forage Seeding Strategies In West Virginia., Ivan Andres Wong

Graduate Theses, Dissertations, and Problem Reports (ETD)

Feed and harvested forage represent a major share of production costs in Appalachian cow-calf systems, where a pronounced summer forage gap forces producers to rely on purchased hay. This thesis evaluates whether adopting diverse forage seeding strategies reduces production costs relative to the existing pasture management practice, accounting for the spatial heterogeneity of West Virginia’s production environments. The analysis proceeds in two steps. First, an unsupervised K-means clustering of 14 farms enrolled in the NRCS Conservation Innovation Grant field trial groups the farms into two agroclimatic clusters, Highland-Cool and LowlandWarm, using elevation, growing-season Growing Degree Days, growing-season precipitation, and soil …

Element-Based Predictive Modeling Of Hydrothermal Liquefaction Bioproducts Derived From Corn Stover, Isamu Umeda, Meicen Liu, Yi Zheng, Jiefu Wang, Zhiwu Wang, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

The hydrothermal liquefaction (HTL) process offers an energetic advantage over pyrolysis because it does not require prior drying of the biomass feedstock. However, there are significant challenges in simultaneously estimating both the yields and characteristics of products from the HTL of biomass with theoretical support. This study developed a unique element-based kinetic model to predict the yields, higher heating values, and fuel characteristics of solid residue and heavy bio-oil, based on the temperature, residence time, solid loading, and elemental composition (C, H, N, and O) of corn stover. Furthermore, the model predicted the weights of dissolved carbon and nitrogen in …

Harnessing Activated Sludge For The Treatment Of Hydrothermal Liquefaction Wastewater: A Proof-Of-Concept Study, Cyrus Li, Jiefu Wang, Meicen Liu, Yi Zheng, Sandeep Kumar, Isamu Umeda, Chandan Mahata, John Norton

Civil & Environmental Engineering Faculty Publications

Although hydrothermal liquefaction (HTL) is the leading technology in converting wet biomass into bioenergy, the treatment of its toxic-laden aqueous phase wastewater presents a major challenge on its path toward commercial viability. This study presents the first-ever assessment of sewage sludge-fed HTL wastewater (SS-HTLWW) treatment and toxic compound removal using municipal activated sludge (AS) by optimizing its cultivation condition. It was found that AS with optimized pretreatment can remove up to 91.2% of the soluble chemical oxygen demand (sCOD) in SS-HTLWW, of which up to 82% can be attributed to biological mineralization and adsorption of sCOD by AS. Conventional bioprocess …

Resilient Built Environment: An Overview On Design Strategies For Coastal Adaptation To Sea Level Rise, Farzaneh Soflaei, Gelareh Abdolzadeh, Navid Ziaee, Mohammad Amin Jafari, Faeghe Borhani

Civil & Environmental Engineering Faculty Publications

This paper delves into the escalating risks faced by urban coastal communities due to tidal and storm flooding, exacerbated by climate change-induced Sea Level Rise (SLR). Projections indicate a potential increase in sea levels by at least 3 feet by 2100, with historical data revealing an average annual rise of 1.2-1.7 mm since the 1900s. With over 300 million individuals inhabiting coastal areas, low-lying regions emerge as particularly vulnerable to the impacts of SLR. This accelerated rise amplifies the significant challenge of nuisance flooding, a local-scale issue aggravated by high tide and winds, leading to inundation, road closures, infrastructure deterioration, …

Chesapeake Bay Water Clarity: Challenges And Successes, Jessica S. Turner, Carl T. Friedrichs, David B. Parrish, Kelsey A. Fall

OES Faculty Publications

The Chesapeake Bay is a large estuarine system spanning multiple jurisdictions and serves as a model for estuarine health worldwide. Historically, nutrient loading degraded water quality, prompting the need for regulation. Water clarity, one component of water quality, is vital for benthic communities and serves as a key indicator of overall ecosystem health. Here, physical resuspension and salinity gradients, nutrient and sediment inputs, production of organic detritus by phytoplankton, and benthic communities all interact to drive clarity patterns, with high spatial variability. Trends over the last 50 years show improvement, though with a temporary increase in organic detritus in response …

Contribution Of Non-Linear Internal Waves To Marine Net Primary Production Has Been Underestimated, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Shoude Guan, Fuh-Kuo Shiah

OES Faculty Publications

Field observations in the northern South China Sea (NSCS) indicate that elevated concentrations of chlorophyll a (Chl_a) associated with non-linear internal waves (NIWs) were more pronounced in the subsurface than at the sea-surface. At a given surface Chl_a, the vertically integrated Chl_a in an NIW-active area was 45% higher than that in an area where the NIW activities were minimal. As a result, net primary production (PP_eu) estimated from surface Chl_a from remote sensing by using the current Chl_a-based PP_eu model (e.g. VGPM) would have underestimated the true value by the same amount. If this correction is …

Unintended Consequences Of Estuarine Management Within The Trajectory Of Recovery: Examples From The Chesapeake Bay, Jessica S. Turner, Fei Da, Molly M. Mitchell

OES Faculty Publications

Estuaries are vital ecosystems that support biodiversity, human populations, and economic activities such as fisheries, aquaculture, and tourism. Managing estuarine systems often involves interventions to regulate sediment and nutrient inputs with the goal of improving water quality, and subsequently the economic values of the estuary. However, these management strategies can produce unintended consequences. The Chesapeake Bay is an estuary recovering from eutrophication which provides clear case studies for these patterns. In the Chesapeake Bay, decreased sediment inputs, resulting from shoreline stabilization and watershed modifications, can impair marsh resilience to sea level rise and disrupt sediment-light-algal interactions affecting water clarity. Likewise, …

Swimming In Uncertainty: Filling Data Gaps And Providing An Educational Platform For Beach Water Quality At Tybee Island, Georgia, Lukas Roberson

College of Graduate Studies: Theses & Dissertations

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Swimming in beaches water contaminated with high levels of bacteria can make you sick. Current monitoring at the public beaches on Tybee Island consists of weekly monitoring and enumeration of fecal indicator bacteria that takes 24 hours for results. If the number of bacteria exceed regulatory limits, a public health advisory is issued, and affected waters are retested until …

Investigation Of Mercury Bioaccessibility In Subsistence Fishes From The Canadian Subarctic, Kiran Mateo Sharma Mr

Theses and Dissertations (Comprehensive)

Fish consumption is the primary pathway for human exposure to methylmercury (MeHg), a global contaminant of concern known to cause adverse health effects. Fort Albany First Nation, a remote Indigenous community in northern Ontario that relies on fish for both subsistence and cultural practices, has expressed concern regarding the safety of local fish consumption. Community members and leaders have communicated several priorities for scientific research that are the foundation of this thesis. Specifically, consumers of wild-caught fish have asked how traditional cooking methods may affect mercury concentrations in fish, and how mercury concentrations in little-studied organs, such as liver and …

Satellite Observations Reveal Ecosystem Resistance And Resilience To Short-Term Water Stress Driven By Dominant Vegetation Along A Rainfall Gradient In Australia, Huanhuan Wang, Qiaoyun Xie, Sally E. Thompson, Caitlin E. Moore, David L. Miller, Erik J. Veneklaas, Richard P. Silberstein, Xing Li, Jingfeng Xiao, Belinda E. Medlyn, William K. Smith

Research outputs 2022 to 2026

Climate change is projected to intensify water stress in many ecosystems and poses threats to their stability, which can be quantified through ecosystem resistance and resilience. Relevant studies mostly focused on multi-year or annual droughts, and in spatially homogeneous or species-specific ecosystems. However, resilience and resistance within complex ecosystems, where different plants exhibit different adaptations and recovery behaviours, are less understood. Using productivity data from satellite-derived GOSIF (Global Orbiting Carbon Observatory-2 Solar-Induced Fluorescence) and flux towers, we examined vegetation responses to short-term (<1 year) water stress events from 2000 to 2018 along the North Australia Tropical Transect, which spans a 1600 mm rainfall gradient and transitions from seasonal mesic to non-seasonal arid ecosystems. We define resistance as productivity maintained during stress relative to a multi-year average baseline, and resilience as the extent to which productivity recovered one year after stress relative to the same baseline. Our results show that ecosystem resistance to water stress was lowest in semi-arid regions but higher in both arid and mesic regions, while ecosystem resilience showed the opposite pattern. These spatial patterns occurred regardless of seasonality and were mainly associated with dominant vegetation type. Woody savanna-dominated mesic regions exhibited highest resistance (0.82 ± 0.13, p < 0.001) and lowest resilience (0.26 ± 0.19, p < 0.001), shrublands in arid areas had intermediate values of both resistance (0.81 ± 0.14, p < 0.001) and resilience (0.27 ± 0.22, p < 0.001), while the grasslands in semi-arid regions had low resistance (0.78 ± 0.15, p < 0.001) and high resilience (0.38 ± 0.24, p < 0.001). The highest likelihood (>75.0 %) of full recovery (i.e., exceeding baseline after one year) occurred during the wet season in …

The Value Of Saltbush Revegetation For Biodiversity In A Highly Fragmented Landscape, Robert A. Davis, Michael D. Craig, Tim S. Doherty, Jonathan D. Majer, Eddie J.B. Van Etten

Research outputs 2022 to 2026

Secondary salinization is a significant global issue affecting up to 1 billion hectares of land, impacting biodiversity and particularly vegetation. One form of revegetation that can provide a return to landholders is saltbush (Atriplex spp.), which provides forage for a wide range of livestock. The effectiveness of saltbush plantings in providing useful habitat for fauna in agricultural landscapes suffering from secondary salinity is poorly understood. We aimed to address this knowledge gap by surveying bird, ant, and spider communities, and quantifying vegetation structure and floristic composition in saltbush and native woodlands in agricultural landscapes affected by secondary salinization in Western …

Biomarkers Of Foraging And Reproduction In Captive Adult Female Hawksbill Sea Turtles (Eretmochelys Imbricata), Joslyn Blessing Kent, Kari Renee Dawson, Shingo Fukada, Masae Makabe, Isao Kawazu, Ken Maeda, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hawksbill sea turtles (Eretmochelys imbricata) are listed as critically endangered by the International Union for the Conservation of Nature (IUCN). To implement best conservation practices for this species, its biology should be well understood. Attempting to characterize the foraging physiology of free-ranging hawksbill sea turtles is complicated by the fact that sampling is typically limited to nesting females during the reproductive season. Without data from non-reproductive periods, it is difficult to determine whether observed physiological values reflect baseline conditions or are specific to the energetically demanding nesting season. Accordingly, in this study, we described the physiology of foraging in …

A Critical Perspective On The Society Of Environmental Toxicology And Chemistry's Adherence To Founding Principles— Opportunities For The Future, Barnett A. Rattner, Annegaaike Leopold, Carys L. Mitchelmore, Glenn W. Suter, Mark S. Johnson, Adriana C. Bejarano, Lawrence A. Kapustka, Niranjana Krishnan, Derek C. G. Muir, Beatrice O. Opeolu, Martha Georgina Orozco-Medina, April Reed, Bruce W. Vigon, Adam R. Wronski

Epidemiology, Biostatistics, & Environmental Health Faculty Publications

The Society of Environmental Toxicology and Chemistry (SETAC) is a global organization whose mission is the advancement of environmental science and management through collaboration, leadership, communication and education. On SETAC's 45th anniversary, the following question was raised: Are the 1979 founding principles of SETAC, multidisciplinary approaches to solving environmental problems, multisector engagement and scientific objectivity, still useful, adequate and effective in fulfilling its mission? In a special session held at the 45th Annual Meeting in Fort Worth, Texas, United States, a critical evaluation of the founding principles was initiated by reviewing SETAC's history and ongoing activities, and recommendations were made …