Digital Commons Network^™

Modeling Recreational Risk Factors On The Landscape: A Predictive Gis Analysis Of Recreation Accident Response Near North Bend, Washington., Naomi S.J. Van Roon

All Master's Theses

Search and Rescue (SAR) teams in Washington respond to approximately 900 incidents annually, many stemming from outdoor recreation near Interstate 90 surrounding North Bend. This study utilized predictive GIS analysis to identify areas of concern within state lands, including Mount Si and Middle Fork Snoqualmie Natural Resource Conservation Areas, Raging River State Forest, and Rattlesnake Mountain Scenic Area. The predictive model was calibrated using SAR responses to hiking-related incidents between March and November from 2020 to 2023, and incorporated an analysis of risk factors influencing recreationalist incident probability. This research then developed a decision support system to aid land managers …

Big Tracks, Little Tracks: Following Animal Prints (1999) By Millicent E. Selsam, Maughn Rollins Gregory

Picture Books

Coming up with the most reasonable explanation of the available clues is something we all do on a daily basis. This book describes animal tracks as clues from which children can make inferences about what kind of animal left them and what they were doing when they did.

Possum That Didn't (1950/2016) By Arthur Frank Tashlin, Maughn Rollins Gregory, Peter Shea

Picture Books

The possum ‘that didn’t’ is a very contented animal who smiles in sunshine and rain, but when a group of human picnickers spot him hanging by his tail, they read his smile as a frown and call him stupid for insisting that he is happy. They decide to take him to the city to find amusement and, because he won’t climb down from the tree, they excavate it and transport tree and hanging possum together. Frank Tashlin's book goes philosophical in two different directions. One is the direction of satire: We laugh at humans taking a possum to a nightclub, …

How Beautiful (2021) By Antonella Capetti, Maughn Rollins Gregory

Picture Books

The question of what is and isn’t beautiful occurs to the caterpillar in this elaborate picture book when a giant Unknown Thing (human) lifts him out of his familiar leaf bed world and tells him, “You’re so beautiful.” The caterpillar wonders, “But what does beautiful mean?” The question leads him on a day-long trek through the forest, where other animals offer a variety of perplexing answers.

Depth Of The Lake And The Height Of The Sky (2017) By Kim Jihyun, Megan Jane Laverty

Picture Books

The Depth of the Lake and the Height of the Sky (2017) is KimJihyun’s first picture book; it is composed entirely of pictures. It “tells” the story of a young boy and his dog who spend a day swimming and sunbathing at a lake that is within walking distance from his grandparents' home, whom he is visiting with his parents. At first glance, the story might seem unremarkable, recounting an experience familiar to many. However, Kim’s illustrations challenge this assumption by drawing us into the boy’s encounter with nature. She creates a visual journey that guides us through a perceptual …

Testing The Effect Of Source And Environment On Native Seed Germination To Inform Seed-Based Restoration Of Grasslands, Brandon Clark

Electronic Theses and Dissertations

Grasslands are one of the most endangered ecosystems on the planet, and they provide a variety of important ecosystem services that people rely on. Losses of grasslands can be mitigated through restoration. Seed-based restoration is a regularly used practice due to its practicality and cost-effectiveness. Planting non-local seed that may not be suitable for its destination environment can have consequences in plant establishment and subsequent restoration success. This experiment tested the response (final germination and germination rate) of seed from 11 perennial tallgrass species sourced from 3 different locations to different germination temperature conditions. Seeds from three sources of each …

When Emotions Flare: Solar Rhythms, Emotions And Cycles Of Political Revolution, Andreas Hernandez, Carolina Zilli Vieira, Alexandra Smith, Rebecca Olson

Geography and Environmental Studies Faculty Publications

Revolutions are among the most transformative events in human history. Analyzing 395 revolutionary episodes from 1900 to 2014, we find that major waves cluster around solar maxima - periods of intensified geomagnetic activity. Drawing on biomedical research linking geomagnetic disturbances to cardiovascular and stress regulation, and thus to emotional states, we propose that solar cycles modulate the affective ecologies within which revolutions arise. Solar activity may accelerate, shape, and amplify revolutionary cycles by heightening emotional climates and tipping fragile systems toward mass mobilization. This reframes revolutions as planetary events - entanglements of political conflict, embodied emotion, and cosmic …

El Maíz Del Abuelo: Fidel Márquez Sanchez’S Legacy And Mexico’S Historical Maize Agriculture, Lucia Marquez-Uppman

Scripps Senior Theses

The Green Revolution was an era of scientific development in productive agricultural methods and technologies in the mid-twentieth century. High-yielding seed varieties, artificial fertilizers, irrigation infrastructure, pesticides, and herbicides all developed from this period. Texcoco, Mexico was the center of much of the Green Revolution's education and research from the 1940s onward at the Autonomous University of Chapingo, a prestigious agricultural school, with funding from the US-based philanthropic Rockefeller Foundation. Powerful consequences in the globe's agriculture emerged from the Green Revolution, including the production of maize, a staple crop in Mexico, especially for Indigenous and campesino populations. My abuelo, Fidel …

The Signal Of Airplane Combustion In Soil At A Small Airport In Ohio, Rachel Engels

Williams Honors College, Honors Research Projects

Leaded gas has been banned for automobile use in the interest of public health since 1996. However, leaded gas is still used for small piston aircraft so the engine can run safely. To investigate potential environmental impacts of leaded gas, 90 soil samples were taken from around a small airport in Ohio. Soil elemental composition was measured by X-ray fluorescence (XRF), soil organic content determined by Loss-on-Ignition (LOI), and soil ferrimagnetic content measured by magnetic susceptibility. There is an unmistakable airplane fuel combustion signal in the soil at the ends of the runway, where aircraft wait to take off on …

Navigating Online Perceptions Of Offshore Wind On Social Media: Facebook Discussions On Recent Whale Strandings, Giselle Hausmann

Open Access Master's Theses

The Biden-Harris administration implemented a goal to achieve 30 GW of offshore wind energy by 2030 (US Department of Interior, 2021). The rapid increase in offshore wind activity on the East Coast, combined with NOAA’s declared unusual mortality event in 2016/2017, has sparked a discussion about offshore wind being a potential cause of whale deaths. This paper aims to analyze the discourse on offshore wind and whales through a content analysis of Facebook comments. Facebook pages from Massachusetts (The New England Aquarium), Rhode Island (Rhode Island DEM), New York (The Atlantic Marine Conservation Society), New Jersey (Marine Mammal Stranding Center), …

From Lawns To Life: Landscaping For Biodiversity On Mason’S Island, Margit Burgess

Open Access Master's Theses

The collapse of biodiversity is an existential threat to life on Earth. Residential landscapes, dominated by open lawns maintained in turfgrass, do not support biodiversity. In the United States, turfgrass has replaced native landscapes in over 40 million acres, with 500 square miles added each year (Tallamy, 2019). Of the 78% of the U.S. land that is privately owned, approximately 135 million acres - nearly twice the size of all national parks combined - are residential (Milesi et al., 2005). With a shift in private landscape management, this land could present a largely untapped opportunity for biodiversity restoration and social …

Investigating The Effectiveness Of Best Management Practices In Reducing Fecal Bacteria In Narrow River, Rhode Island, Katherine Thompson

Open Access Master's Theses

Fecal bacterial contamination shapes how communities manage and use estuarine waters, with consequences for ecosystem health and public access. In Rhode Island's Narrow River, elevated concentrations of fecal coliforms and enterococci have restricted shellfishing for decades despite ongoing management efforts. From 2004 to 2018, local organizations implemented Best Management Practices (BMPs) to address water quality challenges, yet their effectiveness remains incompletely understood. This study analyzes three decades of monitoring data using linear regression, generalized additive models, and Before After Control Impact methods to evaluate BMP effectiveness and identify key drivers of contamination. Linear regression revealed spatially variable trends, with bacterial …

Spectrum Of The Lakes: Using Satellite Remote Sensing To Unveil Water Color In Minnesota's Sentinel Lakes For Water Quality Monitoring, Andrew J. Dooley, Wondwosen M. Seyoum, Catherine M. O'Reilly

Faculty Publications - Geography, Geology, and the Environment

Traditional water quality monitoring methods often face limitations of equipment costs and labor demands, requiring innovative approaches to effectively assess the ecological health of inland lakes across vast areas. This research explores the application of free, publicly available water color chromaticity analysis for midcontinent lakes in Minnesota, USA. We examined water color variations in Minnesota’s Sentinel Lakes using Landsat 8 OLI data to analyze surface reflectance samples collected from the deepest area within each lake during the late summer, corresponding to peak annual insolation and trophic activity. The median dominant visible wavelength was used to characterize water color. Results indicate …

Computational Assessment Of Vitrimers Self-Healing For Renewable Energy And Aerospace Structures, Walaaeldin Mohamed Ahmed Derbala

Browse all Theses and Dissertations

Self-healing polymers, particularly vitrimers, are emerging as promising candidates in the development of advanced materials for renewable energy and aerospace structures. These materials exhibit dynamic covalent bond exchange mechanisms that enable reprocess ability, damage repair, and extended operational lifetime under harsh conditions. This study presents a density functional theory (DFT)-based computational investigation of the mechanistic pathways and energetics of bond exchange reactions in model vitrimer systems. We explore transition states, energy barriers, and thermodynamic features corresponding to associative and dissociative self-healing reactions in vitrimers. The study focuses on Diaminodiphenyl disulfide (AFD), a bifunctional molecule composed of two para-substituted aminophenyl rings …

Estimating The Carbon Footprint Of Sheep Production In Western Australia, Tafesse Estifanos, Christophe D'Abbadie, Johnny Machon, Amir Abadi Abadi Ghadim, Gus Manatsa, Paul Mattingley, Ross Kingwell, Kevin Foster

Farm Systems and Economics published reports

Western Australia’s broadacre mixed farming systems combine cropping and sheep production and are the largest component of the state’s agricultural sector. The south west Western Australia (WA) agricultural area hosts about 98% of the state's sheep flock. The sheep industry contributed $1.5 billion to the state’s economy in 2021-22 and accounts for about a quarter of on-farm greenhouse gas (GHG) emissions. Most sheep industry emissions (over 80%) come from methane produced by the sheep. Despite this environmental impact, only 9.9% of Australian sheep producers have estimated their emissions, which limits the industry's ability to monitor and manage carbon footprints effectively. …

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 …

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 …

It’S Time To Stop Calling People "Stakeholders", Bethann Garramon Merkle, Evelyn Valdez-Ward, Priya Shukla, Skylar R. Bayer

Human–Wildlife Interactions

Although the term “stakeholder” has been widely used in science communication, recent expansion in the discourse around the negative connotations of the term necessitate that scientists and practitioners cease using the term. We discuss why this shift is necessary, how it affects our own praxis, and suggest resources for working through more respectful and just language. Looking to the science communication literature can help recalibrate terminology in positive ways.

Food Rescue, Food Waste, And Policy In New York: A Mixed-Methods Study Of Food System Impacts, Mariana Torres Arroyo

Electronic Theses & Dissertations (2024 - present)

This dissertation investigates how food donation policies in New York State influence the recovery, redistribution, and waste of surplus fresh produce, with a focus on fruits and vegetables. Using an interdisciplinary, systems-based approach that integrates system dynamics modeling with qualitative, community-engaged research, the study analyzes the effectiveness and unintended consequences of three major policies: Nourish New York, the Farm to Food Bank tax credit, and the Food Donation and Food Scraps Recycling Law.

Chapter 2 uses simulation modeling to examine how the tax credit and waste ban affect produce recovery and redistribution. Results show that while both policies can boost …

Comparison Of Methane Emission Quantification Methods At Landfills In New York State, Alexandra M. Catena

Electronic Theses & Dissertations (2024 - present)

Greenhouse gas (GHG) emission increases are a consequence of global population rise and economic growth. It is well known that carbon dioxide is the dominant GHG by mass, but methane has received increasing attention recently due to its high warming potential and relatively short lifetime of about a decade. Methane has several different types of both natural and anthropogenic sources including wetlands, waste management, energy, agriculture and farming, and wildfires, which makes tracking and reducing methane emissions a complex problem. The emission rates of each of these sources are highly uncertain due to differing emission estimation methods, which can be …

How To Be A Nature Detective (1966) By Millicent E. Selsam, Maughn Rollins Gregory

Picture Books

Coming up with the most reasonable explanation of the available clues is something we all do on a daily basis. This book describes animal tracks as clues from which children can make inferences about what kind of animal left them and what they were doing when they did.

Behavioral Response Of Wild Greater Caribbean Manatees (Trichechus Manatus Manatus) To Playbacks Of Conspecifics In Maya Beach, Belize, Phoebe Sonia Hodson

Antioch University Dissertations & Theses

The behavioral response of the wild Greater Caribbean manatee (Trichechus manatus manatus) to the acoustic vocalizations of their closely related subspecies, the Florida manatee (Trichechus manatus latirostris), was examined for the first time in Placencia Lagoon, Maya Beach, Belize. The main goal of this study was to determine how vocalizations from conspecifics influence the behavior of the wild Greater Caribbean manatee and how this behavioral change may give insight into the functionality of manatee vocalizations. Three call types (squeak, squeal and high squeak) and chewing sounds were played to varying size aggregations of manatees. Broad behavioral …

Substrate Preference And Foraging Behavior Of Two Declining Warblers In Appalachian Shrublands, Samantha Fishman

Theses and Dissertations

Abstract Shrubland and early successional habitats (ESH) support a diversity of wildlife, including many declining songbirds. However, nonnative shrubs increasingly dominate these habitats, potentially altering habitat quality by influencing prey availability. Habitat quality can be assessed by observing foraging behaviors of songbirds and identifying preferred and avoided substrates as well as testing the predictions of optimal foraging theory; specifically that birds will maximize their energy gain relative to the costs. We examined foraging behaviors of Golden-winged Warblers (Vermivora chrysoptera; GWWA) and Chestnut-sided Warblers (Setophaga pensylvanica; CSWA) in ESH on private lands in Virginia with varying amounts …

Climate Variability Study For Arid Regions, Faisal Almutairi

Electronic Theses and Dissertations

Water is the primary source for all living species to thrive, and water scarcity has been a primary concern for biological species and plants in arid regions due to urban planning, population growth, poor water management, and overgrazing. The objective of this research was to study the climate variability in precipitation and temperature for an arid region. This research encompasses two distinct studies. The first study examined the impact of climate variability on precipitation in Phoenix. Precipitation data were acquired from NOAA from 1948 to 2023 and the study was broken down into three time scales: annually, seasonally, and monthly. …

Prospective Use Of Detection Dogs As A Screening Tool For Mycoplasma Ovipneumoniae In Bighorn Sheep (Ovis Canadensis), Michele C. Lovara

Electronic Theses and Dissertations

Mycoplasma ovipneumoniae is a bacterium that can spill over from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis), with effects in bighorn sheep ranging from low to no lamb recruitment to whole-herd all-age die-offs from resulting pneumonia. Fast and reliable pathogen or disease detection is essential for managing outbreaks in bighorn sheep and emergences in affected populations. Detection dogs are increasingly being enlisted to close gaps and further complement various disease, pathogen and virus research and response efforts. This thesis explores the use of conservation detection dogs as a potential tool for M. ovipneumoniae surveillance in bighorn sheep through …

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 …

Quantifying Biodiversity In The Absence Of Taxonomic Data: A Study Of Thailand’S Economic Development Zones, Nikorn Mahawan, Wanpen Charoentrakulpeeti

Applied Environmental Research

The biodiversity status measures the ecological capacity of a given area. However, biodiversity assessments in developing countries are limited by the absence of taxonomic data on plants and animals. By developing methods to evaluate biodiversity via alternative data, it is now possible to quantify the ecological carrying capacity in areas where taxonomic data are lacking. The relationship between forest ecosystem health and biodiversity values can be used to estimate biodiversity values by considering the proportions of different land use types that are associated with forest ecosystem abundance. The biodiversity value of the area can be assessed by adding the abundance …

Using A Water Quality Index To Assess The Impacts Of Heavy Metals Contamination For Sustainable Water Management: A Case Study Of The Bang Pakong River, Thailand, Khin Yadana Soe, Pokchat Chutivisut, Wilailuk Niyommaneerat

Applied Environmental Research

Anthropogenic activities such as improper waste disposal, excessive fertilizer use, and industrial effluents cause heavy metal contamination in water, soil, and the atmosphere. Herein, the water quality index (WQI) was used to characterize heavy metal (i.e., cadmium (Cd), arsenic (As), and mercury (Hg)) contamination in the Bang Pakong River, Thailand. Specifically, water samples were collected during the dry season from four stations along the river from 2012–2022. The heavy metal concentrations in the samples were analyzed via atomic absorption spectrophotometry, and WQI values were calculated on the basis of standard water quality parameters. At the four sampling stations, high As …

Halotolerant Biodegradation And Detoxification Of Synthetic Dyes By Marine-Derived Penicillium Oxalicum M6a: Metabolite Profiling And Ecotoxicity Assessment, Ugochukwu Okechukwu Ozojiofor, Mohammed Sani Abdulsalami, Nkechi Eucharia Egbe, Ahmed Ali Haroun, Yakubu Magaji

Applied Environmental Research

The complex aromatic structures of synthetic dyes in contaminated water bodies make them difficult to degrade, posing a serious environmental challenge and representing a significant emerging pollutant that warrants urgent intervention. This study evaluated the biodegradation and detoxification potential of a halotolerant, marine-derived fungal strain, Penicillium oxalicum M6A, isolated from the Nigerian coastline, against Indigo carmine (IC) and Remazol Brilliant Blue R (RBBR). The effects of pH, temperature, salinity, and dye concentration on degradation efficiency, alongside enzymatic activity, were assessed. FTIR and GC‒MS analyses were employed to identify degradation products and predict metabolic pathways, whereas toxicity was evaluated in three …

Investigating Spatial And Temporal Changes In Vegetation Via Remote Sensing Indicators And Revealing Their Trends In The Central Desert Of Iran, Peyman Akbarzadeh, Shima Nikoo, Mehran Akbarzadeh

Applied Environmental Research

Vegetation changes can significantly affect the conditions and productivity of ecosystems. Consequently, studying vegetation dynamics across various temporal and spatial scales has emerged as a critical environmental concern. The aim of this study was to investigate changes in vegetation cover via vegetation indices, including the normalized difference vegetation index (NDVI), ratio vegetation index (RVI), soil adjusted vegetation index (SAVI), and difference vegetation index (DVI), derived from multitemporal Landsat 5, 7, and 8 satellite images processed via the Google Earth Engine. The study area is located in the Damghan arid and desert watershed, which represents the central desert of Iran. Furthermore, …