Matching Items (129)
Description
ABSTRACT Over the past several decades, the dilemma of free-roaming horses in the U.S. has proven to be one of the most divisive issues in management of public lands. According to federal land management agencies, without population regulation, horses can increase at the rate of 15-20% a year on arid rangelands with inadequate numbers of natural, large predators. Horses compete for valuable forage and water resources alongside cattle and native wildlife in delicate riparian areas highly susceptible to the negative ecological effects of soil compaction and overgrazing. Most U.S. management policies, therefore, call for increased removal of free-roaming horses as they are categorized as “un-authorized livestock” or "non-native" species. Wild horse advocates, however, continue to petition for improvement in animal welfare and expansion of the horses’ territory. With heightened social conflict spurred by animal rights and ecological concerns, not to mention the often-stark differences over what really “belongs” on the landscape, the success of appropriate management strategies hinges on managing agencies’ preparedness and ability to respond in a timely and inclusive manner. A critical element of the management context is the public’s views toward the wild horse and the science used to manage them. Synthesizing the vast literature in the history and philosophy of wildlife management in the American West, and utilizing an ethnographic and case study approach, my research examines the range of stakeholder concerns and analyzes the factors that have led to the disconnect between public values of wild horses and public policy for the management of the federally protected free-roaming horses in Arizona’s Apache-Sitgreaves National Forests.
ContributorsMurphree, Julie Joan (Author) / Minteer, Ben A. (Thesis advisor) / Schoon, Michael (Thesis advisor) / Bradshaw, Karen (Committee member) / Chew, Matthew (Committee member) / Arizona State University (Publisher)
Created2022
Description
Dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) are crucial nutrients for autotrophic and heterotrophic microbial life, respectively, in hydrothermal systems. Biogeochemical processes that control amounts of DIC and DOC in Yellowstone hot springs can be investigated by measuring carbon abundances and respective isotopic values. A decade and a half of field work in 10 regions within Yellowstone National Park and subsequent geochemical lab analyses reveal that sulfate-dominant acidic regions have high DOC (Up to 57 ppm C) and lower DIC (up to 50 ppm C) compared to neutral-chloride regions with low DOC (< 2 ppm C) and higher DIC (up to 100 ppm C). Abundances and isotopic data suggest that sedimentary rock erosion by acidic hydrothermal fluids, fresh snow-derived meteoric water, and exogenous carbon input allowed by local topography may affect DOC levels. Evaluating the isotopic compositions of DIC and DOC in hydrothermal fluids gives insight on the geology and microbial life in the subsurface between different regions. DIC δ13C values range from -4‰ to +5‰ at pH 5-9 and from -10‰ to +3‰ at pH 2-5 with several springs lower than -10‰. DOC δ13C values parkwide range from -10‰ to -30‰. Within this range, neutral-chloride regions in the Lower Geyser Basin have lighter isotopes than sulfate-dominant acidic regions. In hot springs with elevated levels of DOC, the range only varies between -20‰ and -26‰ which may be caused by local exogenous organic matter runoff. Combining other geochemical measurements, such as differences in chloride and sulfate concentrations, demonstrates that some regions contain mixtures of multiple fluids moving through the complex hydrological system in the subsurface. The mixing of these fluids may account for increased levels of DOC in meteoric sulfate-dominant acidic regions. Ultimately, the foundational values of dissolved carbon and their isotopic composition is provided in a parkwide study, so results can be combined with future studies that apply different sequencing analyses to understand specific biogeochemical cycling and microbial communities that occur in individual hot springs.
ContributorsBarnes, Tanner (Author) / Shock, Everett (Thesis advisor) / Meyer-Dombard, D'Arcy (Committee member) / Hartnett, Hilairy (Committee member) / Arizona State University (Publisher)
Created2023
Description
Communications around sustainability have been found to be incongruent with eliciting the transformative change required to address global climate change and its' repercussions. Recent research has been exploring storytelling in sustainability, specifically with an emphasis on reflexive and emancipatory methods. These methods encourage embracing and contextualizing complexity and intend to target entire cognitive hierarchies. This study explores the possibility of using emancipatory and reflexive storytelling as a tool to change attitudes pertaining to the Valley Metro Light Rail, an example of a complex sustainability mitigation effort. I explore this in four steps: 1) Conducted a pre-survey to gauge preexisting attitudes and predispositions; 2) Provided a narrative that uses storytelling methodologies of reflexivity and emancipation through a story about the light rail; 3) Conducted a post-survey to gauge attitude shift resulting from the narrative intervention; 4) Facilitated a focus group discussion to examine impact qualitatively. These steps intended to provide an answer to the question: How does emancipatory and reflexive storytelling impact affective, cognitive and conative attitudes regarding local alternative transportation? By using tripartite attitude model, qualitative and quantitative analysis this paper determines that reflexive and emancipatory storytelling impacts attitudinal structures. The impact is marginal in the survey response, though the shift indicated a narrowing of participant responses towards one another, indicative of participants subscribing to emancipation and reflexivity of their held attitudes. From the group discussion, it was evident from qualitative responses that participants engaged in emancipating themselves from their held attitudes and reflected upon them. In doing so they engaged in collaboration to make suggestions and suggest actions to help those with experiences that differed from their own. Though this research doesn’t provide conclusive evidence, it opens the door for future research to assess these methodologies as a tool to elicit shared values, beliefs and norms, which are necessary for collective action leading to transformative change in response to global climate change.
ContributorsSwanson, Jake Ryan (Author) / Roseland, Mark (Thesis advisor) / Larson, Kelli (Committee member) / Calhoun, Craig (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
As air quality standards become more stringent to combat poor air quality, there is a greater need for more effective pollutant control measures and increased air monitoring network coverage. Polluted air, in the form of aerosols and gases, can impact respiratory and cardiovascular health, visibility, the climate, and material weathering. This work demonstrates how traditional networks can be used to study generational events, how these networks can be supplemented with low-cost sensors, and the effectiveness of several control measures. First, an existing network was used to study the effect of COVID-19 travel restrictions on air quality in Maricopa County, Arizona, which would not have been possible without the historical record that a traditional network provides. Although this study determined that decreases in CO and NO2 were not unique to the travel restrictions, it was limited to only three locations due to network sparseness. The second part of this work expanded the traditional NO2 monitoring network using low-cost sensors, that were first collocated with a reference monitor to evaluate their performance and establish a robust calibration. The sensors were then deployed to the field to varying results; their calibration was further improved by cycling the sensors between deployment and reference locations throughout the summer. This calibrated NO2 data, along with volatile organic compound data, were combined to enhance the understanding of ozone formation in Maricopa County, especially during wildfire season. In addition to being in non-attainment for ozone standards, Maricopa County fails to meet particulate matter under 10 μm (PM10) standards. A large portion of PM10 emissions is attributed to fugitive dust that is either windblown or kicked up by vehicles. The third part of this work demonstrated that Enzyme Induced Carbonate Precipitation (EICP) treatments aggregate soil particles and prevent fugitive dust emissions. The final part of the work examined tire wear PM10 emissions, as vehicles are another significant contributor to PM10. Observations showed a decrease in tire wear PM10 during winter with little change when varying the highway surface type.
ContributorsMiech, Jason Andrew (Author) / Herckes, Pierre (Thesis advisor) / Fraser, Matthew P (Committee member) / Shock, Everett (Committee member) / Arizona State University (Publisher)
Created2023
Description
The prevalence and unique properties of airborne nanoparticles have raised concerns regarding their potential adverse health effects. Despite their significance, the understanding of nanoparticle generation, transport, and exposure remains incomplete. This study first aimed to assess nanoparticle exposure in indoor workplace environments, in the semiconductor manufacturing industry. On-site observations during tool preventive maintenance revealed a significant release of particles smaller than 30 nm, which subsequent instrumental analysis confirmed as predominantly composed of transition metals. Although the measured mass concentration levels did not exceed current federal limits, it prompted concerns regarding how well filter-based air sampling methods would capture the particles for exposure assessment and how well common personal protective equipment would protect from exposure. To address these concerns, this study evaluated the capture efficiency of filters and masks. When challenged by aerosolized engineered nanomaterials, common filters used in industrial hygiene sampling exhibited capture efficiencies of over 60%. Filtering Facepiece Respirators, such as the N95 mask, exhibited a capture efficiency of over 98%. In contrast, simple surgical masks showed a capture efficiency of approximately 70%. The experiments showed that face velocity and ambient humidity influence capture performance and mostly identified the critical role of mask and particle surface charge in capturing nanoparticles. Masks with higher surface potential exhibited higher capture efficiency towards nanoparticles. Eliminating their surface charge resulted in a significantly diminished capture efficiency, up to 43%. Finally, this study characterized outdoor nanoparticle concentrations in the Phoenix metropolitan area, revealing typical concentrations on the order of 10^4 #/cm3 consistent with other urban environments. During the North American monsoon season, in dust storms, with elevated number concentrations of large particles, particularly in the size range of 1-10 μm, the number concentration of nanoparticles in the size range of 30-100 nm was substantially lower by approximately 55%. These findings provide valuable insights for future assessments of nanoparticle exposure risks and filter capture mechanisms associated with airborne nanoparticles.
ContributorsZhang, Zhaobo (Author) / Herckes, Pierre (Thesis advisor) / Westerhoff, Paul (Committee member) / Shock, Everett (Committee member) / Fraser, Matthew (Committee member) / Arizona State University (Publisher)
Created2023
Description
Understanding the dynamic interactions between humans and wildlife is essential to establishing sustainable wildlife-based ecotourism (WBE). Animal behavior exists within a complex feedback loop that affects overall ecosystem function, tourist satisfaction, and socioeconomics of local communities. However, the specific value that animal behavior plays in provisioning ecosystem services has not been thoroughly evaluated. People enjoy activities that facilitate intimate contact with animals, and there are many perceived benefits associated with these experiences, such as encouraging pro-environmental attitudes that can lead to greater motivation for conservation. There is extensive research on the effects that unregulated tourism activity can have on wildlife behavior, which include implications for population health and survival. Prior to COVID-19, WBE was developing rapidly on a global scale, and the pause in activity caused by the pandemic gave natural systems the chance to recover from environmental damage from over-tourism and provided insights into how tourism could be less impactful in the future. Until now it has been undetermined how changes in animal behavior can alter the relationships and socioeconomics of this multidimensional system. This dissertation provides a thorough exploration of the behavioral, ecological, and economic parameters required to model biosocial interactions and feedbacks within the whale watching system in Las Perlas Archipelago, Panama. Through observational data collected in the field, this project assessed how unmanaged whale watching activity is affecting the behavior of Humpback whales in the area as well as the socioeconomic and conservation contributions of the industry. Additionally, it is necessary to consider what a sustainable form of wildlife tourism might be, and whether the incorporation of technology will help enhance visitor experience while reducing negative impacts on wildlife. To better ascertain whether this concept of this integration would be favorably viewed, a sample of individuals was surveyed about their experiences about using technology to enhance their interactions with nature. This research highlights the need for more deliberate identification and incorporation of the perceptions of all stakeholders (wildlife included) to develop a less-impactful WBE industry that provides people with opportunities to establish meaningful relationships with nature that motivate them to help meet the conservation challenges of today.
ContributorsSurrey, Katie (Author) / Gerber, Leah (Thesis advisor) / Guzman, Hector (Committee member) / Minteer, Ben (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
University-level sustainability education in Western academia attempts to focus on eliminating future harm to people and the planet. However, Western academia as an institution upholds systems of oppression and reproduces settler colonialism. This reproduction is antithetical to sustainability goals as it continues patterns of Indigenous erasure and extractive relationships to the Land that perpetuate violence towards people and the planet. Sustainability programs, however, offer several frameworks, including resilience, that facilitate critical interrogations of social-ecological systems. In this thesis, I apply the notion of resilience to the perpetuation of settler colonialism within university-level sustainability education. Specifically, I ask: How is settler colonialism resilient in university-level sustainability education? How are, or could, sustainability programs in Western academic settings address settler colonialism? Through a series of conversational interviews with faculty and leadership from Arizona State University School of Sustainability, I analyzed how university-level sustainability education is both challenging and shaped by settler colonialism. These interviews focused on faculty perspectives on the topic and related issues; the interviews were analyzed using thematic coding in NVivo software. The results of this project highlight that many faculty members are already concerned with and focused on challenging settler colonialism, but that settler colonialism remains resilient in this system due to feedback loops at the personal level and reinforcing mechanisms at the institutional level. This research analyzes these feedback loops and reinforcing mechanisms, among others, and supports the call for anti-colonial and decolonial reconstruction of curriculum, as well as a focus on relationship building, shifting of mindset, and school-wide education on topics of white supremacy, settler colonialism, and systems of oppression in general.
ContributorsBills, Haven (Author) / Klinsky, Sonja (Thesis advisor) / Goebel, Janna (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2022
Description
In 1996, a floral and faunal inventory of the southeastern slopes of the Marojejy Massif, which falls in a protected area known as the Parc national de Marojejy, was conducted in an ascending series of altitudinal transect zones. The 1996 research team worked in five altitudinal zones (referred to as transect zones). Between 3 October and 15 November 2021, a floral and faunal inventory was completed, replicating the locations surveyed in 1996 and closely the dates. Detected bird species were analyzed for changes in elevational distribution between 1996 and 2021. Birds were divided into three feeding behavior groups and tolerance to forest habitat degradation was considered.
ContributorsLangrand, Tahiry (Author) / Schoon, Michael (Thesis director) / Goodman, Steve (Committee member) / Barrett, The Honors College (Contributor) / School of Complex Adaptive Systems (Contributor) / School of International Letters and Cultures (Contributor) / School of Sustainability (Contributor)
Created2022-05
Description
Lithium (Li) is a trace element in kerogen, but the content and isotopic distribution (δ7Li) in kerogen has not previously been quantified. Furthermore, kerogen has been overlooked as a potential source of Li to sedimentary porefluids and buried sediments. Thus, knowing the content and isotopic composition of Li derived from kerogen may have implications for research focused on the Li-isotopes of buried sediments (e.g., evaluating paleoclimate variations using marine carbonates).The objective of this work is to better understand the role of kerogen in the Li geochemical cycle. The research approach consisted of 1) developing reference materials and methodologies to measure the Li-contents and δ7Li of kerogen in-situ by Secondary Ion Mass Spectrometry, 2) surveying the Li-contents and δ7Li of kerogen bearing rocks from different depositional and diagenetic environments and 3) quantifying the Li-content and δ7Li variations in kerogen empirically in a field study and 4) experimentally through hydrous pyrolysis.
A survey of δ7Li of coals from depositional basins across the USA showed that thermally immature coals have light δ7Li values (–20 to – 10‰) compared to typical terrestrial materials (> –10‰) and the δ7Li of coal increases with burial temperature suggesting that 6Li is preferentially released from kerogen to porefluids during hydrocarbon generation. A field study was conducted on two Cretaceous coal seams in Colorado (USA) intruded by dikes (mafic and felsic) creating a temperature gradient from the intrusives into the country rock. Results showed that δ7Li values of the unmetamorphosed vitrinite macerals were up to 37‰ lighter than vitrinite macerals and coke within the contact metamorphosed coal.
To understand the significance of Li derived from kerogen during burial diagenesis, hydrous pyrolysis experiments of three coals were conducted. Results showed that Li is released from kerogen during hydrocarbon generation and could increase sedimentary porefluid Li-contents up to ~100 mg/L. The δ7Li of coals becomes heavier with increased temperature except where authigenic silicates may compete for the released Li. These results indicate that kerogen is a significant source of isotopically light Li to diagenetic fluids and is an important contributor to the global geochemical cycle.
ContributorsTeichert, Zebadiah (Author) / Williams, Lynda B. (Thesis advisor) / Bose, Maitrayee (Thesis advisor) / Hervig, Richard (Committee member) / Semken, Steven (Committee member) / Shock, Everett (Committee member) / Arizona State University (Publisher)
Created2022
Description
The Greater Obsidian Pool Area just south of the Mud Volcano area in Yellowstone National Park is an active and ever-changing hot spring region. Situated next to a lake in a meadow between several hills of glacial deposits, north of the Elephant Back rhyolite flow, a diverse group of hot springs has been developing. This study examines the geologic and geomorphic context of the hot springs, finding evidence for a previously undiscovered hydrothermal explosion crater and examining the deposits around the region that contribute to properties of the groundwater table. Hot spring geochemical measurements (Cl- and SO4-2) taken over the course of 20 years are used to determine fluid sourcing of the springs. The distribution of Cl-, an indicator of water-rock interaction, in the hot springs leads to the theory of a fissure delivering hydrothermal fluid in a line across the hot spring zone, with meteoric water from incoming groundwater diluting hot springs moving further from the fissure. A possible second dry fissure delivering mostly gas is also a possible explanation for some elevated sulfate concentrations in certain springs. The combination of geology, geomorphology, and geochemistry reveals how the surface and subsurface operate to generate different hot spring compositions.
ContributorsAlexander, Erin (Author) / Shock, Everett (Thesis director) / Whipple, Kelin (Committee member) / Barrett, The Honors College (Contributor) / School of Earth and Space Exploration (Contributor) / School of Molecular Sciences (Contributor)
Created2022-05