Matching Items (47)
Description
Marine plastic pollution (MPP) has emerged as one of the most pressing global environmental challenges of the anthropocene. There has been an upsurge in investment to mitigate MPP; however, interventions can be costly, inequitable, and ineffective in achieving their objectives. In my dissertation, I aim to research key considerations for creating cost-effective, equitable mitigation strategies for MPP and its impacts to marine biodiversity and coastal communities. In chapter one, I introduce the challenges plastic pollution poses. In chapter two, I use seascape ecology theory to present the concept of the plastic-scape and describe how seascape ecology principles, methods, and approaches to transdisciplinary science can inform research to mitigate MPP. In chapter three, I present a framework to help decision makers estimate the total cost of MPP interventions and partial costs accrued by stakeholder groups. I then apply this framework to two quantitative case studies and four comparative case studies to exemplify its use and highlight the ways spatial scale, temporal scale, and socio-economic conditions influence the intervention cost and cost distribution. In chapter four, I employ a trait-based approach to produce a framework for developing indices of species vulnerability to macroplastic pollution. Finally, in chapter five, I implement the framework developed in the previous chapter and present a multi-taxonomic, macroplastic vulnerability index for three marine taxa—mammals, birds, and turtles—to identify the marine species most vulnerable to macroplastic pollution in Hawai‘i. Overall, my dissertation shows how policy-driven, systemic research of MPP and its interventions can improve efforts to address MPP and its socio-economic and ecological consequences.
ContributorsMurphy, Erin (Author) / Gerber, Leah R (Thesis advisor) / Polidoro, Beth (Thesis advisor) / Rochman, Chelsea (Committee member) / Dooley, Kevin (Committee member) / Arizona State University (Publisher)
Created2023
Description
Las Cienegas National Conservation Area (LCNCA), located in southeastern Arizona, is a place of ecological and historical value. It is host to rare native, threatened and endangered fauna and flora. as well as the site of the oldest operating ranch in the state. The first chapter of this thesis provides a preliminary flora of vascular plants at LCNCA assembled from field collections, photographs and herbarium specimens, and published through the online database SEINet. This preliminary flora of LCNCA identified 403 species in 76 families. Less than 6% of the flora is non-native, perennial forbs and grasses are the most abundant groups, and over a third of species in the checklist are associated with wetlands. LCNCA has been the target of adaptive management and conservation strategies to preserve its biotic diversity, and results from this study will help inform actions to preserve its rare habitats including cottonwood willow forests, mesquite bosques, sacaton grasslands, and cienegas. The second chapter investigates poorly understood aspects of the life history of the endangered Huachuca Water Umbel (Lilaeopsis schaffneriana subsp. recurva. Apiaceae) (hereafter HWU). This wetland species occurs in scattered cienegas and streams in southeastern Arizona and northern Sonora, Mexico. Three studies were conducted in a greenhouse to investigate seed bank establishment, seed longevity, and drought tolerance. A fourth study compared the reproductive phenology of populations transplanted at LCNCA to populations transplanted at urban sites like the Phoenix Zoo Conservation Center and the Desert Botanical Garden (DBG). Results from the greenhouse studies showed that HWU seeds were capable of germinating 15 years in a dormant state and that HWU seeds are present in the seed banks at sites where populations have been transplanted. Also, greenhouse experiments indicated that colonies of HWU can tolerate up to 3 weeks without flowing water, and up to 2 weeks in dry substrate. Transplanted populations at LCNCA monitored in the fourth study produced a higher abundance of flowers and fruit relative to urban sites (i.e. DBG) suggesting that in-situ conservation efforts may be more favorable for the recovery of HWU populations. Findings from these studies aim to inform gaps in knowledge highlighted in USFWS recovery plan for this species.
ContributorsSolves, Jean-Philippe Yvan (Author) / Pigg, Kathleen B (Thesis advisor) / Salywon, Andrew (Committee member) / Makings, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2020
Description
Understanding how wildlife interact with humans and the built environment is critical as urbanization contributes to habitat change and fragmentation globally. In urban and suburban areas, wildlife and people are often in close quarters, leading to human-wildlife interactions (HWI). In the greater Phoenix Metropolitan Area, Arizona, HWI can involve reptiles such as venomous (family Viperidae, e.g., rattlesnakes) and nonvenomous (family Colubridae, e.g., gophersnakes) snakes. Rattlesnake Solutions, LLC, a local business, removes and relocates snakes from homes and businesses in the Phoenix area and, as a collaborator, has provided records of snake removals. Using these records, I investigated taxa-specific habitat trends at two spatial scales. At the neighborhood scale (n = 60), I found that removals occurred in yards with abundant cover opportunities. At the landscape scale (n = 764), nonvenomous snakes were removed from areas of higher urbanization compared to venomous snakes. Clients of Rattlesnake Solutions, LLC, were asked to answer a short survey, designed by K. Larson and colleagues, regarding the circumstances of their snake removal event and their attitudes, perceptions, and experiences with snakes. I used responses from this survey (n =271) to investigate if prior experience with snakes influences reported attitudes towards snakes. Respondents with prior snake experiences reported more positive attitudes towards snakes and were more consistent across their responses than those without prior snake experiences. Continuing inquiry into the urban ecology of these snakes is important to fostering coexistence between snakes and people that call Phoenix home.
ContributorsEnloe, Annika (Author) / Bateman, Heather L (Thesis advisor) / Lewis, Jesse (Committee member) / Larson, Kelli (Committee member) / Arizona State University (Publisher)
Created2023
Description
Wildlife rehabilitation as a practice in the United States exists in a complicated ethical landscape. The Wildlife Rehabilitator's Code of Ethics exists to guide the profession and states that rehabilitators must respect the wildness and maintain the dignity of an animal in their care. This thesis explores the question: How do the attitudes and actions of wildlife rehabilitators exemplify the ways in which they understand and enact respect for an animal’s dignity and wildness while in their care? Additionally, in what circumstances do rehabilitators align and diverge from each other in their interpretation and demonstration of this respect? These questions were answered through a literature review, interviews with rehabilitators, and site visits to wildlife rehabilitation centers in the Phoenix metropolitan area. My results suggest that rehabilitators are aligned in their understanding of respect for wildness and dignity as it applies to the animals in their care that are actively undergoing rehabilitation. Rehabilitators achieved consensus on the idea that they should interact with the animals as little as possible while providing their medically necessary care. Rehabilitators began to diverge when considering the animals in their sanctuary spaces. Specifically, they varied in their perception of wildness in sanctuary animals, which informed how some saw their responsibilities to the animals. Lesser perceived wildness correlated to increased acceptance of forming affectionate relationships with the sanctuary animals, and even feelings of obligation to form these relationships. Based on my research, I argue that the Wildlife Rehabilitator's Code of Ethics should be revised to reflect the specific boundary that wildlife rehabilitators identified in the rehabilitation space and provide substantive guidance as to what respecting wildness and dignity means in this field.
ContributorsBernat, Isabella Elyse (Author) / Minteer, Ben (Thesis advisor) / Ellison, Karin (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
The southwestern US will experience more frequent heat waves, prolonged droughts, and declining water supply. Riparian ecosystems are particularly at-risk under climate change predictions, but little is known about the thermal tolerance of plant species inhabiting these ecosystems. Populus fremontii, a pioneer and foundation tree species in riparian ecosystems throughout the southwest, is of concern given its importance in driving community structure and influencing ecosystem processes. This study compared leaf thermal tolerance across populations of P. fremontii to determine if local adaptation affects leaf thermal tolerance. I hypothesized that warm-adapted (low-elevation) populations would have larger leaf thermal tolerance thresholds, thermal safety margins, and thermal time constants than cool-adapted (high-elevation) populations. I expected warm-adapted populations to maintain lower maximum leaf temperatures due to local adaptation affecting leaf thermal regulation. Using a common garden at the warm edge of this species’ range, I measured leaf thermal tolerance metrics in eight populations spanning a 1,200 m elevational gradient. Data collection occurred in May, during mild air temperatures, and in August, during high air temperatures. The first two metrics were leaf thermal tolerance thresholds. The critical temperature (Tcrit) is the temperature at which the electron transport capacity of PSII is disrupted. T50 is the temperature at which the electron transport capacity decreases to 50%. The next metric was thermal safety margins (TSMs), which reflect a leaf’s vulnerability to reaching thermal tolerance thresholds. TSMs are the difference between either Tcrit or T50 and an experienced environmental variable such as leaf or air temperature. The last metric was the thermal time constant (?), which is a trait that represents how quickly leaf temperatures respond to changes in air temperatures. Tcrit, T50, and ? were not correlated with elevation regardless of season, suggesting that acclimation or phenotypic plasticity is affecting these metrics. Conversely, TSMs using maximum leaf temperature were negatively correlated with elevation in August because warm-adapted populations maintained lower maximum leaf temperatures. These findings suggest that warm-adapted populations are locally adapted to maintain cooler leaf temperatures, which is critical for their future survival since they do not maintain higher leaf thermal tolerance thresholds than cool-adapted populations.
ContributorsMoran, Madeline (Author) / Hultine, Kevin (Thesis advisor) / Throop, Heather (Thesis advisor) / Butterfield, Bradley (Committee member) / Arizona State University (Publisher)
Created2022
Description
Understanding the effects of fire on the Sonoran Desert is of critical importance as rising temperatures and changing weather patterns increase the frequency and size of wildfires. Seed banks are an important component in post-fire landscape recovery as the seeds that remain in the soil are an indicator of a landscape’s future trajectory. The purpose of this study is to determine the lasting impacts of fire on the soil seed bank of the Sonoran Desert and to identify potential concerns affecting post-fire recovery and restoration. The study site was located in the Arizona Upland division of the Sonoran Desert, Arizona, United States. Soil samples were collected from five burned sites with increasing time since fire, and five nearby unburned sites used as a control. A seedling emergence test was conducted to investigate the density and richness of the seed bank of burned and unburned sites. Seed densities and species richness for sites were calculated using germination results. Findings were analyzed using non-parametric analyses comparing changes in burned and unburned sites over time.
Results found that burn status and time since fire had no significant impact on seed density. Graminoid and forb densities were statistically consistent across burn status and time since fire. While species richness was consistent across both plot types, burned samples typically had fewer species than unburned samples. Burned and unburned plots revealed a dominance of annual species with limited presence of woody perennials. While seed densities and species richness are relatively unchanged across burned and unburned sites over time, the lack of woody perennials in the seed bank raises concerns about landscape recovery trajectories in burned sites. These results suggest that restoration efforts focused on maintaining the presence of woody trees and shrubs in the landscape may have the most impact.
ContributorsCountryman, Kristen (Author) / Makings, Elizabeth (Thesis advisor) / Pigg, Kathleen (Thesis advisor) / Lata, Mary (Committee member) / Arizona State University (Publisher)
Created2023
Description
This project analyzes the efforts of Seoul Grand Park Zoo (the largest and most important zoo on the Korean peninsula) to develop and achieve the highest standards in conservation, education, animal welfare, and research over the last three decades. Founded primarily as an entertainment venue in 1984, the zoo has struggled to become a scientific center that adequately provides for the animals under its care and promotes the advancement and dissemination of knowledge. Drawing on interviews from zoo officials, academics, conservationists, and animal-rights activists, I explore the animal welfare management and conservation priorities of a prominent Asian institution. Although the zoo has made significant improvements in animal welfare, it remains constrained by limited resources and government indifference. These constraints have also restricted the zoo’s ambition to become a major center for conservation; it currently concentrates on a handful of projects with broad popular appeal. Based on my interviews, greater collaboration, better communication with other researchers, and more systematic sharing of data would be especially beneficial for expanding the zoo’s conservation agenda. As research and conservation become a more prominent part of the zoo’s portfolio, potential conflicts may arise with zoo’s current emphasis on the welfare of the individual animals under its care.
ContributorsClay, Anne Safiya (Author) / Minteer, Ben (Thesis advisor) / Collins, James (Committee member) / Broglio, Ronald (Committee member) / Arizona State University (Publisher)
Created2015
Description
Prior to the COVID-19 global pandemic, ecotourism represented the tourism industry’s fastest growing segment with projections estimating that ecotourism would become the world’s largest tourism type by 2030. While the tourism industry will need several years to rebound, if historic trends tell us anything, it is that ecotourism will continue to represent a large portion of the overall industry and will continue to grow at a rate that outpaces all other tourism types. In theory, ecotourism promotes sustainable socioeconomic development while also minimizing negative environmental impacts. Unfortunately, research suggests that this is not always true, and many examples exist of ecotourism causing more harm than good. In order to combat these potential negative impacts, the ecotourism industry has become increasingly reliant on ecotourism certification programs to act as an assessment tool that identifies ecotourism’s best practitioners while minimizing false advertising present within the industry. Despite these beliefs in the efficacy of certification, there is a lack of empirical research to actually support certification as an effective assessment tool. Furthermore, little research has been conducted that assesses the impacts that certification itself has on ecotourism businesses (both certified and uncertified) and the local communities dependent on ecotourism.
My dissertation employs a mixed methods design and combines qualitative and quantitative research methods spanning multiple geographic scales to develop an understanding of certification programs as they exist today and to discern the impacts that certification itself may cause for all those either directly or indirectly involved in ecotourism. My findings ultimately suggest that certification reform is needed if certification programs are expected to be the assessment tool ecotourism experts claim them to be. Specifically, as certification exists presently, there is: no universal guideline or standard for existing certification programs to follow, a disconnect between the advertised benefits certification offers and the actual benefits received, and a lack of market penetration both amongst ecotourists and ecotourism businesses. Each of these must be addressed before certification can live up to its full potential. Furthermore, I found that certification may impact community socioeconomic dynamics, particularly by creating or exacerbating community wealth distribution.
My dissertation employs a mixed methods design and combines qualitative and quantitative research methods spanning multiple geographic scales to develop an understanding of certification programs as they exist today and to discern the impacts that certification itself may cause for all those either directly or indirectly involved in ecotourism. My findings ultimately suggest that certification reform is needed if certification programs are expected to be the assessment tool ecotourism experts claim them to be. Specifically, as certification exists presently, there is: no universal guideline or standard for existing certification programs to follow, a disconnect between the advertised benefits certification offers and the actual benefits received, and a lack of market penetration both amongst ecotourists and ecotourism businesses. Each of these must be addressed before certification can live up to its full potential. Furthermore, I found that certification may impact community socioeconomic dynamics, particularly by creating or exacerbating community wealth distribution.
ContributorsDavila, Ryan (Author) / Kinzig, Ann (Thesis advisor) / Perrings, Charles (Committee member) / Collins, James (Committee member) / Schoon, Michael (Committee member) / Buzinde, Christine (Committee member) / Arizona State University (Publisher)
Created2020
Description
Cetacean-based ecotourism is a popular activity and an important source of revenue for many countries. Whale watching, a subset of cetacean-based ecotourism, is vital to supporting conservation efforts and provides numerous benefits to local communities including educational opportunities and job creation. However, the sustainability of whale-based ecotourism depends on the behavior and health of whale populations and is therefore vital that ecotourism industries consider the impact their activities have on whale reproductive behavior. To address this statement, behavioral data (e.g. direction change, breaching, slap behaviors, diving, and spy hops) were collected from humpback whales (Megaptera novaeangliae) in Las Perlas Archipelago off the Pacific coast of Panama to determine if vessel presence had an influence on whale behaviors. Studies were recorded during their breeding season from August through September in 2019. Based on 47 behavioral observations, higher boat density corresponded with humpback whales changing direction which is believed to be a sign of disturbance. This result is important given Panamanian regulations implemented on February 13 of 2007 prohibit whale-based tourism from disturbing whales, which is measured as changes in behavior. Because there is no systematic monitoring of whale watching activity to enforce the regulations, there is currently little compliance among tour operators. The integration of animal behavior research into management planning will result in more effective regulation and compliance of conservation policies.
ContributorsAmrein, Arielle (Author) / Gerber, Leah R. (Thesis advisor) / Guzman, Hector M (Committee member) / Polidoro, Beth (Committee member) / Arizona State University (Publisher)
Created2020
Description
Echinomastus erectocentrus (J.M. Coulter) Britton & Rose var. acunensis (W.T. Marshall) Bravo, the Acuña cactus, is a small, single-stemmed spherical cactus with a restricted distribution across the Sonoran Desert in southern Arizona and into northern Sonora, Mexico. Populations of E. erectocentrus var. acunensis are threatened by loss of habitat, climate change, predation, and border related impacts. Due to the severity of these threats and shrinking population sizes, E. erectocentrus var. acunensis was federally listed as endangered by the United States Fish and Wildlife Service in 2013. The varieties of Echinomastus erectocentrus, E. erectocentrus var. acunensis and E. erectocentrus var. erectocentrus (J.M. Coulter) Britton & Rose, share many morphological characteristics that make them difficult to distinguish from one another. Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter, a presumed closely related species, also has a high level of morphological overlap that further complicates our understanding of species boundaries and detailed morphological data for these three taxa indicate a geographical cline. The goal of this project is to document the genetic diversity within and among populations of E. erectocentrus var. acunensis, and its close relatives E. erectocentrus var. erectocentrus and E. johnsonii. To accomplish this, populations of E. erectocentrus var. acunensis, E. erectocentrus var. erectocentrus, E. johnsonii and the outgroup Echinomastus intertextus (Engelm.) Britton & Rose were sampled. Deoxyribonucleic acid (DNA) was extracted, and data were collected for nine microsatellite regions developed specifically for these taxa, and two microsatellite regions developed for Sclerocactus, a closely related genus. Standard population genetic measures were used to determine genetic variation and structure, and this observed genetic differentiation was then compared to the current morphological understanding of the group. These analyses help improve the knowledge of the genetic structure of E. erectocentrus var. acunensis and inform the understanding of species boundaries and evolutionary relationships within the group by revealing genetic distinctiveness between all four taxa and hybrid populations between the two varieties. This information also reveals patterns of gene flow and population locations that have the highest conservation priority, which can be incorporated into efforts to conserve and protect this endangered species.
ContributorsWillis, Alison (Author) / Wojciechowski, Martin F (Thesis advisor) / Fehlberg, Shannon D (Thesis advisor) / Makings, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2020