Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- All Subjects: Ecology
Description
The National Wilderness Preservation System (NWPS) is a collection of more than 800 areas designated as wilderness under the Wilderness Act of 1964. The Act defines wilderness as an “area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain.” Wilderness lands are supposed to be pristine examples of nature where the overseeing agency has not allowed any post-designation development. The language of the act describes land designated as wilderness as “untrammeled” by people, discounting thousands of years of human influence. It also discounts the potential effect of surrounding lands and visitors on the wilderness. The management of these lands falls to all four federal land management agencies, and they each had – and still have – their own organizational perspectives on the Wilderness Act and their agency’s role in its implementation. Although the Act provided criteria for designating and managing wilderness, concrete guidance is lacking. This ambiguity has allowed a rift to emerge between those who believe that wilderness should be actively managed and those who believe that wilderness should be preserved and left alone as much as possible. The diversity of views and agency approaches have created administrative divides between wilderness lands and other land types. In parallel, the introduction of subsequent environmental laws have placed additional legal boundaries on the land, creating parcels next to and within wilderness that are subject to different uses and requirements. This study, which marshals dozens of expert interviews and explores a series of wilderness cases across the United States, focuses on several unanticipated challenges of stewarding the NWPS in the 21st Century. These include: the impacts of public land parceling due to legal obligations; how statuary ossification affects current interpretations of the various laws bearing on wilderness lands; and ultimately how land managers and agencies – who are looking toward a future of increased anthropogenic impacts on wildlife biodiversity and endangered/threatened species on wilderness lands – approach these challenges.
ContributorsFacemire, Challie Renee (Author) / Minteer, Ben A (Thesis advisor) / Ellison, Karin (Thesis advisor) / Bradshaw, Karen (Committee member) / Hahn, Beth (Committee member) / Budruk, Megha (Committee member) / Arizona State University (Publisher)
Created2022
Description
Invasive plants harm the ecological properties of natural systems, human health,
and local economies. However, the negative impacts of invasive species are not always
immediately visible and may be disregarded by local communities if social benefits of
control efforts are not clear. In this dissertation, I use a mixed-methods approach to
investigate the drivers of invasive plant distribution, potential financially feasible
management techniques to control invasion, and community forest user perceptions of
those techniques. In this work, I aim to incorporate the diverse perspectives of local
people and increase the long-term success of invasive species control activities in socio
economically vulnerable populations.
Integrating a spatially and temporally diverse data set, I explore the social and
ecological drivers of invasive plant abundance across 21 buffer zone community forests
in the Western Chitwan Valley of Nepal. I evaluate to what extent forest user and
collective manager activities, the legacies of historic activities, and ecological properties
influence present-day invasive plant abundance. I built upon this study to identify areas
with critically high levels of invasion then initiated a three-year, community-based
management intervention to evaluate traditional and adaptive land management
approaches to control invasive plants. I found that both approaches reduced invasive
plant abundance relative to the surrounding, untreated forest. I then interviewed focus
groups to investigate their perceived efficacy of the various treatment types and found
that almost all forest users and managers preferred the adaptive approach over the
traditional management approach. Notably, forest users cited the importance of the
availability of forest resources and lack of harmful plants in the plots that had undergone
this method. Understanding how forest users relate to and experience invasive plants has
been relatively understudied but can influence forest user engagement in different
management approaches. For this reason, I performed in-depth ethnoecological
interviews to explore how forest users perceive, how they utilize, and to what extent they
value invasive plants. This mixed-methods approach contributes to a more holistic
understanding of the role that local people play in invasive plant management and
restoration activities.
and local economies. However, the negative impacts of invasive species are not always
immediately visible and may be disregarded by local communities if social benefits of
control efforts are not clear. In this dissertation, I use a mixed-methods approach to
investigate the drivers of invasive plant distribution, potential financially feasible
management techniques to control invasion, and community forest user perceptions of
those techniques. In this work, I aim to incorporate the diverse perspectives of local
people and increase the long-term success of invasive species control activities in socio
economically vulnerable populations.
Integrating a spatially and temporally diverse data set, I explore the social and
ecological drivers of invasive plant abundance across 21 buffer zone community forests
in the Western Chitwan Valley of Nepal. I evaluate to what extent forest user and
collective manager activities, the legacies of historic activities, and ecological properties
influence present-day invasive plant abundance. I built upon this study to identify areas
with critically high levels of invasion then initiated a three-year, community-based
management intervention to evaluate traditional and adaptive land management
approaches to control invasive plants. I found that both approaches reduced invasive
plant abundance relative to the surrounding, untreated forest. I then interviewed focus
groups to investigate their perceived efficacy of the various treatment types and found
that almost all forest users and managers preferred the adaptive approach over the
traditional management approach. Notably, forest users cited the importance of the
availability of forest resources and lack of harmful plants in the plots that had undergone
this method. Understanding how forest users relate to and experience invasive plants has
been relatively understudied but can influence forest user engagement in different
management approaches. For this reason, I performed in-depth ethnoecological
interviews to explore how forest users perceive, how they utilize, and to what extent they
value invasive plants. This mixed-methods approach contributes to a more holistic
understanding of the role that local people play in invasive plant management and
restoration activities.
ContributorsClark, Michele Diane (Author) / Hall, Sharon J. (Thesis advisor) / Shrestha, Milan (Committee member) / Yabiku, Scott (Committee member) / Budruk, Megha (Committee member) / Arizona State University (Publisher)
Created2020
Description
The plateau pika (Ochotona curzoniae), a small burrowing lagomorph that occupies the high alpine grassland ecosystems of the Qinghai-Tibetan Plateau in western China, remains a controversial subject among policymakers and researchers. One line of evidence points to pikas being a pest, which has led to massive attempts to eradicate pika populations. Another point of view is that pikas are a keystone species and an ecosystem engineer in the grassland ecosystem of the QTP. The pika eradication program raises a difficult ethical and religious dilemma for local pastoralists, and is criticized for not being supported by scientific evidence. Complex interactions between pikas, livestock, and habitat condition are poorly understood. My dissertation research examines underpinning justifications of the pika poisoning program leading to these controversies. I investigated responses of pikas to habitat conditions with field experimental manipulations, and mechanisms of pika population recovery following pika removal. I present policy recommendations based on an environmental ethics framework and findings from the field experiments. After five years of a livestock grazing exclusion experiment and four years of pika monitoring, I found that grazing exclusion resulted in a decline of pika habitat use, which suggests that habitat conditions determine pika population density. I also found that pikas recolonized vacant burrow systems following removal of residents, but that distances travelled by dispersing pikas were extremely short (~50 m). Thus, current pika eradication programs, if allowed to continue, could potentially compromise local populations as well as biodiversity conservation on the QTP. Lethal management of pikas is a narrowly anthropocentric-based form of ecosystem management that has excluded value-pluralism, such as consideration of the intrinsic value of species and the important ecological role played by pikas. These conflicting approaches have led to controversies and policy gridlock. In response, I suggest that the on-going large-scale pika eradication program needs reconsideration. Moderation of stocking rates is required in degraded pika habitats, and Integrated Pest Management may be required when high stocking rate and high pika density coexist. A moderate level of livestock and pika density can be consistent with maintaining the integrity and sustainability of the QTP alpine steppe ecosystem.
ContributorsBadingqiuying (Author) / Smith, Andrew T. (Thesis advisor) / Wu, Jianguo (Committee member) / Minteer, Ben (Committee member) / Anderies, John (Committee member) / Harris, Richard B. (Committee member) / Arizona State University (Publisher)
Created2016