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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The relationship between biodiversity and ecosystem functioning (BEF) is a central issue in ecology, and a number of recent field experimental studies have greatly improved our understanding of this relationship. Spatial heterogeneity is a ubiquitous characterization of ecosystem processes, and has played a significant role in shaping BEF relationships.

The relationship between biodiversity and ecosystem functioning (BEF) is a central issue in ecology, and a number of recent field experimental studies have greatly improved our understanding of this relationship. Spatial heterogeneity is a ubiquitous characterization of ecosystem processes, and has played a significant role in shaping BEF relationships. The first step towards understanding the effects of spatial heterogeneity on the BEF relationships is to quantify spatial heterogeneity characteristics of key variables of biodiversity and ecosystem functioning, and identify the spatial relationships among these variables. The goal of our research was to address the following research questions based on data collected in 2005 (corresponding to the year when the initial site background information was conducted) and in 2008 (corresponding to the year when removal treatments were conducted) from the Inner Mongolia Grassland Removal Experiment (IMGRE) located in northern China: 1) What are the spatial patterns of soil nutrients, plant biodiversity, and aboveground biomass in a natural grassland community of Inner Mongolia, China? How are they related spatially? and 2) How do removal treatments affect the spatial patterns of soil nutrients, plant biodiversity, and aboveground biomass? Is there any change for their spatial correlations after removal treatments? Our results showed that variables of biodiversity and ecosystem functioning in the natural grassland community would present different spatial patterns, and they would be spatially correlated to each other closely. Removal treatments had a significant effect on spatial structures and spatial correlations of variables, compared to those prior to the removal treatments. The differences in spatial pattern of plant and soil variables and their correlations before and after the biodiversity manipulation may not imply that the results from BEF experiments like IMGRE are invalid. However, they do suggest that the possible effects of spatial heterogeneity on the BEF relationships should be critically evaluated in future studies.
ContributorsYuan, Fei (Author) / Wu, Jianguo (Thesis advisor) / Smith, Andrew T. (Committee member) / Rowe, Helen I (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Worldwide, riverine floodplains are among the most endangered landscapes. In response to anthropogenic impacts, riverine restoration projects are considerably increasing. However, there is a paucity of information on how riparian rehabilitation activities impact non-avian wildlife communities. I evaluated herpetofauna abundance, species richness, diversity (i.e., Shannon and Simpson indices), species-specific responses,

Worldwide, riverine floodplains are among the most endangered landscapes. In response to anthropogenic impacts, riverine restoration projects are considerably increasing. However, there is a paucity of information on how riparian rehabilitation activities impact non-avian wildlife communities. I evaluated herpetofauna abundance, species richness, diversity (i.e., Shannon and Simpson indices), species-specific responses, and riparian microhabitat characteristics along three reaches (i.e., wildland, urban rehabilitated, and urban disturbed) of the Salt River, Arizona. The surrounding uplands of the two urbanized reaches were dominated by the built environment (i.e., Phoenix metropolitan area). I predicted that greater diversity of microhabitat and lower urbanization would promote herpetofauna abundance, richness, and diversity. In 2010, at each reach, I performed herpetofauna visual surveys five times along eight transects (n=24) spanning the riparian zone. I quantified twenty one microhabitat characteristics such as ground substrate, vegetative cover, woody debris, tree stem density, and plant species richness along each transect. Herpetofauna species richness was the greatest along the wildland reach, and the lowest along the urban disturbed reach. The wildland reach had the greatest diversity indices, and diversity indices of the two urban reaches were similar. Abundance of herpetofauna was approximately six times lower along the urban disturbed reach compared to the two other reaches, which had similar abundances. Principal Component Analysis (PCA) reduced microhabitat variables to five factors, and significant differences among reaches were detected. Vegetation structure complexity, vegetation species richness, as well as densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrows had a positive correlation with at least one of the three herpetofauna community parameter quantified (i.e., herpetofauna abundance, species richness, and diversity indices), and had a positive correlation with at least one herpetofauna species. Overall, rehabilitation activities positively influenced herpetofauna abundance and species richness, whereas urbanization negatively influenced herpetofauna diversity indices. Based on herpetofauna/microhabitat correlations established, I developed recommendations regarding microhabitat features that should be created in order to promote herpetofauna when rehabilitating degraded riparian systems. Recommendations are to plant vegetation of different growth habit, provide woody debris, plant Populus, Salix, and Prosopis of various ages and sizes, and to promote small mammal abundance.
ContributorsBanville, Mélanie Josianne (Author) / Bateman, Heather L (Thesis advisor) / Brady, Ward (Committee member) / Stromberg, Juliet (Committee member) / Arizona State University (Publisher)
Created2011
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Description
ABSTRACT For this study, I chose to look at the influence that linguistics has on the publishing industry, both in writing and editing literary fiction. Both sides of publishing deal with the words and language of a novel, which is what the study of linguistics entails. Throughout this

ABSTRACT For this study, I chose to look at the influence that linguistics has on the publishing industry, both in writing and editing literary fiction. Both sides of publishing deal with the words and language of a novel, which is what the study of linguistics entails. Throughout this study, I researched the different areas of the publishing industry, academic programs that focus on publishing, and how-to guides on writing literary fiction in order to find out to what extent--if any--linguistics is involved. Also, through editors that I have worked with, and recommendations from various acquaintances, I interviewed two authors--one published and one unpublished--to see if they used any aspects of linguistics in their writing techniques. I found that linguistics was never specifically mentioned in the descriptions of publishing courses, in the how-to guides, nor in the answers from the authors on different writing techniques used; however, linguistics may be used or studied unintentionally.
ContributorsMoeser, Amy (Author) / Gelderen, Elly van (Thesis advisor) / Major, Roy (Committee member) / Szuter, Christine (Committee member) / Arizona State University (Publisher)
Created2011
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The current study employs item difficulty modeling procedures to evaluate the feasibility of potential generative item features for nonword repetition. Specifically, the extent to which the manipulated item features affect the theoretical mechanisms that underlie nonword repetition accuracy was estimated. Generative item features were based on the phonological loop component

The current study employs item difficulty modeling procedures to evaluate the feasibility of potential generative item features for nonword repetition. Specifically, the extent to which the manipulated item features affect the theoretical mechanisms that underlie nonword repetition accuracy was estimated. Generative item features were based on the phonological loop component of Baddelely's model of working memory which addresses phonological short-term memory (Baddeley, 2000, 2003; Baddeley & Hitch, 1974). Using researcher developed software, nonwords were generated to adhere to the phonological constraints of Spanish. Thirty-six nonwords were chosen based on the set item features identified by the proposed cognitive processing model. Using a planned missing data design, two-hundred fifteen Spanish-English bilingual children were administered 24 of the 36 generated nonwords. Multiple regression and explanatory item response modeling techniques (e.g., linear logistic test model, LLTM; Fischer, 1973) were used to estimate the impact of item features on item difficulty. The final LLTM included three item radicals and two item incidentals. Results indicated that the LLTM predicted item difficulties were highly correlated with the Rasch item difficulties (r = .89) and accounted for a substantial amount of the variance in item difficulty (R2 = .79). The findings are discussed in terms of validity evidence in support of using the phonological loop component of Baddeley's model (2000) as a cognitive processing model for nonword repetition items and the feasibility of using the proposed radical structure as an item blueprint for the future generation of nonword repetition items.
ContributorsMorgan, Gareth Philip (Author) / Gorin, Joanna (Thesis advisor) / Levy, Roy (Committee member) / Gray, Shelley (Committee member) / Arizona State University (Publisher)
Created2011
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"No civil discourse, no cooperation; misinformation, mistruth." These were the words of former Facebook Vice President Chamath Palihapitiya who publicly expressed his regret in a 2017 interview over his role in co-creating Facebook. Palihapitiya shared that social media is ripping apart the social fabric of society and he also sounded

"No civil discourse, no cooperation; misinformation, mistruth." These were the words of former Facebook Vice President Chamath Palihapitiya who publicly expressed his regret in a 2017 interview over his role in co-creating Facebook. Palihapitiya shared that social media is ripping apart the social fabric of society and he also sounded the alarm regarding social media’s unavoidable global impact. He is only one of social media’s countless critics. The more disturbing issue resides in the empirical evidence supporting such notions. At least 95% of adolescents own a smartphone and spend an average time of two to four hours a day on social media. Moreover, 91% of 16-24-year-olds use social media, yet youth rate Instagram, Facebook, and Twitter as the worst social media platforms. However, the social, clinical, and neurodevelopment ramifications of using social media regularly are only beginning to emerge in research. Early research findings show that social media platforms trigger anxiety, depression, low self-esteem, and other negative mental health effects. These negative mental health symptoms are commonly reported by individuals from of 18-25-years old, a unique period of human development known as emerging adulthood. Although emerging adulthood is characterized by identity exploration, unbounded optimism, and freedom from most responsibilities, it also serves as a high-risk period for the onset of most psychological disorders. Despite social media’s adverse impacts, it retains its utility as it facilitates identity exploration and virtual socialization for emerging adults. Investigating the “user-centered” design and neuroscience underlying social media platforms can help reveal, and potentially mitigate, the onset of negative mental health consequences among emerging adults. Effectively deconstructing the Facebook, Twitter, and Instagram (i.e., hereafter referred to as “The Big Three”) will require an extensive analysis into common features across platforms. A few examples of these design features include: like and reaction counters, perpetual news feeds, and omnipresent banners and notifications surrounding the user’s viewport. Such social media features are inherently designed to stimulate specific neurotransmitters and hormones such as dopamine, serotonin, and cortisol. Identifying such predacious social media features that unknowingly manipulate and highjack emerging adults’ brain chemistry will serve as a first step in mitigating the negative mental health effects of today’s social media platforms. A second concrete step will involve altering or eliminating said features by creating a social media platform that supports and even enhances mental well-being.

ContributorsGupta, Anay (Author) / Flores, Valerie (Thesis director) / Carrasquilla, Christina (Committee member) / Barnett, Jessica (Committee member) / The Sidney Poitier New American Film School (Contributor) / Computer Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Americans today face an age of information overload. With the evolution of Media 3.0, the internet, and the rise of Media 3.5—i.e., social media—relatively new communication technologies present pressing challenges for the First Amendment in American society. Twentieth century law defined freedom of expression, but in an information-limited world. By

Americans today face an age of information overload. With the evolution of Media 3.0, the internet, and the rise of Media 3.5—i.e., social media—relatively new communication technologies present pressing challenges for the First Amendment in American society. Twentieth century law defined freedom of expression, but in an information-limited world. By contrast, the twenty-first century is seeing the emergence of a world that is overloaded with information, largely shaped by an “unintentional press”—social media. Americans today rely on just a small concentration of private technology powerhouses exercising both economic and social influence over American society. This raises questions about censorship, access, and misinformation. While the First Amendment protects speech from government censorship only, First Amendment ideology is largely ingrained across American culture, including on social media. Technological advances arguably have made entry into the marketplace of ideas—a fundamental First Amendment doctrine—more accessible, but also more problematic for the average American, increasing his/her potential exposure to misinformation. <br/><br/>This thesis uses political and judicial frameworks to evaluate modern misinformation trends, social media platforms and current misinformation efforts, against the background of two misinformation accelerants in 2020, the COVID-19 pandemic and U.S. presidential election. Throughout history, times of hardship and intense fear have contributed to the shaping of First Amendment jurisprudence. Thus, this thesis looks at how fear can intensify the spread of misinformation and influence free speech values. Extensive research was conducted to provide the historical context behind relevant modern literature. This thesis then concludes with three solutions to misinformation that are supported by critical American free speech theory.

ContributorsCochrane, Kylie Marie (Author) / Russomanno, Joseph (Thesis director) / Roschke, Kristy (Committee member) / School of Public Affairs (Contributor) / Walter Cronkite School of Journalism and Mass Comm (Contributor, Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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This research covers the landscape of influencer marketing and combines it with the knowledge of 11 content creators and one social media specialist, ultimately producing an actionable handbook. Participants were asked questions that were intended to discover key strategies, level of difficulty, and overall insight into the content creator world.

This research covers the landscape of influencer marketing and combines it with the knowledge of 11 content creators and one social media specialist, ultimately producing an actionable handbook. Participants were asked questions that were intended to discover key strategies, level of difficulty, and overall insight into the content creator world. Best practices and key findings are identified in the research paper, and outlined into four parts in the handbook. The handbook serves as a compilation framework derived from my primary and secondary sources designed to provide anyone interested in becoming a content creator or social media influencer on steps they may take given what their predecessors have done to successfully launch their careers in the space.

ContributorsEsparza, Alexa (Author) / Giles, Charles (Thesis director) / Schlacter, John (Committee member) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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The use of discourse markers (DMs) is present in speech to both structure and organize the discourse (Fung & Carter, 2007). However, despite the different studies about the use of DMs, less attention has been paid to specific Spanish DMs such as pues, ‘so, well’ luego, ‘then, therefore’ and entonces

The use of discourse markers (DMs) is present in speech to both structure and organize the discourse (Fung & Carter, 2007). However, despite the different studies about the use of DMs, less attention has been paid to specific Spanish DMs such as pues, ‘so, well’ luego, ‘then, therefore’ and entonces ‘so, then’ about their reduction. The focus of this study is on the phonetic variation of these DMs from a corpus of speakers of Mexican Spanish from Salinas, California (Brown & Alba, 2017). This paper analyzed dependent and independent variables to show their influence on the reduction of DMs. Also, chunking phenomena and special reduction were part of the study as they can reflect patterns of change in the language.

ContributorsQuimbaya, Yazmin (Author) / Gradoville, Michael (Thesis director) / Fernández, Sofía (Committee member) / Brown, Earl Kjar (Committee member) / School of International Letters and Cultures (Contributor) / Department of English (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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This study was designed to produce a comprehensive flora of Usery Mountain Regional Park and Pass Mountain of the Tonto National Forest. A total of 168 vascular plant species representing 46 families and 127 genera were collected or documented at this study area. Sixteen species were not native to the

This study was designed to produce a comprehensive flora of Usery Mountain Regional Park and Pass Mountain of the Tonto National Forest. A total of 168 vascular plant species representing 46 families and 127 genera were collected or documented at this study area. Sixteen species were not native to the flora of Arizona and represent 9.5% of the flora. Nevertheless, the study area does not appear to be significantly damaged or degraded in spite of its historical and current land use. The location and types of invasive species recorded in this study will assist with implementing preventative measures to prevent further spreading of certain species. The complete list of all vascular species recorded in this study will provide a valuable tool for land management decisions and future restoration projects that may occur at this area or similar sites and invasive species control. The distribution of the saguaro (Carnegiea gigantea) population on Pass Mountain was documented through the measurement of saguaros by random sampling. ArcGIS was used to generate 50 random points for sampling the saguaro population. Analysis to determine saguaro habitat preferences based on the parameters of aspect, slope and elevation was conducted through ArcGIS. The saguaro population of Pass Mountain significantly favored the southern aspects with the highest concentration occurring in the southwest aspects at an average density of 42.66 saguaros per hectare. The large numbers of saguaros recorded in the younger size classes suggests a growing populations.
ContributorsMarshall, Laura Lee (Author) / Steele, Kelly P (Thesis advisor) / Miller, William H. (Committee member) / Alford, Eddie J (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Non-native saltcedar (Tamarix spp.) has invaded many riparian communities and is the third most abundant tree in Southwestern riparian areas. I evaluated lizard populations and microhabitat selection during 2009 and 2010 along the Virgin River in Nevada and Arizona to determine the impact of saltcedar. Along the riparian corridor, I

Non-native saltcedar (Tamarix spp.) has invaded many riparian communities and is the third most abundant tree in Southwestern riparian areas. I evaluated lizard populations and microhabitat selection during 2009 and 2010 along the Virgin River in Nevada and Arizona to determine the impact of saltcedar. Along the riparian corridor, I observed common side-blotched lizards (Uta stansburiana) within two vegetation types: monotypic non-native saltcedar stands or mixed stands of cottonwood (Populus fremontii), willow (Salix spp.), mesquite (Prosopis spp.) and saltcedar. I predicted that population parameters such as body condition, adult to hatchling ratio, abundance, and persistence would vary among vegetation types. Also, I predicted the presence of saltcedar influences how lizards utilize available habitat. Lizard population parameters were obtained from a mark-recapture study in which I captured 233 individual lizards. I examined habitat selection and habitat availability using visual encounter surveys (VES) for lizards and recorded 11 microhabitat variables where 16 lizards were found. I found no significant difference in population parameters between mixed and non-native saltcedar communities. However, population parameters were negatively correlated with canopy cover. I found that lizards selected habitat with low understory and canopy cover regardless of vegetation type. My results indicate that lizards utilize similar structural characteristics in both mixed and non-native vegetation. Understanding impacts of saltcedar on native fauna is important for managers who are tasked with control and management of this non-native species.
ContributorsNielsen, Danny (Author) / Bateman, Heather L. (Thesis advisor) / Miller, William H. (Committee member) / Sullivan, Brian K. (Committee member) / Arizona State University (Publisher)
Created2011