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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Modified and artificial water sources can be used as a management tool for game and non-game wildlife species. State, federal, and private agencies allocate significant resources to install and maintain artificial water sources (AWS) annually. Capture mark recapture methods were used to sample small mammal communities in the vicinity of five AWS and five paired control sites (treatments) in the surrounding Sonoran desert from October 2011 to May 2012. I measured plant species richness, density, and percent cover in the spring of 2012. A Multi-response Permutation Procedure was used to identify differences in small mammal community abundance, biomass, and species richness by season and treatment. I used Principle Component Analysis to reduce 11 habitat characteristics to five habitat factors. I related rodent occurrence to habitat characteristics using multiple and logistic regression. A total of 370 individual mammals representing three genera and eight species of rodents were captured across 4800 trap nights. Desert pocket mouse (Chaetodipus penicillatus) was the most common species in both seasons and treatments. Whereas rodent community abundance, biomass, and richness were similar between seasons, community variables of AWS were greater than CS. Rodent diversity was similar between treatments. Desert pocket mouse abundance and biomass were twice as high at AWS when compared to controls. Biomass of white-throated woodrat (Neotoma albigula) was five times greater at AWS. Habitat characteristics were similar between treatments. Neither presence of water nor distance to water explained substantial habitat variation. Occurrence of rodent species was associated with habitat characteristics. Desert rodent communities are adapted for arid environments (i.e. Heteromyids) and are not dependent on "free water". Higher abundances of desert pocket mouse at AWS were most likely related to increased disturbance and debris and not the presence of water. The results of this study and previous studies suggest that more investigation is needed and that short term studies may not be able to detect interactions (if any) between AWS and desert small mammal communities.
ContributorsSwitalski, Aaron (Author) / Bateman, Heather L (Thesis advisor) / Miller, William (Committee member) / Alford, Eddie (Committee member) / Arizona State University (Publisher)
Created2013
Description
Niche variation among sexes and life stages within a population has been documented in many species, yet few studies have investigated niche variation within demographic groups or across ecological contexts. We examined the extent to which pregnant California sea lions (Zalophus californianus) at each of three breeding colonies target alternative prey resources and habitats. The three colonies are distributed across distinct regions of the Gulf of California, Mexico and have divergent population dynamics. We compared the nature of niche variation among colonies and investigated the fitness consequences of different foraging strategies within each colony. We analyzed the δ13C and δ15N values from fur collected from 206 suckling pups to characterize relative maternal foraging locations (δ13C) and trophic levels (δ15N) during the metabolically demanding late stages of gestation and lactation that occur simultaneously in California sea lions. The δ13C and δ15N values were regressed against pup body condition index values to compare the relative individual-level fitness benefits of different maternal foraging strategies. We found that the nature and extent of niche variation differed among colonies. Niche variation was most pronounced at the two largest colonies that appear to experience the highest levels of intraspecific competition and the variation was consistent with habitat features. One colony (Granito) displayed two distinct foraging groups with indistinguishable median pup body condition values, whereas the second (San Jorge) exhibited continuous niche variation and pup body condition varied in relation to maternal foraging location and trophic level, suggesting disparities among alternative foraging strategies. For the smallest colony (Los Islotes), females occupy similar niches with a few outliers. Body condition values of pups at this colony were most variable, but did not vary with maternal foraging strategy. Our results provide evidence for intrapopulation niche variation among demographically similar individuals during a period of high metabolic stress and reproductive importance. This work suggests possible fitness benefits conferred by alternative foraging strategies, and calls into question the common assumption that members of a population are ecologically equivalent. Future research aimed at understanding animal foraging strategies should consider the nature and extent of niche variation in the context of local ecological conditions.
ContributorsCrawford, Tara Gancos (Author) / Gerber, Leah R. (Thesis advisor) / Ogle, Kiona (Committee member) / Kurle, Carolyn M (Committee member) / Arizona State University (Publisher)
Created2013
Description
Arizona has become infamous for its strong nativist and anti-immigrant climate, gaining national and international attention for legislation and policing practices that are in violation of civil and human rights. Despite the grave injustices perpetuated against migrants and communities of color, they exist in an environment of acceptance. Applying Critical Pedagogy, Critical Race Theory/ Latina(o) Critical Race Theory, and Chicana Feminist epistemologies, this study interrogates the polarized discourse that has intensified in Arizona, within the immigration movement and across its political spectrum, from 2006 to 2008. I present an auto-ethnographic account, including use of participant action research, narrative, and storytelling methods that explores ways in which resistance is manifested and the implications for creating sustainable social change. I argue that legislation, raids, and local immigration enforcement tactics reinforce the dominant group's fear of the "other," resulting in micro and macro aggressions that legitimize racial profiling and help safeguard and fortify White privilege through the fabrication of racialized identities. Simultaneously, organizing strategies and discourse of immigrant rights advocates reflect an entanglement of perceived identities and a struggle to negotiate, contest, and redefine boundaries of public space. The raids, coupled with protests and counter demonstrations, produced a public spectacle that reinforces anti-immigrant connections between race and crime. Lastly, I apply and introduce Border Crit, a new and emerging theory I propose to better address research in the borderlands.
ContributorsMaldonado, Angeles (Author) / Swadener, Elizabeth B. (Thesis advisor) / Scott, Kimberly (Committee member) / Mckinley Jones Brayboy, Bryan (Committee member) / Arizona State University (Publisher)
Created2013
Description
Human activity has increased loading of reactive nitrogen (N) in the environment, with important and often deleterious impacts on biodiversity, climate, and human health. Since the fate of N in the ecosystem is mainly controlled by microorganisms, understanding the factors that shape microbial communities becomes relevant and urgent. In arid land soils, these microbial communities and factors are not well understood. I aimed to study the role of N cycling microbes, such as the ammonia-oxidizing bacteria (AOB), the recently discovered ammonia-oxidizing archaea (AOA), and various fungal groups, in soils of arid lands. I also tested if niche differentiation among microbial populations is a driver of differential biogeochemical outcomes. I found that N cycling microbial communities in arid lands are structured by environmental factors to a stronger degree than what is generally observed in mesic systems. For example, in biological soil crusts, temperature selected for AOA in warmer deserts and for AOB in colder deserts. Land-use change also affects niche differentiation, with fungi being the major agents of N2O production in natural arid lands, whereas emissions could be attributed to bacteria in mesic urban lawns. By contrast, NO3- production in the native desert and managed soils was mainly controlled by autotrophic microbes (i.e., AOB and AOA) rather than by heterotrophic fungi. I could also determine that AOA surprisingly responded positively to inorganic N availability in both short (one month) and long-term (seven years) experimental manipulations in an arid land soil, while environmental N enrichment in other ecosystem types is known to favor AOB over AOA. This work improves our predictions of ecosystem response to anthropogenic N increase and shows that paradigms derived from mesic systems are not always applicable to arid lands. My dissertation also highlights the unique ecology of ammonia oxidizers and draws attention to the importance of N cycling in desert soils.
ContributorsMarusenko, Yevgeniy (Author) / Hall, Sharon J (Thesis advisor) / Garcia-Pichel, Ferran (Thesis advisor) / Mclain, Jean E (Committee member) / Schwartz, Egbert (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation investigates spatial and temporal changes in land cover and plant species distributions on Cyprus in the past, present and future (1973-2070). Landsat image analysis supports inference of land cover changes following the political division of the island of Cyprus in 1974. Urban growth in Nicosia, Larnaka and Limasol, as well as increased development along the southern coastline, is clearly evident between 1973 and 2011. Forests of the Troodos and Kyrenia Ranges remain relatively stable, with transitions occurring most frequently between agricultural land covers and shrub/herbaceous land covers. Vegetation models were constructed for twenty-two plant species of Cyprus using Maxent to predict potentially suitable areas of occurrence. Modern vegetation models were constructed from presence-only data collected by field surveys conducted between 2008 and 2011. These models provide a baseline for the assessment of potential species distributions under two climate change scenarios (A1b and A2) for the years 2030, 2050, and 2070. Climate change in Cyprus is likely to influence habitat availability, particularly for high elevation species as the relatively low elevation mountain ranges and small latitudinal range prevent species from shifting to areas of suitable environmental conditions. The loss of suitable habitat for some species may allow the introduction of non-native plant species or the expansion of generalists currently excluded from these areas. Results from future projections indicate the loss of suitable areas for most species by the year 2030 under both climate regimes and all four endemic species (Cedrus brevifolia, Helianthemum obtusifolium, Pterocephalus multiflorus, and Quercus alnifolia) are predicted to lose all suitable environments as soon as 2030. As striking exceptions Prunus dulcis (almond), Ficus carica (fig), Punica granatum (pomegranate) and Olea europaea (olive), which occur as both wild varieties and orchard cultigens, will expand under both scenarios. Land cover and species distribution maps are evaluated in concert to create a more detailed interpretation of the Cypriot landscape and to discuss the potential implications of climate change for land cover and plant species distributions.
ContributorsRidder, Elizabeth (Author) / Fall, Patricia L. (Thesis advisor) / Myint, Soe W (Committee member) / Hirt, Paul W (Committee member) / Arizona State University (Publisher)
Created2013
Description
Exiting prostitution is a process whereby women gradually leave prostitution after a number of environmental, relational, and cognitive changes have taken place. Most women attempting to leave street prostitution reenter five or more times before successfully exiting, if they are able to at all. Prostitution-exiting programs are designed to alleviate barriers to exiting, but several studies indicate only about 20-25% of participants enrolled in such programs are successful. There is little quantitative knowledge on the prostitution exiting process and current literature lacks a testable theory of exiting. This mixed-methods study defined and operationalized key cognitive processes by applying the Integrative Model of Behavioral Prediction (IMBP) to measure intentions to exit street-level prostitution. Intentions are thought to be a determinant of behavior and hypothesized as a function of attitudes, norms, and efficacy beliefs. The primary research objective was to measure and test a theory-driven hypothesis examining intentions to exit prostitution. To accomplish these aims, interviews were conducted with 16 men and women involved in prostitution to better capture the latent nuances of exiting (e.g., attitudinal changes, normative influence). These data informed the design of a quantitative instrument that was pilot-tested with a group of former prostitutes and reviewed by experts in the field. The quantitative phase focused on validating the instrument and testing the theory in a full latent variable structural equation model with a sample of 160 former and active prostitutes. Ultimately, the theory and instrument developed in this study will lay the foundation to test interventions for street prostituted women. Prior research has only been able to describe, but not explain or predict, the prostitution exiting process. This study fills a gap in literature by providing a quantitative examination of women's intentions to leave prostitution. The results contribute to our understanding of the cognitive changes that occur when a person leaves prostitution, and the validated instrument may be used as an intervention assessment or an exit prediction tool. Success in predicting an individual's passage through the exiting process could have important and far-reaching implications on recidivism policies or interventions for this vulnerable group of women.
ContributorsCimino, Andrea N (Author) / Gerdes, Karen E. (Thesis advisor) / Sun, Fei (Committee member) / Gillmore, Mary R (Committee member) / Arizona State University (Publisher)
Created2013
Description
Purpose: This study examines the role of social support on adjustment to widowhood. Past research has indicated that the role of social support on adjustment to widowhood remains inconclusive, and needs further examination. This study examines the varying coping trajectories of middle-aged and retired bereaved spouses. Additionally, this study examines how bereavement stage may also influence one's adaptation to widowhood. Methods: This study used in-depth and semi-structured interviews as a means of understanding the role of social support on adjustment to widowhood. Participants were recruited through two hospice services available in a major metropolitan area in the United States. Convenient and purposive samplings are used in this study; this study will execute a grounded theory approach in order to determine the inconclusive role of social support on adjustment to widowhood. This study is contrasting between two stages- life course stages (middle aged versus retirement aged people) and bereavement stages (a year or less time following the death of a spouse versus three or more years following the death of a spouse). As a means of reducing bias and subjectivity, all data collected during the interview will be transcribed immediately. Results: Middle-aged bereaved spouses reported higher levels of motivation for adjusting positively and quickly towards widowhood due to their concern for protecting the well-being of their surviving young children compared to retired bereaved spouses. Differences between middle-aged widows and widowers have been found in this study; middle-aged widowers have a higher linkage to negative health behaviors. Retired bereaved spouses may fare better depending upon their housing location. Living in a retirement center may lower negative effects of bereavement on retired spouses' health. Conclusions: Types of social support received and expected varied between middle-aged widows and widowers. Gender norms may influence the type of social support widows and widowers receive. Middle-aged widowers are less likely to receive emotional support which may explain their higher linkage to negative health behaviors. Bereavement stage and housing location may be the key factors that influence widowhood trajectories of retired bereaved spouses. Living in a retirement center may lower the negative effects of bereavement on overall health.
ContributorsRafieei, Noshin (Author) / Kronenfeld, Jennie (Thesis advisor) / Haas, Steven (Committee member) / Damgaard, Anni (Committee member) / Arizona State University (Publisher)
Created2013
Description
Criminologists have directed significant theoretical and empirical attention toward the institution of marriage over the past two decades. Importantly, the momentum guiding this line of research has increased despite the fact that people are getting married far less often and much later in the life course than in any point in American history. The aim of this dissertation is to address this disconnect by focusing attention to nonmarital romantic relationships and their instability during emerging adulthood. To do so, it uses data from the Pathways to Desistance Study, a longitudinal study of 1,354 at-risk males and females who were adjudicated from the juvenile and adult systems in Phoenix and Philadelphia between 2000 and 2003. The project focuses attention to the following issues: (1) the effect of romantic dissolution on aggressive and income-based offenses; (2) the extent to which strain
egative emotionality and peer influence/exposure account for the effect of romantic dissolution on crime; and (3) the extent to which certain relationship and individual circumstances moderate the effect of romantic dissolution. The models reveal a few key findings. First, romantic dissolution is strongly related to an increase in both aggressive and income-based crime, but is more strongly related to income-based crime. Second, the effect of romantic dissolution is reduced when measures of strain
egative emotionality and peer influence/exposure measures are added to models, but the peer influence/exposure measures account for the strongest reduction. Finally, romantic dissolution does not serve as a positive life event among these at-risk youth, but its effect is exacerbated under a number of contexts (e.g. when an individual is unemployed). This study closes with a summary of these findings as well as its key limitations, and offers insight into potential policy implications and avenues of future research.
egative emotionality and peer influence/exposure account for the effect of romantic dissolution on crime; and (3) the extent to which certain relationship and individual circumstances moderate the effect of romantic dissolution. The models reveal a few key findings. First, romantic dissolution is strongly related to an increase in both aggressive and income-based crime, but is more strongly related to income-based crime. Second, the effect of romantic dissolution is reduced when measures of strain
egative emotionality and peer influence/exposure measures are added to models, but the peer influence/exposure measures account for the strongest reduction. Finally, romantic dissolution does not serve as a positive life event among these at-risk youth, but its effect is exacerbated under a number of contexts (e.g. when an individual is unemployed). This study closes with a summary of these findings as well as its key limitations, and offers insight into potential policy implications and avenues of future research.
ContributorsLarson, Matthew Joseph (Author) / Sweeten, Gary (Thesis advisor) / Piquero, Alex (Committee member) / Spohn, Cassia (Committee member) / Wallace, Danielle (Committee member) / Arizona State University (Publisher)
Created2013
Description
This thesis builds upon previous research exploring the different factors that influence divorce access attitudes, using data drawn from the General Social Survey in 1991, 1994, and 2008. I examine different social values and economic characteristics and their influence on divorce access attitudes, and explore gender differences within these factors. I examine how information drawn from this analysis supports the argument for Second Demographic Transition Theory as a theoretical framework to explain influential factors in the formation of divorce access attitudes. I conclude that social values variables related to attitudes towards sex behaviors remain significant predictors of divorce access attitudes. I also recognize that socioeconomic context bears influence on the formation of divorce access attitudes. Gender differences lead to the conclusion that behavior and interactions around divorce access attitude formation are dynamic and complex, but are effectively explained using Second Demographic Transition Theory.
ContributorsFrump, Jonathan (Author) / Hayford, Sarah (Thesis advisor) / Glick, Jennifer (Committee member) / Yabiku, Scott (Committee member) / Arizona State University (Publisher)
Created2013
Description
Livestock-grazing, in particular cattle grazing, is a common use of public and private lands in western North America. As a result, the effects of grazing on both plants and animals are widely studied. Few studies, however, look directly at the long-term effects that cattle grazing may have on a particular species. The goal of this experiment was to continue research begun in 1988, to determine if the effects of cattle grazing are still seen in the age structure of two populations of saguaros (Carnegiea gigantea [Engelm.] Britton & Rose) at Saguaro National Park - Rincon Mountain District (SNP-RMD). The null hypothesis stated that enough time has elapsed since the cessation of grazing, and there is no difference in the age distribution of the saguaros of the two populations. The study area was comprised of a former fence line where grazing ceased on the western side of the fence in 1958 and the eastern side in 1978. Belt transects were laid on each side of the fence line and height was measured for each saguaro encountered in a transect. Approximate age of the individual was then calculated using an age-height correlation for SNP-RMD. Individuals were then placed into age classes of 10 year increments and a Log-Likelihood test was performed. The resulting calculated P value of 0.12 meant the null hypothesis was not rejected and there was no statistical difference between the age structure of the two populations. After 34 and 54 years rest from grazing, the negative effects of cattle grazing on the retention and recruitment of saguaro seedlings have ended, and replenishment of the populations is now dependent upon factors such as temperature and precipitation. Other factors such as climate change, increasing fire frequency, encroachment by invasive species, and poaching are sources of concern and increased mortality for these and other saguaros.
ContributorsKrone, Elizabeth AnnMarie Stewart (Author) / Alford, Eddie (Thesis advisor) / Brady, Ward (Committee member) / Green, Douglas (Committee member) / Arizona State University (Publisher)
Created2013