Matching Items (27)
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- All Subjects: conservation
- All Subjects: Agriculture
- All Subjects: Nitrogen
- Creators: School of Sustainability
Description
The Mexican gray wolf (Canis lupus baileyi) is a genetically distinct subspecies of the gray wolf (Canis lupus) that was driven to the brink of extinction as a result of human persecution. The wolf is listed as Endangered under the Endangered Species Act, and a recovery program is underway in Arizona and New Mexico to restore its population. However, the wolf is struggling to recover due to high mortality, which is a result of continued human hostility toward it. This thesis examines historical and current human attitudes toward the wolf and the implications that they have had on the extermination and recovery of the subspecies. An overview is given of wolf biology, the history of wolf extermination and recovery, and recent events relating to the recovery of the wolf. Negative impacts on ranching, hunting, and human safety are the main reasons for opposition toward wolves and wolf recovery; these concerns are analyzed, and solutions to them are proposed, with the goal of addressing them while fostering non-lethal coexistence with the wolf. In addition, opposition to wolves and wolf recovery is tied in with larger socio-political issues and is influenced by the representation of the wolf in culture; these issues in the context of wolves are also analyzed.
ContributorsLenk, Heather Nicole (Author) / Smith, Andrew (Thesis director) / Minteer, Ben (Committee member) / Brown, David E. (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Locusts are a major crop pest in many parts of the world and different species are endemic to different countries. In Latin America, the South American Locust (Schistocerca cancellata) is the predominant species found mostly in Argentina, Chile, Bolivia, Paraguay, and southern Brazil with Argentina being the most affected. Several control and management practices, including biological control, have been implemented in these countries in the past to control the locusts and reduce their impact on crop and vegetation, however, effective long-term control and management practices will require a detail understanding of how the predominant locust species in this region responds to resource variation. Research has shown that there is strong evidence that locusts, and many other organisms, will actively balance dietary macronutrients (protein, carbohydrates, and lipids) to optimize growth, survival, and/or reproduction. A study by Cease et. al, 2017, on the dietary preferences of the Mongolian locust (Oedaleus asiaticus) showed that it prefers diets that are high in carbohydrates over diets that are high in protein, in this case locusts self-selected a 1:2 ratio of protein:carbohydrate. This and many other studies provide vital insight into the nutritional and feeding preferences of these locust species but the effects that this difference in protein: carbohydrate preferences has on growth, egg production, flight potential, and survival has yet to be fully explored, hence, this study investigates the effects that nitrogen fertilization of wheatgrass will have on the growth, egg production, survival, and flight muscle mass of the South American locust in a controlled, laboratory environment.
ContributorsManneh, Balanding (Author) / Cease, Arianne (Thesis director) / Overson, Rick (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This thesis examines how the wording of proposed government policies can affect the level of public support that a given policy generates. By surveying 158 Phoenix residents, I tested the differing degrees of support that voters would have for a proposed city ordinance, which would stop Homeowners' Associations from restricting the use of native desert plants in residential landscaping. The ordinance was framed in the survey as a self-governance issue or a water conservation issue. I found that the message frames had little effect on the overall level of support for the ordinance, since most residents had moderate support for the policy. However, participants who were either residents of Homeowners' Associations that did not have native plant restrictions, or native residents of Arizona, demonstrated greater levels of support for the self-determination frame of the proposed ordinance. These findings have implications for policy makers who use targeted messages to establish pro-environmental policies at the local level.
ContributorsSmith, Mary Hannah (Author) / Darnall, Nicole (Thesis director) / Ramirez, Mark (Committee member) / Tetreault, Colin (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Politics and Global Studies (Contributor)
Created2013-05
Description
This thesis was conducted in order to determine the role played by food miles metrics in making the agricultural industry more sustainable. In an effort to analyze the importance of eat locally this study utilizes a partial life cycle assessment. This study looks at oranges grown in Arizona and California and inputs such as water, energy, fertilizer, herbicide, pesticide, frost mitigation, and distance in order to conduct the partial life cycle assessment. Results of this study indicate that food miles are not as significant, in relation to overall energy input, as the locavore movement claims. This is because production processes account for a larger portion of the total energy used in the food chain than what these claims suggest. While eating locally is still a significant way of reducing energy use, this thesis shows that decisions about eating sustainably should not only focus on the distance that the products travel, but place equal, if not more, importance on energy use differences due to geographic location and in-farm operations. Future research should be completed with more comprehensive impact categories and conducted for different crops, farming, and locations. Further research is needed in order to confirm or challenge the results of this thesis. With more research conducted regarding this topic, ecological labeling of agricultural products could be improved to help consumers make the most informed choices possible.
ContributorsMaggass, Melissa Gail (Author) / Manuel-Navarrete, David (Thesis director) / Martin, Thomas (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / W. P. Carey School of Business (Contributor) / Department of Management (Contributor)
Created2014-05
Description
Chytridiomycosis, an infectious disease caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), has played a significant role in global amphibian declines. Researchers studying Bd aim to gain a better understanding of how this pathogen survives in unique microhabitats to promote persistence of amphibians in their natural habitat. The Arizona Game and Fish Department has worked for the last 12 years to recover populations of Chiricahua Leopard Frogs to ensure the species survives in the Huachuca Mountains in southeastern Arizona. During this time, the department tested for Bd throughout their release sites. As a result of large differences in prevalence noted in prior sampling for Bd in Miller and Ramsey canyons, I investigated abiotic factors that could explain these differences. I analyzed water samples from two canyons in the Huachuca Mountains and used nutrient analysis and filter extraction to test for differences in abiotic factors between these two sites that could affect Bd transmission. Results show that Ramsey Canyon was a positive site for Bd, while Miller Canyon remained negative. Results from water temperature estimates as well as a test for 30 elements revealed possible reasons for differences in Bd transmission between the two canyons.
ContributorsSmith, Paige Gabrielle (Author) / Collins, James P. (Thesis director) / Franklin, Janet (Committee member) / Sredl, Michael J. (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Current farming demographics in the United States indicate an aging and overwhelmingly white group of farmers, stimulating the need for engaging a younger and more diverse population. There is an opportunity to engage these populations through farm-based internship and apprenticeship programs, which are immersive programs on small-scale, sustainable farms. These programs are unique in providing hands-on training, housing, meals, and a stipend in return for labor, presenting a pathway to social empowerment. The potential outcomes of increasing diversity and inclusion in farm programs are absent from the research on the benefits of diversity and inclusion in other work environments, such as the corporate setting. This paper presents the results of a study aimed at determining levels of diversity and inclusion in United States farm-based internship programs, and the viability of these programs as an effective opportunity to engage marginalized young people in farming. The study of 13 farm owners and managers across the U.S. found that the participants are focused on fostering education and training, environmental benefits, and a sense of community in their respective programs. All participants either want to establish, or believe they currently have, an inclusive workplace on their farm, but also indicated a barrier to inclusivity in the lack of a diverse applicant pool. Future recommendations for removing that barrier and involving more young, diverse interns include increased outreach and access to these programs, the use of inclusive language, and further research.
ContributorsLascola, Dania (Co-author) / Biel, Braden (Co-author) / Cloutier, Scott (Thesis director) / MacFadyen, Joshua (Committee member) / School of International Letters and Cultures (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Elevated nitrate (NO3-) concentration in streams and rivers has contributed to environmental problems such as downstream eutrophication and loss of biodiversity. Sycamore Creek in Arizona is nitrogen limited, but previous studies have demonstrated high potential for denitrification, a microbial process in which biologically active NO3- is reduced to relatively inert dinitrogen (N2) gas. Oak Creek is similarly nitrogen limited, but NO3- concentration in reaches surrounded by agriculture can be double that of other reaches. We employed a denitrification enzyme assay (DEA) to compare potential denitrification rate between differing land uses in Oak Creek and measured whole system N2 flux using a membrane inlet mass spectrometer to compare differences in actual denitrification rates at Sycamore and Oak Creek. We anticipated that NO3- would be an important limiting factor for denitrifiers; consequentially, agricultural land use reaches within Oak Creek would have the highest potential denitrification rate. We expected in situ denitrification rate to be higher in Oak Creek than Sycamore Creek due to elevated NO3- concentration, higher discharge, and larger streambed surface area. DEA results are forthcoming, but analysis of potassium chloride (KCl) extraction data showed that there were no significant differences between sites in sediment extractable NO3- on either a dry mass or organic mass basis. Whole-reach denitrification rate was inconclusive in Oak Creek, and though a significant positive flux in N2 from upstream to downstream was measured in Sycamore Creek, the denitrification rate was not significantly different from 0 after accounting for reaeration, suggesting that denitrification does not account for a significant portion of the NO3- uptake in Sycamore Creek. Future work is needed to address the specific factors limiting denitrification in this system.
ContributorsCaulkins, Corey Robert (Author) / Grimm, Nancy (Thesis director) / Childers, Daniel (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The Prosopis genus of trees, also known as mesquites, are uniquely equipped to allow for an agroforestry regime in which crops can be grown beneath the canopy of the tree. Mesquites have the ability to redistribute water moisture in such a way that allows plants under the canopy to use water that has been brought up by the roots of mesquite trees. This means that there is a potential for food crops to be grown under the trees without using additional irrigation measures. This could be used where access to water is limited or for a sustainability-minded farmer who is trying to reduce water inputs in an arid environment. Mesquite trees produce a variety of products, including lumber and bean pods that can be ground down into an edible flour. Both products demand a high price in the marketplace and are produced in addition to the crops that can potentially be grown beneath the mesquite tree. In order to determine whether or not it is possible to grow crops under mesquite trees, I reviewed a wide range of literature regarding hydraulic redistribution, mesquite trees in general, and what plants might be best suited for growing beneath a mesquite. The list of plants was narrowed down to four crops that seemed most likely to survive in shaded, low water conditions in a hot environment. There has not been any research done on crops growing beneath mesquite trees, so the next step for research would be to experiment with each of the crops to determine how well each species can adapt to the specified conditions.
ContributorsMesser, Luke Winston (Author) / Eakin, Hallie (Thesis director) / Hall, Sharon (Committee member) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
City managers and policy makers are increasing looking to environmental systems to provide beneficial services for urban systems. Constructed wetland systems (CWS), highly managed and designed wetland ecosystems, are being utilized to remove pollution, particularly excess nitrogen (N), from treated wastewater. Various wetland process remove N from effluent, such as denitrification, direct plant uptake, and soil accumulation. Emergent macrophytes provide direct uptake of N and improve conditions for microbially-mediated N processing. The role of different macrophytes species, however, is less understood and has primarily been examined in mesocosm and microcosm experiments and in mesic environments. I examined the effects of community composition on N removal and processing at the whole ecosystem scale in an aridland, constructed wetland (42 ha) through: 1) quantifying above- and belowground biomass and community composition from July 2011 \u2014 November 2012 using a non-destructive allometric technique, and; 2) quantifying macrophyte N content and direct macrophyte N uptake over the 2012 growing season. Average peak biomass in July 2011 & 2012 was 2,930 g dw/m2 and 2,340 g dw/m2, respectively. Typha spp. (Typha domingensis and Typha latifolia) comprised the majority (approximately 2/3) of live aboveground biomass throughout the sampling period. No statistically significant differences were observed in macrophyte N content among the six species present, with an overall average of 1.68% N in aboveground tissues and 1.29% N in belowground tissues. Per unit area of wetland, Typha spp. retained the most N (22 g/m2); total N retained by all species was 34 g/m2. System-wide direct plant N uptake was markedly lower than N input to the system and thus represented a small portion of system N processing. Soil accumulation of N also played a minor role, leaving denitrification as the likely process responsible for the majority of system N processing. Based on a literature review, macrophyte species composition likely influences denitrification through oxygen diffusion into soils and through the quality and quantity of carbon in leaf litter. While this study and the literature indicates Typha spp. may be the best species to promote wetland N processing, other considerations (e.g., bird habitat) and conditions (e.g., type of wastewater being treated) likely make mixed stands of macrophytes preferable in many applications. Additionally, this study demonstrated the importance of urban wetlands as scientific laboratories for scientists of all ages and as excellent stepping-off points for experiments of science-policy discourse.
ContributorsWeller, Nicholas Anton (Author) / Daniel L., Childers (Thesis director) / Grimm, Nancy (Committee member) / Turnbull, Laura (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Public Affairs (Contributor) / Graduate College (Contributor)
Created2013-05
Description
American youth are not well exposed to animal- and nature-related careers. This is especially important to consider due to the recent push to be more environmentally conscious. In addition, youth are spending less time outside and more time in front of screens. This is driving down biophilia strength. The combination of a weaker connection with nature and more screen time has been connected to a new condition named Nature-Deficit Disorder. In order to expose youth to animal- and nature-related careers while attempting to combat the growing presence of Nature-Deficit Disorder, a three day teaching program named Wild Careers was created. This program was presented to teens in December 2015 through a partnership with the education department of Arizona Animal Welfare League. The curriculum was centered on highlighting relevant careers and background information. Topics such as animal welfare and conservation were taught as cornerstones during the program due to their encompassing importance to the career fields in question. It was felt to be important to inform participants about the context of these fields through specially planned activities and guest speakers. Participants were challenged to conduct online research, think critically, and get hands-on during this program. Wild Careers also exposed the participants to animals and the relevant species management stories. The surveys given before and after the presentation of the created curriculum provided evidence that supported an increased understanding of careers and enjoyment of participants. I propose that other non-formal teaching environments should be created that target exposing youth to animals, nature, and related careers.
ContributorsTaubel, Samantha Kay (Author) / Smith, Andrew (Thesis director) / Minteer, Ben (Committee member) / Arthur, Emilie (Committee member) / Division of Teacher Preparation (Contributor) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05