Matching Items (20)
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- All Subjects: Food Systems
- All Subjects: Nitrogen
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- Creators: School of Sustainability
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
Community gardens are used worldwide to promote sustainable, urban living. They can be used to improve the physical, mental, emotional, and social health of the gardeners and volunteers who utilize their grounds. The gardens may also have a positive impact on the local environment and wider community. This study examines a community garden seeking to expand its involvement in the local neighborhood and searching for ways to include local residents in garden related activities. To this end, the garden was waiting for approval on their non-profit, 501(c)3 status, and was seeking additional data on local residents and perceptions of the garden's activities. This thesis first reviews the literature on the benefits community gardens provide for the individuals living in their communities and their impact on urban development. The thesis then turns to an analysis of one garden, Mesa Urban Garden, rooted in the Downtown District of Mesa, Arizona, and how they are impacting their neighborhood and how garden organizers can respond in new and creative ways to local residents.
ContributorsBooher, Samantha Rose (Author) / Glick, Jennifer (Thesis director) / Dumka, Larry (Committee member) / Barrett, The Honors College (Contributor) / Hugh Downs School of Human Communication (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
Community gardens are used worldwide to promote sustainable, urban living. They can be used to improve the physical, mental, emotional, and social health of the gardeners and volunteers who utilize their grounds. The gardens may also have a positive impact on the local environment and wider community. This study examines a community garden seeking to expand its involvement in the local neighborhood and searching for ways to include local residents in garden related activities. To this end, the garden was waiting for approval on their non-profit, 501(c)3 status, and was seeking additional data on local residents and perceptions of the garden's activities. This thesis first reviews the literature on the benefits community gardens provide for the individuals living in their communities and their impact on urban development. The thesis then turns to an analysis of one garden, Mesa Urban Garden, rooted in the Downtown District of Mesa, Arizona, and how they are impacting their neighborhood and how garden organizers can respond in new and creative ways to local residents.
ContributorsBooher, Samantha Rose (Author) / Glick, Jennifer (Thesis director) / Dumka, Larry (Committee member) / Barrett, The Honors College (Contributor) / Hugh Downs School of Human Communication (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
There are three known materials that readily undergo fission, allowing their use as a base for nuclear fuel: uranium-235, a naturally-occurring but uncommon isotope; plutonium, created from irradiated natural uranium; and uranium-233, produced from thorium. Of the three, uranium-235 and plutonium feature heavily in the modern nuclear industry, while uranium-233 and the thorium fuel cycle have failed to have significant presence in the field. Historically, nuclear energy development in the United States, and thorium development in particular, has been tied to the predominant societal outlook on the field, and thorium was only pursued seriously as an option during a period when nuclear energy was heavily favored, and resources seemed scarce. Recently, thorium-based energy has been experiencing a revival in interest in response to pollution concerns regarding fossil fuels. While public opinion is still wary of uranium, thorium-based designs could reduce reliance on fossil fuels while avoiding traditional drawbacks of nuclear energy. The thorium fuel cycle is more protected against proliferation, but is also much more expensive than the uranium-plutonium cycle in a typical reactor setup. Liquid-fueled molten salt reactor designs, however, bypass the prohibitive expense of U-233 refabrication by avoiding the stage entirely, keeping the chain reaction running with nothing but thorium input required. MSRs can use any fissile material as fuel, and are relatively safe to operate, due to passive features inherent to the design.
ContributorsGalbiati, Joseph Nicco (Author) / Martin, Thomas (Thesis director) / Foy, Joseph (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
Solutions to mitigating the negative externalities of climate change are deemed necessary for a sustainable future. Residential community composting, such as the Community Compost Program at Vista del Sol, could potentially play an important role within Arizona State University’s (ASU) solution to develop a sustainable institution as programs aspire to develop sustainable behaviors and integrate environmentally positive practices within students’ lives. The research and review of how universities can utilize a residential community compost program to ignite sustainable action within on-campus communities could present helpful information for additional universities to implement on their own. This review will aim to tackle the research question: how can the operational functions of existing university residential composting programs and behavioral science research be implemented within the Community Compost Program at Arizona State University? The review from existing university residential composting programs and behavioral sciences will be completed to provide an explanation of how residential community composting can overall be effectively prompted.
ContributorsKovacs, Amelia (Author) / Wharton, Christopher (Thesis director) / Daniel, Fischer (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Local food sustainability has gained significant recent attention over the past decade. Considerable research points to a host of economic, social, and environmental benefits resulting from engagement with local food systems. These benefits are more apparent when contrasted with a model in which individuals participate in larger, non-local food systems for all or most of their food sourcing. As such, this project was designed to explore possible barriers, such as lack of awareness, to engagement in local foods among Arizona State University (ASU) students on the main Tempe campus. Furthermore, this creative project aimed to evaluate how a local foods program conducted in a university dining hall might impact students’ awareness and interest in local foods served on site.
ContributorsBakeman, Taylor Melissa (Author) / Wharton, Christopher (Thesis director) / Popova, Laura (Committee member) / College of Health Solutions (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The purpose of this thesis is to imagine and predict the ways in which humans will utilize technology to feed the world population in the 21st century, in spite of significant challenges we have not faced before. This project will first thoroughly identify and explain the most pressing challenges the future will bring in climate change and population growth; both projected to worsen as time goes on. To guide the prediction of how technology will impact the 21st century, a theoretical framework will be established, based upon the green revolution of the 20th century. The theoretical framework will summarize this important historical event, and analyze current thought concerning the socio-economic impacts of the agricultural technologies introduced during this time. Special attention will be paid to the unequal disbursement of benefits of this green revolution, and particularly how it affected small rural farmers. Analysis of the technologies introduced during the green revolution will be used to predict how 21st century technologies will further shape the agricultural sector. Then, the world’s current food crisis will be compared to the crisis that preceded the green revolution. A “second green revolution” is predicted, and the agricultural/economic impact of these advances is theorized based upon analysis of farming advances in the 20th century.
ContributorsWilson, Joshua J (Author) / Strumsky, Deborah (Thesis director) / Benjamin, Victor (Committee member) / Department of Supply Chain Management (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The rise in urban populations is encouraging cities to pursue sustainable water treatment services implementing constructed treatment wetlands (CTW). This is especially important in arid climates where water resources are scarce; however, research regarding aridland CTWs is limited. The Tres Rios CTW in Phoenix, Arizona, USA, presents the tradeoff between greater water loss and enhanced nitrogen (N) removal. Previous research has suggested that water loss due to transpiration is replaced by a phenomenon termed the Biological Tide. This trend has been documented since 2011 by combining transpiration values with a nitrogen budget. Calculations were made at both the marsh and whole-system scale. The purpose of this paper is to demonstrate how the Biological Tide enhances N uptake throughout the CTW. Results indicate that about half of the nitrogen taken up by the vegetated marsh is associated with new water entering the marsh via the Biological Tide with even higher values during warmer months. Furthermore, it is this phenomenon that enhances N uptake throughout the year, on average, by 25.9% for nitrite, 9.54% for nitrate, and 4.84% for ammonium at the whole-system scale and 95.5%, 147%, and 118% within the marsh. This paper demonstrates the Biological Tide’s significant impact on enhanced N removal in an aridland CTW.
ContributorsTreese, Sawyer Matthew (Author) / Childers, Daniel L. (Thesis director) / Grimm, Nancy (Committee member) / School of Geographical Sciences and Urban Planning (Contributor) / School of Sustainability (Contributor) / School of Public Affairs (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Freshwater ecosystems are increasingly threatened by anthropogenic eutrophication (Kolzau et al., 2014) and require mitigation efforts to prevent oxygen depletion and subsequent biodiversity loss. Tres Rios Constructed Treatment Wetland (CTW) relies on wetland ecosystem functioning to reduce nutrient concentrations in order to meet regulatory guidelines. I investigated the impact of solar irradiance, temperature, and nutrient availability on aquatic net primary productivity, ecosystem respiration, and nutrient cycling using statistical analysis and quantitative modeling informed by field data generated by ASU’s Wetland Ecosystem Ecology Lab (WEEL) in partnership with the City of Phoenix Water Services Department. I found that the extent of daily solar insolation controls Aquatic Net Primary Productivity (ANPP) rates and the seasonal aquatic nutrient processing capacity of Tres Rios, resulting in the following approximate relationship: ANPP = 0.001344(W/m²) - 0.32634 (r² = 0.259; p = 0.005).
This formula was used to estimate the nutrient uptake performance of aquatic primary producers from sampling observations; ANPP accounted for 16.26 metric tons of system wide N uptake, while aquatic ER contributed 6.07 metric tons N of nighttime remineralization and 5.7 metric tons of N throughout the water column during the day. The estimated yearly net aquatic N flux is 4.49 metric tons uptake, compared to about 12 metric tons yearly N uptake by the vegetated marsh (Treese, 2019). However, not accounting for animal respiration results in an underestimation of system-wide N remineralization, and not accounting for soil processes results in an underestimation of N uptake.
This formula was used to estimate the nutrient uptake performance of aquatic primary producers from sampling observations; ANPP accounted for 16.26 metric tons of system wide N uptake, while aquatic ER contributed 6.07 metric tons N of nighttime remineralization and 5.7 metric tons of N throughout the water column during the day. The estimated yearly net aquatic N flux is 4.49 metric tons uptake, compared to about 12 metric tons yearly N uptake by the vegetated marsh (Treese, 2019). However, not accounting for animal respiration results in an underestimation of system-wide N remineralization, and not accounting for soil processes results in an underestimation of N uptake.
ContributorsEvans, Joseph Barrett (Author) / Childers, Daniel (Thesis director) / Hartnett, Hilairy (Committee member) / Watts College of Public Service & Community Solut (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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