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University of Massachusetts Amherst

Masters Theses

2022

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Manganese Bioavailability Drives Organic Matter Transformations Across Oxic-Anoxic Interfaces Via Biotic And Abiotic Pathways, Nathan A. Chin Oct 2022

Manganese Bioavailability Drives Organic Matter Transformations Across Oxic-Anoxic Interfaces Via Biotic And Abiotic Pathways, Nathan A. Chin

Masters Theses

Soil organic matter decomposition is a critical process that affects nutrient cycling, CO2 emissions, and carbon storage in terrestrial environments. Recent evidence suggests reactive manganese (Mn) phases, potent oxidants that depolymerize compounds like lignocellulose in soil organic matter, act as critical drivers of organic matter decomposition in soil and sediment environments. Furthermore, oxic-anoxic interfaces (OAIs) have been shown to be crucial hotspots for the formation of reactive Mn(III) species and associated organic matter degradation. However, the extent to which microbially mediated Mn(III) formation and subsequently Mn(III)-driven organic matter oxidation depends on Mn availability remains largely unknown. Additionally, the relative …

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Identifying New Invasives In The Face Of Climate Change: A Focus On Sleeper Populations, Ayodelé C. O'Uhuru Oct 2022

Identifying New Invasives In The Face Of Climate Change: A Focus On Sleeper Populations, Ayodelé C. O'Uhuru

Masters Theses

Sleeper populations are established populations of a non-native species whose population growth is limited by one or more abiotic or biotic conditions, such as climate change. While the northeastern US is predicted to be a hotspot for future invasions, identifying potential sleeper populations before they become invasive can inform proactive, climate-smart invasive species management. I focused on 169 introduced species that are established in one or more northeastern states. I used the Environmental Impact Classification for Alien Taxa (EICAT) framework to systematically identify and review the peer-reviewed literature for these candidate species to quantify their negative ecological and socioeconomic impacts. …

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Chromatographic Dynamic Chemisorption, Shreya Thakkar Jun 2022

Chromatographic Dynamic Chemisorption, Shreya Thakkar

Masters Theses

Reaction rates of catalytic cycles over supported metal catalysts are normalized by the exposed metal atoms on the catalyst surface, reported as site time yields which provide a rigorous standard to compare distinct metal surfaces. Defined as the fraction of exposed metal surface atoms to the total number of metal atoms, it is important to measure the dispersion of supported metal catalysts to report standardized rates for kinetic investigations. Multiple characterization techniques such as electron microscopy, spectroscopy and chemisorption are exploited for catalyst dispersion measurements. While effective, electron microscopy and spectroscopy are not readily accessible due to cost and maintenance …

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Pre-Agricultural Soil Erosion Rates In The Midwestern U.S., Caroline Lauth Quarrier Jun 2022

Pre-Agricultural Soil Erosion Rates In The Midwestern U.S., Caroline Lauth Quarrier

Masters Theses

Soil erosion undermines agricultural productivity, limiting the lifespan of civilizations. For agriculture to be sustainable, soil erosion rates must be low enough to maintain fertile soil, as was present in many agricultural landscapes prior to the initiation of farming. However, there have been few measurements of long-term pre-agricultural erosion rates in major agricultural landscapes. We quantified geological erosion rates in the Midwestern U.S., one of the world’s most productive agricultural areas. We sampled soil profiles from 14 native prairies and measured concentrations of the cosmogenic nuclide 10Be and chemically immobile elements to calculate physical erosion rates. We used the erosion …

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Three Dimensional Spatio-Temporal Cluster Analysis Of Sars-Cov-2 Infections, Keith W. Allison Jun 2022

Three Dimensional Spatio-Temporal Cluster Analysis Of Sars-Cov-2 Infections, Keith W. Allison

Masters Theses

The COVID-19 pandemic has heightened the need for fine-scale analysis of the clustering of cases of infectious disease in order to better understand and prevent the localized spread of infection. The students living on the University of Massachusetts, Amherst campus provided a unique opportunity to do so, due to frequent mandatory testing during the 2020-2021 academic year, and dense living conditions. The South-West dormitory area is of particular interest due to its extremely high population density, housing around half of students living on campus during normal conditions. Using data gathered by the Public Health Promotion Center (PHPC), we analyzed the …

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Dynamics Of Water Supply And Demand In The Bandama River Watershed Of Cote D'Ivoire, Sarah Alima Traore May 2022

Dynamics Of Water Supply And Demand In The Bandama River Watershed Of Cote D'Ivoire, Sarah Alima Traore

Masters Theses

Water is a fundamental human right supporting life, health, and livelihoods. Yet water-related issues are ranked among the top five global economic risks (WEF, 2020). About two-thirds (4 billion) of the world's population live with severe water scarcity for at least one month, of which about 48% live in both India and China (Mekonnen et al., 2016). In Côte d'Ivoire, the Bandama River, one of the largest in the country, has struggled to meet expected demand, causing recurrent water and electricity shortages. The city of Bouaké in Côte d'Ivoire and neighboring towns experienced a severe water shortage in 2018 with …

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Utilizing Climate Change Refugia For Climate Change Adaptation And Management In The Northeast, Sara A. Wisner Mar 2022

Utilizing Climate Change Refugia For Climate Change Adaptation And Management In The Northeast, Sara A. Wisner

Masters Theses

To account for the effects of climate change, management plans in the northeast need to incorporate climate adaptation. Conserving climate change refugia is one adaptation strategy. Climate change refugia are areas buffered by climate change that enable the persistence of valued physical, ecological, and cultural resources; preserving these areas could be a potential adaptation strategy. Using a translational ecology approach where researchers and managers from the National Park Service, US Geological Survey, the University of Massachusetts, and elsewhere worked together, we focused on identifying refugia for tree, herbaceous plant, mammal, and bird species in order to prioritize them for conservation …

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Assessment Of The Economic And Ecosystem Service Contributions Of Usda Forest Service Landowner Assistance Programs In The Conterminous United States, Jacqueline S. Dias Mar 2022

Assessment Of The Economic And Ecosystem Service Contributions Of Usda Forest Service Landowner Assistance Programs In The Conterminous United States, Jacqueline S. Dias

Masters Theses

Forests provide immense goods and services to both local and regional communities. The USDA Forest Service’s, State and Private Forestry program administer multiple landowner assistance programs aimed at helping private forest owners while supporting the continued supply of ecosystem services (e.g., timber harvesting, recreation, carbon sequestration and storage). The two landowner assistance programs assessed in this study are the Forest Legacy Program (FLP) and the Forest Stewardship Program (FSP). A majority of the nation’s forests are privately owned, many of which are facing deleterious impacts like wildfires, invasive species, development pressures, and other adverse effects from climate change. The goal …

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