Environmental Sciences Commons^™

Organic Fouling Mitigation In Forward Osmosis Technology Through The Use Of Oscilatting Alternating Current Electric Fields, Logan Werner

Graduate College Dissertations and Theses

Forward osmosis (FO) is the term given to osmosis in water filtration applications. FO has many advantages to conventional membrane filtration processes. The lack of external pressure needed to force solvent through the membrane is dramatically decreased in FO, resulting in a lower cost of operation compared to reverse osmosis. Lower external pressures also result in decreased fouling on the membrane surface and improved permeate flux. Fouling is one of the foremost challenges within the membrane filtration industry and is one of the biggest contributors to operating costs. While FO results in less fouling than RO, fouling remains a major …

Community Science And Coyote Stories: Capturing And Communicating Nature's Non-Material Values For Use In Decision-Making, Joshua Wright Morse

Graduate College Dissertations and Theses

The reasons and ways that nature matters underlie every part of environmental decision-making. Yet, there are disparities in how different kinds of benefits from and values about nature are represented in policy and practice. This dissertation explores how decision-makers and community members value nature broadly and also in the context of a specific human-wildlife interaction in Vermont, United States.

In my first chapter, I conduct semi-structured interviews with environmental sector practitioners in Vermont to learn about their awareness of non-material values from nature. I find that practitioners talk readily about both material and non-material ecosystem services as well as multiple …

Unraveling Public Evacuation Likelihood: Structural Equation Models And The Extended Parallel Process Model In Focus, Molly Margaret Myers

Graduate College Dissertations and Theses

This study explores the intricate relationships between risk perception, efficacy appraisal, and evacuation likelihood in the context of flooding among the United States public. The Extended Parallel Process Model (EPPM) developed by Witte (1992) serves as the theoretical framework for this study, emphasizing the two-pronged appraisal process of threat and efficacy, influencing individual responses to risk messaging. Analysis of the data delves into the relationships between risk perception and evacuation likelihood, offering insights into the public's understanding of flood risk and readiness for impending flood events. This study used Structural Equation Modeling (SEM) to discern the impact of threat and …

Forest Management Tradeoffs: Examining Relationships Between Timber Harvest, Carbon Sequestration And Storage, Bioenergy, And Wildlife, Michelle L. Brown

Graduate College Dissertations and Theses

Timber harvesting is the leading cause of adult tree mortality in forests of the northeastern United States. While current rates of harvest are generally sustainable, there is considerable pressure to increase harvest to meet timber production, climate, and energy goals. Maximizing one of these values may compromise other forest resources, including a wide range of ecosystem services and the conservation of native species. This dissertation investigates the effects of timber harvest on carbon sequestration and storage, bioenergy, and wildlife. First, I estimated current harvest regimes for different forest types and regions across the U.S. states of New York, Vermont, New …

Forest Management In The Context Of Global Change: Impacts Of Disturbance, Adaptive Management, And Invasive Species On Northeastern Forests, Jennifer Santoro

Graduate College Dissertations and Theses

Climate change is predicted to have variable and uncertain effects on forested ecosystems globally. In the northeastern US, natural disturbances have historically been a central driver of forest successional dynamics, but as climate warming is projected to alter the frequency and severity of these events, post-disturbance management strategies to sustain biodiversity and ecosystem services must adaptively change to promote forest resilience. A suite of adaptive silvicultural actions has been proposed to promote forest resilience in the face of uncertainty, but due to the multi-decadal scale of forest management, initial field experiments are only beginning to show results. To address these …

Drivers Of Soil Organic Carbon In Rich Northern Hardwood Forests, Sophia Rebecca Marinace

Graduate College Dissertations and Theses

Forests are increasingly being managed for their carbon sequestration potential. As such, an understanding of the factors controlling carbon dynamics across and within sites is becoming increasingly important for guiding carbon management strategies. Given that much of a forest’s carbon is stored in soils, identifying the factors that control how much carbon is stored in soils is critical. This study used detailed vegetation and soil measurements across a rich northern hardwood forest in Corinth, Vermont to identify factors that drive soil carbon storage in a northern hardwood forest, a common type in New England, and investigated how multiple non-native species …

Imaginaries Of The Great Outdoors: Comparing Facebook Postings Across Resource Places, Frances Hoag

Graduate College Dissertations and Theses

Communication across agencies, interested audiences, and the public is central to resource management. While social media expands agencies’ communication options, it also may present opportunities for constructing and presenting “imaginaries” – collectively imagined discourses that that shape understandings of place and influence the world views of followers. Imaginaries are “socially constructed, taken-for-granted meanings about reality that make everyday social and cultural practices seem obvious and sensible to people” (Stokowski et al., 2021). Extending prior research, we sought to understand whether/how resource management agencies used social media to construct and deploy imaginaries. Data were collected during 2021-2022 from resource management agencies …

Socio-Ecological Economic Impact Analysis Of Food Systems Initiatives Using Mixed Methods And Community-Based Research Approaches, Josiah J. Taylor

Graduate College Dissertations and Theses

Many NGO and government community development programs seek to alleviate complex problems related to food systems and agriculture. Yet, without integrated social, ecological, and economic impact analysis we cannot understand or communicate the value of such interventions. For this research, we partnered with food and agriculture organizations using participatory action research approaches to co-develop and test tools for holistic program analysis. We then used these tools to conduct and co-produce a holistic analysis and evaluation of program impacts. The first chapter provides background and context for the body of the dissertation. Chapter two details work with Hunger Free Vermont to …

Groundwater Governance And Agricultural Sustainability: Examining Farmer Interactions With California’S Sustainable Groundwater Management Act, Zachary Matthew Goldstein

Graduate College Dissertations and Theses

Climate change has exacerbated groundwater depletion globally, and policymakers have struggled to effectively manage groundwater resources. California enacted the Sustainable Groundwater Management Act (SGMA) in 2014 to restore groundwater to sustainable levels.

The first paper of this thesis examines the drivers associated with uptake of groundwater conservation practices in agriculture. While a rich body of research has explored farmers’ conservation practice adoption, understanding of groundwater conservation practices is more limited. This study explores how information sources influence the actual and intended adoption of groundwater management practices in California. Using survey data from farmers (n = 553) in three largely agricultural …

Paleolimnological Data Synthesis To Assess Long-Term Ecological Change In Vermont Lakes, Ismar Biberovic

Graduate College Dissertations and Theses

Lakes are excellent early indicators of environmental change on a landscape scale. Due to their connectedness in the landscape, any alteration of land-cover extends beyond a single watershed and can only be amplified by the effects of climate change. These processes can reflect differently across lakes of various characteristics, however, combined, they can leave a lasting impact on biogeochemical processes of a lake, resulting in profound effects on biological communities residing in it. Lake sediments are terrific archives that integrate and preserve this evidence, which then allows us to investigate the extent to which a lake has changed given its …

Riparian Buffer Establishment Using Different Management Techniques, Stever H. Bartlett

Graduate College Dissertations and Theses

ABSTRACT

In riparian areas of the northeastern United States, well-established reed canary grass (Phalaris arundinacea) stands are common and have proven to be a challenge for the success of tree plantings during riparian forest restoration projects. The impacts of reed canary grass (RCG) on the habitats it invades are numerous. Reed canary grass reduces biological diversity by homogenizing habitat structure, richness, and environmental variability. Its rapid growth rate and invasive nature limits tree regeneration in riparian forests by shading and crowding out seedlings. Riparian forests improve water quality, wildlife habitat, flood control, and provide a variety of other ecosystem services. …

Changing Environmental Conditions And The Response And Potential Adaptability Of Freshwater Whitefishes, Taylor R. Stewart

Graduate College Dissertations and Theses

Changes in winter conditions, such as increased temperatures and decreased ice coverage, have been observed worldwide. The responses of many lake fish populations to changing winters are projected to be inadequate to counter the speed and magnitude of climate change. Such environmental changes have been hypothesized to explain the low recruitment observed in freshwater whitefishes (Salmonidae Coregoninae). My research focused on measuring the impact changing winter conditions may have on coregonine reproductive phenology and developmental and morphological traits to better predict changes in coregonine populations as a result of climate change.

I used experimental incubation methods and modeling to explore …

Multi-Scale Assessment Of Gully Erosion At Road Drainage Outlets, Emma Louise Estabrook

Graduate College Dissertations and Theses

Gully erosion and sediment deposition from roads are underrated sources of sediments entering receiving waterways. While gully erosion has been studied throughout the world, the monitoring of the temporal and spatial erosional processes related to culverts and road drainage is rare. The objectives of this study are to quantify rates of gully erosion from Vermont’s transportation drainage networks at multiple temporal scales and report on insights gained from a multi-scale approach to monitoring gully erosion. To quantify event to seasonal timescales of gully erosion, high resolution terrestrial LiDAR surveys were conducted at 13 field sites. Field sites were monitored at …

Revealing The Direct And Indirect Effects Of Climate Change On Soil Nutrient Dynamics And Forage Resources In Mountain Ecosystems, Kenna Elizabeth Rewcastle

Graduate College Dissertations and Theses

Modern climate change is already altering the structure and function ofecosystems around the world in nontrivial ways. Mountain ecosystems in particular will continue to experience a greater magnitude and rate of climatic warming than the global average, threatening the stability of key ecosystem processes like nutrient cycling as well as the supply of benefits from ecosystem services provided by mountains. While significant advancements have been made to address the direct effects of rising temperatures on nutrient cycling dynamics, our understanding of the synergies between the direct effects of warming and the indirect effects of climate change, mediated by the response …

Constraint-Aware And Efficiency-Aware Control Of Air-Path In Fuel Cell Vehicles, Eli Bacher-Chong

Graduate College Dissertations and Theses

Fuel cell technology offers the potential for clean, efficient, robust energy productionfor both stationary and mobile applications. But without fast and robust control systems, fuel cells cannot hope to maintain real-life efficiencies near enough to their theoretical potential. This work studies control and constraint management techniques to regulate a nonlinear multivariable air-path system for a proton exchange membrane fuel cell (PEMFC). The control objectives are to avoid oxygen starvation, run at the maximum net efficiency, achieve fast tracking of air flow and pressure set-points, and be easy to calibrate. To operate at maximum efficiency, a set-point map is generated for …

Embracing Uncertainty, Ambiguity, And Complexity In Agriculture, Science, And Policy, Benjamin Timothy Dube

Graduate College Dissertations and Theses

Policy makers say they govern the environment based on scientific evidence, but environmental activists express concern about issues that challenge scientific understandings, such as risk, uncertainty, justice, and participation. This conflict is magnified in agriculture, where many social movements and farmers advocate and create farming systems that are ecological—diverse, heterogenous and adaptive. Ecological farming systems are thus harder for outside experts - researchers, extensionists, development practitioners or policymakers – to understand. Complexity and context-specificity in ecological agriculture presents numerous challenges along the path from scientific inquiry to policy implementation, including in categorizing, systematically studying, modelling and regulating farming systems. In …

Management For Amphibians In Complex Ecosystems, Lindsey Pekurny

Graduate College Dissertations and Theses

Effective conservation is becoming more difficult as threats to wildlife increase. Natural resource managers are pressured to make difficult decisions with limited resources, and in many instances, some degree of uncertainty. Scientists and managers tasked with the conservation of a species need tools to help guide efficient decision making. Often, information for management decisions is insufficient. Tools that help to inform decision makers and address uncertainty will be invaluable to effective conservation initiatives. Here, we create two models to help managers navigate the complexities associated with decision making. The objective our first study was to create a model to best …

A Holistic Approach To River Restoration Design And Conservation Planning On The Reach And Basin Scales Using Hydraulic Modeling And Multi-Objective Optimization Tools, Lindsay Courtney Worley

Graduate College Dissertations and Theses

Flooding events around the world cost billions (USD) in damages each year. For decades, engineers have combated flood related damages by implementing flood mitigation controls such as channelization, levees or berms, and armoring. Recent advances in the study of river dynamics, however, have challenged the efficacy of these traditional flood mitigation techniques and pose that these structures are disconnecting channels from their floodplains, increasing flow rates, and contributing to more erosion. The effects of climate change combined with future predictions of increased storm frequency and intensity make it necessary to revise flood hazard mitigation strategies. A more nature-based alternative to …

Assessing Recovery And Reuse Of Nutrients Using Grid-Based Spatial Modeling: A Case Study Of Sri Lanka, Maya Fein-Cole

Graduate College Dissertations and Theses

Identifying and implementing strategies for recovering resources from waste streams for reuse helps to minimize natural resource extraction and reduces waste generation. Spatial modeling can guide resource cycling by optimizing co-location of recovery and reuse. These models can help assess feasibility and effectiveness (e.g., meeting crop nutrient needs) of circular economy practices at a landscape scale. Though many useful models exist, there is a need for an adaptable grid-based tool to address reuse on a per area basis (e.g., kg nitrogen per hectare of cropland). A model like this could be applied to any landscape and would utilize input data …

Implications Of Population Genetics And Physiological Responses On The Conservation Of Moose (Alces Alces Americana), Elias Rosenblatt

Graduate College Dissertations and Theses

Wildlife populations around the globe are facing numerous, complex challengesto their persistence, yet conservation efforts are hindered by limited information about these populations and the anthropogenic pressures they face. North American moose (Alces alces americana), despite being of ecological, cultural, and economical importance, inhabit remote landscapes, making population monitoring difficult. At the same time, many moose populations, including in Vermont and eastern North America, have experienced recent declines mainly due to winter tick (Dermacentor albipictus) epizootics. Anthropogenic landscape change and climate-mediated pressures pose future challenges for moose across the southern extent of their distribution. Though impacts of winter tick infestation …

The Origins Of Manufactured Dissent And The Efficacy Of Climate Change Narratives, Emma Elisabeth Giering

Graduate College Dissertations and Theses

The year of 2020 revealed many things about the fragility of socially constructed institutions and the public trust which grants such entities legitimacy, which is perhaps what reinvigorated social discourse surrounding the existential threat posed by climate change. Amid a pandemic, Americans watched wildfires engulf much of the west coast, environmental regulations unravel in the hands of the Trump administration, and Wall Street begin trading futures contracts on the U.S.’s water supply. Given the ever-expanding record of environmental travesties, how are citizens to respond, and from where should they derive their inspiration for response?

This thesis answers the above question …

Trace Metal Contamination In Urban Soils: A Field To Laboratory Methodological Framework For Characterization And Education, Sandra Leighanne Walser

Graduate College Dissertations and Theses

Urban soils around the world have been found to possess elevated concentrations of toxic trace metals such as As, Cd, Cu, Pb, Mn, Hg, Zn known to pose human health risks. Tightening environmental legislation and further elucidation of the detrimental health impacts from trace metals has necessitated more efficient means of contamination assessment, as well as greater public awareness. Within this thesis, I sought to develop an array of tools to holistically approach the socially relevant environmental challenges derived from heavy metal soil contamination. These tools consist in providing means to simplify Pb, Zn and Cu analysis in-situ, develop strategies …

Modeling Moose Habitat Use And Fitness Consequences Of Habitat Selection In Vermont, Usa, Joshua Alexander Blouin

Graduate College Dissertations and Theses

The moose (Alces alces) population has been declining across the northeastern US largely due to the impacts of winter ticks (Dermacentor albipictus). In epizootic years, an individual moose can host a staggering number of ticks (> 60,000), affecting both survival and reproduction. Habitat management may be used to improve the status of the moose population and health of individuals, but this requires knowledge of key habitat types used by moose and their spatial distribution. We investigated 1) habitat use by moose and 2) the fitness consequences of habitat selection during two critical winter tick life stages in northeastern Vermont. To …

An International Pilot Study Of Volunteer Stream Monitoring Groups: The Role Of Place Attachment In Volunteer Motivations, Rachel Pierson

Graduate College Dissertations and Theses

Engaging the public in scientific research through volunteer monitoring (a form of community science) has potential to expand knowledge of conditions and to improve collaborative decision-making. Many studies have sought to understand motivations for participation and potential resulting actions or behaviors that benefit the environment. Place-based connections have been demonstrated to lead people to adopt environmentally responsible behaviors. However, few studies have considered possible differences in motivations across countries or the role place attachment may play as a driver of initial or sustained participation.

The aim of this research was to determine the extent to which place attachment influences people’s …

Upcycling Dairy Manure Fine Solids Captured By Dissolved Air Flotation As Part Of A Phosphorus Recovery And Reuse Strategy, Katherine Keith Porterfield

Graduate College Dissertations and Theses

Dissolved air flotation (DAF) has shown potential to substantially improve phosphorus (P) mass balance on dairy farms by capturing P associated with fine solids from liquid manure, enabling new management options. However, at < 25% total solids, further dewatering and other upcycling is necessary to facilitate export of recovered fine solids off farm for use in bagged or bulk products. I generated plant foods using DAF-captured dairy manure fine solids thermally dried to 45% total solids blended with other organic residuals. Dry biomass of tomato and marigold seedlings amended with 6% v/v plant food was six-times greater than the unamended control and not significantly different from a market alternative treatment. Because thermal dewatering can be prohibitively costly, I generated a second batch of plant foods using DAF-captured dairy manure fine solids conditioned with 3, 4.5 and 6% (w/w) quicklime or lime kiln dust (LKD) and dewatered using a benchtop press for comparison with thermally dried fine solids. Tomato seedling biomass was similar for thermally dried and LKD plant foods, but quicklime plant foods had no effect compared to the unamended control. Quicklime and LKD conditioned fine solids contained approximately 30 and 10 times less plant-available P than thermally dried fine solids, respectively—likely due to precipitation of Ca-P minerals. These studies indicate that DAF-captured dairy manure fine solids could be upcycled to bagged horticultural products with substantial agronomic value, however sustainable materials drying remains a key challenge to realizing this potential.

Enhancing Ecosystem Services And Climate Resilience In Agriculture: A Transdisciplinary Approach, Alissa White

Graduate College Dissertations and Theses

A complex of social, economic and environmental factors influences agricultural management in the northeastern US. Farmers often balance goals of farm viability, environmental stewardship, and resilience to climate change, while also under public pressure to enhance the provisioning of ecosystem services from their landscapes. Changes in farm management have been identified as cost-effective ways to address both local water quality issues, and global anthropogenic influences on greenhouse gas concentrations. Individual decision-making on the part of farmers that determines the fate of ecosystem service provisioning from agroecosystems, placing increasing importance on understanding how policy, outreach and research can support farmers’ capacity …

Coastal Resilience At The Nexus Of Food, Energy, And Water: An Interdisciplinary Perspective For Resilience Planning, Kristin Raub

Graduate College Dissertations and Theses

Global climate change poses increased threats to coastal communities. The resilience of coastal communities relies on the protection and continued availability of essential services such as food, energy, and water (FEW) systems. However, the intersection of FEW nexus research and coastal resilience planning has not been well explored. This dissertation seeks to further the goal of operationalizing resilience planning by examining the usefulness of resilience tools and toolkits that have been developed in recent years and exploring how the FEW nexus approach has been applied to coastal resilience planning in both academic and grey literature. The first chapter provides the …

After The Flood: Exploring The Influence Of Risk Perception And Decision Criteria Preference On Flood Mitigation In The Lake Champlain Richelieu River Basin, Emma Jane Spett

Graduate College Dissertations and Theses

In April of 2011, heavy rainfall paired with snow melt from the Green and Adirondack Mountains caused unprecedented flooding in the Lake Champlain Richelieu River (LCRR) basin. A study was subsequently convened by the International Joint Commission (IJC), and was tasked with identifying how flood forecasting, preparedness, and mitigation could be improved in order to reduce the impact of flooding in this transboundary watershed, and build the greater community’s resilience to flooding. A component of this study includes an assessment of the social acceptability and political feasibility of potential flood mitigation measures, which was in part carried out through the …

Shaping Soil: Examining Relationships Between Agriculture And Climate Change, Lindsay Barbieri

Graduate College Dissertations and Theses

As the ripple-effects of a changing climate shape our planet, understanding relationships between agriculture and climate change is critical. With agricultural practices shaping soils on over a third of the earth’s land surface, the soils and lands where food is produced are integral grounds for examining these relationships. While not all humans practice agriculture in similar or damaging ways, nevertheless, dominant agricultural practices are displacing beings and ecosystems and perturbing global nutrient cycles across the planet. These entwined imbalances of dominance and nutrients result in flows of excess nitrogen, phosphorus, and carbon that are responsible for nearly three-fourths of the …

Multiscale Assessment Of Drinking Water Treatment Residuals As A Phosphorus Sorbing Amendment In Stormwater Bioretention Systems, Michael Rick Ament

Graduate College Dissertations and Theses

Bioretention systems can reduce stormwater runoff volumes and filter pollutants. However, bioretention soil media can have limited capacity to retain phosphorus (P), and can even be a P source, necessitating P-sorbing amendments. Drinking water treatment residuals (DWTRs) have promise as a bioretention media amendment due to their high P sorption capacity. This research explores the potential for DWTRs to mitigate urban P loads using a combination of lab experiments, field trials, and an urban watershed model.

In the laboratory portion of this research, I investigated possible tradeoffs between P retention and hydraulic conductivity in DWTRs to inform bioretention media designs. …