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Modeling Response Of Water Quality To Land-Use And Climate Change In Lake Auburn, Me, Nicholas Messina

Electronic Theses and Dissertations

Lake Auburn, Maine, USA, is a historically unproductive lake that has experienced multiple algal blooms since 2011. The lake is the water supply source for a population of ~60,000. We modeled past temperature, and concentrations of dissolved oxygen (DO) and phosphorus (P) in Lake Auburn by considering the watershed and internal contributions of P as well as atmospheric factors, and predicted the change in lake water quality in response to future climate and land-use changes. A stream hydrology and P-loading model (SimplyP) was used to generate input from two major tributaries into a lake model (MyLake) to simulate physical mixing, …

Listen For The Desert: An Ecopsychological Autoethnography, Dorothy Cashore

Electronic Theses and Dissertations

What does it mean for human beings to be part of nature – not just as a conceptual justification for doing right by the planet, but actually as an embodied, emotional, and sensuous experience? What happens to the experience of being human when notions as fundamental as voice, absence, suffering, and psyche are re-encountered from a perspective rooted within, rather than apart from, the natural world? While this dissertation responds to these questions, it initially took shape in response to something that felt less like a research question and more like a summons. Following a startling experience of feeling called …

Heat Waves And Heat-Related Mortality In East Tennessee, Taiwo Adesoba

Electronic Theses and Dissertations

Heat waves represent a public health challenge that requires multiple responses and warnings to protect vulnerable populations. Although studies have reported an increasing trend of heat wave occurrence in many areas of the world, no clear trend exists in East Tennessee. Using data from Parameter-elevated Relationships on Independent Slope Models (PRISM), CDC WONDER and the United States Census Bureau, the relationship between mortality rates and year was estimated during heat wave events between 1999 and 2010. Five heat wave definitions were tested. Overall, 2007 and 2010 stand out as the years with the highest number of heat wave days in …

Evaluating Tree Species' Migration Potential Using Latitudinal Tree Growth Rate Across The Eastern United States, Michelle Marie Field

Electronic Theses and Dissertations

Predicting climate-driven tree species’ future redistribution is a key element to guide preemptive forest management to mitigate the adverse consequences of climate change. This study uses the Forest Inventory and Analysis (FIA) database to determine tree species’ potential. The dynamic variable calculated in the study is the standardized growth rate residual by basal area for a ten-year period (2003-2013). Residuals of growth rate are examined by latitude within each species’ range, indicating on-going habitat preference. This study examined six, US confined species that are climate sensitive. While this study hypothesized that high growth rate residuals would be present at northern …

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler

Electronic Theses and Dissertations

Dissolved organic carbon (DOC) is an important component of lake ecology, as it contributes to light attenuation and carbon cycling. In recent years, DOC declined in a suite of lakes in Greenland. I performed experiments to test potential mechanisms of DOC loss. The tested mechanisms did not reduce DOC concentration, but DOC composition was affected. I also paired water quality data with meteorological observations to evaluate effects of climate drivers on lake variables. The lake variables were temporally coherent and associated with patterns of mean annual precipitation.

In the northeastern U.S., recovery from acidification and climate change have contributed to …

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To …

Living On The Edge: Thermophysiology Of The Southern Flying Squirrel At Its Northern Range Margin, Vanessa R. Hensley

Electronic Theses and Dissertations

Climate change has the potential to upset entire ecological systems, making predictive models of the utmost importance. The incorporation of physiological parameters into predictive models not only bolsters their accuracy but also provides a mechanistic explanation for ecological changes already observed and those yet to come. North American flying squirrels, for example, have already experienced dramatic range shifts northward over recent decades, with climate change being the suspected driver. While other studies have focused on warming winter temperatures, I explored the hypothesis that rising summer temperatures were driving the observed range shifts. Unable to find a reliable population of the …

Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner

Electronic Theses and Dissertations

In boreal regions, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however less is known about the extent and implications of these events on lakes. We assessed the effects of precipitation events on six drinking water lakes in Maine, USA to better understand how DOC concentration and quality change in response to precipitation events. Our results revealed three types of responses: (1) an initial spike in DOC concentrations and quality metrics; (2) a sustained increase in DOC concentrations and quality metrics and; (3) no change during all sampling periods. Lake residence time was a …

A Child Shall Lead Them: Exploring Discourses Of Efficacy And Climate Change As They Appear In Children's Animated Film, Jason Derry

Electronic Theses and Dissertations

Recent climate change discourse has tended to presume scientific knowledge and rational argumentation as the principle factor in convincing peoples and publics toward climate action. However, scholarship across numerous fields reveals myriad other contributing factors in how people think about and respond to this environmental crisis, which leans predominately toward silence and apathy. Alongside this, children are often centered as inheriting a calamity, yet find themselves largely disempowered. From out of this rhetorical milieu I interject by way of a multidisciplinary grounding to examine the predominate framings of efficacy in the context of children, climate change, and environmental discourse. To …

The Independent And Combined Effects Of Hypoxia And Tributyltin On The Eastern Oyster, Crassostrea Virginica, Ann Fairly Barnett

Electronic Theses and Dissertations

Oysters are vital to the health of estuarine ecosystems and provide critical ecosystem services, such as water quality improvement, nursery habitat for commercially important fisheries, and shoreline stabilization. Despite their ecological and economic importance, oyster reefs are exposed to many stressors, and oyster populations in Mississippi have declined dramatically in recent years. The present study focuses on the effects of hypoxia and tributyltin (TBT) on the Eastern oyster, Crassostrea virginica. Hypoxic events are increasingly comin coastal ecosystems worldwide, and TBT is a legacy toxicant once used as an antifoulant. The effects of these stressors were assessed on adult oysters deployed …

Effects Of Halogen Bonding And Nir Tuning Of Dyes For Dye-Sensitized Solar Cells, Alexandra Baumann

Electronic Theses and Dissertations

With current energy demands being met through the utilization of energy sources such as petroleum, natural gas, and coal, the non-renewable nature of these sources will eventually approach depletion as world wide energy consumption increases yearly. As a result the need for a renewable energy alternative has become imminent. One appealing alternative that has gained considerable attention since its development due to a low cost and a high solar to electric conversion efficiency are dye-sensitized solar cells (DSCs). This dissertation describes efforts to design and synthesize improved organic dyes utilizing three analogous methods: first, through decreasing non-productive pathways such as …

Youth Screening Protocol For General Psychopathology, Steven Bishop

Electronic Theses and Dissertations

There is a high prevalence rate of psychopathology among US youth, with at least one in four youth meeting clinical criteria for a mental health condition. Those youths who experience psychopathology tend to demonstrate greater functional impairments and have more adverse outcomes compared to youth who do not have these frequently occurring conditions. It is unfortunate that many of these conditions, along with their deleterious effects, are poorly identified in pediatric settings despite the availability of screening instruments. Most screening instruments, however, assess for domain-specific areas of psychopathology only, and can require substantial time to administer and interpret within the …

Stream Flow Analysis Of The Big Sioux River Just South Of Brookings, South Dakota, Samuel Ruppert

Electronic Theses and Dissertations

Floods are the most common type of natural disaster in the world and one of the most damaging. Changes in climate conditions such as precipitation and temperature are causing changes in stream flow. This means that in order to better understand flooding and possibly develop a system for making flood predictions, stream flow needs to be analyzed more closely. The primary objective of this thesis is to analyze the Big Sioux River just south of Brookings, South Dakota, both annually and seasonally. The United States Geological Survey (USGS) has stream gauges placed in rivers and streams all over the United …

Prenatal Stress As A Potential Adaptive Modulator Of Offspring Survival, Phenotype, And Performance In Response To Elevated Temperatures, Theresa Renee Warriner

Electronic Theses and Dissertations

Climate change is increasing global water temperatures, and by altering temperatures, is subsequently impacting aquatic life, particularly ectothermic fish. When mothers encounter environmental stressors such as elevated temperatures during follicular recruitment (maternal stress), resultant offspring often have altered phenotypes. Recent studies suggest that this maternal stress signal may prepare offspring for a similarly stressful environment (environmental match). I applied the environmental match hypothesis to investigate whether a maternal stress signal can prepare offspring to cope in a stressful environment. Specifically, I exposed Lake Ontario Chinook salmon (Oncorhynchus tshawytscha) eggs to a biologically relevant maternal stress signal (1000ng/mL cortisol …

Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer

Electronic Theses and Dissertations

Wetlands are one of the world's largest known carbon sinks while comprising only a small amount of the Earth's surface. However, the amount of carbon sequestered by wetlands is shrinking as droughts and human disturbance increases. Carbon in wetlands is stored through the contrast of decomposition and sedimentation of organic matter and absorption of CO₂ from the atmosphere by soil microbes. Understanding how changing hydrological regimes and increased wildfires will affect wetland soil and microbial processes is important in the face of predicted climate change for future wetland conservation practices. Specifically, I seek to understand the response of southeastern …

Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras

Electronic Theses and Dissertations

Climate change projections estimate a 2-3°C increase in water temperatures by the end of the century. The amount of habitat with suitable temperature and oxygen concentration for aquatic organisms will also be reduced. Striped bass (Morone saxatilis) inhabiting the rivers in Southeastern Georgia make an interesting study system as they do not participate in summer coastal migrations typical of their northern conspecifics. Instead, fish in this southern population remain in freshwater environments that experience warming and decreases in dissolved oxygen. The present study aims to determine the thermal and low oxygen tolerance of juvenile striped bass collected from …