Digital Commons Network^™

Incorporating Biodiversity-Ecosystem Function Relationships Into Models And Conservation Planning, Sarah R. Weiskopf

Doctoral Dissertations

Unsustainable use of nature and climate change are leading to unprecedented biodiversity declines. These declines have cascading impacts on ecosystem function and ecosystem services, and ultimately on human well-being. International agreements have been adopted that aim to address both crises. The Paris Agreement, adopted in 2015, set global emission reductions targets. In 2022, most countries agreed to the Kunming-Montreal Global Biodiversity Framework (GBF). The GBF sets 23 ambitious targets for 2030 ranging from reducing threats to biodiversity, meeting people’s needs through sustainable use and benefit sharing, and solutions for implementation. Although adopting global goals and targets is an important first …

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi

Doctoral Dissertations

Anadromous river herring (alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)) make annual spring spawning migrations from the ocean to freshwater, where juveniles reside before emigrating to the ocean. Climate change may alter environmental and biological cues that prompt both adult migration and juvenile emigration, with implications for adult spawning success and offspring survival for these imperiled species. Shifts in adult migration have been observed in some rivers, while impacts on reproductive success and juvenile survival remain unknown. Cues for juvenile emigration are poorly understood as they have been explored at limited spatial and temporal scales. …

Water Resources Planning Under Deep Uncertainty For Physically, Socially, And Politically Complex Systems, Sarah St. George Freeman

Doctoral Dissertations

Water supply systems, particularly those of large cities, are complex systems linking supply, regulatory and distribution infrastructure, and points of use. Despite their physical complexities, it is infrequent that full supply, distribution, end use, and feedbacks therein are considered in an integrated manner. These complex systems-of-systems face large uncertainties related to physical aspects such as degradation of infrastructure, changing demand, and climate variability and change. Though great, such physical uncertainties often pale in comparison to the those related to the human systems in place to manage them and yet uncertainty in the decision-making landscape is often grossly simplified in our …

Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen

Doctoral Dissertations

Water quality deterioration is a global and pervasive issue due to pollution caused by industrialization, urbanization, agriculturalization, and human population growth in the modern era. This issue is even more challenging in the context of climate change due to warming temperatures and the intensification of precipitation. Therefore, assessing the potential impacts of climate change on water quality is a concern. Assessment is necessary so that planners can prepare for and reduce the negative impacts on water quality. At present, climate change impact assessment frameworks are relatively adolescent. Most studies rely on climate projections from General Circulation Models for simulations of …

The Roles Of Identity And Beliefs About Social Change In Decision Making Processes For Identity-Laden Social Change Efforts, Joel Ginn

Doctoral Dissertations

This dissertation presents three investigations into distinct processes that attempt to explain people’s decision making around social change action in three identity-laden domains. Chapter 1 reviews existing literature and theory on how social identity and social change beliefs can impact social change action. Chapter 2 examines identity-based motivated cognition by showing how identification as a meat-eater leads to biased estimates of meat reduction’s climate change impacts. Chapter 3 examines cisgender student reactions to faculty who use gender pronouns as an inclusion strategy for transgender and gender nonconforming students to examine if this action leads to stereotyping and judgement. Chapter 4 …

The Global Impact Of The Antarctic Ice Sheet In A Warming World: Using Numerical Modeling And Critical Physical Geography To Assess Climate Change, Sea Level Rise, And Climate Justice

Doctoral Dissertations

Anthropogenic climate change is causing disruptions in the Earth system with negative ramifications for life on our planet. Increasing atmospheric greenhouse gas concentrations lead to accumulated heat content and the cryosphere is one of the earliest places to show changes in response to rising temperatures. The melting of the Antarctic Ice Sheet will have myriad effects on global climate due to interconnections and feedbacks between the ice sheet, ocean, and atmosphere. In this dissertation I use numerical modeling and critical geography to assess future climate conditions that occur in response to changes in Antarctic Ice Sheet melt as well as …

Coping With Climate Change, Andrea Yj Mah

Masters Theses

Climate change is a source of anxiety and stress. To be resilient to the changes that are occurring, individuals must cope with that stress. Because there are many ways that people might manage stress we examined variation in coping strategy use among Americans who reported some concern about climate change to understand generally how people cope with such stress, and whether it can be predicted from individual difference factors, namely degree of climate change concern and political ideology. We examined these variables specifically because in the study of responses to climate change, conservatives and liberals often report divergent beliefs, attitudes, …

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 …

The Influence Of Climate Change On The Ecology Of The Arctic Ground Squirrel In Denali National Park, Ak., Nigel A. Golden

Doctoral Dissertations

This dissertation research focuses on the ecology of the Arctic ground squirrel (Urocitellus parryii) in Denali National Park and Preserve, AK. The Arctic ground squirrels is a species of interest for monitoring efforts under the National Park Services’ Vital Signs Monitoring Program under the Vital Signs Monitoring program. The focus of this program is to monitor what is considered to be the most significant indicators of ecological conditions of the specific park resources that are of the greatest concern. The CAKN designated the Arctic ground squirrel (Urocitellus parryii) as one indicator species of park ecosystems. Despite being easy to observe …

A Tipping Point In The Ecuadorian Amazon Rainforest: Current And Future Land-Use And Climate Change Trends, Alula Shields

Masters Theses

Many regions of the Amazon are experiencing drastic changes as deforestation and climate change drive the world’s largest continuous rainforest towards a ‘tipping point’. These disturbances are changing natural cycles that once past a critical threshold, will mark an unstoppable transition to an altered ecosystem. Losing areas of the Amazon rainforest will have implications for the global climate, global carbon budget, and global hydrological regimes. Scholars have projected these tipping points for areas of the eastern Amazon rainforest, but much less scholarship focuses on the headwaters of the Western Amazon, an area of great cultural and biological importance. Ecuador is …

Three Essays On The Political Economy Of Global Inaction On Climate Change, Tyler A. Hansen

Doctoral Dissertations

This dissertation contributes three essays exploring the political economy of global inaction on climate change. Chapter 1 asks whether climate stabilization means the end of capitalism. Two influential perspectives within environmental political economy—the “degrowth” perspective from ecological economics and the “revolution” perspective from ecological Marxism—answer in the affirmative. If they are right, climate policy programs within capitalism, like the Green New Deal, are non-solutions. I evaluate their arguments, concluding that while environmental sustainability in general likely requires moving beyond capitalism, climate stabilization in particular does not. Given the urgency of the climate crisis, I conclude the chapter by outlining a …

Patterns And Mechanisms Of Intraspecific Trait Variation Across Thermal Gradients In A Marine Gastropod, Andrew R. Villeneuve

Masters Theses

As the earth’s climate changes due to anthropogenic emissions, it has increasingly become an imperative within the ecological community to understand existing species adaptations to climate change. Much focus has been paid to how a species might react to climate change, but the role of locally adapted traits and responsible environmental mechanisms have received less attention. Quantifying how sublethal (e.g. growth rates) and lethal (e.g. thermal tolerance) trait performance vary between populations can thus improve our understanding of how populations, and the entire species, will react to climate change. Here, I quantified the spatial patterns of performance of several traits …

The Role Of Vegetative Cover In Enhancing Resilience To Climate Change And Improving Public Health, Anastasia D. Ivanova

Masters Theses

Changing temperature and precipitation patterns are causing degraded soil, water, and air quality which is negatively affecting the safety and health of people, and the productivity of urban and rural communities. However, research shows that implementing urban forests and cover crops into urban and rural landscapes, respectively, can mitigate these effects by providing ecosystem services. As extreme precipitation and heat events continue to intensify, there is a need for comprehensively assessing these ecosystem services under changing climates and for this information to be easily accessible by communities for rapid land-use decision making. Therefore, I investigated the role of urban forests …

Getting The Message Across: Flexitarians As Messengers For Meat's Climate Change Impacts, Joel Ginn

Masters Theses

Meat consumption has been a prominent part of humanity’s dietary culture, particularly in modern, Western developed nations. However, recent research has shown that collectively reducing our consumption of animal products can have major benefits for mitigating our environmental footprint. Despite a consensus among climate scientists on its potential impact, the public does not recognize the effectiveness of this behavioral shift. Recent efforts to address this have created movements and organizations that focus on reduction of meat consumption (e.g. flexitarianism, reducetarianism, Meatless Mondays), rather than elimination of meat consumption (e.g. vegetarianism, veganism) with the intent of creating a more acceptable message, …

Interacting Effects Of Climate And Biotic Factors On Mesocarnivore Distribution And Snowshoe Hare Demography Along The Boreal-Temperate Ecotone, Alexej P. Siren

Doctoral Dissertations

The motivation of my dissertation research was to understand the influence of climate and biotic factors on range limits with a focus on winter-adapted species, including the Canada lynx (Lynx canadensis), American marten (Martes americana), and snowshoe hare (Lepus americanus). I investigated range dynamics along the boreal-temperate ecotone of the northeastern US. Through an integrative literature review, I developed a theoretical framework building from existing thinking on range limits and ecological theory. I used this theory for my second chapter to evaluate direct and indirect causes of carnivore range limits in the northeastern US, …

Modeling The Pleistocene History Of The Greenland Ice Sheet, Benjamin Andrew Keisling

Doctoral Dissertations

One of the most profound and immediate consequences of anthropogenic climate change is sea level rise, which in large part is driven by the melting of polar ice sheets. The Greenland Ice Sheet (GrIS) contains enough ice to raise global sea level by ~7 meters. Fluctuations of the GrIS in response to past climate change provide an opportunity to better understanding the stability of the ice sheet during periods of climatic change. In this thesis, we use numerical ice-sheet models to understand the causes and consequences of past fluctuations of the Greenland ice sheet. In Chapters 3 and 4, we …

Evaluation Of The Adaptive Capacity Of Mole Salamanders (Ambystomatidae) To A Changing Climate In Western Massachusetts, Kristopher Winiarski

Doctoral Dissertations

The primary goal of my dissertation was to investigate the adaptive capacity of mole salamanders in western Massachusetts, specifically marbled salamanders (Ambystoma opacum), to future changes in climate. This involved the analysis of two existing datasets including i) a nearly decade-long photograph capture-recapture dataset (first described by Gamble et al. 2009) and ii) a landscape genetics dataset (first described by Whitely et al. 2014). My dissertation also included two chapters focused on computer simulations to better understand the behavior and inferences from the statistical models fit to the empirical datasets I modeled and the effects of error in …

Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney

Masters Theses

Trees provide countless environmental, economic, and societal benefits to the urban environment, and may become increasingly important to maintaining environmental quality and human well-being in the face of increasing urbanization and climate change. However, trees in these urban areas are rapidly diminishing across the United States. Much of this loss can be prevented with proper planning and management, focused on selecting tree species that are both well-suited to the area’s growing conditions and able to survive the many stress factors in an urban setting. Choosing which tree species to plant in Massachusetts is especially challenging considering the lack of resources …

Wildfires In The Northeastern United States: Evaluating Fire Occurrence And Risk In The Past, Present, And Future, Daniel R. Miller

Doctoral Dissertations

Climate change is one of the most complex and challenging issues facing the world today. A changing climate will affect humankind in many ways and alter our physical environment, presenting ethical challenges in how we respond. The impact of climate change will likely be exacerbated in heavily populated regions of the planet, such as the Northeastern United States (NEUS). The NEUS is comprised of complex, sprawling urban centers and rural regions, both of which are vital to the economic and cultural character of the region. Furthermore, both urban and rural areas in the NEUS contain communities that have been historically …

Modeling The Abundance And Distribution Of Terrestrial Plants Through Space And Time, Caroline Curtis

Doctoral Dissertations

Anthropogenically-driven changes threaten ecosystems and species over regional to global scales. I addressed several questions related to how species ranges will respond to these changes over large spatial and temporal extents to better understand what determines where a species occurs. First, I modeled presence and abundance of two widespread invasive plants in the southwest U.S. under current and projected future climatic conditions, from which I inferred impact risk. These results provide more insight than presence modeling alone and highlight the possibility of increased invasion pressure in the future. Second, I tested the assumption that expert-based climatic tolerance data will better …

Preparing Water Supply Systems For Climate Change: The Role Of Hydrologic Forecasting In The Northeast, Leslie Decristofaro

Doctoral Dissertations

Fresh water is a resource strongly impacted by climactic conditions. Water supply systems in the northeastern United States will see the effects of climate change on their water quality and quantity in various ways, including changes in seasonality of flows, changes in the frequency and magnitude of extreme precipitation events, and changes in the variability of precipitation and water availability. Five northeastern water supplies examined are expected to maintain at least 95% monthly reliability over a range of climates wider than the current projections. However, model results indicate that turbidity levels in New York City's Ashokan Reservoir will change with …

Evaluating Policy And Climate Impacts On Water Resources Systems Using Coupled Human-Natural Models, Hassaan Furqan Khan

Doctoral Dissertations

Extensive human intervention in the terrestrial hydrosphere means that virtually every river basin globally reflects the interaction between human and natural hydrologic processes. Thus, sustainable watershed management needs to not only account for the diverse ways humans benefit from the environment but also incorporate the impact of human actions on the natural system. Informed policy making to address our water challenges requires a comprehensive understanding of these feedbacks and how they might be affected by future changes in climate. This work develops coupled human-natural models for improved surface water and groundwater management in water-scarce regions under future changes in climate. …

Flood Risk Assessment, Management And Perceptions In A Changing World, Katherine Schlef

Doctoral Dissertations

Floods are a global challenge that is increasing due to changes in climate and human populations. Using an interdisciplinary approach, this work contributes novel methodologies and knowledge to three key challenges associated with floods. The first chapter builds upon the atmospheric and statistical sciences to provide a general methodology for climate informed approaches to projecting long-term flood events based on large-scale ocean-atmospheric processes. The second chapter builds upon the engineering, decision analysis, and economics disciplines to integrate climate-informed projections with decision-scaling, a decision-making under uncertainty framework, to further flood risk management. The third chapter builds upon the social sciences to …

Resilient Architecture: Adaptive Community Living In Coastal Locations, Erica Shannon

Masters Theses

How can architects design for coastal inundation caused by climate change, what are the methods and strategies currently being implemented as a response to coastal inundation, and how can these strategies influence the design approach for a self-sustaining community that can survive and thrive in a low-lying coastal area?

Climate change is caused by an expenditure of planet-harming resources being improperly or inefficiently utilized and consumed. This can lead to a rise of global sea level and an increased severity of storm surges.

Resilience is defined as the ability to overcome challenges and difficulties. Coastal resilience is the ability for …

Human And Climate Change Influences On Black (Diceros Bicornis) And White (Ceratotherium Simum) Rhinos In Southern Africa, Hlelolwenkhosi S. Mamba

Masters Theses

Rhinos are iconic species of ecological and economic importance in Africa. They represent their range states’ rich natural heritage. White rhinos, currently estimated at approximately 20, 000 animals, recovered from near extinction after heavy poaching and habitat destruction decimated numbers to 50 individuals in the 20^th century. Between 1970 and 1992, black rhino numbers suffered a 96% reduction in Africa. Today, black rhino numbers are estimated between 5, 000 and 5, 500 individuals. Black and white rhinos are currently classified in IUCN’s Red List as Critically Endangered, and Near Threatened respectively. Very few studies investigate the potential effects of …

Assessing Adaptive Capacity Of Pioneer Valley Farmers, Angelica Carey

Masters Theses

This thesis explores Pioneer Valley farmers and their agricultural practices, knowledge and resources as they relate to climate change. Adaptive capacity is used throughout scientific literature, and often includes numerous components; for this thesis the measurement of farmers’ adaptive capacity would be assessed according to only three components: knowledge, past experiences and use of resources. Climate change and its impacts on agriculture have been studied but what is unclear is how prepared farmers are to deal with these impacts. Through literature review, survey development and recorded interviews, data was then analyzed both for quantitative and qualitative results to understand farmer’s …

Decision Analytical Methods For Robust Water Infrastructure Planning Under Deep Uncertainty, Mehmet Umit Taner

Doctoral Dissertations

Deep uncertainties resulting from climate change, demographic pressures, and rapidly evolving socioeconomic conditions are challenging the way that water planners design and operate large-scale infrastructure systems. Conventionally, water infrastructures have been developed using stationary methods, assuming that the underlying uncertainties can be derived from historical data or experience. However, these methods are less useful under deeply uncertain climate and socioeconomic conditions, in which the future can be substantially different from the past and cannot be expressed by well-defined probability distributions. The recognition of deep uncertainties in long-term water resources planning has led to the development of “decision-analytical” frameworks that do …

New York City 2050: Climate Change And Future Of New York | Design For Resilience, Abhinav Bhargava

Masters Theses

The escalating temperature, annual precipitation, sea level rise and carbon footprint will likely lead to an unimagined future which does not have a bright side. With the rise in carbon footprint particularly due to greenhouse gas emissions, burning of fossil fuels and change in land uses; carbon dioxide is 40% higher as compared to era before Industrial Revolution.

The constant increase in temperature is melting the glaciers and increasing the sea levels. The Hudson River is estimated to rise by 1.5-2ft by 2050, directly affecting the low-lying areas of Staten Island, Brooklyn, Queens and Manhattan. Amongst the multiple coastal cities …

The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.

Doctoral Dissertations

In this dissertation several research studies are discussed that characterize the effects of anthropogenic, or human-induced, stress on both ammonia-oxidizing and total bacterial soil microbial communities. The disturbances of land-use change in tropical, South American rainforests and artificial warming and nitrogen (N) fertilization in temperate, North American forests were investigated as these disturbances represent past and current disturbances caused by human landscape alteration and climate change. Initially, the response of soil ammonia-oxidizing microbial communities to land-use change from primary rainforest to pasture and, finally, back to secondary forest was determined. Next, these analyses of land-use change effects were expanded to …

Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence

Doctoral Dissertations

Modern and historic flood risk management involves accommodating multiple sources of sources of uncertainty and potential impacts across a broad range of interrelated sectors. Sources of uncertainty that affect planning include internal climate variability, anthropogenic changes such as land use and system performance expectations, and more recently changes in climatology that affect the resources supporting the system. Flood management systems potentially impact human settlements within and beyond the systems’ scope of planning, local weather patterns, and associated ecological systems. Federal guidelines across nations have called for greater consideration of uncertainty and impacts of water resources planning projects, but methods for …