Doctor of Philosophy / Department of Geography / Lisa M. Harrington / Land-change science has become a foundational element of global environmental change. Understanding how complex coupled human and natural systems (CHANS) affect land change is part of understanding our planet and also helps us determine how to mitigate current and future problems. Upland birds such as the Ring-Necked Pheasant (Phasianus colchicus) have been widely studied. While myriad studies have been done that show relationships between land change driving forces and the pheasant, what are not found are long-term, comprehensive approaches that show the historical importance of how past land change drivers can be used to gain knowledge about what is happening today or what may happen in the future. This research set out to better understand how human and natural driving forces have affected land change, pheasants, and pheasant hunting in South Dakota from the early 1900s to the present. A qualitative historical geography approach was used to assemble information from historic literature and South Dakota Game, Fish, and Parks Department annual reports to show the linkages between human and natural systems and how they affect pheasant populations. A quantitative approach was used to gather information from hunters who participated in the 2006 pheasant hunting season. Two-thousand surveys were mailed that gathered socioeconomic data, information on types of land hunted, thoughts on land accessibility issues, as well as spatial information on where hunters hunted in South Dakota. Results from the hunter surveys provided some significant information. Non-resident and resident hunters tended to hunt in different parts of the state. Non-resident hunters were older, better educated, and had higher incomes than resident hunters. Resident hunters, when asked about issues such as crowded public hunting grounds and accessibility to private lands had more negative responses, whereas non-resident hunters, especially those who hunt on privately-held lands, were more satisfied with their hunting experiences. Linkages were also seen between changes in human and natural systems and pheasant populations. Some of the most important contributors to population changes were large-scale conservation policies (Conservation Reserve Program) and agricultural incentives, as well as broader economic issues such as global energy production and national demands for increases in biofuel production (ethanol and biodiesel). Many of the changes in pheasant populations caused by changes in human systems have been exacerbated by changes in natural systems, such as severe winter weather and less-than-optimal springtime breeding conditions.

Human and freshwater ecosystems are intrinsically interconnected. To better design effective policies, modeling tools and valuation methods are necessary to help understanding the complex reciprocal linkages between ecosystem processes and human actions, and coupled human and natural systems (CNHS) sets up a critical paradigm to do so. It is thus of both academic and empirical appeal to integrate reliable economic valuation methods with tools and models from multiple disciplines in order to quantify the feedbacks between human and natural systems and to inform better policy design. Using freshwater resources as an example, this dissertation contains three essays which integrate natural science and economics models to understand how changes in human behavior and societal policies lead to changes in ecosystem services, and how changes in ecosystem services, in return, affect human decisions. The first two essays focus on agricultural nonpoint source pollution problems in United States and examines the impacts of potential water polices on both water polluters and water demanders. Specifically, in the first essay, a novel coupling between an ecological model of within-lake hydrodynamics and an economic model of hedonic property prices has been developed to quantify the connections between nutrient loading, lake water quality, and economic outcomes. Linking ecological processes with human decision-making provides a basis for enhanced evidence-based decision making in the context of reducing nonpoint-source pollution. In the second essay, an economic mathematical programming model is coupled with an agro-ecosystem model to investigate the behavioral adjustments and environmental pollution outcomes of water quality policies. A complete quantification of costs from all regulating sources are necessary to help pinpoint the efficient water policy design and reflecting the connection between human decisions and ecosystem processes. The third essay focus on the water quantity problem in another developed country, Australia. A discrete choice experiment method has been explored and used to provide estimates of willingness to pay for purchasing irrigation rights to restore a Ramsar-convention wetland. Water policy scenario described in this essay could directly affect the feedback between human and ecosystem processes and serve as a baseline for future planning and policy designs. By offering both conceptual and methodological advancements, this dissertation aims to improve the understanding of coupled human and natural systems and the implementation of water policies. This dissertation also provides a framework to establish multi-disciplinary dialogues and cooperation between scientists and economists in the search of efficient water polices. / Doctor of Philosophy / Freshwater resources are one of the most important elements in our daily life. It provides important goods and services to our society, but at the same time, due to human behaviors, freshwater resources are under threat in both their quality and quantity. This dissertation contains three essays which integrate knowledge from multiple disciplines to help understand and quantify the linkages between human and freshwater resources, and provides information to come up with better water polices. In the first essay, I explore the connections between nutrient loading, lake water quality, and the economic outcomes. The essay illustrates how potential change in nutrient loadings affect lake water quality, and how that induces people’s housing purchase behavior, property sales price and local governments’ property tax revenue. In the second essay, I focus on the agricultural production problem, which is one of the largest source for water quality degradation. By exploring the impacts of water policy on farmers’ production decisions, the essay sheds light on how to better design water polices to maintain farmers’ profit while simultaneously alleviating the impact of agricultural production to water qualities. In the third essay, I utilize a survey method, choice experiments, to elicit people’s willingness to pay for wetland ecosystem health. This could better allocate water resources between agricultural production use and residential use and come up with better water quantity polices.

Humans have fled environmental degradation for many millennia. Due partially to climate change, environments across the world have often degraded to the point that they can no longer securely sustain livelihoods. Entire communities and households have been displaced by extreme, rapid or creeping disasters; during their flight, they have left footprints across the globe that merit tracing. Sometimes this mobility is forced and at other times it is purely voluntary; for both, the mobility has roots in a changing environment. The footprint of environmentally influenced mobility (EIM) was traced through a series of three independent but related studies. The first study gained foundational perspective through an exploration of connections between climate drivers and natural and human impacts of climate change. This inquiry sought to answer the question, "How important is human mobility in the greater scheme of changing environments and changing climate?" Human mobility was one among 15 different climate drivers and impacts studied; the connections between all of them were examined to enable a quantitative comparison of system susceptibility, driving force, tight coupling and complexity. While degradation was the most complex of all natural elements, mobility surfaced as the human system element exerting the greatest forcing on other elements within the coupled system. The next study focused only on human mobility to explore how scholarly literature portrayed the two possible directions of the link between mobility and degrading environments--with a particular focus on urbanization as one manifestation of the phenomenon. Type A links, in which human mobility triggers environmental degradation, are portrayed in the literature as often as Type B links, in which degrading environments trigger human mobility. Surprisingly, science has not lent support to urbanization being a result of environmental change; plausible reasons for this are discussed. The final study canvassed expert opinion to examine why no scientific, humanitarian or governmental entity has succeeded in providing systematic support (e.g.., policy and interventions) to populations enduring environmentally influenced mobility. Four very different discourses emerged: Determined Humanists, Benevolent Pragmatists, Cynical Protectionists and Critical Realists. The complexity these discourses manifest help explain the inaction--a stalemate between actors--while confirming the inappropriateness of one-sided terminology and linear quantifications of environmentally influenced mobility. The results of these three studies demonstrate that human mobility has unequivocally destructive force that can trigger non-linear effects, potentially casting the coupled system into an unprecedented state; that the visible lack of scholarly exploration of environmentally influenced urbanization (EIU) can be partially explained by high system complexity and disciplinary research; and most important, that despite diametrically opposed viewpoints, experts unanimously agree that human mobility has strong connections to environmental change. Together, the results merge to confirm a "well-founded fear" on the part of those who dwell in degrading environments, and to highlight a pressing need to offer solutions both to those who remain in such environments as well as a name and protected status to those who flee them.

Human activities worldwide have altered nature in ways that create new combinations of species and environmental processes. To understand so-called "novel ecosystems" it is important to consider both the natural and the societal factors that shape them, and how those factors are interconnected or "coupled." We used such an approach to explore options for managing a non-native invasive frog, the coqui, which has become established on the island of Hawaii and threatens to spread to other parts of the state. The nighttime calls of the coqui create a nuisance for property owners when populations become dense enough, as often occurs in Hawaii where the frogs have no natural enemies. Humans have tried various ways to eliminate coqui on the island of Hawaii with little success. Therefore we studied how property owners cope with their presence, both through management practices and psychological coping strategies. We also examined results of those efforts. People whose properties had more frogs were more likely to take action to reduce their numbers, but also attitudes toward the coqui were less negative when people had grown used to having to share their properties with the frogs. For those who cannot cope psychologically, we found it would be possible to manage properties to reduce densities but only when leaf litter and low shrubs were completely removed from near a home. Information campaigns about managing coqui should be different when targeting people that already host frogs and those that do not.