UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

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Subject: search.filters.subject.Urban Ecology

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Now showing 1 - 4 of 4
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    THE EFFECTS OF LEAF LITTER MANAGEMENT PRACTICES ON OVERWINTERING INSECT COMMUNITIES AND ECOSYSTEM FUNCTION: IMPACTS AND APPLICATIONS IN RESIDENTIAL LANDSCAPES
    (2024) Ferlauto, Max; Burghardt, Karin T; Entomology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Fallen leaf management is a widespread landscaping practice in urban areas that not only influences soil health but also affects the overwintering individuals of subsequent year's aboveground arthropod communities. There has been considerable public and scientific interest in the ecological effects of this disturbance, yet little experimental research making it difficult to provide evidence-based landscaping recommendations to stakeholders. This dissertation aims to narrow this knowledge gap, provide information for the creation of best management practices, and encourage further research on this critical topic. In Chapter 2, I compare spring arthropod emergence in residential areas where fallen leaves were removed or retained across different levels of maintenance intensity. In Chapter 3, I focus on the legacies of long-term leaf removal to soil organic carbon dynamics. And in Chapter 4, I examine the efficacy of alternative leaf management practices—such as shredding and leaf piling—on soil microclimates, arthropod biodiversity, and decomposition rates while exploring if tree canopy diversity mitigated impacts to these ecosystem functions. The results of these three experimental studies were consistent across years and habitat types. Leaf removal reduced the spring emergence of Lepidoptera by about 35-45% and reduced spiders by about 50-67%, altered parasitic wasp community composition, reduced soil moisture and temperature buffering, and ultimately led to legacy effects in the soil of reduced decomposition and soil organic carbon. The context in which leaves were managed also mattered, as unique resources attracted overwintering arthropods more when they were scarce in the environment. Despite the potential for high plant diversity in leaf-managed areas to create ecosystem traps for arthropods, tree diversity actually mitigated some negative effects of fallen leaf disturbance to ecosystem function. Overall, I find that some practices like leaf removal and shredding degrade ecosystem processes while others like piling leaves and planting a diverse tree canopy can support ecosystem services. This dissertation is the first to quantify the ecological impacts of leaf management as an urban disturbance and addresses critical questions necessary for developing urban best management practices.
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    Razing the Bar: Coastal Resilience and Community Cohesion through Ecological Design
    (2024) Nivison, Erin Hamilton; Kelly, Brian; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Separated by iron fences, dense trees and drastic changes in elevation, two seemingly close communities are divided by economic greed, a lack of urban planning and community engagement. Over the last two decades the shoreline along National Harbor, Maryland has transformed from abandoned plantation land to a revitalized urban center. Now home to the MGM Casino, Gaylord Convention Center, Tanger Outlet Malls, the iconic Capital Wheel, and million-dollar townhouses, National Harbor’s master plan has been realized into a dense economic hub. While it has grown extensively, it lacks connectivity to the surrounding suburbs of Fort Washington on a multitude of scales. On a macro scale, it is one of the few suburbs of DC that isn’t serviced by a metro line and on a micro scale it lacks porosity to neighboring developments. Iron fences aren’t the only issue Fort Washington is facing, with the continued effects of climate change, sea levels are expected to rise an additional two feet by 2100 and commercial and residential developments will be put at risk. While the Potomac River is finally showing signs of improvement after half a century of pollution from sewage, agricultural runoff and sediment runoff, how can we protect both the natural and built environments harmoniously?
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    THE EFFECTS OF HISTORICAL AND CURRENT LAND USE ON THE HABITAT USE AND COMMUNITIES OF URBAN WILDLIFE IN THE WASHINGTON, D.C. METROPOLITAN AREA
    (2024) Collins, Merri Kathleen; Gallo, Travis; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Understanding past legacies of urban land use is important to identify ecological processes and inform best management practices for wildlife-friendly cities in the future. My first dissertation chapter is an overview of my personal research philosophy and how it relates to this dissertation. The second chapter is a systematic literature review that addresses the state of global urban wildlife research. Urban wildlife research is predominantly conducted in North America, Europe, and Australia by academic researchers, and less so in the Global South. The third chapter explores how a gregarious species, the Eastern wild turkey (Meleagris gallopavo silvestris) once extant from the Washinton, D.C. landscape, is making a comeback. Wild turkey had a higher probability of occupying sites further from roads and at lower elevations. The fourth and concluding chapter looks at historic neighborhood valuation in Washington, D.C. to identify any legacy effects of racist and discriminatory urban planning on mammal communities. While I did not find any relationship, I did find similar mammal communities across the city regardless of neighborhood categorization and I derive management implications from this information.
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    Ecological Restoration Drives Functional Composition and Diversity in Urban Forest Patches
    (2020) Do, Sara Miya; Johnson, Lea R; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Urbanization greatly alters environmental conditions, affecting biodiversity in cities and ecological processes. To restore processes and native biodiversity, land managers have turned to ecological restoration of urban forest patches. Urban forest patches, nested within urban ecosystems, are subject to urban influences during ecological succession. Building on a long-term study evaluating outcomes of ecological restoration in New York City, I examined the effects of urban conditions, restoration, and forest succession on functional composition and diversity of restored and unrestored urban forest patches after 15-20 years. Functional traits play an essential role in community assemblages and influence the resilience and ecosystem functioning of urban ecosystems. I found that restored plots had greater functional evenness. Differences in functional composition indicated direct influence from restoration, succession, urban conditions, and success in meeting restoration goals. These results demonstrate that ecological restoration drives changes in functional composition and diversity of urban forest patches.