Theses and Dissertations from UMD
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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 give thesis/dissertation in DRUM
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Item Bat-plant pollination interactions in southern Thailand(2016) Stewart, Alyssa; Dudash, Michele R; Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The overwhelming majority of flowering plant species depend on animals for pollination, and such pollinators are important for the reproductive success of many economically and environmentally important plant species. Yet pollinators in the Old World tropics are relatively understudied, particularly paleotropical nectarivorous bats (Pteropodidae), and much is unknown about their interactions with night-blooming plant species. To better understand these bat-plant pollination interactions, I conducted fieldwork in southern Thailand for a total of 20 months, spread across three years. I examined the foraging times of pteropodid bat species (Chapter 1), and found that strictly nectarivorous species foraged earlier, and for a shorter duration, than primarily frugivorous species. I also studied year-long foraging patterns of pteropodid bats to determine how different species track floral resources across seasons (Chapter 2). Larger species capable of flying long distances switched diets seasonally to forage on the most abundant floral species, while smaller species foraged throughout the year on nearby plant species that were low-rewarding but highly reliable. To determine which pteropodid species are potentially important pollinators, I quantified the frequency and effectiveness of their visits to six common bat-pollinated plant taxa for an entire year (Chapter 3). The three strictly nectarivorous species were responsible for almost all pollination, but pollinator importance of each bat species varied across plant species. I further examined the long-term reliability of these pollinators (Chapter 4), and found that pollinator importance values were consistent across the three study years. Lastly, I explored mechanisms that reduce interspecific pollen transfer among bat-pollinated plants, despite having shared pollinators. Using a flight cage experiment, I demonstrated that these plant species deposit pollen on different areas of the bat’s body (mechanical partitioning), resulting in greater pollen transfer between conspecific flowers than heterospecific flowers (Chapter 5). Additionally, while I observed ecological and phenological overlap among flowering plant species, pollinators exhibited high floral constancy within a night, resulting in strong ethological separation (Chapter 6). Collectively, these findings illustrate the importance of understudied Old World bat pollinators within a mixed agricultural-forest system, and their strong, interdependent interactions with bat-pollinated plant species within a night, across seasons, and across years.Item Human Trafficking on the International and Domestic Agendas: Examining the Role of Transnational Advocacy Networks Between Thailand and United States(2008-05-23) Bertone, Andrea Marie; Schreurs, Miranda; Government and Politics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Thai activists, nonstate organizations, and transnational networks have been involved in trying to influence the Thai and international anti-trafficking agendas through their involvement with transnational and domestic advocacy networks since the early 1980s. Despite significant activism against human trafficking and related issues in Thailand throughout the 1980s and 1990s, the U.S. government and the broader international community did not seriously begin paying attention to human trafficking until the late 1990s. It was not until 2000 that both the U.S. government and the United Nations developed significant anti-trafficking policies. Why did it take until 2000 for the international community, including the U.S. government and many U.S.-based nonstate actors, to put the issue of trafficking on their political agendas, despite the fact that Thai-based nonstate actors and other Asian activists had been advocating for a response for nearly two decades? When the U.S. and the international community did finally put this issue on their agendas, how did Thai-based nonstate actors respond to international and U.S. styles of agenda-setting in Thailand? The issue of human trafficking has been put on the national political agendas in both the United States and Thailand; however, the issue took very different paths on its way to the agenda in each country. In the case of Thailand, we can find Thai activists working on related issues since the early 1980s, connecting and networking domestically and transnationally to advocate for a governmental response to complex international problems. In the case of the United States, an unlikely coalition of conservatives and feminist abolitionists has clashed with human rights organizations with regard to framing and defining human trafficking. One argument of this dissertation is that the emergence and operation of domestic and transnational advocacy networks have been instrumental in framing human trafficking in such a way to keep the issue on the national political agendas of the United States and Thailand. The primary drivers of the transnational advocacy networks are nonstate actors, and they have played key roles in spotlighting this issue, networking with one another, and interacting with governments in creative ways to address human trafficking.Item Factors Affecting Agricultural Expansion in Forest Reserves of Thailand: The Role of Population and Roads(2006-04-27) Puri, Jyotsna; Cropper, Maureen L; Bockstael, Nancy; Agricultural and Resource Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In this dissertation, I examine the role of population and transportation costs in determining agricultural expansion in 670 villages located in Forest Reserves of Thailand, over the period 1986-1996. Specifically, I examine the role of population and transportation costs as drivers of agricultural decisions regarding crop adoption and area planted, and in determining the intensity of cultivation and agricultural expansion. I also contrast the impact of these variables on two groups of villages in Forest Reserves - villages whose residents 'have no secure property rights' and those whose 'land rights are ambiguous'. I examine Feder et al.'s (1988) conclusions about the importance of property rights in Thai forest reserves and find that there is some evidence supporting their conclusions in this study. Differences in property rights account for some difference in the agricultural decisions of the two groups of villages, but that the nature of data does not allow a sharper distinction. Results reported in the study are consistent with other studies of the area. The study suggests that decisions regarding crop adoption and crop area are sensitive to population but the magnitudes of impact are small. Lack of significance of transport costs in determining cropping decisions suggests that rural road building programs will not necessarily promote deforestation in the study area, contrary to evidence in other parts of the world. This is particularly important given the large number of Forest Reserve residents in Thailand, and the fact that, Forest Reserves are the last bastions of forests, and consequently of biodiversity, in Thailand. One policy implication of this is that investments in roads that help to increase access to markets and aid poverty alleviation may not have the deleterious effects on forests that would otherwise be expected.