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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Genetic determination of phragmites and small mammals use of remnant patches along the Central Platte River, Nebraska

Frisch, Jennifer Dawn 11 June 2015 (has links)
<p> Invasive phragmites (<i>Phragmites australis</i>) has encroached on the central Platte River in recent years potentially out-competing native stands of phragmites. Invasive stands are thought to have an overall negative impact on ecosystems, but do provide ecological benefits to some species as food or shelter. Little research has been conducted on its impacts on small mammals. The goals of this project were to identify potential native and invasive stands along the central Platte River and determine small mammals use of invasive phragmites. I examined 35 phragmites samples along the central Platte River using restriction fragment length polymorphism. I used molecular sequencing and morphological features to identify stands. All samples were determined to be invasive. Four study sites along the Platte River were selected to evaluate phragmites use and potential impacts on small mammals. Each study site was in a wooded grassland area and consisted of three patches of invasive phragmites and three patches of wooded grassland vegetation. Study sites were sampled using Sherman live traps from April to October 2014. I found no significant difference in overall small mammal use between vegetation types and no seasonal difference between use of phragmites and wooded grassland stands. I did, however, catch fewer individuals in both habitat types during August. Deer mice (<i> Peromyscus maniculatus</i>) selected native vegetation whereas the white-footed mouse (<i>Peromyscus leucopus</i>), meadow vole (<i>Microtus pennsylvanicus</i>) hispid cotton rat (<i>Sigmodon hispidus</i>) and meadow jumping mouse (<i>Zapus hudsonius</i>) selected phragmites. Capture of hispid cotton rat was the first documentation of this species in Dawson County, Nebraska. Differences in selection by these species could be attributed to their different life histories or habitat preferences. The focus of management for invasive phragmites may not need to focus on total eradication. Additional sampling would be required to document the spatial extent of native phragmites stands along the central Platte River.</p>
102

Effects of intercropping switchgrass in managed pine stands on plant communities and white-tailed deer forage production

Wheat, Bradley Robert 09 September 2015 (has links)
<p> Interest in renewable energy and governmental mandates has motivated land managers to consider cellulosic feedstocks for bioenergy. I investigated plant community response to a system including switchgrass (<i> Panicum virgatum</i>) as a feedstock intercropped with loblolly pine (<i>Pinus taeda</i>). I estimated plant species evenness, richness, and diversity and biomass production, with emphasis on white-tailed deer (<i> Odocoileus virginianus</i>) forages. I detected 225 species in 2,220 1-m<sup>2</sup> quadrats, and 7,495 biomass samples (96.4 kg dry weight) from 960 quadrats. Intercropping reduced plant species diversity, total non-pine tree biomass, and biomass of deer forages during switchgrass establishment. These effects were no longer apparent at treatment level two years after switchgrass establishment, except that deer browse and total deer forage biomass remained less in intercropped interbeds. Intercropping in managed pines may temporarily effect plant communities but further studies are needed to examine longer term effects and to quantify effects on nutritional carrying capacity for deer.</p>
103

A park under pressure| The impacts of human disturbance in Murchison Falls Conservation Area, Uganda

Fuda, Rebecca K. 09 September 2015 (has links)
<p> The extent of human disturbance is increasing, even in protected areas. I evaluated human disturbance impacts in Murchison Falls Conservation Area (MFCA), Uganda, a park in the Albertine Rift biodiversity hotspot, using two approaches. First, I quantified vegetation patterns and edge effects using remote sensing data in the MFCA interior, a boundary zone, and exterior zone. I observed abrupt changes in productivity between the park and adjacent unprotected areas, indicating a "hard edge", and found evidence of edge effects that extended 4-6 km into MFCA. Second, I evaluated the impact of restored oil pads, roads, the park boundary, and anthropogenic noise on mammal distribution using camera traps and occupancy modeling. Few species avoided, and some were attracted to, more disturbed sites, where restoration may have provided food resources. As human populations continue growing around MFCA and oil production begins, evaluating human disturbance impacts on the landscape will be increasingly important.</p>
104

Social and Scientific Factors Impacting Mule Deer Habitat Conservation in the Intermountain West

Trulove, Nicholas F. 31 July 2013 (has links)
<p> For mule deer (<i>Odocoileus hemionus</i>) in the Intermountain West, alterations to habitat are outpacing strategies to mitigate human disturbance on critical seasonal ranges and migration routes. </p><p> Conserving mule deer habitat requires cooperation between a diverse group of stakeholders, state wildlife agencies, and federal land management agencies. The first chapter of this thesis explores the current and historical relationship between state wildlife agencies, citizen stakeholders, and federal agencies in order to highlight opportunities to improve cooperative habitat conservation in the United States. Conservation is a result of social, political, and economic action, but relies upon science to inform policy. The second chapter explores the seasonal habitat use of mule deer in southwestern Wyoming. In response to low fawn recruitment, the Wyoming Game and Fish Department deployed 15 GPS collars on adult female mule deer in an effort to enhance knowledge of mule deer population dynamics, migrations, and habitat use. The study captured two winter climate regimes, with greater winter severity during the 2010-11 winter compared to the winter of 2011-12. Deer migrated an average of 23.9 km (SE = 2.2) between seasonal ranges, and completed spring migrations nearly one month earlier following the milder winter of 2011-12 (<i>t</i>19 = 5.53, df = 19, <i>P</i> &le; 0.001). Pooled, the average area of winter ranges (1057 ha, SE = 103, <i>n</i> = 26) was larger than summer ranges (423 ha, SE = 51 ha, <i>n</i> = 25) (<i>t</i> = &minus;5.44, df = 49, <i>P</i> &amp;le; 0.001), with no increase or decrease in size of seasonal ranges detected between years (<i>P</i> = 0.243) according to a post-hoc Tukey HSD test. Between years, deer were observed to shift the geographic center of winter ranges (2.9 km, SE = 1.1, <i> n</i> = 12) to a larger degree than summer ranges (0.4 km, SE = 0.1, <i> n</i> = 12) (<i>t</i> = &minus;2.20, df = 22, <i>P</i> = 0.040). Survival and pregnancy rates (86% and 96%, respectively) correlated closely with other mule deer studies, and neither factor appears to negatively impact population growth. </p><p> Identifying seasonal ranges and migration routes, and quantifying seasonal habitat use, will assist Wyoming Game and Fish Department efforts to protect mule deer seasonal habitats and migration routes, and direct vegetation manipulations intended to improve the nutritional quality of habitats. On average, winter ranges included a later percentage of shrub-dominated habitat (83.8%, SE = 0.3, <i>n</i> = 26) than summer ranges (57.5%, SE = 2.0, <i> n</i> = 25) (<i>t</i> = &minus;4.42, df = 49, <i>P</i> &le; 0.001). Summer ranges averaged a greater proportion of agricultural lands (2.8%, SE = 1.1, <i>n</i> = 25) and aspen (<i>Populus tremuloides </i>) habitats (9.0%, SE = 2.2, <i>n</i> = 25) than winter ranges (0.1%, SE = 0.1, <i>n</i> = 26 and 0.2%, SE = 0.0, <i> n</i> = 26, respectively) (<i>t</i> = 3.03, df = 49, <i>P</i> = 0.004 and <i>t</i>= 3.86, df = 49, <i> P</i> &le; 0.001, respectively). Mule deer ranges are primarily located on Bureau of Land Management (73%, SE = 2.8, <i>n</i> = 51) and privately owned (17.3%, SE = 2.9, <i>n</i> = 51) lands, highlighting opportunities for cooperative partnerships for mule deer habitat conservation. </p>
105

Survival, habitat use, and spatiotemporal use of wildlife management areas by female mallards in Mississippi's Alluvial Valley

Lancaster, Joseph David 17 January 2014 (has links)
<p>The Mississippi Alluvial Valley (MAV) is an important region for wintering mallards (Anas platyrhynchos) in North America, yet little is known about their spatiotemporal habitat use and related survival in Mississippi. I tracked 126 radio-marked female mallards to quantify survival, habitat use, and use of wildlife management areas (WMAs) with experimental hunt regimes in the south MAV of Mississippi during winters 2010-2012. Daily survival was greatest in agricultural (0.997) and moist-soil (0.999) habitats in winters 2010-2011 and 2011-2012, respectively. Overall interval survival across both winters was 0.60 (SE = 0.02). Forested (40-54%) and moist-soil wetlands (41-59%) received greatest use diurnally and nocturnally, respectively. Mallards used WMAs similarly (P > 0.22) whether they were hunted 2- or 4-days/week. My data suggest that complexes of flooded cropland, forest, and moist-soil habitats are suitable habitats for mallards in the MAV, WMAs can be hunted 4-days/week, and sanctuaries should be revised at two WMAs.
106

Essays on regulation policy, wildlife quality, and excess demand

Olanie, Aaron Z. 28 November 2013 (has links)
<p> The second chapter examines how both domestic and foreign tobacco regulations affect the flow of tobacco trade. I develop a gravity equation incorporating a comprehensive set of domestic and foreign tobacco regulations into a country's tobacco import demand and estimate their bilateral effects. The results suggest a country's tobacco imports are significantly affected by their trading partner's tobacco regulations. There are two important results: spatial regulations reduce tobacco trade regardless of trade direction and marketing regulations in importing countries may actually increase tobacco imports. These results highlight the importance of understand regulations in an increasingly multilateral economy. </p><p> The third chapter investigates the effects of varying levels of access and excludability on a common pool resource with intrinsic quality characteristics. I analyze the case of deer hunting on leased properties by hunting clubs and estimate the lease size elasticity of both harvest and antler quality. The results suggest lease size has a small but significant effect. For all clubs with smaller than average hunting leases, a simulated increase to the average size results in approximately a 4.5 percent increase in the average antler quality of deer harvested. Although I analyze properties leased by hunting clubs, the results are applicable to various other management scenarios. </p><p> The fourth chapter develops the relationship between excess demand and purchase options. I illustrate a mechanism allowing firms to smooth sales across periods with uncertain quality and increase expected profit over the market clearing strategy. By "underpricing" high quality goods and offering a purchase option guaranteeing a single price regardless of quality, firms create excess demand and increase consumer willingness to pay for their purchase option. The firm maximizes profit by choosing a guaranteed price low enough to create sufficient excess demand and consumer willingness to pay for the purchase option that markets clear when quality is low. Using a numeric example, I demonstrate a case where this behavior increases profit over the market clearing strategy.</p>
107

Applying a social-ecological systems approach to human-bear encounters across the Pacific Rim| Advancing resilient human-wildlife management strategies

Jochum, Kim A. 22 November 2014 (has links)
<p> Wildlife management is challenged with addressing human resource needs while simultaneously conserving wildlife populations. Conflicts between humans and wildlife have increased across Northern countries with the expansion of human communities and environmental changes. Lack of information exists about reasons for such occurrences. This study explores adaptive capacity and resilience in coupled human-wildlife systems through the analysis of social and ecological factors contributing to perceptions of negative and positive human-bear (<i> Ursus</i> spp.) encounters. I first developed a theory to evaluate human perceptions and behaviors during human-wildlife encounters. Secondly I adopted an interdisciplinary framework to analyze human-bear encounters in urbanizing regions of south Sakhalin Island, Russian Far-East, and southcentral Alaska, USA. These case studies facilitate an analysis of perception development across spatial and social scales while incorporating approaches of both social and ecological sciences. Hunting, tourism and overall anthropogenic impacts are central to bear management, whereas cultural and social interests are perceived to not be considered in bear management decision-making across study regions. In Alaska, political interests are prevalent in bear management, whereas on Sakhalin, economic interests, including illegal animal trade and poaching prevail. Across study regions the perception of an encounter with a bear was dependent on the socio-economic situation of the individual having the encounter. The higher a person's socio-economic status was, the higher was their probability to perceive bear encounters as positive. Further, spatial and social scales across which perceptions vary are identified. Scales include urban-non-urban areas, wildland-urban interfaces, and a recreation-subsistence interest divide. Outside of urban areas, people's interests in recreation versus subsistence affect their perceptions toward bear encounters. Subsistence collectors of fish, game or plants are more likely to have negative encounters. Within urban areas, increased experience with encountering bears and length of residency are associated with positive encounters, whereas closeness to residences while not in sheltered environments increases negative encounters. These findings constitute spatial and social barriers and benefits to individualistic perception formation during human-bear encounters. Their identification advances resilience in researched human-wildlife systems and helps us to understand the adaptive capacities within these communities. The successful spatially-explicit integration of social and ecological variables promotes the opportunities for integrating human dimensions in wildlife management.</p>
108

Moose management and browsing dynamics in boreal forest /

Månsson, Johan, January 2007 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2007. / Thesis documentation sheet inserted. Includes appendix of four papers and manuscripts, three co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
109

Orang-utan conservation : epidemiological aspects of health management and population genetics /

Warren, Kristin Shannon. January 2001 (has links)
Thesis (Ph.D.)--Murdoch University, 2001. / Thesis submitted to the Division of Veterinary and Biomedical Sciences. Bibliography: leaves 242-275.
110

Adoption-diffusion of wildlife management innovations by nonindustrial private forestland owners /

Green, Champe Brockenbrough. January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 124-136). Also available via the Internet.

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