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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.
191

Optimal Control of Species Augmentation Conservation Strategies

Bodine, Erin Nicole 01 August 2010 (has links)
Species augmentation is a method of reducing species loss via augmenting declining or threatened populations with individuals from captive-bred or stable, wild populations. In this dissertation, species augmentation is analyzed in an optimal control setting to determine the optimal augmentation strategies given various constraints and settings. In each setting, we consider the effects on both the target/endangered population and a reserve population from which the individuals translocated in the augmentation are harvested. Four different optimal control formulations are explored. The first two optimal control formulations model the underlying population dynamics with a system of ordinary differential equations. Each of these two formulations utilizes a different function to model the cost of augmentation. For each optimal control formulation we find a characterization for the optimal control and show numerical results for scenarios of different illustrative parameter sets. The second two optimal control formulations model the underlying population dynamics with systems of discrete difference equations. The difference between these two optimal control formulations is the order in which events occur within each time step in the population models. In the first formulation the population is augmented before the natural growing season in each time step (augment then grow model), whereas in the second formulation the population is augmented after the natural growing season in each time step (grow then augment model). These two discrete time models, which differ only in their order of events, lead to structurally different models. The formulation with the augment then grow model cannot utilize discrete time optimal control theory and a brute force method of finding the optimal augmentation strategy is used. The formulation with the grow then augment model does utilize optimal control theory and we find the characterization of the optimal control. For both formulations, we explore several scenarios of different illustrative parameter sets. In each of the four optimal control formulations, the numerical results provide considerably more detail about the exact dynamics of optimal augmentation than can be readily intuited. The work presented here are the first steps toward building a general theory of population augmentation, which accounts for the complexities inherent in many conservation biology applications.
192

Classification and Fertility of Soils in the Big South Fork National River and Recreation Area Based on Landscape Position and Geology

Blair, Ryan H 01 May 2010 (has links)
The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to determine baseline soil fertility through chemical analysis, to provide fertilizer recommendations for Bicolor Lespedeza (Lespedeza bicolor) to be grown as wildlife food plots. The parent materials and site- specific geology, including the Pennington Formation, were compared to the profiles in order to establish any relationships that might exist. The methods of chemical analysis included: total carbon analysis, cation exchange capacity, percent base saturation, pH, particle size analysis, KCl total acidity, total elemental analysis and Mehlich I extraction. From the data, soils examined from an upland summit have the lowest Mehlich I extractable phosphorus (M1P) ranging from 0.8-3.14 mg kg-1, and this soil was classified as a Typic Hapludult. Soils examined on backslopes and sideslopes had M1P values ranging from 0.3-11.53 mg kg-1 and these soils were classified as either Lithic Dystrudepts or Typic Dystrudepts. The footslope soils examined have M1P values ranging from 1.95-19.79 mg kg-1 and were classified as Typic Hapludults. Floodplain soils had M1P values from 7.69-56.85 mg kg-1 and were classified as Fluventic Dystrudepts. Landscape position and parent material play major roles in the formation of soils, and their degree of weathering controls the amount of plant available nutrients. Using geologic and topographic maps for comparison, it was concluded that the development of these soils was directly related to the underlying geology and the surrounding topography throughout various landscapes. This information can be used as a guide to aid in predicting the chemical and physical properties of native soils on the Cumberland Plateau.
193

Atrazine Contamination and Suspended Sediment Transport within Logsdon River, Mammoth Cave, Kentucky

Schenck Brown, Julie Eileen 01 December 2008 (has links)
Understanding the potential for karst aquifer contamination by sediment-sorbed pesticides is important for cave conservation efforts in agricultural landscapes. Flow rate, water quality parameters and suspended sediment concentrations were measured in Logsdon River, a ~10km karst conduit within the Turnhole Spring Groundwater Basin of Mammoth Cave National Park to determine characteristics of storm-period transport of sediment-sorbed atrazine through a conduit-flow karst aquifer. Analysis of two independent precipitation events occurring in the Spring of 2008 from May 2-4 and May 27-29 demonstrated the rapid response of the Logsdon River to precipitation events with detections of atrazine increasing during the initial turbidity peak and decline in spC, indicating that the atrazine arrives with the initial flush of surface waters that enters the conduit. Distinct peaks of atrazine did not coincide with fine grained (silt and clay-sized) sediment peaks and concentrations of atrazine remained elevated on the falling limb of the hydrograph as turbidity declined. In addition, no systematic relation between filtered and unfiltered samples was evident. There was also exceedingly weak correlation between the concentration of atrazine and suspended sediment, suggesting that if atrazine is sorbed to fine sediment particles this sorption involves only the fractions finer than 0.22 μm.
194

National Park Service Cave and Karst Resources Management Case Study: Great Smoky Mountains National Park

Nolfi, Daniel C. 01 May 2011 (has links)
As discussed in the National Parks Service’s (NPS) Directors Orders/Natural Resources Management Reference Manual #77 and the 2006 NPS Management Policy Handbook, implementing a management plan specifically for cave and karst resources within a national park is paramount to afford these resources appropriate protection. With support from the Federal Cave Resources Protection Act and the National Park Service Organic Act of 1906, management actions protecting caves has begun to place significant importance outside the traditional cave environment onto a broader karst landscape. The need to understand and protect the karst environment and caves as a karst resource has taken a much larger role in the scientific literature and has increased interest in its federal management application. Proactive management through the use of holistic karst wide management plans and programs is shown to provide superior measures for resource protection when compared to the shortcomings associated with reactive cave focused management. The use of Great Smoky Mountains National Park (GRSM) as a case study supports the need to develop and implement a proactive cave and karst management plan specific to their resources. Management decisions with regards to cave and karst resources currently follow the park's general directives and Superintendent's Compendium. GRSM’s caves and karst areas represent unique resources, such as extensive vertical relief and rare biota, requiring special management in order to effectively protect them and to manage those who study and recreate within them. Characteristics such as these necessitate holistically addressing management of these resources.
195

Watershed Condition Assessment for Little River Canyon National Preserve, Alabama

Rinehart, Nathan DeMille 01 December 2008 (has links)
No description available.
196

Suspended Sediment Transport Dynamics and Sediment Yields in Relation to Watershed Characteristics, Upper Green River Basin, Kentucky

Otoo, James Nii Aboh 01 April 2010 (has links)
Sediment delivery is a major problem in the Green River, Kentucky, home of 71 of the state’s 103 known mussel species and 151 fish species. The river also provides water for many of its surrounding counties. This research focuses on how suspended sediment loads, grain size, and sediment concentration during runoff events are related to watershed characteristics. The research characterized suspended sediment loads, grain size, and sediment concentration during runoff events and how they were related to watershed characteristics such as hydro-climatic regime, watershed size, geology and soils, topography and landuse conditions and land cover conditions. The study focused on Brush Creek and Pitman Creek watersheds in the Upper Green River Basin. This research can help in the planning and development of effective environmental strategies by screening out mitigation measures that would not be effective for implementation to minimize sediment load and suspended sediment concentration in the Green River, thereby improving the water quality of the river. Water quality was monitored using data sondes positioned at selected sites in the two watersheds. Water samples were collected during turbidity thresholds of 100 NTU and analyzed for suspended sediment concentrations. Regression models between ‘discharge and stage’ and also between ‘average turbidity and suspended sediment concentration’ were formulated and load estimates were made and compared. Four sets of samples were collected, two at Brush Creek on 11 April (Brush Creek’s event 1) and 3 May (Brush Creek’s event 2) and the other two at Pitman Creek on the 12 February (Pitman Creek’s event 1) and 3 March (Pitman Creek’s event 2) all in the year 2008. The suspended sediment samples collected for all four events were well graded but had relatively more silt than clay and sand. This could be due to the fact that more time and energy was needed to break the bonds in clay minerals or particles and also to the fact that more energy was also needed to transport sand compared to silt. Brush Creek watershed’s particles had smaller grain sizes than Pitman Creek watershed’s particles. All four events showed clockwise hysteresis indicating that most of the sediments from both watersheds during the events were derived from the bed and banks of the channel or area adjacent to the channel. The 11 April event (Brush Creek’s event 1) produced an estimated load of 1.1 x 105 kg and a sediment yield of 5.3 x 102 kg/km2. The 3 May event (Brush Creek’s event 2) produced an estimated load of 3.8 x 104 kg and a sediment yield of 1.8 x 102 kg/km2. Brush Creek watershed’s estimated load for the period compared was 4.9 x 105 kg and a sediment yield of 2.3 x 103 kg/km2 (53 kg/km2/day). The 12 February event (Pitman Creek’s event 1) produced an estimated load of 2.9 x 105 kg and a sediment yield of 8.4 x 102 kg/km2. The 3 March event (Pitman Creek’s event 2) produced an estimated load of 5.7 x 105 kg and a sediment yield of 1.6 x 103 kg/km2. Pitman Creek watershed’s estimated load for the period compared was 1.1 x 106 kg and a sediment yield of 3.1 x 103 kg/km2 (71 kg/km2/day). Pitman Creek watershed’s higher number of stream network per unit area, its high elevation and relief, its high percentage of erodible soil per unit area, its lesser area of protection of erodible soil by its vegetation compared to Brush Creek watershed’s are responsible for its higher sediment load and yield.
197

Classification and Fertility of Soils in the Big South Fork National River and Recreation Area Based on Landscape Position and Geology

Blair, Ryan H 01 May 2010 (has links)
The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to determine baseline soil fertility through chemical analysis, to provide fertilizer recommendations for Bicolor Lespedeza (Lespedeza bicolor) to be grown as wildlife food plots. The parent materials and site- specific geology, including the Pennington Formation, were compared to the profiles in order to establish any relationships that might exist. The methods of chemical analysis included: total carbon analysis, cation exchange capacity, percent base saturation, pH, particle size analysis, KCl total acidity, total elemental analysis and Mehlich I extraction. From the data, soils examined from an upland summit have the lowest Mehlich I extractable phosphorus (M1P) ranging from 0.8-3.14 mg kg-1, and this soil was classified as a Typic Hapludult. Soils examined on backslopes and sideslopes had M1P values ranging from 0.3-11.53 mg kg-1 and these soils were classified as either Lithic Dystrudepts or Typic Dystrudepts. The footslope soils examined have M1P values ranging from 1.95-19.79 mg kg-1 and were classified as Typic Hapludults. Floodplain soils had M1P values from 7.69-56.85 mg kg-1 and were classified as Fluventic Dystrudepts. Landscape position and parent material play major roles in the formation of soils, and their degree of weathering controls the amount of plant available nutrients. Using geologic and topographic maps for comparison, it was concluded that the development of these soils was directly related to the underlying geology and the surrounding topography throughout various landscapes. This information can be used as a guide to aid in predicting the chemical and physical properties of native soils on the Cumberland Plateau.
198

THE EFFECTS OF MOUNTAINTOP REMOVAL MINING AND VALLEY FILLS ON STREAM SALAMANDER COMMUNITIES

Muncy, Brenee' Lynn 01 January 2014 (has links)
Mountaintop removal mining and valley filling (MTR/VF) is a common form of land conversion in Central Appalachia and threatens the integrity of stream ecosystems. We investigated the effects of MTR/VF on stream salamander occupancy probabilities and community structure by conducting area constrained active searches for stream salamanders within intermittent streams located in mature forest (i.e., control) and those impacted by MTR/VF. During March to June of 2013, we detected five stream salamander species (Desmognathus fuscus, D. monticol, Eurycea cirrigera, Pseudotriton ruber, and Gyrinophilus porphyriticus) and found that the probability of occupancy was greatly reduced in MTR/VF streams compared to control streams. Additionally, the salamander community was greatly reduced in MTR/VF streams; the mean species richness estimate for MTR/VF streams was 2.09 (± 1.30 SD), whereas richness was 4.83 (± 0.58 SD) for control streams. Numerous mechanisms may be responsible for decreased occupancy and diminished salamander communities at MTR/VF streams, although water chemistry of streams may be a particularly important mechanism. Indeed, we detected elevated levels of specific conductivity, pH, total organic carbon, and dissolved ions in MTR/VF streams. Our results indicate that salamander communities, with other invertebrates, fish, and other aquatic and/or semi-aquatic animals, are susceptible to MTR/VF mining practices.
199

Changing The Climate Narrative: How A Long-Term Climate Change Might Save Our Lives

Harreld, Natalie P 01 January 2014 (has links)
The goal of this paper is to offer new insights into the climate change debate by shifting away from the heated anthropologic arguments that dominate politics, media, and popular science. Instead, I choose to rely on the long-term impacts of a changing climate on our planet. The paper begins with a break down of key processes involved in short-term and long-term climate change, using the latest research. After a foundational understanding of climate sciences is established, we will discuss the failure of the climate change debate in educating the general public about the facts of a changing climate. Finally, the importance of long-term foresight in climate policy and education, and how this perspective could drastically progress the climate debate, will be discussed.
200

Addressing Water Resource Issues In Barbados Through An Isotopic and Atmospheric Characterization of Precipitation Variability

Hall, Veronica 01 May 2014 (has links)
Numerous studies have analyzed isotopic variation of meteoric and dripwater in karst environments for paleoclimate reconstructions or aquifer recharge capacity. What is poorly understood is how the isotopic signal of δ18O and δ2H is transferred through the hydrologic cycle based upon storm type, frequency, intensity, and teleconnection activity in the tropical karst areas. At Harrison’s Cave, Barbados, a Hobo Onset event data logger was attached to a tipping bucket rain gauge to count the tips and record the total rainfall every 10 minutes. In the cave a Hobo data logger was used to record relative humidity and temperature at 10-minute intervals. Rainwater, dripwater, and stream water samples were collected at a weekly resolution and refrigerated before sample analysis. The study period was from July, 2012 to October, 2013, with data from the data loggers only until June, 2013 due to inability to reach the study site. The samples were analyzed using the Picarro Cavity Ring Down Spectroscopy Unit-Water L1102-I through laboratories at the University of Kentucky and the University of Utah. The samples were reported in per mil and calibrated. The teleconnection (NAO, AMO, and ENSO) and other atmospheric data were obtained from the Climate Prediction Center or the NOAA Earth System Research Laboratory-Physical Sciences Division. The weekly isotope signatures were linearly regressed against total rainfall for Harrison’s Cave and surface temperature with no statistically significant correlation, indicating the amount effect was not present at a weekly resolution. The amountweighted precipitation δ18O values were calculated on a monthly basis and compared to TRMM monthly rainfall and island-wide monthly rainfall, and a statistically significant negative correlation was found between both datasets. This confirmed that the amount effect dominates the island’s rainfall isotopic signature at a monthly resolution, and that specific atmospheric influences represented in weekly rainfall were less influential on a weekly basis. It is hypothesized that the variation in weekly rainfall is due to quick initiating, rain-out, and dissipation of convective storm systems over the island. In terms of evaporative influences, the samples do not deviate much from the Global Meteoric Water Line (GMWL), indicating minimal evaporation, which is typical for tropical locations. When the d-excess parameters were calculated, there were distinct variations with minimal evaporation occurring in the 2013 calendar year. This is attributed to coastal storm formation in the tropics.

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