Life Sciences Commons^™

The Utility Of Environmental Dna And Species Distribution Models In Assessing The Habitat Requirements Of Twelve Fish Species In Alaskan North Slope Rivers, James B. Eddings

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subsistence fishing is a vital component of Alaska’s North Slope borough economy and culture that is being threatened by human disturbance. These threats mean the fish must be protected, but the size of the region makes conservation planning difficult. Fortunately, advances in species distribution models (SDMs), environmental DNA (eDNA), and remote sensing technologies provide potential to better understand species’ needs and guide management. The objectives of my study were to: (1) map the current habitat suitability for twelve fish species, occurring in Alaska’s North Slope, (2) determine if SDMs based on eDNA data performed similarly to, or improved, models based …

Forage Inventory And Modeling In Uintah And Ouray Reservation Rangelands, Scott N. Zimmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uintah and Ouray Reservation in northeastern Utah has not been widely studied, and access to non-tribal members is highly restricted. We sampled vegetation to summarize condition in 300,000 acres of unsurveyed Reservation lands in 2017-2018, combining these data with data collected by the Bureau of Indian Affairs from 2010-2015 to complete an initial rangeland vegetation inventory of the Reservation. This survey was designed to inform management of the area by determining cattle stocking rates and overall ecological condition across the Reservation. Both the density of forage available to cattle and appropriate cattle stocking rates vary greatly throughout management units …

Modeling The Effect Of Post-Dispersal Seed Predation On Tropical Tree Species In Panama, Justin Tirrell

Fall Student Research Symposium 2018

Palm trees provide a unique opportunity to study what conditions optimize the probability that a seed will grow successfully. The seeds of palm trees, endocarps, are large and easy to locate. When they don't grow, predators leave marks on them that tell the story of their fate. The focus of my experiment is to determine how the current distribution pattern of parent palm trees in Panama Palm trees affects the the future distribution of seedlings. I have programmed a versatile model that takes the assumption that bruchid beetles are the sole predators acting on the seeds, and that these fall …

Ncer Assistance Agreement Annual Progress Report For Grant #83582401 - Assessment Of Stormwater Harvesting Via Manage Aquifer Recharge (Mar) To Develop New Water Supplies In The Arid West: The Salt Lake Valley Example, Ryan Dupont, Joan E. Mclean, Richard C. Peralta, Sarah E. Null, Douglas B. Jackson-Smith

Civil and Environmental Engineering Faculty Publications

The goals of the original proposed project remain the same, that is, to test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially and environmentally acceptable, economically viable, and legally feasible option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources. The project is being carried out via three distinct but integrated components that include: 1) Monitoring of existing distributed MAR harvesting schemes involving a growing number of demonstration Green Infrastructure (GI) test sites; 2) Integrated stormwater/vadose zone/groundwater/ ecosystem services modeling; and …

Ncer Assistance Agreement Annual Progress Report For Grant #83582401 - Assessment Of Stormwater Harvesting Via Manage Aquifer Recharge (Mar) To Develop New Water Supplies In The Arid West: The Salt Lake Valley Example, Ryan Dupont, Joan E. Mclean, Richard C. Peralta, Sarah E. Null, Douglas B. Jackson-Smith

Civil and Environmental Engineering Faculty Publications

The aims of the original proposed project remain the same, that is, to test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially and environmentally acceptable, economically viable, and legally feasible option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources. The project is being carried out via three distinct but integrated components that include: 1) Monitoring of existing distributed MAR harvesting schemes involving a growing number of demonstration Green Infrastructure (GI) test sites; 2) Integrated stormwater/vadose zone/groundwater/ ecosystem services modeling; and …

Developing A Parameterization Approach For Soil Erodibility For The Rangeland Hydrology And Erosion Model (Rhem), Osama Z. Al-Hamdan, Frederick B. Pierson, Mark A. Nearing, Christopher Jason Williams, Mariano Hernandez, Jan Boll, Sayjro K. Nouwakpo, Mark A. Weltz, Kenneth Spaeth

Articles

Soil erodibility is a key factor for estimating soil erosion using physically based models. In this study, a new parameterization approach for estimating erodibility was developed for the Rangeland Hydrology and Erosion Model (RHEM). The approach uses empirical equations that were developed by applying piecewise regression analysis to predict the differences of erodibility before and after disturbance (i.e., wildfire, prescribed fire, and tree encroachment) and across a wide range of soil textures as a function of vegetation cover and surface slope angle. The approach combines rain splash, sheet flow, and concentrated flow erodibilities into a single parameter for modeling erodibility …

Ncer Assistance Agreement Annual Progress Report For Grant #83582401 - Assessment Of Stormwater Harvesting Via Manage Aquifer Recharge (Mar) To Develop New Water Supplies In The Arid West: The Salt Lake Valley Example, Ryan Dupont, Joan E. Mclean, Richard C. Peralta, Sarah E. Null, Douglas B. Jackson-Smith

Civil and Environmental Engineering Faculty Publications

The aims of the original proposed project remain the same, that is, to test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially and environmentally acceptable, economically viable, and permittable option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources. The project is being carried out via three distinct but integrated components that include: 1) Monitoring of existing distributed Managed Aquifer Recharge (MAR) harvesting schemes involving a growing number of demonstration Green Infrastructure (GI) test sites; 2) Integrated stormwater/vadose zone/groundwater/ ecosystem services …

Modeling The Ecological Consequences Of Visitor Behavior In Off-Trail Areas Of Dispersed Recreation Use, Ashley L. D'Antonio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Parks and protected areas are often created to protect important social, ecological, or cultural resources from impairment. In the United States, a large majority of these parks and protected areas are also public land where recreational activities such as hiking or scenic driving are allowed. Managers of many parks and protected areas must therefore try to protect resources while also allowing for recreation use that may put these resources at risk for damage. The field of recreation ecology is interested in understanding how recreation use in parks and protected areas can sometimes cause ecological impacts to vegetation, soil, wildlife, water, …

Interdisciplinary Modeling For Water-Related Issues Graduate Course, Laurel Saito, Alexander Fernald, Timothy Link

All ECSTATIC Materials

The science and management of aquatic ecosystems is inherently interdisciplinary, with issues associated with hydrology, atmospheric science, water quality, geochemistry, sociology, economics, environmental science, and ecology. Addressing water resources issues in any one discipline invariably involves effects that concern other disciplines, and attempts to address one issue often have consequences that exacerbate existing issues or concerns, or create new ones (Jørgensen et al. 1992; Lackey et al. 1975; Straskraba 1994) due to the strongly interactive nature of key processes (Christensen et al. 1996). Thus, research and management of aquatic ecosystems must be interdisciplinary to be most effective, but such truly …

Modeling Usa Stream Temperatures For Stream Biodiversity And Climate Change Assessments, Ryan A. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stream temperature in one of the most biologically important aspects of water quality, but we lack temperature information for the vast majority of streams within the USA. Stream temperature can be influenced by several types of landscape and waterway alteration including upstream urbanization, agriculture, and reservoir releases. Stream temperatures are also expected to be affected by climate change over the next
century. We need to know how stream temperatures vary naturally, how they are influenced by human activity, and how they will respond to climate changes to effectively manage stream ecosystems. I used data from several thousand streams within the …

15n Tracer And Modeling Analyses Of Nutrient Transport Through Lakes In A Subalpine Watershed, David M. Epstein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lakes have historically been overlooked as important nutrient processors within their watersheds. In general ecologists have focused on streams as zones of uptake and transformation, while viewing lakes as simple nutrient traps. However, recent research has highlighted the large influence that lakes may have on water chemistry within their watersheds. Within the field of limnology, researchers have traditionally focused on the pelagic zone for in-lake production. Further research in shallow lakes has highlighted the role benthic production within the littoral zone plays in the lake ecosystem. The greater influence of lakes is highlighted when comparing watersheds containing lakes with watersheds …

Gregarious Behavior In Large Mammals: Modeling, Methodology, And Application, Thomas L. Morton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gregarious behavior of ungulates was considered in four ways. The first concern was W. D. Hamilton's hypothesis that a simple movement rule could reduce predation risk and encourage grouping behavior. Simulations showed little effect of this nearest-neighbor rule on predation risk. Similar, more complicated rules reduced predation risk by up to two thirds.

The second focus was on the accuracy of ground observers in diagramming individual animal locations in small herds of elk. A remotely controlled airplane was used to photograph the herds from above. A substantial distance discrepancy was found between "true" and "observed" animal locations. This discrepancy increased …

The Modeling And Measurement Of Respiratory Carbon Use And Net Carbon Gain Of Two Agropyron Bunchgrasses, Halldor Thorgeirsson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The rate of photosynthetic carbon fixation and of root and shoot respiratory carbon use was measured in the laboratory and in the field (shoots only) for Agropyron desertorum (Fisch. ex Link) Schult. and Agropyron spicatum (Pursh) Scribn. and Smith. The rate of respiratory carbon use of the root system declined within hours of the shading or defoliation of the shoot system, resulting in as much as 60% reduction in specific rate of root respiration. The mean whole-plant growth efficiency (the ratio of whole-plant net carbon gain to gross photosynthetic carbon fixation) in full irradiance in the laboratory was 0.53 and …

A New Approach To Forest Site Quality Modeling, David L. Verbyla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiple regression and discriminant analysis procedures are commonly used to develop forest site quality models. 'When they contain many independent variables relative to sample size, these models may be subject to predicton bias. Fit statistics such as R² in regression and classification tables in discriminant analysis show the apparent model accuracy but this may be a biased estimate of the model's actual accuracy. Sample splitting methods such as cross-validation and the bootstrap can be used to get an unbiased actual accuracy estimate.

A discriminant procedure called classification tree analysis uses cross-validation to build the classifier with the greatest estimated …

Electron Image Simulation: A Complementary Processing Technique, Michael A. O'Keefe

Scanning Electron Microscopy

At present it is difficult to use direct image processing techniques to determine the specimen structure from electron micrographs obtained under non-linear imaging conditions, and impossible when the effects of dynamical scattering are strong (as in the case of thicker specimens). However, computing techniques are available to simulate high-resolution transmission electron microscope (HRTEM) images of postulated model structures. With these techniques it is possible to confirm the validity of interpretation of recorded micrographs, to help analyze crystal defects, to characterize microscope parameters, and to determine the ranges of validity of commonly used interpretive approximations. Because processed micrographs can lead to …

Modeling Of Depth Distribution Of X-Ray Production, J. D. Brown

Scanning Electron Microscopy

Knowledge of X-ray production as a function of depth by electrons (𝜙(𝜚z) curves) is important in quantitative electron probe microanalysis and other electron beam technologies. Extensive measurements of such curves have been made for electron energies between 6 and 30 keV and for many X-ray lines and matrix elements. Two experimental techniques based on measurements on sandwich or wedge shaped specimens have been used.

A number of expressions have been used to model 𝜙(𝜚z) curves from a square function through complicated polynomial expressions. Recently, a Gaussian model has been proposed which accurately reflects the shape of the 𝜙(𝜚z) curves and …