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Utah State University

2019

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Articles 1 - 30 of 269

Full-Text Articles in Physical Sciences and Mathematics

Ueb Parallel: Distributed Snow Accumulation And Melt Modeling Using Parallel Computing, Tseganeh Z. Gichamo, David G. Tarboton Dec 2019

Ueb Parallel: Distributed Snow Accumulation And Melt Modeling Using Parallel Computing, Tseganeh Z. Gichamo, David G. Tarboton

Publications

The Utah Energy Balance (UEB) model supports gridded simulation of snow processes over a watershed. To enhance computational efficiency, we developed two parallel versions of the model, one using the Message Passing Interface (MPI) and the other using NVIDIA's CUDA code on Graphics Processing Unit (GPU). Evaluation of the speed-up and efficiency of the MPI version shows that the effect of input/output (IO) operations on the parallel model performance increases as the number of processor cores increases. As a result, although the computation kernel scales well with the number of cores, the efficiency of the parallel code as a whole …


Climate Diagnostics Of The Extreme Floods In Peru During Early 2017, Rackhun Son, Shih-Yu Simon Wang, Wan-Ling Tseng, Christian W. Barreto Schuler, Emily Becker, Jin-Ho Yoon Dec 2019

Climate Diagnostics Of The Extreme Floods In Peru During Early 2017, Rackhun Son, Shih-Yu Simon Wang, Wan-Ling Tseng, Christian W. Barreto Schuler, Emily Becker, Jin-Ho Yoon

Plants, Soils, and Climate Faculty Publications

From January through March 2017, a series of extreme precipitation events occurred in coastal Peru, causing severe floods with hundreds of human casualties and billions of dollars in economic losses. The extreme precipitation was a result of unusually strong recurrent patterns of atmospheric and oceanic conditions, including extremely warm coastal sea surface temperatures (SST) and weakened trade winds. These climatic features and their causal relationship with the Peruvian precipitation were examined. Diagnostic analysis and model experiments suggest that an atmospheric forcing in early 2017, which was moderately linked to the Trans-Niño Index (TNI), initiated the local SST warming along coastal …


A 100-M-Scale Modeling Study Of A Gale Event On The Lee Side Of A Long Narrow Mountain, Halie Xue, Jian Li, Tingting Qian, Hongping Gu Dec 2019

A 100-M-Scale Modeling Study Of A Gale Event On The Lee Side Of A Long Narrow Mountain, Halie Xue, Jian Li, Tingting Qian, Hongping Gu

Plants, Soils, and Climate Faculty Publications

In this study, a gale event that occurred on the lee side of a long narrow mountain was investigated, together with the associated mountain flows, using a realistic-case large-eddy simulation (LES) that is based on the Weather Research and Forecasting Model. The mountain is located on the southeastern Tibetan Plateau, where approximately 58 gales occur annually, mostly in the afternoons during the winter season. Benefitting from realistic topography and high horizontal resolution as fine as 111 m, the LES can replicate features similar to the wind fields observed during the gale period. Investigation of the early morning wind structure over …


Evidence For Accelerated Weathering And Sulfate Export In High Alpine Environments, John T. Crawford, Eve-Lyn S. Hinckley, M. Iggy Litaor, Janice Brahney, Jason C. Neff Dec 2019

Evidence For Accelerated Weathering And Sulfate Export In High Alpine Environments, John T. Crawford, Eve-Lyn S. Hinckley, M. Iggy Litaor, Janice Brahney, Jason C. Neff

Watershed Sciences Faculty Publications

High elevation alpine ecosystems—the 'water towers of the world'—provide water for human populations around the globe. Active geomorphic features such as glaciers and permafrost leave alpine ecosystems susceptible to changes in climate which could also lead to changing biogeochemistry and water quality. Here, we synthesize recent changes in high-elevation stream chemistry from multiple sites that demonstrate a consistent and widespread pattern of increasing sulfate and base cation concentrations or fluxes. This trend has occurred over the past 30 years and is consistent across multiple sites in the Rocky Mountains of the United States, western Canada, the European Alps, the Icelandic …


Data-Driven Multiscale Modeling Reveals The Role Of Metabolic Coupling For The Spatio-Temporal Growth Dynamics Of Yeast Colonies, Jukka Intosalmi, Adrian C. Scott, Michelle Hays, Nicholas Flann, Olli Yli-Harja, Harri Lähdesmäki, Aimée M. Dudley, Alexander Skupin Dec 2019

Data-Driven Multiscale Modeling Reveals The Role Of Metabolic Coupling For The Spatio-Temporal Growth Dynamics Of Yeast Colonies, Jukka Intosalmi, Adrian C. Scott, Michelle Hays, Nicholas Flann, Olli Yli-Harja, Harri Lähdesmäki, Aimée M. Dudley, Alexander Skupin

Computer Science Faculty and Staff Publications

Background: Multicellular entities like mammalian tissues or microbial biofilms typically exhibit complex spatial arrangements that are adapted to their specific functions or environments. These structures result from intercellular signaling as well as from the interaction with the environment that allow cells of the same genotype to differentiate into well-organized communities of diversified cells. Despite its importance, our understanding how this cell–cell and metabolic coupling lead to functionally optimized structures is still limited.

Results: Here, we present a data-driven spatial framework to computationally investigate the development of yeast colonies as such a multicellular structure in dependence on metabolic capacity. For this …


Exploratory Measurements Of Large Winds And Shears In The Lower Thermosphere And Their Variability Using An Enhanced Sodium Lidar, Tao Yuan Dec 2019

Exploratory Measurements Of Large Winds And Shears In The Lower Thermosphere And Their Variability Using An Enhanced Sodium Lidar, Tao Yuan

Funded Research Records

No abstract provided.


Development Of A Low-Cost, Open Source Miniature Rotary Cell Culture System To Simulate Microgravity Within An Irradiated Environment, Elizabeth Vargis, Jr Dennison Dec 2019

Development Of A Low-Cost, Open Source Miniature Rotary Cell Culture System To Simulate Microgravity Within An Irradiated Environment, Elizabeth Vargis, Jr Dennison

Browse all Datasets

A major challenge for astronauts in long-duration space travel is combatting the hazardous spaceflight environment caused by microgravity and increased levels of ionizing radiation. Microgravity damages cellular DNA by increasing the production of harmful reactive oxygen species, while ionizing radiation damages DNA by creating double-stranded DNA (dsDNA) breaks. Cellular damage due to microgravity and radiation has been investigated using ground-based models, but most models consider microgravity and ionizing radiation alone, or asynchronously. Synchronous modeling better mimics spaceflight conditions and can be used to understand the combined effects of microgravity and ionizing radiation. However, commercially available devices to model microgravity and …


Resurgence Of An Apex Marine Predator And The Decline In Prey Body Size, Jan Ohlberger, Daniel E. Schindler, Eric J. Ward, Timothy E. Walsworth, Timothy E. Essington Dec 2019

Resurgence Of An Apex Marine Predator And The Decline In Prey Body Size, Jan Ohlberger, Daniel E. Schindler, Eric J. Ward, Timothy E. Walsworth, Timothy E. Essington

Watershed Sciences Faculty Publications

In light of recent recoveries of marine mammal populations worldwide and heightened concern about their impacts on marine food webs and global fisheries, it has become increasingly important to understand the potential impacts of large marine mammal predators on prey populations and their life-history traits. In coastal waters of the northeast Pacific Ocean, marine mammals have increased in abundance over the past 40 to 50 y, including fish-eating killer whales that feed primarily on Chinook salmon. Chinook salmon, a species of high cultural and economic value, have exhibited marked declines in average size and age throughout most of their North …


Beavers Alter Stream Macroinvertebrate Communities In Northeastern Utah, Susan E. Washko, Brett B. Roper, Trisha Brooke Atwood Dec 2019

Beavers Alter Stream Macroinvertebrate Communities In Northeastern Utah, Susan E. Washko, Brett B. Roper, Trisha Brooke Atwood

Watershed Sciences Faculty Publications

  1. Understanding changes in macroinvertebrate communities is important because they play a large role in stream ecosystem functioning, and they are an important food resource for fish. Beaver‐induced changes to stream morphology could alter macroinvertebrate communities, which in turn could affect food webs and ecosystem function. However, studies investigating the effects of North American beaver activities on macroinvertebrates are rare in the inter‐mountain west, an area with high potential for beaver‐assisted restoration.
  2. The aim of this study was to quantify differences in the macroinvertebrate community between unaltered segments of streams and within beaver ponds in north‐eastern Utah, U.S.A. We assessed macroinvertebrate …


Normalized Multi-Bump Solutions For Saturable Schrödinger Equations, Xiaoming Wang, Zhi-Qiang Wang Dec 2019

Normalized Multi-Bump Solutions For Saturable Schrödinger Equations, Xiaoming Wang, Zhi-Qiang Wang

Mathematics and Statistics Faculty Publications

In this paper, we are concerned with the existence of multi-bump solutions for a class of semiclassical saturable Schrödinger equations with an density function:

We prove that, with the density function being radially symmetric, for given integer k ≥ 2 there exist a family of non-radial, k-bump type normalized solutions (i.e., with the L2 constraint) which concentrate at the global maximum points of density functions when ε → 0+. The proof is based on a variational method in particular on a convexity technique and the concentration-compactness method.


Evaluating Data Quality Of Newborn Hearing Screening, Maria C. Sanchez Gomez, Kelly Dundon, Xidong Deng Dec 2019

Evaluating Data Quality Of Newborn Hearing Screening, Maria C. Sanchez Gomez, Kelly Dundon, Xidong Deng

Journal of Early Hearing Detection and Intervention

Scope

Jurisdictional-based Early Hearing Detection and Intervention Information Systems (EHDI-IS) collect data on the hearing screening and follow-up status of infants across the United States. These systems serve as tools that assist EHDI programs’ staff and partners in their tracking activities and provide a variety of data reports to help ensure that all children who are deaf/hard of hearing (D/HH) are identified early and receive recommended intervention services. The quality and timeliness of the data collected with these systems are crucial to effectively meeting these goals.

Methodology

Forty-eight EHDI programs, funded by the Centers for Disease Control and Prevention (CDC), …


Coordination Of Anions By Noncovalently Bonded Σ-Hole Ligands, Steve Scheiner, Mariusz Michalczyk, Wiktor Zierkiewicz Dec 2019

Coordination Of Anions By Noncovalently Bonded Σ-Hole Ligands, Steve Scheiner, Mariusz Michalczyk, Wiktor Zierkiewicz

Chemistry and Biochemistry Faculty Publications

Research on σ-hole interactions that include halogen, chalcogen, pnicogen, and tetrel bonding has been accelerating in recent years. These cousins of the H-bond have many similar properties, including geometric preferences and energetics. Most of the work to date has focused on neutral complexes, with less known about these bonds to anions. This review summarizes the current state of knowledge about the complexes of anions with ligands that engage in these sorts of noncovalent bonds. Of particular interest are comparisons with H-bonds, and how the geometry of the fully coordinated complex varies as the number of surrounding ligands increases. A specific …


North American Winter Dipole: Observed And Simulated Changes In Circulations, Yu-Tang Chien, Shih-Yu (Simon) Wang, Yoshimitsu Chikamoto, Steve L. Voelker, Jonathan D.D. Meyer, Jin-Ho Yoon Dec 2019

North American Winter Dipole: Observed And Simulated Changes In Circulations, Yu-Tang Chien, Shih-Yu (Simon) Wang, Yoshimitsu Chikamoto, Steve L. Voelker, Jonathan D.D. Meyer, Jin-Ho Yoon

Plants, Soils, and Climate Faculty Publications

In recent years, a pair of large-scale circulation patterns consisting of an anomalous ridge over northwestern North America and trough over northeastern North America was found to accompany extreme winter weather events such as the 2013–2015 California drought and eastern U.S. cold outbreaks. Referred to as the North American winter dipole (NAWD), previous studies have found both a marked natural variability and a warming-induced amplification trend in the NAWD. In this study, we utilized multiple global reanalysis datasets and existing climate model simulations to examine the variability of the winter planetary wave patterns over North America and to better understand …


Relaxation Of Radiation Effects In Polymers, Alexandra Hughlett Nelson Dec 2019

Relaxation Of Radiation Effects In Polymers, Alexandra Hughlett Nelson

Physics Capstone Projects

Radiation can create atomic-scale defect states in polymers, leading to changes in their optical, electrical and mechanical properties. Recent studies of polymers have shown that these defect states are sensitive to oxygen or water exposure. It is believed that oxygen cause the number of defect states to decrease and the polymers to revert to their original states. However, the time scale of this regression is not known. This experiment quantified the time that it takes five polymers to recover and the extent of said recovery; polypropylene (PP), low density polyethylene (LDPE), fluorinated ethylene propylene (FEP), polymide (PI), and poly ether …


Model‐Based Properties Of The Dayside Open/Closed Boundary: Is There A Ut‐Dependent Variation?, David A. Smith, Jan Josef Sojka Dec 2019

Model‐Based Properties Of The Dayside Open/Closed Boundary: Is There A Ut‐Dependent Variation?, David A. Smith, Jan Josef Sojka

All Physics Faculty Publications

The open‐closed boundary (OCB) defines a region of significant transformation in Earth's protective magnetic shield. Principle among these changes is the transition of magnetic field lines from having two foot points, one in each hemisphere, to one foot point at Earth, the other mapping to the solar wind. Charged particles in the solar wind are able to follow these open field lines into Earth's upper atmosphere. The OCB also defines the polar cap boundary. Being able to identify and track the OCB allows study of several components of the geomagnetic system. Among them are the electrodynamics of the geomagnetic field …


Modeling Lake Temperature Response To Climate Change In The Alaskan Arctic, Thomas Balkcom Dec 2019

Modeling Lake Temperature Response To Climate Change In The Alaskan Arctic, Thomas Balkcom

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This thesis study focuses on simulating lake temperature and ice duration for four lakes at the Arctic Long-Term Ecological Research site, near the Toolik Field Station in Alaska. Model projections were driven by the representative global climate model outputs under different carbon emission scenarios. Results show that my simple lake model can reproduce historical lake temperature and ice duration observations, indicating the reliability of the model for future projections. Model projections show that JuneSeptember lake temperatures would increase by 4.3-5.8 °C from the historical period with most progressive carbon emission scenarios, but by 0.7-2.2 °C in the conservative scenarios. Results …


Assessing & Protecting Dark Night Skies In El Morro National Monument, Leslie Kobinsky Dec 2019

Assessing & Protecting Dark Night Skies In El Morro National Monument, Leslie Kobinsky

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Light pollution is causing the disappearance of dark night skies around the world. In the United States alone, 1/3 of people are unable to see the Milky Way where they live (Ramlagan, 2016). National Park Service sites contain some of the darkest skies in the country. Here at El Morro National Monument, these dark skies are a beautiful and healthy benefit to people in the local community and visitors traveling from afar. El Morro’s current park legislation does not include specific measures of protection for the night sky. This capstone project will create a baseline data set of night sky …


Assessing Beaver Dam Dynamics In The Logan-Little Bear Watershed, Connor Penrod Dec 2019

Assessing Beaver Dam Dynamics In The Logan-Little Bear Watershed, Connor Penrod

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This paper seeks to address a knowledge gap concerning how flood events impact beaver dams over time. To address this gap, I took four time-snapshots of beaver dams, mapping them across the Utah portion of the Logan-Little Bear watershed, from 2009 to 2016 to bookend a large flood event in 2011. I assessed dam status (intact, breached, or blown out) for each dam mapped to assess the impact of the large spring runoff on the dam status. Assessing dam status over time allowed me to assess the change in condition over time, from before to several years after, while also …


Deep Reinforcement Learning Pairs Trading, Andrew Brim Dec 2019

Deep Reinforcement Learning Pairs Trading, Andrew Brim

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This research applies a deep reinforcement learning technique, Deep Q-network, to a stock market pairs trading strategy for profit. Artificial intelligent methods have long since been applied to optimize trading strategies. This work trains and tests a DQN to trade co-integrated stock market prices, in a pairs trading strategy. The results demonstrate the DQN is able to consistently produce positive returns when executing a pairs trading strategy.


Decomposing The Hamiltonian Of Quantum Circuits Using Machine Learning, Jordan Burns, Yih Sung, Colby Wight Dec 2019

Decomposing The Hamiltonian Of Quantum Circuits Using Machine Learning, Jordan Burns, Yih Sung, Colby Wight

Physics Capstone Projects

Quantum computing is one of the most promising techniques for simulating physical systems that cannot be simulated on classical computers[1]. A significant drawback of this approach is the inherent difficulty in designing circuits that can represent these systems on quantum computers. Every quantum circuit is built out of small components called quantum gates. Each of these gates manipulate the quantum system in a specific way. When used in combination, a finite subset of these gates, the set of universal gates, can be used to construct any possible quantum circuit[2].


Evolution Of The Book Cliffs Dryland Escarpment In Central Utah - Establishing Rates And Testing Models Of Escarpment Retreat, Nicholas R. Mccarroll Dec 2019

Evolution Of The Book Cliffs Dryland Escarpment In Central Utah - Establishing Rates And Testing Models Of Escarpment Retreat, Nicholas R. Mccarroll

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since the earliest explorations of the Colorado Plateau, geologists have suspected that cliffs are retreating back laterally. Clarence Dutton envisioned “the beds thus dissolving edge wise until after the lapse of millions of centuries their terminal cliffs stand a hundred miles or more back from their original position” when he wrote about the landscape in 1882. While many geologic studies have determined how fast rivers cut down through the Plateau, only a few studies have calculated how quickly cliffs retreat laterally, and geologists have been arguing since the 1940’s what exactly drives cliffs to retreat in the first place. We …


The Farm As Place In A Changing Climate: Capturing Women Farmers' Experiences In Idaho, United States And Victoria, Australia, Tagen Towsley Baker Dec 2019

The Farm As Place In A Changing Climate: Capturing Women Farmers' Experiences In Idaho, United States And Victoria, Australia, Tagen Towsley Baker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Australia and the US, women play a vital role in the agricultural sector. However, historically farmwomen’s contributions to agriculture as well as their individual knowledge and social resilience to stressors like climate and climate change have been unrecognized and rendered invisible. Drawing on interdisciplinary scholarship from geography and the humanities, this dissertation explores the farm as place in a changing climate, drawing on women farmers’ experiences, under three distinct themes: identity, place, and photography. The dissertation research includes three distinct parts. First, incorporating non-fiction writing and photography, I explore my agricultural and religious heritage, as well as familial connections …


Boundaries And Bridges In Rangeland Social-Ecological Systems: Studies Of Collaboration, Innovation, And Information Flow, Gwendŵr R. Meredith Dec 2019

Boundaries And Bridges In Rangeland Social-Ecological Systems: Studies Of Collaboration, Innovation, And Information Flow, Gwendŵr R. Meredith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Public rangelands are managed by a mixture of federal, state, and local governments. Often, these groups are charged with managing adjacent lands that are part of the same greater landscape. To do this effectively, communication and collaboration is required. This dissertation examines federal, state, and local agencies’ level of communication through three projects.

The first project examined barriers to agencies adopting management tools from each other. I found that individuals within agencies were mainly staying within their own agency when seeking advice, so individuals were not communicating about tools or their findings across agencies. Furthermore, agency policies and fear of …


Plug-And-Play Web Services, Arihant Jain Dec 2019

Plug-And-Play Web Services, Arihant Jain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The goal of this research is to make it easier to design and create web services for relational databases. A web service is a software service for providing data over computer networks. Web services provide data endpoints for many web applications. We adopt a plug-and-play approach for web service creation whereby a designer constructs a “plug,” which is a simple specification of the output produced by the service. If the plug can be “played” on the database then the web service is generated. Our plug-and-play approach has three advantages. First, a plug is portable. You can take the plug …


Power V. Threshold: Near-Channel Morphology Controls Sediment Rating Curve Shape In Coastal Redwood Watersheds, Adam Caspian Nebraska Fisher Dec 2019

Power V. Threshold: Near-Channel Morphology Controls Sediment Rating Curve Shape In Coastal Redwood Watersheds, Adam Caspian Nebraska Fisher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River sediment is one of the most pervasive pollutants in the world. Excess amounts of fine sediment can reduce water quality, damage stream ecosystems, and harm aquatic life. Both natural and human-caused processes can add sediment to a river, such as tectonic uplift, landslides, and timber harvesting. Therefore, it is important to understand how fine sediment enters and moves through a rive system to inform policymakers and land-managers on effective ecosystem management.

In this study, we determined how the relationship between river flow and suspended sediment changed among watersheds along the North Coast of California. We found a rise in …


Using A Discrete Choice Experiment To Estimate Willingness To Pay For Location Based Housing Attributes, Kristopher C. Toll Dec 2019

Using A Discrete Choice Experiment To Estimate Willingness To Pay For Location Based Housing Attributes, Kristopher C. Toll

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1993, a travel study was conducted along the Wasatch front in Utah (Research Systems Group INC, 2013). The main purpose of this study was to assess travel behavior to understand the needs for future growth in Utah. Since then, the Research Service Group (RSG), conducted a new study in 2012 to understand current travel preferences in Utah. This survey, called the Residential Choice Stated Preference survey, asked respondents to make ten choice comparisons between two hypothetical homes. Each home in the choice comparison was described by different attributes, those attributes that were used are, type of neighborhood, distance from …


Assessing Amendment Treatments For Sodic Soil Reclamation In Arid Land Environments, Sandra Udy Dec 2019

Assessing Amendment Treatments For Sodic Soil Reclamation In Arid Land Environments, Sandra Udy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plugged and abandoned well pads throughout the Uintah Basin face reclamation challenges due to factors including a harsh climate, invasive species, and high salt loads. Finding ways to alleviate soil sodicity could improve soil reclamation success. Gypsum, sulfur, activated carbon, and Biochar are being applied to improve soil parameters negatively impacted by sodicity, but the direct impact of these amendments on Uintah Basin soils is still largely unknown. The aim of this study was two-fold. (1) Evaluate the effectiveness of gypsum, sulfuric acid, Biochar, activated carbon, and combinations of these amendments in reducing the impact of soil sodicity of the …


Implementation And Effects Of University College Algebra Growth Mindset Structured Assessments In Large Lectures, Hannah Mae Lewis Dec 2019

Implementation And Effects Of University College Algebra Growth Mindset Structured Assessments In Large Lectures, Hannah Mae Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent scientific evidence shows the incredible potential of the brain to grow and change. Students with a growth mindset view errors and obstacles as opportunities for growth. These students welcome challenges and the opportunity to learn from their mistakes. Although some university instructors are incorporating growth mindset into their lectures, attitudes, and exams in small classes, the traditional exam method used in large lecture undergraduate mathematics classrooms follows a fixed mindset model. The growth mindset structured assessments developed for this study incorporate a testing center portion (matching, short answer, fill in the blank and free response) with structured rework opportunities, …


Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard Dec 2019

Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historically wildfires have been beneficial to forests, however, human developments have encroached on forests when wildfire was artificially suppressed by federal and state agencies. The area burned by wildfire each year has increased twenty-fold in the past three decades. Large, high severity fires pose increased threats to human and aquatic communities within and downstream of the burned area due to post-wildfire effects on flooding and sedimentation. We need to understand the impacts of wildfires to be able to mitigate their damages and to recognize their potential benefits. This research addresses the questions: 1) Do wildfires impact rural and urban economies …


A Model Explaining Medusahead Invasion And Novel Targeted Grazing Approaches Of Control, Casey N. Spackman Dec 2019

A Model Explaining Medusahead Invasion And Novel Targeted Grazing Approaches Of Control, Casey N. Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is currently one of the biggest threats to rangelands and livestock operations in the Western US. High silica concentrations in medusahead contribute to its invasiveness. I developed a model to explain how silica is involved in the invasion process, and attempted to manipulate silica to increase use of the grass by livestock. Experiments were conducted to determine: 1) whether rotational grazing on established forages of improved nutritional quality would provide supplemental nutrients to increase cattle use of medusahead; 2) evaluate intake of and preference for medusahead treated with a glyphosate herbicide at different rates …