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Full-Text Articles in Earth Sciences

A Conceptual Model Evaluation Framework For Adaptive Governance And Adaptive Management In Large-Scale Restoration Programs, Chadwin Smith Dec 2020

A Conceptual Model Evaluation Framework For Adaptive Governance And Adaptive Management In Large-Scale Restoration Programs, Chadwin Smith

School of Natural Resources: Dissertations, Theses, and Student Research

Adaptive management (AM) has become a kind of plastic phrase applied as a formulaic panacea for most major species recovery and ecosystem restoration efforts now underway across the United States. AM emerged as an application of the scientific method to resource management, closely tying management to science learning through experimental actions. The phrase “learning by doing” best captures the premise behind developing an experimental management approach that could be applied on the larger scale of a river system or ecosystem. In nearly five decades of application, however, examples of successful AM implementation at large scales are few and conflict remains …


Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier Dec 2020

Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier

School of Natural Resources: Dissertations, Theses, and Student Research

Modification of natural prairie grasslands into irrigated and rainfed agriculture in the Great Plains produced significant impacts on regional weather and climate including temperatures, precipitation, energy fluxes, and the planetary boundary layer (PBL) atmosphere. The Great Plains Irrigation Experiment (GRAINEX) during the 2018 growing season collected data over irrigated and non-irrigated crop fields to further understand these impacts. The data were collected during two intensive observation periods (IOPs) in early June (IOP 1: 30 May – 13 June of 2018) and late July (IOP 2: 16 July – 30 July of 2018). The data analyzed include latent (LE) and sensible …


Population Demographics, Distribution, And Environmental History Of Asian Carp In A Great Plains River, Jake Werner Dec 2020

Population Demographics, Distribution, And Environmental History Of Asian Carp In A Great Plains River, Jake Werner

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix, Bighead Carp H. nobilis, and Black Carp Mylopharyngodon piceus, collectively known as Asian carp, are a group of invasive fishes in the U.S.A. that have garnered much attention over the last couple decades. Most research devoted to this group of fishes has been focused in the Mississippi River basin with little investigation in the Missouri River drainage, particularly in tributary systems. The Kansas River is a major tributary to the Missouri River that has multiple anthropogenic barriers creating varying levels of connectivity within the Kansas River itself, and with the Missouri River. Information …


Use Of Citizen Science In Monitoring Groundwater Quality: A Case Study From Nebraska, Christopher Olson Aug 2020

Use Of Citizen Science In Monitoring Groundwater Quality: A Case Study From Nebraska, Christopher Olson

School of Natural Resources: Dissertations, Theses, and Student Research

Citizen science has a key role in modernizing effective communication between professional scientists and the general public. However, citizen science differs to that of professional science due to equipment and experience and is a topic argued against citizen science. However, technology in water quality testing has developed in simplicity and affordability to a point where high school students, with hands-on training, can collect groundwater samples and test for quality themselves. Nebraska groundwater quality is a critical part of the state and can utilize high school students as citizen scientists for their communities. High school students from rural communities across Nebraska …


Nitrate Dynamics And Source Within Nested Watersheds Of An Agricultural Stream, Nebraska, Usa, Galen Richards Aug 2020

Nitrate Dynamics And Source Within Nested Watersheds Of An Agricultural Stream, Nebraska, Usa, Galen Richards

School of Natural Resources: Dissertations, Theses, and Student Research

Nitrate concentrations have been increasing throughout the globe, primarily due to heightened agricultural activity. Nitrate concentrations in Bazile Creek, located in Northeastern Nebraska, have been steadily rising since the early 2000s. Groundwater nitrate concentrations within the Bazile Creek watershed are high (> 10 mg/L nitrate-N), and there is strong connectivity between groundwater and surface water systems. This study aimed to better understand temporal nitrate concentration variability within the watershed through sampling tributaries and the main channel during baseflow conditions. Nitrate source was also investigated though the use of dual δ15N and δ18O nitrate isotopes, with samples …


Using Return Intervals And Nutrient Spiraling To Examine The 2019 Nebraska Flood, Alexa Davis Jul 2020

Using Return Intervals And Nutrient Spiraling To Examine The 2019 Nebraska Flood, Alexa Davis

School of Natural Resources: Dissertations, Theses, and Student Research

In March of 2019, flooding levels in many parts of Nebraska was the worst that streams and rivers had in decades, and in some locations, on record. Theses historic floods present an optimal case study to examine how current technological resources can be used to enhance our understanding of floods and how these floods impact in situ stream ecosystem processes like nitrogen and phosphorus cycling. Currently, there are only a few resources available to quantify the extent of floods; for my thesis, I will focus on satellite imagery and in situ water level gages. Unfortunately, due to technical issues with …


Geoscience Education Research: Trends And Applications In Undergraduate Courses, Diane Lally May 2020

Geoscience Education Research: Trends And Applications In Undergraduate Courses, Diane Lally

School of Natural Resources: Dissertations, Theses, and Student Research

Water resources are progressively under pressure from anthropogenic uses. Students need to learn about water systems as they are the future decision-makers and problem solvers who will be faced with unknown challenges in the future. The overarching goals of this dissertation were: 1) to identify ways in which geoscience instructors are incorporating systems thinking and science modeling in their teaching along with the accompanying methods for improving systems thinking and modeling implementation and 2) explore how the implementation of science modeling and systems thinking increase student evaluation of models and the understanding of hydrologic content. Data for these studies came …


Charismatic Predators In Modern Africa: Spotted Hyena (Crocuta Crocuta) And Human Coexistence In The Northern Tuli Game Reserve, Botswana, Jazmin Castillo May 2020

Charismatic Predators In Modern Africa: Spotted Hyena (Crocuta Crocuta) And Human Coexistence In The Northern Tuli Game Reserve, Botswana, Jazmin Castillo

School of Natural Resources: Dissertations, Theses, and Student Research

Increasing human populations has led researchers to investigate the impacts of high human population density and its impact on carnivore populations. Spotted hyenas (Crocuta crocuta) hold a unique place in African ecosystems due to being a very successful top predator with an adaptable diet whereas other top predators, like the African lion, are rapidly decreasing in abundance. We investigated past and current spotted hyena abundance within the Northern Tuli Game Reserve to better aid in wildlife management. Spotted hyenas showed no significant difference in the change in population abundance throughout the different years of the study (2008-2016). Spotted …


The Effects Of Temperature On Evacuation Rates And Absorption Efficiency Of Flathead Catfish, Zach Horstman Apr 2020

The Effects Of Temperature On Evacuation Rates And Absorption Efficiency Of Flathead Catfish, Zach Horstman

School of Natural Resources: Dissertations, Theses, and Student Research

Knowledge of fish gastric evacuation rates are a necessary component for both field and laboratory studies when trying to understand feeding rates, modeling energy budgets, and understanding trophic dynamics of aquatic ecosystems. Many freshwater fish encounter a broad range of environmental temperatures across life history stages, but the mechanistic link between temperature and physiological processes often remains poorly understood. We designed three recirculating aquatic systems capable of rearing Flathead Catfish Plyodictis olivaris in order to quantify gastric evacuation rates and gross energy absorption at three temperatures (17º C, 22º C and 25º C). We examined the relationship between temperature and …


In Hot Water: Influence Of Multiple Stressors On Thermal Tolerance Of Fathead Minnows Pimephales Promelas, Alexander Engel Apr 2020

In Hot Water: Influence Of Multiple Stressors On Thermal Tolerance Of Fathead Minnows Pimephales Promelas, Alexander Engel

School of Natural Resources: Dissertations, Theses, and Student Research

Freshwater aquatic systems around the globe are often subjected to physical, biological, and chemical alterations to support societal needs. The Great Plains contains one of the largest agricultural industries in North America, but its productivity has ecological repercussions for adjacent freshwater ecosystems. Specifically, the dependency on surface water irrigation and application of chemical treatments has altered the thermal and chemical composition of freshwater ecosystems throughout the region. Stressors such as elevated temperatures, altered flow regimes, increased contaminant loads affect the physiology and behavior of fishes and can lead to long-term population effects. We examined thermal tolerance of Fathead minnows Pimephales …


Comprehensive And Agricultural Greenhouse Gas Emissions Inventories For Nebraska And The Midwest As Baselines For Climate Change Mitigation, Eric R. Holley Apr 2020

Comprehensive And Agricultural Greenhouse Gas Emissions Inventories For Nebraska And The Midwest As Baselines For Climate Change Mitigation, Eric R. Holley

School of Natural Resources: Dissertations, Theses, and Student Research

Climate change is the paramount challenge of today for a sustainable future. Mitigation of greenhouse gas (GHG) emissions is necessary to reduce the associated risks and impacts on society. Using the EPA’s SIT and literature review, comprehensive GHG-emissions inventories were developed for the state of Nebraska over 25 years (1990-2015) and agricultural GHG emissions inventories were developed for the Midwest U.S for one year (2016). Nebraska’s net emissions increased from 56.2 million metric tons of carbon dioxide equivalent (MMtCO2e) in 1990 to 87.4 MMtCO2e in 2016. Agriculture was found to be the sector with the most …


Impact Of Streambank Stabilization On Sediment Deposition And Erosion In Central Nebraska Streams, Matthew Russell Apr 2020

Impact Of Streambank Stabilization On Sediment Deposition And Erosion In Central Nebraska Streams, Matthew Russell

School of Natural Resources: Dissertations, Theses, and Student Research

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of these practices has been insufficiently monitored and assessed to date. Sound monitoring practices promote engineered effectiveness, in addition to allowing adjustments in implementation and maintenance to improve practices over time. However, current methods to quickly and efficiently quantify deposition and erosion within a stream continue to be costly and inefficient. Therefore, the objectives of this project were to 1) Measure streambank migration of three reaches at Cedar River in Nebraska, from 1993 to 2006 (pre-stabilization) and from 2006 to 2018 (post-stabilization) using aerial …


Exploring How Graduates Of The Nebraska Water Leaders Academy Influence Community Capitals: Two Case Studies, Dakota Staggs Apr 2020

Exploring How Graduates Of The Nebraska Water Leaders Academy Influence Community Capitals: Two Case Studies, Dakota Staggs

School of Natural Resources: Dissertations, Theses, and Student Research

Natural resources are foundational to any community and so leadership regarding those resources is a key factor to consider in order to understand communities. The vitality and strength of a community, however, is not solely dependent upon the natural resources available to it but depends on the collection of assets and individuals within it. This study sought to understand how individual leaders, graduates of the Nebraska Water Leaders Academy, influence each of the seven community capitals outlined by Flora, Flora, and Gasteyer (2016), and how their individual civic capacity, as defined by Sun and Anderson (2012), contribute to community capacity. …