Digital Commons Network^™

Teaching Agroecology Through Play: A Board Game On Companion Planting Using Agroecological Principles, Ashmita Das, Julie Capito-Hernandez, Estelí Jiménez-Soto

School of Geosciences Faculty and Staff Publications

Board games themed around environmental topics are promising tools for promoting awareness of complex sustainability issues, as the materiality, sociality, and multidimensionality of gameplay can help overcome some of the inherent limitations of more traditional learning formats. To explore the potential relevance of board games for communicating about agrifood system topics in particular, we designed and tested a game called Companion: An Agroecological Adventure, in which players take on the role of community gardeners who must apply both social and ecological principles of agroecology to cultivate a thriving garden plot. In this paper, we present the results of a study …

Food Sovereignty Among Migrant Farmworkers: The Role Of Agrobiodiversity For Autonomy And Resistance In A Mexican Coffee Plantation, Estelí Jiménez-Soto, Sanya Cowal, April Lopez

School of Geosciences Faculty and Staff Publications

Coffee agroecosystems represent the economic base for thousands of small growers and agricultural workers, as well as a significant proportion of many regional economies in Latin America. Every year, the production of coffee in this region attracts a great number of laborers and their families, particularly during the harvest season. Despite being essential workers in the food system, agricultural workers continue to be one of the most marginalized actors in the coffee production chain. Even with an environment of precarity, agricultural workers exercise their autonomy and food sovereignty—the process by which agricultural workers, in this case, define their food system …

Evaluating Annual Precipitation Extremes In The Us Great Plains Using Prism Data, Sumiaya Amin Preota, Gaurav Talukdar, Sam Zipper

School of Earth, Environmental, & Marine Sciences Faculty Publications

Understanding hydroclimatic extremes in the U.S. Great Plains (USGP) is crucial for effective water resource management, resiliency of agricultural systems, and mitigation of climate change impacts. This study examines changing hydroclimatic conditions in the USGP, with a focus on annual-resolution precipitation trends and extremes over the past 119 years (1904–2022) using precipitation data from the gridded PRISM climate dataset. We categorized annual-scale precipitation totals into six categories of hydroclimatic extremes: (1) isolated wet extremes, (2) isolated dry extremes, (3) dry-to-dry recurring extremes, (4) wet-to-wet recurring extremes, (5) dry-to-wet whiplash extremes, and (6) wet-to-dry whiplash extremes. “Recurring” and “whiplash” are both …

Nesting Population Trend Of The Leatherback Sea Turtle In Bocas Del Toro Province And Comarca Ngäbe-Buglé, Panama For The Period 2002–2022, Sonia Gutiérrez Parejo, Susan E. Piacenza, Raúl García, Cristina Ordóñez, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Sea turtle biologists have made sustained efforts to understand the global status of leatherback sea turtle populations. However, despite progress in assessments, demographics, and ecology, key uncertainties persist in tracking leatherback population trends. Trend analyses have historically focused on nesting beaches, with nest counts providing a widely used index for population abundance. Here, we analysed 20 years of annual nest abundance at four main nesting beaches (Soropta, Bluff, Playa Larga and Chiriquí) in Bocas del Toro province and the Comarca Ngäbe-Buglé, Panama, which constitute the largest nesting leatherback sea turtle population in Central America. We conducted daily nest counts during …

Dataset On Indoor And Outdoor Pm2.5 Concentrations At Two Residences Using Low-Cost Sensors In The Rio Grande Valley Region Of South Texas, Kabir Bahadur Shah, Sai Deepak Pinakana, Mkhitar A. Hobosyan, Armando Montes, Amit U. Raysoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Fine particulate matter (PM2.5) is one of the criteria air pollutants associated with adverse respiratory and cardiovascular health effects. This dataset contains hourly and daily averaged measurements of PM2.5 concentrations (µg/m3) collected from two residential homes in the Rio Grande Valley (RGV) Region of South Texas, using PurpleAir-II-SD low-cost sensor. In addition, the dataset also includes temperature (ºC) and relative humidity (%) measured by the sensors. The data was collected for one month during the summer season from indoor (kitchen) and outdoor (front yard) environments at two locations: Home-1 in Weslaco City from June 16, 2024, to July 16, 2024, …

Stream Response To A Dam Removal: Mill Creek, Davenport, Ca, Jessica J. Williamson

Master's Theses

Dams have many effects on stream morphology and ecology, including a loss of sediment supply downstream, reduced access to the entire stream for aquatic fauna, and a flooded area upstream of the dam. Dams are a hurdle for migrating organisms such as anadromous fish, which is a group of concern. An over 100-year-old dam on Mill Creek, a stream draining a coastal watershed in central California, was removed in the fall of 2021. The site is in the Santa Cruz Mountains, where endangered salmonids such as steelhead, Oncorhynchus mykiss, have historically lived. To study the change in the stream from …

When Emotions Flare: Solar Rhythms, Emotions And Cycles Of Political Revolution, Andreas Hernandez, Carolina Zilli Vieira, Alexandra Smith, Rebecca Olson

Geography and Environmental Studies Faculty Publications

Revolutions are among the most transformative events in human history. Analyzing 395 revolutionary episodes from 1900 to 2014, we find that major waves cluster around solar maxima - periods of intensified geomagnetic activity. Drawing on biomedical research linking geomagnetic disturbances to cardiovascular and stress regulation, and thus to emotional states, we propose that solar cycles modulate the affective ecologies within which revolutions arise. Solar activity may accelerate, shape, and amplify revolutionary cycles by heightening emotional climates and tipping fragile systems toward mass mobilization. This reframes revolutions as planetary events - entanglements of political conflict, embodied emotion, and cosmic …

Geochronology And Geomorphology Of The Brule Spillway Of Glacial Lake Duluth, Madeline Josephine Laaksonen

All Graduate Theses, Dissertations, and Other Capstone Projects

During the Late Pleistocene and Early Holocene, a series of dyssynchronous advances and retreats resulted in the evolution of the Upper St. Croix River Valley. Proglacial lakes forming at the margins of the retreating ice within the Lake Superior Basin and subsequent multiple drainage events through the Brule Spillway have also drastically shaped the landscape. As a result, the Brule Spillway and broader St. Croix River valley presents an important case study to spillover processes occurring in proglacial landscapes and the reorganization of regional drainage networks and creation of a new hydrogeomorphic regime. While prior literature on the Spillway exists, …

Advancing The Characterization Of Geophysical Signals Through Array Processing And Artificial Intelligence, Miro Ronac Giannone

Earth Sciences Theses and Dissertations

In geophysics, seismic and infrasound observations are routinely employed to constrain the nature and origin of events. Seismoacoustics, as a discipline, is built upon the simultaneous detection and integrated analysis of these data types. This joint approach is critical not only for advancing scientific understanding but also for supporting global monitoring efforts in hazard mitigation and nuclear explosion treaty verification. The data analyzed in this dissertation were recorded by array deployments, which consist of multiple sensors arranged in predetermined configurations to enhance signal detection, resolve directionality, and quantify waveform coherence. Leveraging these array recordings, I introduce novel approaches which combine …

The Signal Of Airplane Combustion In Soil At A Small Airport In Ohio, Rachel Engels

Williams Honors College, Honors Research Projects

Leaded gas has been banned for automobile use in the interest of public health since 1996. However, leaded gas is still used for small piston aircraft so the engine can run safely. To investigate potential environmental impacts of leaded gas, 90 soil samples were taken from around a small airport in Ohio. Soil elemental composition was measured by X-ray fluorescence (XRF), soil organic content determined by Loss-on-Ignition (LOI), and soil ferrimagnetic content measured by magnetic susceptibility. There is an unmistakable airplane fuel combustion signal in the soil at the ends of the runway, where aircraft wait to take off on …

Insights On The Cranial Anatomy And Osteohistology Of Cyonosaurus, Alexander Acker

Dissertations

This study investigates the cranial anatomy and life history of the small-bodied gorgonopsian Cyonosaurus. Previous research on gorgonopsians has disproportionately focused on larger members of the clade, leaving smaller forms relatively understudied. This gap has led to several unresolved questions, the most pressing of which concerns gorgonopsian ontogeny. Specifically, it remains unclear whether small-bodied gorgonopsians represent genuinely diminutive adult individuals or juveniles of larger species. The specimen NHCC LB1087 presents an ideal opportunity to address this issue and gain new insights into the biology of small-bodied gorgonopsians. The first chapter focuses on cranial anatomy. Due to the specimen’s preservation, many …

Fiber Optic Distributed Acoustic Sensing For Surface Wave Inversion In Terrestrial And Marine Environments, Constantine Coclin

Open Access Master's Theses

The use of distributed acoustic sensing (DAS) has gained popularity for a variety of seismic sensing applications due to its capability to sense broadband frequency ranges on spatial scales unattainable with conventional point sensors. The ability to sense and characterize vibrational surface waves in the near-surface can provide valuable information about the subsurface structure of an environment. The objective of this study is to evaluate the use of DAS to sense surface wave propagation for the multi-channel analysis of surface waves (MASW) methodology, such that a sub-surface shear wave velocity profile can be obtained in both a terrestrial and near-shore …

Investigation Of Dynamic Adsorption And Desorption Of Polymer Nanogel In Porous Media Through Microfluidics, Junchen Liu, Fuqiao Bai, Abdulaziz A. Almakimi, Mingzhen Wei, Xiaoming He, Ibnelwaleed A. Hussein, Baojun Bai

Mathematics and Statistics Faculty Research & Creative Works

Understanding the transport and retention of elastic nanogel and microgel particles in porous media has been a significant research subject for decades, essential to the application of enhanced oil recovery (EOR). However, a lack of dynamic adsorption and desorption studies, in which the kinetics in porous media are seldom investigated, hinders the design and application of polymer nanogel in underground porous media. In this work, we visualized and quantified the transport and dynamic adsorption of polymer nanogel in 3D glass micromodels that were manufactured by packing glass beads in capillaries. Calibrating the linearity of fluorescence intensity to concentration, we calculated …

Controls On Longitudinal Stream Profile Evolution In Guadalupe Mountains National Park, Samuel Schoenmann, Lisa Tranel, Eric W. Peterson, Jonathan Boyd Thayn

Faculty Publications - Geography, Geology, and the Environment

Canyons in Guadalupe Mountains National Park are excellent locations to study the discrete boundary conditions that influence longitudinal channel profile evolution including climate, tectonics, hydrology, and lithology. The Guadalupe Mountain landscape records deep earth mantle processes in combination with surficial channel erosion and incision. Knickpoints and convex segments in longitudinal river profiles document impacts of climate change, tectonics, or surface processes. This study combines field observations with an analysis of longitudinal profile slopes and residual errors to evaluate how bedrock strength can be distinguished from features created by climate change, faulting, or subsidence in Pine Springs and McKittrick Canyons within …

A Unionid Mussel Biodiversity Hotspot Experiencing Unexplained Declines: Evaluating The Influence Of Chemical Stressors Using Caged Juveniles, W. Aaron Wilson, Christine Bergeron, Jennifer Archambault, Jason M. Unrine, Jess Jones, Braven Beaty, Damian Shea, Peter R. Lazaro, Jody L. Callihan, Jennifer J. Rogers

Plant and Soil Sciences Faculty Publications

Unionid mussel populations in a section of the Clinch River in Virginia, USA, has declined substantially, but the causes of the decline remain unknown. To investigate this zone of decline (ZOD), we deployed juvenile freshwater mussels (Villosa iris in 2012 and Lampsilis fasciola in 2013) in both cages and silos at sites within the Clinch River System. We analyzed mussel tissues for trace element and organic contaminant concentrations, shells for trace elements, and environmental media (total water, dissolved water, particulate sediment, and bedload sediment) for both inorganic and organic contaminants. We found a few differences between mussels deployed in cages …

Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas

Physics Dissertations - Archive

Earth’s magnetosheath is a region of shocked plasma that mediates energy and momentum transfer from the solar wind to the magnetosphere. The dynamics and thus the plasma structures of this region are highly dependent on upstream solar wind conditions. As such, the region is often characterized as a turbulent environment, with the most intense periods of turbulence occurring often under quasi-parallel bow shock conditions. This magnetosheath turbulence displays as variable and large-scale fluctuations with in-situ measurements. Given that turbulence is a characteristic feature of the magnetosheath, this dissertation asks two questions: (1) How are plasma structures inside the sheath affected …

Quantifying So₂ Emissions From Explosive Events Of The 2021 La Soufrière Eruption Using Dscovr/Epic, Yuxi Jin

Dissertations, Master's Theses and Master's Reports

Volcanic eruptions release large quantities of gases, including sulfur dioxide (SO₂), aerosol precursors, and ash into the atmosphere. Quantifying the emission fluxes and temporal variability of SO₂ is crucial for understanding volcanic processes and assessing their impacts on air quality, climate, and aviation safety. Episodic vulcanian to sub-Plinian explosive eruptions are a common feature of many arc volcanoes, but the underlying causes of such episodic behavior remain poorly understood. The 2021 La Soufrière eruption (St. Vincent) featured up to 40 discrete eruptive events between April 9 and April 22, presenting a rare opportunity to analyze time-resolved volcanic SO₂ emissions during …

Growth, Survival, And Herbivore Browsing Preferences Of Seedlings Planted In Black Ash Stands Of Northern Michigan And Wisconsin, Seth W. Davenport

Dissertations, Master's Theses and Master's Reports

To mitigate the cascading ecosystem impacts of widespread black ash (Fraxinus nigra) mortality due to the invasive emerald ash borer (Agrilus planipennis), forested wetlands can be underplanted with seedlings of alternative species that later repopulate the vacated canopy. This study examined the survival and growth, factors influencing performance, and herbivore browsing preferences of seven non-ash species planted in northern Michigan and Wisconsin. The best performing species were river birch (Betula nigra), silver maple (Acer saccharinum), and swamp white oak (Quercus bicolor). The worst performing species was black spruce (Picea …

Comprehensive Analysis Of Krauklis Waves And Long Period Seismic Events In Fluid-Filled Fractures Via Integrated Physical And Numerical Modeling, Sananda Ray

Dissertations, Master's Theses and Master's Reports

Long-period (LP) seismic events, commonly recorded in volcanic and hydrothermal environments, are widely attributed to the resonance of fluid-filled fractures and the excitation of Krauklis waves along the solid-fluid interface. These low-velocity, dispersive waves are sensitive to both fluid dynamics and fracture geometry, offering critical insights into subsurface fluid transport, fracture evolution, and seismic source processes. Despite robust theoretical treatments, experimental validation under realistic geological conditions has remained limited. To address this, I aimed to develop a series of laboratory-based experimental models that systematically investigate the key physical mechanisms driving LP signal generation. In the first set of experiments, I …

The Serendipity Of Discovery: Life Of A Geochemist, Willard S. Moore

Faculty Publications

My strategy for writing this autobiography is to use examples of how working on seemingly different projects can often lead to outcomes more important than originally envisioned. Serendipity is a "happy accident"; specifically, the accident of discovering something useful without directly looking for it. This often occurs when two research projects converge unexpectedly. The main text contains examples of how serendipity has led me to important discoveries including: (a) finding surprisingly high ²²⁸Ra activities in the ocean, (b) developing a means of rapidly and quantitatively extracting radium from seawater, (c) devising a rapid, sensitive method of measuring ²²⁴Ra …

The Tyrant King Of The Auction House: The Disastrous “Fine Artification” Of The Dinosaur, Amelia C. Kolstad

Anthós

This article examines how fine art auctioneers market dinosaur fossils as art pieces to wealthy collectors, depriving the paleontological field of specimens for scientific research. Drawing from recent examples of fossils sold at fine art auctions, this article notes how rising auction prices for specimens as ‘art’ prevent museums and research institutions from acquiring specimens for research and restoration. Kolstad concludes that the art auction houses’ marketing of fossils as art is detrimental to paleontological research. To protect fossils and their scientific value, Kolstad proposes alternatives, such as selling replicas to collectors and highlighting the importance of original specimens for …

Conservation And Survey Division 2024 Annual Report, R.M. Joeckel, Michele Waszgis

Conservation and Survey Division: Faculty and Staff Publications

The Conservation and Survey Division of the University of Nebraska - Lincoln is the agency designated by statute to investigate and interpret the geologically related natural resources of the State, to make available to the public the results of these investigations, and to assist in the development and conservation of these resources. It consists of program areas in geology, water, soils and remote sensing-geographic information systems.

Cover Crops Can Reduce Greenhouse Gas Emissions From No-Till Maize In Southern Brazil: Insights From A Long-Term Field Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimélio Bayer

Adam Liska Papers

Brazil is one of the countries that has the most agricultural area under no-till (NT) management. This research study aims to evaluate life-cycle greenhouse gas (GHG) emissions from maize (M) grain production in agroecosystems that used different cover crops under NT management in southern Brazil. The data for this study were from a long-term 41-year field experiment in southern Brazil. The long-term experiment evaluated the effects of fallow (F) and cover crops (oat (O), vetch (V), cowpea (B), pigeon pea (P), and lablab (L)) on nitrous oxide and methane emissions and soil carbon (C) sequestration in maize agroecosystems. Five cropping …

Advancing Root Trait Measurements For A Deeper Understanding Of Soil Biogeochemistry, Brian Rinehart

Theses and Dissertations--Plant and Soil Sciences

Climate change is disrupting (agro)ecosystems, with the potential for significant losses in crop productivity and ecosystem resilience due to changes in water and biogeochemical cycling. These disruptions can also release more carbon dioxide into the atmosphere through the degradation of soil organic matter. Plant roots have emerged as a potential tool for mitigating these effects, given their roles in plant function and in driving soil biogeochemistry. While this interest is growing, our ability to implement root trait selection is limited due to constraints on characterizing roots and limited clarity on the effects of traits on plant and ecosystem function. My …

Giving Props To Soil Property Predictive Models: Utilizing Mir To Predict Soil Health Properties, Diala M. Abboud

Theses and Dissertations--Plant and Soil Sciences

Soil health is critical to sustaining life on Earth, influencing plant growth, agricultural productivity, water quality, and overall ecosystem sustainability. In response to climate change and intensifying land use, the need to improve our understanding of soil health has become increasingly urgent. The application of mid-infrared (MIR) spectroscopy coupled with statistical modeling has emerged as a promising, cost-effective approach to predict soil health parameters, offering a quicker alternative to traditional wet chemistry analyses. MIR methods have been successfully applied to predict various soil health properties, such as bulk density (BD), cation exchange capacity (CEC), base saturation (BS), electrical conductivity (EC), …

Evidence For Crustal Brines And Deep Fluid Infiltration In An Oceanic Transform Fault, Christine Chesley, Katherine Enright

All Student Scholarship

Although oceanic transform faults (OTFs) are ubiquitous plate boundaries, the geological processes occurring along these systems remain underexplored. The Gofar OTF of the East Pacific Rise has gained attention due to its predictable, yet enigmatic, earthquake cycle. Here, we present results from the first ever controlled-source electromagnetic survey of an OTF, which sampled Gofar. We find that the fault is characterized by a subvertical conductor, which extends into the lower crust and thus implies deep fluid penetration. We also image subhorizontal crustal conductors distributed asymmetrically about the fault. We interpret these subhorizontal anomalies as crustal brines, and we suggest that …

Integrating Satellite-Based Precipitation Analysis: A Case Study In Norfolk, Virginia, Imiya M. Chathuranika, Dalya Ismael

Engineering Technology Faculty Publications

In many developing cities, the scarcity of adequate observed precipitation stations, due to constraints such as limited space, urban growth, and maintenance challenges, compromises data reliability. This study explores the use of satellite-based precipitation products (SbPPs) as a solution to supplement missing data over the long term, thereby enabling more accurate environmental analysis and decision-making. Specifically, the effectiveness of SbPPs in Norfolk, Virginia, is assessed by comparing them with observed precipitation data from Norfolk International Airport (NIA) using common bias adjustment methods. The study applies three different methods to correct biases caused by sensor limitations and calibration discrepancies and then …

Using Trace Gas Measurements As A Transport Diagnostic For Tropical Convection: A Combined Model And Observation Study, Albane Hoxha

Dissertations and Theses

No abstract provided.

Spatiotemporal Evolution Of Surface Water Quality And Driving Factors Across Varying Levels Of Human Interference In A Major Subbasin Of The Yellow River Basin, China, Longmei Xie, Ruizhong Gao, Xixi Wang, Limin Duan, Lijing Fang, Hui Tong, Chang Yue, Tingxi Liu

Civil & Environmental Engineering Faculty Publications

Study region

The Dahei River Basin, a sub-basin of the Yellow River Basin, was selected for this study. Encompassing population centers and villages in Inner Mongolia, it supports vital ecosystems and underscores the need to address its unique challenges in water management and protection.

Study focus

This study examines surface water quality dynamics in the Dahei River Basin, a key aspect of sustainable water management. Predicting spatiotemporal variations and driving factors remains challenging. Using 2013–2023 datasets on water quality, hydrology, and meteorology, the composite pollution index (CPI), ANOVA, and generalized additive models were applied to provide insights for effective management. …

Revealing Rainfall Partitioning Characteristics Of Shrubs In Semi-Arid Sandy Land: Based On In-Situ Measurement Data, Hu Liu, Limin Duan, Yongzhi Bao, Xin Tong, Huimin Lei, Zhiming Han, Wenrui Zhang, Xixi Wang, V. P. Singh, Tingxi Liu

Civil & Environmental Engineering Faculty Publications

Rainfall is partitioned by the vegetation canopy into three components: throughfall, stemflow, and canopy interception, which profoundly influence key hydrological processes, including vegetation growth, groundwater recharge, water cycling, and regional water balance. However, research comparing the applicability of throughfall measurement methods in semi-arid shrub communities remains scarce, and quantitative analyses of rainfall partitioning processes based on in-situ observations are still inadequate. This study focuses on the sand-fixing pioneer vegetation of semi-arid sandy land, Caragana microphylla, and conducts simultaneous throughfall measurements using the rain gauge method and the trough method to compare the differences between the two approaches. Based on …