Earth Sciences Commons^™

The Formation Of Glacier Dirt Cones, Ryan M. Strickland, Matthew D. Covington

Geosciences Faculty Publications and Presentations

Glacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. …

Enhancing Tree Species Mapping In Arkansas’ Forests Through Machine Learning And Satellite Data Fusion: A Google Earth Engine–Based Approach, Abdullah Al Saim, Mohamed Aly

Geosciences Faculty Publications and Presentations

Arkansas' subtropical climate nurtures extensive forested regions, particularly within the Ozark-St. Francis and Ouachita National Forests. Despite this, the state lacks an up-to-date high-resolution map detailing the distribution of tree species within its forests. This study harnesses the power of machine learning, specifically the Random Forest (RF), Gradient Tree Boosting (GTB), Support Vector Machine (SVM), and K-Nearest Neighbors (K-NN) classifiers, within the Google Earth Engine (GEE) framework. These classifiers are applied to classify tree species distribution in Arkansas' forests by integrating data from various sources, including Sentinel-1/-2, Landsat-8, and the National Agriculture Imagery Program (NAIP). The study evaluates the classification …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2024, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams

Entomology and Plant Pathology Faculty Publications and Presentations

Abstract

The scale and scope of comparative trait data are expanding at unprecedented rates, and recent advances in evolutionary modeling and simulation sometimes struggle to match this pace. Well-organized and flexible applications for conducting large-scale simulations of evolution hold promise in this context for understanding models and more so our ability to confidently estimate them with real trait data sampled from nature. Results

We introduce TraitTrainR, an R package designed to facilitate efficient, large-scale simulations under complex models of continuous trait evolution. TraitTrainR employs several output formats, supports popular trait data transformations, accommodates multi-trait evolution, and exhibits flexibility …

Evaluation Of Industrial Hemp Cultivar And Biochar Rate To Remediate Heavy-Metal-Contaminated Soil From The Tar Creek Superfund Site, Usa, Dietrich V. Thurston, Kristofor R. Brye, David M. Miller, Philip A. Moore Jr., Donald M. Johnson, Mike Richardson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Soil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek superfund site in northeast Oklahoma, United States, remains a threat to the environment and local ecosystem. Phytoremediation with industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), biochar rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- (AG) and belowground dry matter …

Rice Response To Struvite And Other Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye, Diego Della Lunga, Kristofor R. Brye

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH₄PO₄⋅6H₂O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was …

Carbon Dioxide Dynamics In The Carbonate Critical Zone, Savoy Experimental Watershed, Arkansas, Usa, Michael Darvin Jones

Graduate Theses and Dissertations

The dynamics of carbon dioxide (CO₂) within the Earth’s critical zone (CZ) are essential for driving spatial and temporal variations of carbonate dissolution and precipitation, which are fundamental to subsurface porosity and permeability development. However, there is still a significant knowledge gap regarding the patterns of CO₂ transport and production within the carbonate critical zone (CCZ). In this study, we investigated these dynamics within a mantled karst terrain at the Savoy Experimental Watershed (SEW) in Northwest Arkansas.

Previous monitoring of partial pressure of CO₂ (PCO₂) and dissolution rates at karst springs in …

Early Season Wheat Response To Electrochemically Precipitated Struvite In Various Soils In The Greenhouse, Tatum Simms, Kristofor R. Brye, Trenton L. Roberts, Lauren F. Greenlee

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Fertilizer-phosphorus (P) materials can be recovered from wastewater and used to supplement mined phosphate rock, where one such material is struvite [MgNH4PO4·6(H2O)]. This study aimed to compare electrochemically precipitated struvite (ECST) reclaimed from synthetic wastewater to other commercial fertilizer-P sources in cultivated soils from Arkansas [silty clay loam (AR-SiCL) and silt loam (AR-SiL)], Missouri [(silt loam; MO-SiL 1 and 2)], and Nebraska [silt loam (NE-SiL) and sandy loam (NE-SL)]. A greenhouse pot study was conducted for 60 days with unvernalized wheat (Triticum aestivum) using five fertilizer-P sources [ECST, chemically precipitated struvite (CPST), monoammonium phosphate (MAP), triple superphosphate (TSP), …

Peri-Gondwanan Sediment In The Arkoma Basin Derived From The North: The Detrital Zircon Record Of A Uniquely Concentrated Non-Laurentian Source Signal In The Late Paleozoic, Tyson M. Smith, Marieke Deshesne, Jaime A.M. Hirtz, Glenn R. Sharman, Mark R. Hudson, Brandon M. Lutz, Neil Griffis

Geosciences Faculty Publications and Presentations

During the assembly of Pangea, peri-Gondwanan terranes collided with the eastern and southern margins of Laurentia and brought with them unique detrital zircon U-Pb signatures. Discriminating between individual peri-Gondwanan terranes in the detrital record is difficult due to their similar geologic histories. However, characterization of this provenance is critical for understanding late Paleozoic sediment routing during development of Pangea. Along southeastern Laurentia, in the Arkoma Basin (present-day Arkansas and eastern Oklahoma, southeastern United States), we identified Middle Pennsylvanian (Desmoinesian) strata that exhibit a concentrated peri-Gondwanan detrital zircon signature (e.g., ca. 800–550 Ma). Although several southern peri-Gondwanan terranes (e.g., Maya, Suwannee) …

Rock Wall Fracturing As A Potential Control On River Valley Width In The Buffalo National River, Arkansas, Kindle Hon

Graduate Theses and Dissertations

Quantifying bedrock properties that control the persistence of fallen rock material (talus) along bedrock walls bounding river valleys may be a key factor in understanding what controls the rate at which these river valleys widen. My work is a component of a collaborative research project focused on the overarching hypothesis that the persistence vs. erodibility of talus that buffers river valley walls can be a first-order control on valley widening rates. I hypothesize that the primary control for creating erodible or persistent talus is the fracture spacing of bedrock valley walls as it sets the maximum block size of collapsed …

Environments And Controls Of Erosional Bedforms In Soluble Channels, Ethan W. Oleson

Graduate Theses and Dissertations

Erosional bedforms, such as scallops, preserve valuable information on the paleohydrologic conditions forming soluble channels in karst systems. While these bedforms are commonly used to interpret past conditions, questions about their formation remain. Mathematical models of speleogenesis in turbulent flow predict that the conditions for forming scallops do not occur in natural carbonate systems. However, scallops are readily found in caves throughout the world. This conundrum has several possible resolutions, but each lacks field-based observations. We present a field-based study of the environments and controls of scallops in gypsum, limestone, and dolostone caves. Our results are based on field observation, …

Struvite Effects On Greenhouse Gas Emissions From Flood- And Furrow-Irrigated Rice In The Greenhouse, Chandler Arel

Graduate Theses and Dissertations

Over time, as the influences of climate-change and declining, mineable, global phosphorus (P) reserves begin to impact agricultural production systems, alternative fertilizer sources and management practices, such as struvite (MgNH₄PO₄ · 6H₂O) and furrow-irrigation, will be necessary to accommodate nutrient and water demands. The precipitation and use of struvite as a fertilizer-P source could reduce environmental damages caused by nutrient-rich wastewater streams, supplement domestic P supply, and improve the sustainability of flood-, and furrow-irrigated rice production by reducing greenhouse gas emissions. The study of struvite from both chemical and electrochemical precipitation processes is well documented, …

Cover-Crop Effects On Near-Surface Soil Properties Over Time In The Lower Mississippi River Valley, Cooper Fanning

Graduate Theses and Dissertations

Human population growth and climate change are present stressors that continue to put pressure on current agricultural production systems, where typical row-crop agricultural practices can negatively impact soil health. Extensive use of cover crops (CC) to increase soil health remains widely unrealized. Soil health in Arkansas is a major concern for sustaining agricultural output, therefore research into CC implementation across Arkansas to maintain or improve soil health is needed. The objective of this study was to evaluate the effects of CC (i.e., with and without CC) across various physical, hydraulic, biological, and chemical soil indicators in the Lower Mississippi River …

Controls On The Development Of Hummocky Topography On Debris-Covered Glaciers, Ryan M. Strickland

Graduate Theses and Dissertations

Rock debris covers many glaciers in Earth’s highest mountains and the debris impacts glacier response to changes in climate. Interactions between debris, drainage, glacier dynamics, and climate produce contrasts in melt rates that cause debris-covered glaciers to develop complex, hummocky topography. Contrasts in melt rate produce thousands of hills–hummocks–and depressions. Ponds and ice cliffs often form in the depressions. Although ponds and ice cliffs occupy only a small fraction of the surface, they account for nearly half of glacier melt. Understanding the processes that control the development of hummocky topography is key to predicting the evolution of debris-covered glaciers. In …

Arkansas Corn And Grain Sorghum Research Studies 2023, Jason Kelley, Travis Faske

Arkansas Agricultural Experiment Station Research Series

The 2023 edition of the Arkansas Corn and Grain Sorghum Research Studies Series includes research results on topics pertaining to corn and grain sorghum production, including weed, disease, and insect management; economics; irrigation; agronomics; soil fertility; mycotoxins; cover crop management; and research verification program results. Our objective is to capture and broadly distribute the results of research projects funded by the Arkansas Corn and Grain Sorghum Board. The intended audience includes producers and their advisors, current investigators, and future researchers. The Series serves as a citable archive of research results.

Perspectives On Modifiable Spatiotemporal Unit Problems In Remote Sensing Of Agriculture: Evaluating Rice Production In Vietnam And Tools For Analysis, Brad G. Peter, Joseph P. Messina, Victoria Breeze, Cadi Y. Fung, Abhinav Kapoor, Peilei Fan

Geosciences Faculty Publications and Presentations

Measuring agricultural productivity is a multiscale spatiotemporal problem that requires multiscale solutions. In Vietnam, rice comprises a substantial portion of the cultivated area and is a major export crop that supplies much of the global food system. Understanding the when and where of rice productivity is vital to addressing changes to yields and food security, yet descriptive summarizations will vary depending on the spatial or temporal scale of analysis. This paper explores rice trends across Vietnam over a 19-year period, giving specific attention to modifiable spatiotemporal unit problems by evaluating productivity across multiple time periods and administrative levels. A generalizable …

Diet Specialization Mediates Drivers Of Cucurbita Herbivory In A Semi-Arid Agroecosystem, Hannah L. Gray, Nicholas A. Ivers, Elizabeth Lopez, Brad G. Peter, Scott D. Longing, Magarita M. Lopez-Uribe, Shalene Jha

Geosciences Faculty Publications and Presentations

Herbivory is a major fitness pressure for plants and a key driver of crop losses in agroecosystems. Dense monocultures are expected to favor specialist herbivorous insects, particularly those who primarily consume crop species; yet, levels and types of herbivory are not uniform within regional cropping systems. It is essential to determine which local and regional ecological factors drive variation in herbivory in order to support functional agroecosystems that rely less on chemical inputs. Crops in the genus Cucurbita host a suite of both generalist and specialist herbivores that inflict significant damage, yet little is known about the relative contribution of …

Looking For The Oldest Diatoms, Karolina Brylka, Sylvain Richoz, Andrew J. Alverson, David J. Conley

Biological Sciences Faculty Publications and Presentations

Paleontological observations of ancient flora and fauna provide powerful insights into past diversity and relationship dynamics between organisms and their environments. Diatoms are globally distributed protists that influence major biogeochemical cycles and sustain oceanic food webs. The fossil diatom record extends 120 million years back to the Early Cretaceous where rare deposits were discovered worldwide and are occasionally represented by diverse communities. However scarce, the taxonomic richness and geographical spread of these diatom communities suggest prior evolutionary events and therefore earlier deposits. To complement the existing fossil information and to discover diatom deposits predating 120 Ma, we examined 33 study …

Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to rapidly decreasing rock phosphate reserves. Struvite can be generated via chemical and/or electrochemical precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice cultivar (Gemini 214, RiceTec) grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)] in a P-deficient silt …

Temporal Trends And Dental Metric Variation In The Macaca Sylvanus Lineage, Cristina Stan

Graduate Theses and Dissertations

The extensive collection of fossil macaques from Europe, spanning from the Late Miocene to the Late Pleistocene period, is believed to be of the species Macaca sylvanus. However, there has been a prolonged discussion regarding the classification of these specimens into a single taxonomic group as the existing dental sample exhibits a large amount of morphological and metric variation. Specifically, researchers have attempted to identify multiple subspecies based on chronological data of the paleontological locality and, secondly, based on dental metric variation. In this study, I assess temporal trends in the fossil record of Macaca sylvanus and compare overall variation …

Geochemical Analysis Of Basement Rock As A Potential Metal Source In Mississippi Valley-Type Ores, Southern Midcontinent U.S.A., Mackenzie Moorhead

Graduate Theses and Dissertations

Mississippi Valley-Type (MVT) ores are epigenetic, sedimentary hydrothermal base metal deposits that exist worldwide with type localities in the midcontinent United States. These Permian-aged sulfide ores represent an extraordinary concentration of economic metals, Pb and Zn. Ore deposits occur in vast districts that have a rich mining history. The Pb and Zn from these deposits account for 24% of worldwide reserves. The geologic processes responsible for MVT ore genesis are not fully understood, especially the sourcing of ore constituents. In the midcontinent, the Ouachita Orogeny expelled saline hydrothermal brines in response to high rates of subsidence. These fluids migrated through …

Determining The Climatic Effects Of The Central Atlantic Magmatic Province Across The End Triassic Mass Extinction In The Elliot Formation, Southern Africa, Danielle Elizabeth Oberg

Graduate Theses and Dissertations

Understanding the intricate relation between carbon-cycle perturbations, climate change, and biodiversity stability is crucial in the face of ongoing anthropogenic greenhouse-gas emissions. This thesis explores the impacts of rapid climate change induced by carbon-cycle perturbations and their potential repercussions on global climate. Large igneous provinces, particularly the Central Atlantic Magmatic Province, offer a lens through which to examine the nexus of volcanic activity, mass extinctions, and climate change. The emplacement of Central Atlantic Magmatic Province, covering vast regions across continents, emitted substantial amounts of carbon dioxide, profoundly impacting global climate and ecosystems. The end-Triassic Mass Extinction, attributed to Central Atlantic …

Geomorphic Analysis Of The Lower Arkansas River, Usa, Matthew Edwards

Graduate Theses and Dissertations

The Arkansas River is one of several large and important river systems stretching from the Rocky Mountains to the Mississippi River. It meanders across the Great Plains for ~1000 km before plunging into a mountain-bound valley, confined by the Ozarks to the north and Ouachitas to the south. The geologic history of the Arkansas River is poorly understood and crudely constrained to sometime between ~60 Ma and 100 Ka. Questions remain concerning its path(s), potential integration of the upper and lower sections, and overall history. The combination of knickpoint and chi (χ) mapping, tributary grain size analysis, tensile strength testing, …

Remote, Rugged Field Scenarios For Archaeology And The Field Sciences: Object Avoidance And 3d Flight Planning With Suas Photogrammetry, Carla Klehm, Malcolm D. Williamson, Leland C. Bement, Brandi Bethke

Center for Advanced Spatial Technologies Publications and Presentations

Advances built into recent sUASs (drones) offer a compelling possibility for field-based data collection in logistically challenging and GPS-denied environments. sUASs-based photogrammetry generates 3D models of features and landscapes, used extensively in archaeology as well as other field sciences. Until recently, navigation has been limited by the expertise of the pilot, as objects, like trees, and vertical or complex environments, such as cliffs, create significant risks to successful documentation. This article assesses sUASs’ capability for autonomous obstacle avoidance and 3D flight planning using data collection scenarios carried out in Black Mesa, Oklahoma. Imagery processed using commercial software confirmed that the …

An Examination Of Thematic Research, Development, And Trends In Remote Sensing Applied To Conservation Agriculture, Zobaer Ahmed, Aaron Shew, Lawton Nalley, Michael Popp, V. Steven Green, Kristofor Brye

Center for Advanced Spatial Technologies Publications and Presentations

Conservation agriculture seeks to reduce environmental degradation through sustainable management of agricultural land. Since the 1990s, agricultural research has been conducted using remote sensing technologies; however, few previous reviews have been conducted focused on different conservation management practices. Most of the previous literature has focused on the application of remote sensing in agriculture without focusing exclusively on conservation practices, with some only providing a narrative review, others using biophysical remote sensing for quantitative estimates of the bio-geo-chemical-physical properties of soils and crops, and few others focused on single agricultural management practices. This paper used the preferred reporting items for systematic …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2023, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Probable Extirpation Of The Jackrabbit (Lepus Californicus) From Arkansas, D.B. Sasse

Journal of the Arkansas Academy of Science

The black-tailed jackrabbit (Lepus californicus) was first documented in Arkansas during the modern era in Franklin County in 1927. Over the next few decades records were reported from multiple counties in northwest Arkansas and the species was locally common in Benton, Crawford, and Washington counties in the 1950s. The last Arkansas record documented in the scientific literature was from 1968 and since then there have only been three credible reports, with the last being from the late 1980s. The Arkansas Game and Fish Commission solicited reports of jackrabbits from the public and failed to find evidence of them from a …

Ultrastructure Of The Biflagellated Spermatozoon In The Western Siren, Siren Nettingi (Caudata: Sirenidae), Using Scanning Electron Microscopy, S.E. Trauth

Journal of the Arkansas Academy of Science

I investigated the ultrastructure of the biflagellated spermatozoon of the Western Siren, Siren nettingi, using scanning electron microscopy from salamanders collected in northeastern Arkansas. My primary goal in this study was to reveal the general morphology of the distinctive sperm cell components (two axonemes, two undulating membranes, and two axial fibers), which run nearly the entire length of the spermatozoon. These remarkable gamete structures are found in members of the salamander family Sirenidae and do not conform to spermatozoal ultrastructure of any other salamander species. Moreover, the biflagellated sperm are the end product of an extraordinary assemblage of complex maturation …

History And Distribution Of The Wood Stork (Mycteria Americana) In Arkansas, R. Tumlison, L. Serviss

Journal of the Arkansas Academy of Science

Wood Storks (Mycteria americana) were thought to be common visitors to Arkansas in the early 1900s, but observations declined mid-century. Surveys of citizen science data and other online sources indicate that numbers of unique observations and total counts of birds have increased since 2000. Storks do not breed here, but have been reported in 34 of 75 counties, and appear mostly in August and September. Birds apparently originate from Mexico. Number of observations have increased since 2016, but many of those observations include only a few birds rather than larger flocks.

An Annotated Checklist Of The Camel Crickets (Insecta: Orthoptera: Rhaphidophoridae) Of Arkansas, H.W. Robison, C.T. Mcallister

Journal of the Arkansas Academy of Science

A total of 14 native species of camel crickets and one introduced taxon representing three genera (Ceuthophilus, Phrixocnemis, and Diestrammena) of the orthopteran family Rhaphidophoridae, are herein reported from Arkansas. The most diverse genus was Ceuthophilus, with 13 native species, while Phrixocnemis had one native species, and Diestrammena, formerly Tachycines, was represented by one introduced species. This updated checklist is intended to be of use to entomologists, naturalists, professional biologists, and resource managers in evaluating the biodiversity of Arkansas. State distributional maps are provided for each species listed by county, and habitats are discussed in which each species was taken …