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Microbial And Plant Biodiversity In Appalachian Agroecosystems And Their Implications For Soil Health, Kinsey Reed Close

Graduate Theses, Dissertations, and Problem Reports (ETD)

The sustainability of agricultural landscapes depends on understanding the complex interactions between plants, soil, and microbes. In Appalachia, a region shaped by complex terrain and long histories of human and ecological interaction, small family farms produce hay, livestock, and row crops. These agroecosystems, though often treated as “artificial” by many ecologists, have the potential to support both food production and biodiversity conservation if managed with an understanding of ecological complexity. This dissertation examines how plant and microbial diversity interact with soil and management to influence nutrient cycling, soil health, and long-term resilience in Appalachian agricultural systems. A literature review revealed …

Modeling Wild Rice Bed Health: A Dual Metric Approach For Bed Strength And Invasive Impact, Seth Sisneros-Martinez

Journal of Earth and Life Science

Wild rice (mannoomin; Zizania palustris) is an aquatic grain that grows in slow-moving rivers and shallow bays throughout northern Minnesota. In Headquarters Bay on Leech Lake, wild rice has served as a cultural staple for Indigenous communities for centuries. However, its population has declined in recent years due to multiple environmental issues. One potential contributor is Eurasian watermilfoil (Myriophyllum spicatum; EWM), an invasive species that forms dense mats capable of outcompeting native aquatic vegetation, including wild rice. EWM was first recorded on the southern shoreline of Leech Lake in 2005 and has since become widespread. This study …

Seedlings Of Pacific Northwest Plants: A Photographic Guide, Gabriel E. Campbell-Martinez, Roxy Olsson

Rae Selling Berry Seed Bank and Plant Conservation Program

This document presents a visual, non-technical field guide of native and exotic/invasive seedlings that grow wild in the Pacific Northwest. It contains over 550 taxa representing a broad range of families and ecosystems, focusing on species that occur in Oregon and Washington. Species were selected to reflect ecological importance, frequency of occurrence, and relevance to land management, restoration, and conservation. It is intended for a broad audience, including restoration practitioners, land managers, botanists, ecologists, students, naturalists, and others interested in identifying plants at early life stages.

Assessing Understory Along The Elk River (Hikshari') In Headwaters Forest Reserve, Humboldt County, California, Julie R. Meyers, Aliyah M. Ingram, Caleb N. Larkin, Joshua L. Carpenter

Environmental Science & Management Senior Capstones

Northern California’s extensive logging history and lack of forest management has altered old-growth coast redwood (Sequoia sempervirens) forests, leaving dense, homogenous second and third-growth forest stands. This has led to the use of modern restoration techniques such as variable density thinning (VDT) which aims to rehabilitate old-growth forest conditions by improving stand heterogeneity and light availability for understory species. Our study was done in Headwaters Forest Reserve (HFR) along the Elk River (Hikshari’) Trail in Humboldt County, California. Initially, the project was supervised by the Bureau of Land Management (BLM) Arcata Field Office. However, the 2025 U.S. government …

Bridging Prairie Restoration And Regenerative Agriculture With Compost Tea / The Rocket Incident: Post-Fire Soil Microbe Recovery On The Eastern Washington University Restoration Site, April Hersey

EWU Masters Thesis Collection

Inland Pacific Northwest prairie is an endangered ecosystem that has been reduced by conversion to agriculture. There is growing interest in the role of soil microorganisms in prairie ecosystems, which may be crucial for restoration of the plant community through interspecies interactions within the rhizosphere. One method for improving soil microorganism community composition is compost tea: enriched liquid compost extract. Compost tea is used in regenerative agriculture to improve crop yields and protect against pathogens. While research has supported compost tea application in regenerative agriculture, it has not been widely studied in the context of ecosystem restoration. After beginning a …

Adaptation For Whom? Understanding The Impacts Of Dyke Policies On Small-Scale Farmers In Ca Mau Province Of Vietnam, Nguyen Minh Quang, Nguyen Van Minh, Nguyen Vo Chau Ngan, Martha B. Lerski

Publications and Research

Low-lying deltas worldwide are extremely vulnerable to sea-level rise. As the risks of climate-induced flooding become increasingly clear, the thirst for infrastructure-driven adaptation increases. This highlights a patent need to understand the impacts of engineering adaptation solutions, especially those targeting built structures such as dykes and sluices, on farmers from a bottom-up, farmer-centred perspective. The study addresses this call by examining cases where dyke policies, while successful in some dimensions, have undermined small-scale farmer livelihoods in Ca Mau ― Vietnam’s southernmost rural province. It identifies areas in need of attention and adds empirical data related to this group of farmers. …

Assessing The Potential For Bigleaf Maple Syrup Production In Humboldt County, Ca, David A. Reinhart, Juan A. Ramos-Cool, Liam H. Richardson

Undergraduate Scholarship

The bigleaf maple (Acer macrophyllum, Pursh) is the largest maple of the Pacific Northwest. While it has generally been treated as a nuisance in timber harvesting operations, a small amount of research has been conducted on its sugaring ability in Oregon, Washington, and British Columbia. This research has yet to reach further south in the species' range. This study aims to help a California landowner understand which maple trees on his property produce the most maple sap, to gauge what environmental factors contribute to maple sap production, and to find greater implications for the production of maple sap …

Impact Of An Herbicide Treatment In An Annual Grass Invaded Sagebrush Steppe, Jordan Dino Santia

Undergraduate Scholarship

Globally, rangelands are being threatened by invasive annual grasses (IAGs) that alter fire regimes, drive vegetation type conversion, and alter ecosystem function. This study evaluates vegetation responses to an Imazapic treatment applied in 2020 to control a population of Taeniatherum caput-medusae, an IAG, that flourished following a severe wildfire in 2013. The site, located on a Bureau of Land Management (BLM) grazing allotment east of Klamath Falls, Oregon, has been monitored annually using the Assessment, Inventory, and Monitoring (AIM) protocol since the Summer of 2022. Over this period, very little T. caput-medusae has been detected while bare ground has …

Igc Oral Presentation Summary: Xxv Igc Congress, S. Ray Smith, Echo Elizabeth Gotsick, J. R. Weinert-Nelson, Alayna Jacobs, Christopher D. Teutsch, Will Fleming, D. R. Woodfield, James L. Klotz, Jeff Lehmkuhler, Greg S. Halich, Brittany Davis, Brittany Hendrix, Krista Lea

IGC Proceedings (1977-2023)

This paper will give an overview of the XXV International Grassland Congress thematic, keynote, and plenary sessions. The theme of the XXV IGC Congress meeting was “Grasslands for Soil, Animal, and Human Health.” We had many people attending, presenting, and participating in all these sessions. Within a month after the conclusion of the Congress, the proceeding’s papers presented at the meeting will be available on the IGC app. By the end of 2023 all papers will be available for download through any search engine at internationalgrasslands.org.

Tallgrass Prairie Center 2024-2025 Highlights, University Of Northern Iowa. Tallgrass Prairie Center.

Annual Reports

Contents:

--- Staff
--- From our Director
--- Iowa Roadside Management: Enhancing our public roadsides
--- Research and Restoration: Native seeds and methods for prairie reconstruction
--- Plant Materials: A prairie pedigree for Iowa’s roadsides and beyond
--- Irvine Prairie: Restoring a piece of the original Iowa landscape
--- Prairie on Farms: Making prairie practical
--- Prairie Roots Project: A deeper appreciation of the prairie ecosystem
--- Green Iowa AmeriCorps: Service members expand TPC capacity
--- A Hidden Gem - UNI's Biological Preserves: A legacy of service and partnership
--- UNI Students at the TPC: Practical experience in support of …

Performance Of The Dssat Manihot-Cassava Model For Cassava Cultivation In The Recôncavo Baiano, Diego M. De Melo, Paola De F. Bongiovani, Fabio L.S. Costa, Patricia Moreno-Cadena, Alexandre B. Heinemann, Julian Ramirez-Villegas, Mauricio A. Coelho Filho

All Peer-Reviewed Publications

The aim of the present study was to calibrate the DSSAT MANIHOT-Cassava model with information from cassava varieties grown in the Recôncavo Baiano region, Bahia state, Brazil. The database used to calibrate the model was obtained in the dry sub-humid tropical climate in Cruz das Almas city, from 2019 to 2020. The model was calibrated with experimental data obtained under irrigated and rainfed conditions for the BRS Novo Horizonte and Eucalipto varieties. The calibration was carried out by adjusting parameters related to the characteristics of each variety. Model performance was evaluated with statistical indices that indicate the precision and accuracy …

Phytochemical Analysis, Antioxidant, And Antibacterial Properties Of Partition Fractions Of Adansonia Digitata And Annona Muricata Extracts Using Chloroform, Ethyl Acetate, Ethanol, And Aqueous Solvent Systems, Fagbohun Oyenike Bushirat, Hassan Abdusalam Adewuyi, Sakariyau Adio Waheed, Maryam Nana Musa, Timothy God-Giveth Olusegun, Ayomide Babatunde Ishola, Agumage Idoko, Adeola Victor Kolawole, Adesanmi Adefunmilayo Oluwatuyi, Sarah Ngozi Agwasim

Chemistry & Biochemistry Faculty Publications

Adansonia digitata and Annona muricata are traditionally used medicinal plants with reported pharmacological properties. In this study, we aimed to elucidate the phytochemical composition, antioxidant activity, and antibacterial properties of partition fractions of Adansonia digitata and Annona muricata extracts obtained using chloroform, ethyl acetate, ethanol, and aqueous solvent systems. The plant extracts were successively partitioned using chloroform, ethyl acetate, ethanol, and aqueous solvent systems. Phytochemical analysis was performed using standard methods. Antioxidant activity was evaluated using FRAP and DPPH assays. Antibacterial activity was assessed using agar well diffusion and MIC determination. Phytochemical analysis revealed the presence of alkaloids (10.2-15.6%), flavonoids …

Wasting Disease Of A Marine Foundation Species Links Community Interactions To Disease Dynamics, Lillian R. Aoki, Olivia J. Graham, Reyn M. Yoshioka, Rebecca Maher, Lindsay Alma, Eileen E. Hofmann, Colleen A. Burge, Drew Harvell, Maya L. Groner

CCPO Publications

Infectious disease plays a key role in shaping marine communities, including in seagrass meadows, which form biodiverse coastal habitats. Eelgrass (Zostera marina) is the most widespread seagrass species and is susceptible to seagrass wasting disease, caused by the protist Labyrinthula zosterae. As a foundation species, eelgrass strongly influences ecosystem structure, function and services; recent work has begun to explore the links between critical community interactions and seagrass wasting disease. Here, we highlight recent advances about how the eelgrass community regulates and responds to seagrass wasting disease, from the microbiome to herbivores and filter feeders. We further show …

Rwanda's Natural Remedies: A Fresh Look At The Fight Against Malaria, Leandre Nsabimana Ndisanze

Pomona Senior Theses

Malaria remains one of the most devastating parasitic diseases globally, disproportionately affecting sub-Saharan Africa, where Rwanda continues to face high transmission rates and rising resistance to conventional interventions. Despite decades of control efforts, the emergence of drug-resistant Plasmodium falciparum and insecticide-resistant Anopheles mosquitoes threatens to reverse recent gains. This research responds to the urgent need for sustainable and culturally relevant alternatives by exploring the therapeutic potential of Rwandan traditional medicinal plants. These indigenous remedies, long used by local healers, offer an underexplored reservoir of bioactive compounds that may provide the basis for novel antimalarial drugs.

The central hypothesis of this …

A Vascular Flora Of The Sacatar Trail Wilderness, Sierra Nevada, California, Kimberly Schaefer Pivetti

CGU Theses & Dissertations

The Sacatar Trail Wilderness in Inyo and Tulare counties, California, encompasses a bioregional transition zone in the southeastern Sierra Nevada. The ca. 233 km 2 (90 mi 2 ) study area, located 32 km (20 mi) northwest of the city of Ridgecrest, ranges from 930 to 2698 m (3051–8851 ft) in elevation. The highly diverse California Floristic Province, Great Basin, and Mojave Desert converge in the region including the Wilderness creating conditions to support a broad spectrum of vegetation assemblages. The Bureau of Land Management has prohibited vehicular activity in this area since its wilderness designation in 1994; consequently, recent …

Multi-Locas Gwas Mapping And Candidate Gene Analysis Of Anticancer Peptide Lunasin In Soybean (Glycine Max L. Merr), Rikki Locklear, Jennifer Kusumah, Layla Rashad, Felicia Lugaro, Sonia Viera, Nathan Kipyego, Faith Kipkosgei, Daisy Jerop, Shirley Jacquet, Mythy Addelmajid Kassem, Jiazheng Yuan, Elvira De Mejia, Rouf Mian

Biological Sciences Faculty Publications

Soybean (Glycine max) peptide lunasin exhibits significant cancer-preventive, antioxidant, and hypocholesterolemic effects. This study aimed to identify quantitative trait nucleotides (QTNs) associated with lunasin content and to annotate the candidate genes in the soybean genome. The mapping panel of 144 accessions was gathered from the USDA Soybean Germplasm Collection, encompassing diverse geographical origins and genetic backgrounds, and was genotyped using SoySNP50K iSelect Beadchips. The lunasin content in soybean seeds was measured using the enzyme-linked immunosorbent assay (ELISA) method, with lipid-adjusted soybean flour prepared from seeds obtained from the Germplasm Resource Information Network (GRIN) of USDA-ARS in 2003 and …

Quantifying Landscape Variability Of Dynamic Soil Properties In The James River Valley, Eastern South Dakota, Sage Reuter-Schmitt

Electronic Theses and Dissertations

Dynamic soil properties (DSP) are a great tool for monitoring land-use change, and they are frequently used as soil health metrics. The NRCS and other soil researchers often use repeating, single-point or nested-point DSP studies to monitor and better understand the effects of land management decisions. While these studies capture the temporal variability of DSPs, they overlook the field-scale spatial variability of DSPs. Soil organic carbon (SOC) provides critical services to the ecosystem and other environments. These traits, as well as its susceptibility to management decisions, make SOC an important soil health indicator and DSP. Measuring SOC is often time …

The Spatial And Temporal Dimensions Of Plant–Soil Feedback In Native Perennial Monocultures, Bret Lang

Electronic Theses and Dissertations

Plant-soil feedbacks (PSFs) describe how plants change their soil environment in ways that can either negatively or positively affect subsequent plant growth. In doing so, they offer an opportunity to connect ecological processes with agricultural practice. My dissertation examines PSFs created by native perennial monocultures, commonly used for native seed production, across time and space, and through soil legacies. Specifically, I focus on how plant species identity shapes both soil nutrient and soil microbial community responses. To address these questions, I conducted field experiments with monocultures of five forb species native to South Dakota and established plots with these species …

Introduction To Hydroponics- 2025-2026 Workshop Handbook, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Hydroponically grown plants grow faster than traditional production systems, with greater productivity, greater palatability, and having optimal visual character. Three principal components of a system include the plant support platform, a nutrient solution reservoir, and an interface for the root-solution. This publication provides in-depth explanation to system design, evaluation of water quality, nutrient formulation, and prototype systems that can be easily constructed for those wanting to explore hydroponics, such as educators, organizational leaders, or home enthusiasts.

Generational Exposures To Cerium Oxide Nanoparticles And Perfluorooctanesulfonic Acid Affect The Performance Of Daughter Plants, Preston Clubb

Graduate Theses/Dissertations

The effects of parental stress on the performance of next generation exposed to another contaminant were investigated. Wheat was exposed to cerium oxide nanoparticles (CeO2-NPs) in first and second generations and exposed to perfluorooctanesulfonic acid (PFOS) in the third generation. Phenotypic or metabolic responses were assessed at 21-day (short-term exposure) or 90-day (long-term exposure) exposure periods. Biomass production, chlorophyll content, enzyme activity, and membrane damage were measured at short-term exposure, while elemental and PFOS concentrations, and grain metabolites were analyzed in long-term exposure. Results showed that continued exposures to CeO2-NPs and PFOS enhanced chlorophyll content but reduced concentrations of important …

Effects Of Round-Up On The Environment, Sandra J. Marcu

Journal of Earth and Life Science

Many people around the world have used and still currently use Roundup but are unaware of the effects it has on the environment. Roundup is a spray on application weedkiller that is widely used around the world today both residentially and commercially. It enables its user to grow a garden or a field of crops with a no-tilling approach to eliminate weeds. It is a well-known and popular choice for killing weeds that has been around since the mid 1970’s (Oca, 2017). John Franz, a Monsanto scientist discovered that glyphosate (main ingredient in Roundup) was an herbicide or weedkiller, and …

Modeling The Impact Of Climate Change On Plant Hardiness Zones Across The Contiguous United States Using Empirical Bayesian Kriging Regression Prediction, Daniel Donkor

Graduate Theses/Dissertations

Mapping plant hardiness zones is crucial to understanding and predicting the spatial distribution of plants in response to climatic conditions. The United States Department of Agriculture (USDA) developed the plant hardiness zones based on the average of annual extreme minimum temperatures using the Parameter elevation Regression on Independent Slope Model (PRISM). While the USDA’s 2012 and 2023 Plant Hardiness Zone maps remain standard references, they offer limited geostatistical transparency that causes more complications in replicating. This study applies Empirical Bayesian Kriging Regression Prediction (EBKRP) method to generate Plant Hardiness Zone maps, analyze spatial and temporal shifts in the plant hardiness …

Citizen’S Rare Plant Watch, Nora Dunkirk, Gabriel Campbell, Kris Freitag

Rae Selling Berry Seed Bank and Plant Conservation Program

Rare species data for plants is lacking, hindering land management decisions and conservation outcomes. With Citizen's Rare Plant Watch, we empower citizen scientists to provide the “eyes on the ground” and collect data needed for conservation decision making in Oregon.

Physiological And Genetic Studies Of Hydrotropism In The Maize Primary Root, Muyu Gu

Electronic Theses and Dissertations

No abstract provided.

Testing The Effect Of Source And Environment On Native Seed Germination To Inform Seed-Based Restoration Of Grasslands, Brandon Clark

Electronic Theses and Dissertations

Grasslands are one of the most endangered ecosystems on the planet, and they provide a variety of important ecosystem services that people rely on. Losses of grasslands can be mitigated through restoration. Seed-based restoration is a regularly used practice due to its practicality and cost-effectiveness. Planting non-local seed that may not be suitable for its destination environment can have consequences in plant establishment and subsequent restoration success. This experiment tested the response (final germination and germination rate) of seed from 11 perennial tallgrass species sourced from 3 different locations to different germination temperature conditions. Seeds from three sources of each …

Leaf-Based Varietal Categorization Of Sweetpotato (Ipomoea Batatas L. Lam.), A Potentially Healthful Vegetable, Using Image Processing And K-Means Clustering, Shahidul Islam, Md Towfiqur Rahman, Md Hamidul Rahman, Abdul Momin

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Sweetpotato (Ipomoea batatas Lam) leaves contain higher concentrations of phenolic compounds, flavonoids, and carotenoids that are remarkable in health promotion. However, the nutrient content in sweetpotato leaves varies from variety to variety, and leaf shape and color are the key identifying factors for the varietal classification of sweetpotatoes. So, detecting sweetpotato leaves is essential for the in-situ identification of sweetpotato varieties and for developing intelligent agricultural systems. This study aimed to create a leaf-shape-based varietal classification technique for sweetpotato using image processing techniques coupled with a K-means clustering algorithm. 38 leaf images (RGB) of two sweetpotato cultivars were collected …

In-Season Nitrogen Mmanagement: Leveraging Data Visualization For Precision Agriculture, Chathurika Harshani Narayana

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Effective nitrogen management is vital for sustainable agriculture, impacting both crop yield and environmental health. Traditional methods often use fixed application rates set before planting, which do not adapt to changing crop needs during the season. This can lead to over- or under-application, reducing efficiency and sustainability. While modern tools like sensors, satellites, and UAVs provide valuable real-time data on crop and field conditions, integrating and using this data to guide timely nitrogen decisions remains a major challenge. In-season nitrogen management offers a solution by allowing for dynamic adjustments to nitrogen applications, addressing crop needs as they arise. This approach …

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 …

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 …

Greenhouse Management For The Smaller Structure--Educational And Hobby, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Greenhouses used for teaching or by hobbyist are smaller than those used for commercial production or found in the retail environment. Structural materials, covering, mechanical equipment, and control systems often are packaged as a kit made available through greenhouse suppliers. Supplier construction services may not be available, in which buyers must use local contractors to complete the installation. Greenhouses are unique structures that differ greatly from sheds or other outbuildings. They have coverings that allow maximum light transmittance, protected from UV degradation, and can handle wide inside to outside temperature extremes. This extension circular provides valuable information on the character, …