Digital Commons Network^™

Local Nutrient Addition Drives Plant Diversity Losses But Not Biotic Homogenization In Global Grasslands, Qingqing Chen, Shane A. Blowes, W. Stanley Harpole, Emma Ladouceur, Elizabeth T. Borer, Andrew Macdougall, Erika Hersch-Green, Et Al.

Michigan Tech Publications

Nutrient enrichment typically causes local plant diversity declines. A common but untested expectation is that nutrient enrichment also reduces variation in nutrient conditions among localities and selects for a smaller pool of species, causing greater diversity declines at larger than local scales and thus biotic homogenization. Here we apply a framework that links changes in species richness across scales to changes in the numbers of spatially restricted and widespread species for a standardized nutrient addition experiment across 72 grasslands on six continents. Overall, we find proportionally similar species loss at local and larger scales, suggesting similar declines of spatially restricted …

Interactions Among Nutrients Govern The Global Grassland Biomass–Precipitation Relationship, Philip A. Fay, Laureano A. Gherardi, Laura Yahdjian, Peter B. Adler, Jonathan D. Bakker, Siddharth Bharath, Elizabeth T. Borer, W. Stanley Harpole, Erika Hersch-Green, George R. Wheeler

Michigan Tech Publications

Ecosystems are experiencing changing global patterns of mean annual precipitation (MAP) and enrichment with multiple nutrients that potentially colimit plant biomass production. In grasslands, mean aboveground plant biomass is closely related to MAP, but how this relationship changes after enrichment with multiple nutrients remains unclear. We hypothesized the global biomass–MAP relationship becomes steeper with an increasing number of added nutrients, with increases in steepness corresponding to the form of interaction among added nutrients and with increased mediation by changes in plant community diversity. We measured aboveground plant biomass production and species diversity in 71 grasslands on six continents representing the …

Crop Water Productivity: Within-Field Spatial Variation In Irrigated Alfalfa (Medicago Sativa L.), Keegan Hammond, Ruth Kerry, Ross Spackman, April Hulet, Bryan G. Hopkins, Matt A. Yost, Neil C. Hanson

Plants, Soils, and Climate Faculty Publications

In this study, alfalfa (Medicago sativa L.) is evaluated for suitability of variable rate irrigation (VRI) by analyzing within-field variation in crop water productivity (CWP) under uniform irrigation. The objectives were to (1) measure within-field variation in crop evapotranspiration (ET), (2) quantify spatial variability of alfalfa biomass yield, and (3) assess whether a bivariate analysis of CWP and yield could inform VRI management zones. Research was conducted on a 22.6 ha center-pivot irrigated alfalfa field near Rexburg, Idaho, USA, over three harvest intervals (HIs) in 2021 and 2022. Using a water balance method at 66 field points, ET exhibited …

Seasonal Effects Of Plant Functional Groups On Molecular Biogeochemistry Of Dissolved Organic Matter In Porewater Of A Poor Fen, Zhimin Song, Maryam Khaksari, Erik A. Lilleskov, Evan Kane, Paul V. Doskey

Michigan Tech Publications

Climate change may transform peatlands from net carbon (C) sinks to C sources, which could result in a positive feedback to global warming. Warmer temperatures might lower water tables, increase the abundance of shrubs, slow Sphagnum and sedge growth and further accelerate the decomposition of dissolved organic matter (DOM) with a concomitant release of C from the surface. Studies in which vascular plant functional groups (PFGs) in peatlands have been manipulated to mimic the potential effects of a warming climate on DOM are scarce. In the subject study, seasonal effects of PFGs on the molecular composition of DOM of peat …

Understanding Strain-Level Dynamics In Gut Commensal-Pathogen-Host Interactions, Anna Louise Deveaux

Arts & Sciences Graduate Student Theses and Dissertations

The human gut microbiome is a consortium of trillions of bacteria, archaea, fungi, and viruses that colonizes the gastrointestinal tract and promotes health under homeostatic conditions. This microbial community trains the immune system, modulates inflammation and anticancer immunity, promotes cardiometabolic health, enables nutrient extraction, and prevents pathogen overgrowth. The latter function manifests through colonization resistance, in which microbes occupy spatial and nutritional niches thereby excluding pathogens from the community entirely, and through limiting pathogen population growth if colonization occurs. These roles are facilitated by complex host-microbe and microbe-microbe interactions that underlie differences in susceptibility to microbiome-mediated infectious diseases. The strain-level …

Marine Animalia Diversity And Coral Reef Condition At Big Creek Beach And Boca Del Drago, Bocas Del Toro, Panamá: A Decade Of Change, Lucy Cornett

Panama: Tropical Ecology, Marine Ecosystems, and Biodiversity Conservation

As the oceans’ largest biological structure, coral reefs provide vital ecosystem services, including coastline production, food production, tourism, and preservation of biodiversity. The calm waters provided by the Bocas del Toro archipelago protection from the Caribbeans Sea promotes many coral reefs because of the calmer waters caused by protection from the Caribbean Sea. While many reefs are present, increases in tourism and other anthropogenic threats make monitoring the health of these coral reefs and the diversity of marine organisms of the utmost importance. This study examines the percent substrate cover and the diversity and density marine organisms of two coral …

Climate And Crop Modeling For New England Agricultural Climate Change Adaptation, Madeline K. Wolfe

Geography Undergraduate Senior Theses

As climate change brings increased temperatures and precipitation variability to New England, it is imperative to understand the ways that farmers make decisions about agricultural climate change adaptation for their corn farms. Dairy farming is the largest agricultural industry in New England, with corn being a primary crop to feed these cattle. This project seeks to understand how climate modeling and crop modeling are and are not useful for these corn farm decisions, and contributes research about what types of information are useful and available to farmers making adaptation decisions. Crop modeling over New England reveals that corn farming in …

Dental Disparities: An Analysis Of Dental Caries Risk Factors Promoting Disparities Between Rural And Urban Communities In Nebraska, Nick Lounsbery

Honors Program: Senior Projects (Public)

The prevalence of dental caries in the United States remains a public health concern, as it is one of the most common chronic conditions across people of all ages. Research shows that preventative measures including brushing, fluoridated water, and regular checkups are effective strategies to mitigate tooth decay. However, there appears to be a divide between rural and urban populations, as the presence of dental cavities is significantly greater in remote areas in the State of Nebraska. Research methods used in this analysis included analyzing accredited academic literature to illustrate how cavities form from a biochemical perspective. Research methods also …

Enhancing Remote Sensing Imagery Temporal Resolution Using Starfm Data Fusion Approach For Improved Land Surface Monitoring, Ahmadreza Pourghodrat

School of Computing: Dissertations, Theses, and Student Research

High-resolution remote sensing imagery plays a critical role in various domains, such as farm-level agricultural operations, environmental monitoring, and natural resource management. However, data with high spatial resolution typically have low temporal resolution, and those with high temporal resolution often lack spatial detail. For example, Landsat 8 and 9 satellites deliver high spatial resolution images with a 30-meter pixel size but suffer from low temporal resolution, with a 16-day revisit cycle. In contrast, satellites like MODIS and VIIRS provide daily images but with a much coarser spatial resolution (375 meters or more), reducing spatial details. Additionally, there is a lack …

When Can We Detect Lianas From Space? Toward A Mechanistic Understanding Of Liana-Infested Forest Optics, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Lianas, woody vines acting as structural parasites of trees, have profound effects on the composition and structure of tropical forests, impacting tree growth, mortality, and forest succession. Remote sensing could offer a powerful tool for quantifying the scale of liana infestation, provided the availability of robust detection methods. We analyze the consistency and global geographic specificity of spectral signals—reflectance across wavelengths—from liana-infested tree crowns and forest stands, examining the underlying mechanisms of these signals. We compiled a uniquely comprehensive database, including leaf reflectance spectra from 5424 leaves, fine-scale airborne reflectance data from 999 liana-infested canopies, and coarse-scale satellite reflectance data …

College Of Natural Sciences Newsletter, Spring 2025, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message from Dr. Sen Subramanian
Page 2 Student Spotlights
Page 3 Kaushik honored, Three-Minute Thesis, & Ice Cores revealed
Page 4 Alumni Spotlight
Page 5 Day of Scholars
Page 6 Cyanide research, Record Research Expenditures, Adhikari awarded Miller Research Award
Page 8 Hanson Receives NSF Grant
Page 9 Snow Lab Research Team
Page 10 Faculty Awards
Page 11 Drone Day
Page 13 Khalaf Awarded Presidential Award

The Prillwitz Mammoth: Taxonomy, Sex, Age, & Delayed Skeletal Maturation Of A Geologically Young Mammoth, Anna Rybachek

Honors Theses

The Prillwitz mammoth, a nearly complete mammoth skeleton found in Southwest Michigan in 1962, is one of the geologically youngest mammoths from North America (AMS C-14 date: 11,300 ± 100 BP). Bones are well preserved; some long bones show post-mortem flaking, scratches, or grooves of unknown origin. All long-bone epiphyses remain unfused except the distal humerus, suggesting it was < 28 years old at death. In contrast, the skull and mandible preserve M3s and m3s, respectively, that are in mid-wear, indicating an Asian Elephant Year dental age of ~45-50 years. Long bone size and inferred shoulder height are consistent with the size of a large woolly mammoth (Mammuthus primigenius) or small to mid-sized Columbian mammoth (Mammuthus columbi), but dental evidence is most consistent with M. columbi.

Pelvic dimensions suggest it is a male. The ≥ 17-year mismatch between age inferred from tooth progression and wear (~45 Asian Elephant Years) and age inferred from epiphyseal fusion (< ~28 Asian EY if male) may indicate either substantially accelerated dental progression or delayed skeletal maturation for this mammoth; we deem the latter more likely. Based on modern analogs, delayed maturation could have been due to severe malnutrition, hormonal imbalance, illness, or genetic factors. Given the geologically young age of the Prillwitz mammoth (likely near the time of mammoth extinction), we speculate that delayed skeletal maturation may have been attributed to environmental stressors near the end of the Pleistocene. Further work is warranted on very late mammoths.

Efficiency Of Labor In Winter Pruning Of Apple Trees Using Technological Innovations, Élio Fillipi Dos Santos, Wendel Paulo Silvestre, Lessandra Silva Rodrigues, Carine Cocco

School of Earth, Environmental, & Marine Sciences Faculty Publications

The increase of new technologies in fruit-growing crops has increased productivity in cultural practices and helped farmers expand their production areas. This work aimed to quantify labor performance in winter pruning of apple trees, using manual and electronic scissors associated with utilizing a pruning platform and ladders. The treatments consisted of two types of pruning shears and two support systems. A pruner carried out pruning for 16 days, with a journey of 10 h per day. The average yield in manual pruning with a ladder was 21.35 plants pruned per hour per man. Using a platform, the yield increased to …

College Of Natural Sciences 2024 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 2 Dean's Message
Page 3 Department Highlights
Page 4 One Day for State
Page 5 New Students in Wecota
Page 6-8 Faculty Excellence
Page 9 SDSU Physics Students Recognized
Page 9 Prairie Doc Watch Party
Page 10-11 Student Excellence
Page 11 Connections Abroad
Page 12-13 CNS’s Research Centers
Page 14 Connections Abroad
Page 14 Dean Wolf-Hall Retired
Page 15 Outreach Program
Page 15 Events and Traditions
Page 16 Student Spotlight
Page 17 Alumni Spotlight
Page 18-19 SDSU Alum at Paris Paralympics
Page 20 Work Anniversaries & Programs

Additionality Of Solar Tax Incentives Under Community Choice Aggregation In Ohio, Michael L. Smith, Carson Reeling, Michael D. Wilcox

Department of Agricultural Economics Faculty Publications

In the State of Ohio, the electric regulatory landscape permits local governments to become energy suppliers to residents and small businesses through community choice aggregation (CCA). Some CCAs provide enrollees 100% renewable electricity. Concurrently, the federal government offers an income tax credit (ITC) for the purchase of a solar array. With policy incentives, it is important to ensure they encourage behavior beyond the baseline scenario without the ITC. This is known as “additionality.” Renewable aggregation programs may crowd out the benefits of the ITC, violating additionality. This paper assesses additionality of the ITC in the context of Ohio’s CCA programs. …

Elevated Extinction Risk In Over One-Fifth Of Native North American Pollinators, Tara Cornelisse, David W. Inouye, Rebecca E. Irwin, Sarina Jepsen, Jonathan R. Mawdsley, Margaret Ormes, Jaret Daniels, Diane M. Debinski, Terry Griswold, John Klymko, Michael C. Orr, Leif Richardson, Nicole Sears, Dale Schweitzer, Bruce E. Young

Biology Faculty Publications

Pollinators are critical for food production and ecosystem function. Although native pollinators are thought to be declining, the evidence is limited. This first, taxonomically diverse assessment for mainland North America north of Mexico reveals that 22.6% (20.6 to 29.6%) of the 1,579 species in the best-studied vertebrate and insect pollinator groups have elevated risk of extinction. All three pollinating bat species are at risk and bees are the insect group most at risk (best estimate, 34.7% of 472 species assessed, range 30.3 to 43.0%). Substantial numbers of butterflies (19.5% of 632 species, range 19.1 to 21.0%) and moths (16.1% of …

Racial Differences In Knowledge, Attitudes Toward Vaccination, And Risk Practices Around Lyme Disease In The United States, Madiha Shafquat, Niyati Patel, Brandon Mcfadden, James H. Stark, L. Hannah Gould

Agricultural Economics and Agribusiness Faculty Publications and Presentations

Introduction Lyme disease (LD) incidence in the United States is highly regional, with most cases occurring in 16 high-incidence jurisdictions. LD incidence and severity of disease have been found to vary by race. This study describes racial differences in knowledge, attitudes toward vaccination, and risk practices related to LD.Methods Four web-based surveys were conducted with adults and caregivers of children in high-incidence jurisdictions and 10 states neighboring them. Respondents were recruited via an established online panel to represent the general population. Self-reported race was pooled into 3 categories: 'White', 'Black or African American', and 'Other' for analysis. Analyses were conducted …

Neighborhood Disadvantage And Inequities In Access To Preemptive And Living Kidney Transplantation, Brandon M Fairless, Oluwatunmise A Fawole, Duc T Nguyen, Ankona Banerjee, Kenneth J Nobleza, Abiodun O Oluyomi, Omar Rosales, Jayna M Dave, Elizabeth A Onugha

Children’s Nutrition Research Center Staff Publications

Key Points:

1. Pediatric patients residing in low-resource neighborhoods experienced lower rates of preemptive and living donor kidney transplantation.

2. Household-level factors (single-parent, non-English primary language, and receiving government assistance) may also affect the type of transplant received.

3. Area Deprivation Index scores offer an objective way to quantify neighborhood-level disadvantage and can enhance pretransplant screening.

Background: Living donor kidney transplant (LDKT) generally results in better outcomes than deceased donor kidney transplant (DDKT). Preemptive kidney transplant (KT) allows patients to bypass undergoing maintenance dialysis and is associated with improved patient and graft survival. Studies in the US pediatric population have shown racial-ethnic disparities …

Michigan Academician, Volume 49, Issue 3

Michigan Academician

Michigan Academician Volume 49, Issue 3

The Perceived Benefits Of And Barriers To Open-Water Swimming: A Mixed-Methods Examination, David Elliott Ph.D, Mark A. Christie Ph.D

International Journal of Aquatic Research and Education

This study set out to determine the perceived benefits of, and barriers to, open-water swimming (OWS). Adopting a mixed-methods approach, six hundred and sixty-five open-water swimmers responded to an online survey consisting of the Exercise Benefits and Barriers Scale (EBBS) and a series of open-ended questions. Data from the EBBS revealed the strongest perceived benefits to be ‘Psychological Outlook’ and ‘Life Enhancement.’ In terms of barriers, those presented in the EBBS received low ratings with only ‘Physical Exertion’ considered as being somewhat problematic. Content analysis performed on the open-ended responses showed social aspects, mental well-being, and connection to nature as …

System Change, Not Climate Change: Collaborative Development Of A Few Nexus Experiential Learning Course For A Justice-Centered Comparative Study Abroad Program, Sonya Ahamed

National Collaborative for Research on Food, Energy, and Water Education (NC-FEW)

The International Honors Program (IHP) on Climate Change: The Politics of Land, Water and Energy Justice has been offered by the School for International Training (SIT) since 2013. This thematic multidisciplinary program currently travels to Morocco, Nepal, and Ecuador for one month each, introducing students to local food, water, and energy challenges in the context of a changing climate. In updating the program following its relaunch in 2023, renewed attention was given to the food, energy, and water nexus from a comparative perspective across and within these countries. This presentation will focus on the development of experiential learning cycles for …

Integrating The Few-Nexus Into An Agricultural Issues Course, Christopher M. Estepp, Hannah Scherer

National Collaborative for Research on Food, Energy, and Water Education (NC-FEW)

To address the global challenges facing the agricultural industry, graduates of agricultural degree programs must learn to utilize systems thinking skills, which can help them view the interconnectedness among issues and design holistic solutions. The Food-Energy-Water (FEW)-Nexus is an interdisciplinary framework that can support undergraduate student achievement of sustainability education competencies, including systems thinking. This project utilized the FEW-Nexus framework in an agricultural issues course to help students improve their systems thinking. Students were given lectures on various agricultural issues by experts in those areas. Two assignments, agricultural issue concept maps and critical reflections over each speaker’s session were completed …

Transfer Learning In Junction With A Light Use Efficiency Model For Estimating Grassland Gross Primary Production, Ruiyang Yu, Yunjun Yao, Qingxin Tang, Xueyi Zhang, Changliang Shao, Joshua B. Fisher, Jiquan Chen, Xiaotong Zhang, Yufu Li, Jia Xu, Lu Liu, Zijing Xie, Jing Ning, Jiahui Fan, Luna Zhang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

It is significant to simulate grassland gross primary production (GPP) to understand the terrestrial carbon budget over Inner Mongolia (IMG), China. Nevertheless, there is not sufficient in situ GPP data over this region. In this study, we proposed a novel model-based transfer learning (MTL) approach with generative adversarial networks-long short-term memory (GAN-LSTM) and light use efficiency (LUE) models to derive grassland GPP over IMG, China. We first used 25 grassland eddy covariance sites over the conterminous United States to establish the GAN-LSTM model and then fine-tuned it with six sites over IMG to estimate water constraints that were embedded into …

Corrigendum To “ Phylogenomics Of The Tribe Leonureae Reveals A New Genus: Paraleonurus (Lamiaceae, Lamioideae) , [Turkish Journal Of Botany 48 (Si-1) 2024 427-440] “, Mei-Lin Qian, Ya-Ping Chen, Tuncay Di̇rmenci̇, Yue Zhao, Guo-Xiong Hu, Fei Zhao, Ferhat Celep, Bo Li, Chunlei Xiang

Turkish Journal of Botany

This corrigendum is written to correct an error in our previous publication. The term “ Yi Mu Cao Shu (益母草属; Chinese name).” was incorrectly spelled as “Jia Yi Mu Cao Shu (假益母草属; Chinese name)” in the article. The correct term should be “Yi Mu Cao Shu (益母草属; Chinese name)”. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected.

Link to the original article: https://doi.org/10.55730/1300-008X.2825

Alfred Russel Wallace Notes 35. Natural Selection By Evolution., Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace (1823?1913) is remembered, with Charles Darwin, as the co-originator of the concept of evolution by natural selection. But Wallace’s framing of the idea increasingly became one in which natural selection itself was regarded as a law of nature, not a theory per se.

74/1 | Hellenistic Nysa-Scythopolis Stratigraphy And Architecture, Gabriel Mazor, Walid Atrash, Debora Sandhaus

IAA Reports—Monograph Series of the Israel Antiquities Authority

This is the fifth volume of publications of the Bet She’an Archaeological Project, describing the large-scale IAA excavations at the site of Bet She’an–ancient Nysa-Scythopolis, during 1986–2002. Bet She’an V: Hellenistic Nysa-Scythopolis is the second volume presenting the full excavation report of the IAA excavations at Tel Iẓṭabba, conducted between 1991 and 1994. The first volume in this series, Bet She’an IV (IAA Reports 62), focused on two corpora of finds: stamped amphora handles and sealings. The current volume, Bet She’an V, is comprised of two parts (IAA Reports 74/1, 74/2) dedicated to the stratigraphy, architecture and finds from the …

The Influence Of Historical Climate Cycles On The Diversification And Demography Of Species From The Neotropical Lizard Group Anolis Chrysolepis, Tony Gamble

Biological Sciences Faculty Research and Publications

Historical shifts in climate have significantly influenced the establishment of ecosystems and the evolution of species. Phylogeographical studies integrated with niche modelling can provide insights into divergence events and demography. This study explores the evolutionary history, demographic patterns, and spatiotemporal dynamics of seven South American lizard species of the Anolis chrysolepis species group, which has been proposed to be strongly impacted by Pleistocene climatic fluctuations under the Refugia Hypothesis. We utilized mitochondrial and nuclear DNA sequences to delineate lineages, estimate divergence times, and examine demographic dynamics. Ecological niche models were employed to assess historical range shifts and identify climatic stability …

Difference-Makers For Collecting Sexual Orientation And Gender Identity Data In Oncology Settings, Mandi L Pratt-Chapman, Edward J Miech, Megan A Mullins, Shine Chang, Gwendolyn P Quinn, Shail Maingi, Matthew B Schabath, Charles Kamen

Faculty, Staff and Student Publications

Purpose: The purpose of this analysis was to identify key difference-making conditions that distinguish oncology institutions that collect sexual orientation and gender identity (SOGI) data across a sample of American Society of Clinical Oncology (ASCO) members.

Methods: From October to November 2020, an anonymous 54-item web-based survey was distributed to ASCO members. Coincidence analysis was used to identify difference-making conditions for the collection of SOGI data.

Results: ASCO members' responses to just three items consistently distinguished practices that reported collecting both SO and GI data (n = 25) from those who did not (n = 20): (1)."Do you ask your …

Monitoring And Modeling Legacy Tree Response To Restoration Treatments In The Klamath Mountains, Oregon, Usa, Isaac Joseph Ball

Dissertations and Theses

Climate change and its disruption of historical drought and wildfire patterns pose a substantial threat to forest health in the western United States. This threat is compounded by past management practices like fire suppression. The largest, oldest, and most ecologically valuable trees are particularly vulnerable, making their conservation a key objective of climate-adaptive forest management. Restoration treatments such as mechanical thinning have been shown to enhance tree growth and drought resilience in dry conifer forests, but long-term monitoring is necessary to understand their sustained effects. This study used dendroecological tree-ring analysis to investigate the effects of thinning on the growth, …

Unraveling The Influence Of Structural Complexity,Environmental, And Geographic Factors On Multi-Trophicbiodiversity In Forested Landscapes, Ayanna St Rose, Kusum Naithani

Biological Sciences Faculty Publications and Presentations

Multi-trophic diversity is often overlooked in land management decisions due to the absence of cost- and time-effective assessment methods. Here, we introduce a new method to calculate a combined terrain and canopy structural complexity metric using LiDAR data, enabling the prediction of multi-trophic diversity-a combined diversity metric that integrates diversity across trophic levels. We selected 34 forested sites of the National Ecological Observatory Network to test the model by using observed data on plant presence, beetle pitfall trap, and bird count to calculate multi-trophic diversity. Our results show that multi-trophic diversity increases with increasing structural complexity, but this relationship differs …