Plant Biology Commons^™

Geographic Analysis Of Sex Chromosome Polymorphism In The Virginian Wild Strawberry, Trezalka A. Budinsky

2023 Midwest Ecology & Evolution Conference

The evolution of sex chromosomes is a ubiquitous and essential diversifying mechanism in eukaryotes. Yet early stages of sex-chromosome differentiation are poorly understood. The subdioecious octoploid, Fragaria virginiana, provides a rare opportunity to study the beginnings of sex chromosome evolution due to its young, polymorphic ZW sex system. Females are ZW and males/hermaphrodites are ZZ. F. virginiana has a small sex-determining region (SDR) located on the female W chromosome that has undergone three transposition events between the strawberry's four subgenomes, resulting in three SDR haplotypes: alpha (the result of a first transposition and closest to a pre-sex chromosome ancestral …

Center For Grassland Studies, March 2023

Center for Grassland Studies: Newsletters

Contents

New Assistant Director for The Center for Grassland Studies, David Wedin

Center for Grassland Studies Policy Advisory Committee

Director's Column by Jerry Volesky (Interim Director)

Congratulations December 2022 Graduates

New Grazing Lands Ecologist for Grassland Studies, Nic McMillan

New Administrative Associate for Grassland Studies, Ashley Branting

Apply Now for CGS Scholarships and Assistantship, https://grassland.unl.edu/grassland-systems/grazing-livestock-scholarships

New Guidelines for Reducing Eastern Redcedar in Grasslands by Dillon Fogarty

Year One Barta Brothers Ranch Collaborative Adaptive Management Update by Craig Allen

Nebraska Grazing Conference, August 8-9, 2023 by Daren Redfearn

Forty Years Reflection on Grassland Fire Weather by David Wedin

Nebraska Youth Range …

Developing Best Practices For The Propagation Of Spartina Alterniflora For Use In Salt Marsh Restortaion, Justin Hinson

College of Graduate Studies: Theses & Dissertations

Coastal salt marshes are valuable ecosystems under threat from climate change and sea level rise. Living shorelines offer a promising solution, often incorporating the foundational salt marsh species Spartina alterniflora due to its ability to tolerate natural stressors and maintain sediment stability. However, research suggests that seed-based propagation protocols should be developed on a local scale due to the genetic heterogeneity within and between S. alterniflora populations. Here, we attempt to contribute to the development of one such protocol for coastal Georgia S. alterniflora.

In Fall 2021, seeds were collected bi-monthly from four marshes of varying ocean proximity and …

Influence Of Plant Density On Rainfall Interception By Spartina Alterniflora, Hannah K. Longaberger

Honors College Theses

Abstract

Spartina alterniflora is an abundant plant in eastern US and Gulf coast salt marshes; it is important in maintaining a diverse ecosystem. Salt marshes are impacted by rainstorms, which may affect erosion events. This project examined the partitioning of rainfall on single plants of various sizes and on central plants within different canopy densities of S. alterniflora. By calculating the rain stemflow (SF), throughfall (TF), and water adhered to the stem in S. alterniflora, we gained insight to rainfall partitioning with different plant features. My research found no statistically significant relationship between different plant features and SF, TF, …

The Ecology And Evolution Of Species Rarity In Oaks (Quercus Spp.), Yingtong Wu

Dissertations

Rare species are susceptible to extinction due to ecological and genetic factors. Understanding the distribution, ecology, and evolution of rare species can provide useful information for effective conservation. To investigate species rarity, this dissertation focuses on a species-rich and ecologically diverse genus, Quercus (oaks). In Chapter 1, I aimed to understand how interactions between hosts and soil microbes contribute to habitat restriction in oak species. I performed a soil inoculum experiment on two pairs of sister oak species that show habitat divergence. I found that host-specific soil microbes contribute to habitat divergence and exclusion among sister species of oaks, but …

The Potential Role Of Phenotypic Plasticity In The Ability Of Hydrocotyle Bonariensis To Occupy Two Different Habitats, Harold Ralph Parsons Iii

Honors College Theses

Phenotypic plasticity is the ability of an organism to change morphology and/or physiology in response to changes in the environment. Hydrocotyle bonariensis is a coastal perennial herb found in both coastal sand dunes and inland coastal plain habitats in Georgia. The purpose of this study was to determine if there were differences in leaf morphology for populations of H. bonariensis in coastal sand dune and inland coastal plain habitats. Leaf morphology and microenvironmental variables were compared between H. bonariensis populations at Tybee Island (TI), GA, representing the coastal sand dune habitat, and Georgia Southern University Armstrong Campus (GSU) in Savannah, …

Western Prairie Fringed Orchid Management, Ecology, And Decline At Mormon Island, Andrew J. Caven

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The western prairie fringed orchid (Platanthera praeclara Sheviak & M. L. Bowles; WPFO) was first detected in a vegetative state on Mormon Island in 1978 and identification was confirmed following a mass flowering event in 1982. From a high count of ~60 plants the WPFO slowly declined and has not been observed since 2000 despite flowering season surveys conducted in 15 of the last 20 years. We explore the natural history of the WPFO in the contexts of Mormon Island to establish potential causes for its apparent disappearance and evaluate the possibility it persists in some capacity. Our investigation …

Center For Grassland Studies, March 2022

Center for Grassland Studies: Newsletters

Contents

New Course: Research Experiences in Grasslands by Dan Uden

Center for Grassland Studies Policy Advisory Committee

Director’s Column by Jerry Volesky (Interim Director)

Educational Trunk to Focus on Grasslands by Cheryl Dunn

Form a Team and Grab Your Clubs by Scott Holly

Collaborative Adaptive Management for the Barta Brothers Ranch by Craig Allen

Nebraska Range Short Course, June 20-23

Registration Opens for 2022 Nebraska Ranch Practicum by Troy Walz

Nebraska Sandhills Rates as World’s Most Intact Prairie by Scott Schrage

Nebraska Youth Range Camp, June 6-9, Nebraska College of Technical Agriculture, Curtis, Nebraska

Thermal Tolerances Of The Invasive Macrophyte Hydrilla Verticillata, Joshua Williams

Graduate Research Showcase

Invasive species often rapidly spread due to their ability to adapt to a wide range of habitats they can occupy and lack of competition. Hydrilla verticillata is an invasive aquatic macrophyte that has spread across the United States due to human activities. Like many aquatic plants, Hydrilla has the ability to reproduce through fragmentation of the mother plant. In this method, Hydrilla fragments are then dispersed by water current to other areas where they can settle and grow. To date, little is known about the abiotic conditions that may restrict the spread of invasive Hydrilla. However, compared to other macrophytes …

Center For Grassland Studies, November 2021

Center for Grassland Studies: Newsletters

Contents

Ranchers’ Preferences for Payment for Ecosystem Services Programs in Nebraska by Kyle Martens

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schacht (Interim Director)

Fall Army Worms Reared Their Ugly Heads and Wings in Nebraska in 2021by Roch Gaussoin

Dalbey-Halleck Open House by Margo McKendree

Internships – Let’s Get More Students on the Land! by Shelly Kelly

Jim Gerrish Insightful and Relatable for Grazing Livestock (GLS) Club Members

Center For Grassland Studies, September 2021

Center for Grassland Studies: Newsletters

Contents

Nebraska Grazing Conference Recap by Daren Redfearn

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schacht (Interim Director)

Land Use and Property Taxes by Jordan Johnson

Congratulations August 2021 Graduates

Wildfires are Changing the Future of Nebraska’s Woodland-Grassland Complexes by Amanda Hefner

PGA WORKS Scholarship Recipients Announced by PGA Reach

Grazing Livestock Systems Internships Provide Diverse Experience by Bryan Reiling

Jim Choquette Receives Lifetime Achievement Award

Center For Grassland Studies, July 2021

Center for Grassland Studies: Newsletters

Contents

21st Nebraska Grazing Conference on the Horizon by Daren Redfearn

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schacht (Interim Director)

21st Annual Nebraska Grazing Conference Schedule, August 9-11, 2021

Club Officers Elected for FY 21-22 by Jessica Windh

2021 Fall Seminar Series Schedule

CGS Scholarships and Fellowship Awarded for FY 21-22

Congratulations May 2021 Graduates

Salicylic Acid Response To Simulated Herbivory In Geographically Distinct T. Heterophylla And H. Discolor Populations, Amy E. Castle

Honors Projects

It is commonly known that plants may produce salicylic acid as a chemical defense response to wounding, although the phenomenon has usually been observed with regard to insect herbivory. Stem and leaf tissue of two species, Tsuga heterophylla and Holodiscus discolor, which are often eaten by deer, were extracted in methanol and analyzed by HPLC to quantify salicylic acid concentration in experimentally wounded or control samples. No salicylic acid response was detectable in T. heterophylla, suggesting it is a less useful candidate species for future study. Some but not all H. discolorsamples had a measurable salicylic acid …

Center For Grassland Studies, May 2021

Center for Grassland Studies: Newsletters

Contents

Prescribed Burn Associations by Brian Teeter

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schact (Interim Director)

Looking for a Career in Conservation – How to Apply in USAJOBS for NRCS Positions by Mary Reece

Monitoring Sandhills Rangelands: A Key Step in Understanding Plant Community Dynamics by Mitch Stephenson

Development of Novel Plant Fluorescence Based Techniques for Remote Assessment of Grasslands and Pastures Health and Resilience by Anastasios Mazis

UNL PGA Golf Management Alumni Among Nebraska Section Award Winners by Brad Goetsch

Nebraska’s Grassland Legacy by Walt Schacht

Nebraska Grazing Conference: Save the Date, August 9-11, …

Spore Dispersal Of Slime Molds And Higher Fungi Via Animal Vectors, Courtney Trimble

Graduate Theses and Dissertations

Myxomycetes and dictyostelids are Amoebozoans that are cosmopolitan inhabitants of a variety of habitats, particularly forest environments. Both groups reproduce using spores which are primarily dispersed via wind in myxomycetes but this characteristic poses a problem for dictyostelids. The spores of dictyostelids are incased in a mucilaginous matrix that makes wind ineffective except in exceptional cases. It has been suggested that animals such as birds may play an important yet understudied role in the dispersal of these organisms. This study investigated how animals could potentially serve as vectors for spore dispersal of dictyostelids and myxomycetes with some limited data obtained …

Impact Of Arbuscular Mycorrhizal Fungi On Conyza Canadensis Drought Responses And Possible Mechanisms, Kian G.M. Speck, Ylva Lekberg, Anna Sala

Undergraduate Theses, Professional Papers, and Capstone Artifacts

• Arbuscular mycorrhizal fungi (AMF) are important plant mutualists that can facilitate plant responses to various environmental stressors, such as drought. A plant that may benefit from AMF-induced drought tolerance is Conyza canadensis due to its ability to thrive in dry conditions and its high colonization rate. However, no studies have researched C. canadensis in this context and the exact mechanisms of AMF-induced drought tolerance are still unknown.
• To better understand if and how AMF facilitate drought response in C. canadensis, we conducted a greenhouse experiment comparing the response of mycorrhizal and non-mycorrhizal plants to three watering levels. We measured …

The Mechanisms And Consequences Of Shrub Encroachment On The Virginia Barrier Islands, Lauren K. Wood

Theses and Dissertations

Shrub encroachment is a global phenomenon driven by direct and indirect anthropogenic influence which alters plant communities and ecosystem function. Many studies have investigated drivers and consequences of woody plant establishment, but mesic landscapes are underrepresented in the literature. My objective was to assess the mechanisms of Morella cerifera encroachment into coastal mesic grassland, the potential for self-reinforcement, and consequences on community composition, nutrients, and landscape productivity. I studied temperature and water microclimate modification by Morella cerifera presence and removal to understand ecosystem engineering and community composition changes. Additionally, I examined the influence of shrubs on surrounding grassland species traits …

Plant And Soil Responses To Sediment Deposition And Nutrient Enrichment In Healthy, Deteriorating, And Newly Created Coastal Marshes In Barataria Basin, Louisiana: Implications For Mississippi River Sediment Diversions, Gina N. Groseclose

LSU Master's Theses

To offset wetland loss in the Mississippi River Delta, sediment diversions that will re-introduce river water and sediment into wetlands are being planned for the lower Mississippi River. River diversions will also deliver high nutrient loads, which may reduce belowground plant productivity, reducing inputs of organic matter important for marsh accretion to keep pace with sea-level rise. However, belowground productivity responses to the combinatory effects of sediment and nutrients are unknown. To test the hypotheses that nutrient enrichment and sediment deposition interact to influence vegetation structure, belowground plant productivity and decomposition, and surface accretion, a field experiment was implemented in …

Floodplain Forest Regeneration Dynamics In The Lower Mississippi River Alluvial Valley, Whitney Anne Kroschel

LSU Doctoral Dissertations

Floodplain forest species diversity is driven, in part, by variation in disturbance regime. Flood patterns create heterogeneity in microsite quality from small differences in elevation across a floodplain which, in turn, influence flood timing and duration. Differences in species’ regeneration niches in relation to hydrologic patterns can account for long-term coexistence of various species. In the past century floodplain forests have exhibited a wide range of changes in stand development and species composition as a result of altered hydrology in rivers and floodplains. I evaluated the role of regeneration in floodplain forest systems of the Lower Mississippi River Alluvial Valley …

Eelgrass Health Survey And Results, Nicholas B. Anderson, Catherine M. Ashcraft, Dante D. Torio, Frederick T. Short

Natural Resources & the Environment

Researchers at the University of New Hampshire designed, tested, and conducted an eelgrass health survey. The primary goal of the survey was to collect health ratings from respondents who had viewed pre-selected images of eelgrass representing a wide range of health conditions. Survey results were used as a calibration and validation to a novel eelgrass health index developed using video-monitoring. Two secondary goals of this this survey were the identification of plant-specific and environmental characteristics important to respondents and the introduction of the new eelgrass health index. This published dataset includes de-identified survey respondent background and demographic data, the survey …

Stimulated Growth Response To Sand Burial Of A Coastal Shrub, D. Nicole Keller

Theses and Dissertations

Drivers of vegetation zonation on barrier islands are complex and interconnected. Sand burial is a strong driver in dynamic coastal systems, especially in the foredune community. However, it is not well understood how burial impacts the interdunal swales communities and it is especially difficult to separate the effects of burial from salinity. Climate change is altering the frequency of overwash events as well as expanding the range of the native shrub, Morella cerifera, on the Virginia barrier islands. To accurately forecast island response to climate change it is important to understand how the shrub responds to sand burial. Juvenile …

Watching Grass Grow: How Soil Moisture Affects Vesicular-Arbuscular Mycorrhizae And Growth In Little Bluestem, Laura M. Jones

Honors Scholar Theses

Vesicular-arbuscular mycorrhizae (VAM) are an ancient mutualism in which soil-dwelling fungi enhance plant absorption of phosphorus and nitrogen in exchange for photosynthates. VAM are sensitive to changes in soil moisture and nutrient content, fluctuating between mutualism and parasitism depending on conditions of drought stress and nutrient deficiency. Understanding how VAM respond to precipitation changes is crucial for both conservation and agricultural purposes. To test how soil moisture changes the effects of VAM colonization and growth in little bluestem (Schizachyrium scoparium), a common prairie grass, I planted 300 seeds in a greenhouse in sterilized soil and soil inoculated with …

Observable Persistent Effects Of Habitat Management Efforts In The Ozark Highlands After 10 Years, Maxwell Carnes-Mason

Graduate Theses and Dissertations

I investigated the lasting impacts of a management plan designed to improve oak regeneration and benefit wildlife in the Ozark Highlands in Madison, Co., AR. To assess the efficacy of the management plan, I used variables relevant to the success and establishment of oak trees. Controlled burns and selective logging were used to thin the canopy, increase ground level productivity, and increase the abundance of small mammals. I used measurements of overstory and understory densities, light availability, and the density of mice in the genus Peromyscus across time to look at the lasting impacts of management. Different treatment plots were …

Distribution And Population Structure Of The Invasive Nitellopsis Obtusa (Desv. In Loisel.) J. Groves And Native Species Of Characeae In The Northeast U.S.A., Robin Sleith

Dissertations, Theses, and Capstone Projects

Freshwater ecosystems are some of the most biologically diverse environments on Earth. Billions of humans rely on functioning freshwater ecosystems for drinking water and many other services. These ecosystems are increasingly threatened by human impacts including nutrient pollution, invasive species, and climate change. Here I contribute four research chapters that investigate freshwater diversity and ecosystem threats using the Characeae, a family of freshwater green macroalgae, as a study system. Characeae are a diverse and ancient group with more than 500 extant species and a fossil history spanning at least 250 million years. These algae are macrophytes in freshwater ecosystems, and …

Biogeochemical Response To Vegetation And Hydrologic Change In An Alaskan Boreal Fen Ecosystem, Danielle L. Rupp

Dissertations, Master's Theses and Master's Reports

Boreal peatlands store approximately one third of the earth’s terrestrial carbon, locked away in currently waterlogged and frozen conditions. Peatlands of boreal and arctic ecosystems are affected increasingly by shifting hydrology caused by climate change. The consequences of these relatively rapid ecosystem changes on carbon cycling between the landscape and the atmosphere could provide an amplifying feedback to climate warming. Alternatively, the advancement of terrestrial vegetation into once waterlogged soils could uptake carbon as a sink. Previous work suggests that fens will become an increasingly dominant landscape feature in the boreal. However, studies investigating fens, their response to hydrologic and …

Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young

College of Graduate Studies: Theses & Dissertations

Climate change is altering ecosystems on a global scale, creating novel ecological scenarios with which plant species must cope. Factors such as altered precipitation and fire regimes and non-native plant invasion may negatively affect native plant species, while interactions between these stressors could magnify their impacts. The complexity of multiple stressors and the effects they have on native pine seedlings are difficult to predict without evaluating their combinations in field experiments. In a multi-year study, I investigated the effects of drought and plant invasion on three southeastern pine species under pre and post-fire conditions. We planted longleaf (Pinus palustris …

Yardwork: A Biography Of An Urban Place By Daniel Coleman, Vivian M. Hansen

The Goose

Review of Daniel Coleman's Yardwork: A Biography of an Urban Place.

Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow

LSU New Orleans Theses and Dissertations

Introduced populations of Eichhornia crassipes (Pontederiaceae) possess extremely low levels of genetic diversity due to severe bottleneck events and clonal reproduction. While populations elsewhere have been well studied, North American populations of E. crassipes remain understudied. We used Amplified Fragment Length Polymorphism markers to assess genetic diversity and population structure in North American E. crassipes populations. Patterns of diversity over the past fifty years were analyzed using herbarium specimens. Furthermore, we sampled populations across the Gulf Coast of the United States throughout a year to determine contemporary genetic diversity and assess potential seasonal effects. Genetic diversity was found to be …

Investigating The Ecology Of A Rare Species On St. John, Usvi: Reintroducing Solanum Conocarpum In Light Of Climate Change, Cecilia Rogers

Senior Honors Projects, 2010-2019

Approximately two thirds of St. John is National Park territory. However, the land has been threatened with tourism and development, greatly impacting island biodiversity. One species that may become extinct due to this degradation is Solanum conocarpum. S. conocarpum is a rare shrub, endemic to the dry tropical forests of St. John, USVI. This plant is a species of conservation concern and is one of very few native and endemic plants on this island. Very little is known about the ecology and reproduction of S. conocarpum. Most plants are found on the southern half of the island. Recent observations …

The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne

Human–Wildlife Interactions

The federal government owns approximately 47% of all land in the western United States. In the state of Utah, about 64% of the land base is managed by the federal Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The government has historically issued permits to owners of private lands to allow the owners to graze their livestock on public lands. The permits (allotments) are generally of 10-year duration and allow for an annual season of use. In some cases, continued and repeated historical annual grazing practices may not be ideal for permit holders and their communities nor …