Plant Biology Commons^™

The Genetic Diversity Of An Endangered Buttercup, Ranunculus Triternatus, Ryan Garcia

All Graduate Projects

Ranunculus triternatus, a rare endemic species of the Columbia River Gorge, faces conservation challenges due to its limited range and fragmented populations. This study assesses the genetic diversity of R. triternatus and compares it with its widespread congener, Ranunculus glaberrimus, using inter-primer binding site (iPBS) markers. Genetic data from 80 individuals across eight populations were analyzed using Nei’s genetic diversity, Shannon’s diversity index, and AMOVA. Results showed R. triternatus had higher genetic diversity than western populations of R. glaberrimus, with eastern populations of R. glaberrimus displaying greater diversity than western ones. PCA, UPGMA, and STRUCTURE analysis revealed …

Characterizing New Plant Fossils With Woody Growth From The Battery Point Formation Of Quebec (Canada), Emma T. Casselman

Cal Poly Humboldt theses and projects

The oldest woody growth has been recognized in several Early Devonian (ca. 410-395 Ma) euphyllophytes. Their taxonomic diversity is difficult to evaluate due to a lack of quantitative methods for comparing plants based on secondary xylem anatomy. In turn, this hinders understanding of their implications for the evolution of plant development. To develop metrics that quantify secondary xylem anatomy and allow for conclusive comparisons, I investigated extant taxa and Early Devonian fossil woody taxa. I developed multiple metrics for quantifying tracheid size as a function of position in the secondary xylem and tested them on a dataset of extant gymnosperms. …

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …

Investigating Changing Macronutrient Dynamics At A Plant, Microbe And Plant-Microbe Interactions Scale, Emel Kangi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nutrient limitation drives forest ecosystem processes by altering net primary production, belowground (C) investments, and microbial activity. As such, the availability of essential macronutrients, such as nitrogen (N) and phosphorus (P), can severely impact plant growth, microbial decomposition, and the strength of plant-microbial interactions. However, our understanding of plant and microbe responses to changing nutrient availability, and the extent to which nutrient availability affects plant-microbe interactions, remains somewhat limited. Therefore, in this dissertation, I aimed to investigate nutrient limitation on a plant, microbe, and plant-microbe interaction level. First, to connect the phenotypic responses of nutrient-limited plants to key molecular mechanisms, …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Addressing Water Hyacinth (Pontederia Crassipes) Impacts On Aquatic Biota In Lake Okeechobee, Joseph Salerno

All HCAS Student Capstones, Theses, and Dissertations

The incursion of water hyacinth, Pontederia crassipes in Lake Okeechobee has resulted in management systems to be implemented to reduce the coverage of the invasive macrophyte. Its residence in the Lake Okeechobee ecosystem and the effects it has on organisms in the lake, whether it be positive or harmful is unknown. This study attempted to assess the potential effects that water hyacinth has on aquatic biota in Lake Okeechobee. Biotic data were collected on open water, water hyacinth covered, and native vegetation covered habitats via hook-and-line fishing, electrofishing, baited minnow traps, and the sampling of plant roots over a thirteen-month …

Germination Trends Of American Chaffseed, Schwalbea Americana L., And Factors Affecting First-Year Seedling Development, Trenton Miller

All Theses

Following centuries of exploitation and fire suppression, longleaf pine systems are now the focus of many conservation efforts. Efforts to restore populations of Schwalbea americana L. in longleaf pine savannas have been met with frustratingly low recruitment. While past studies have briefly quantified germination rates for Schwalbea, there have not been any studies yet that truly investigate this plant’s germination requirements. Additionally, there has been little research into characterizing the parasitic relationship between Schwalbea and its various host species. We conducted a germination study in a growth chamber that investigated Schwalbea’s germination rate and time to germinates as …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Variation Of Carbon Stock Of Boca Del Drago Mangrove Forests Based On Salinity And Seaward Proximity, Fiona Wyrtzen

Independent Study Project (ISP) Collection

Mangrove forests, at the intersection of land and sea, are considered one of the most important marine environments for their variety of ecosystem services and their ability to sequester large amounts of carbon in their biomass and adjacent soils. With a changing climate, many of the abiotic and biotic factors influencing mangroves will begin to shift, potentially impacting resilience, growth capacity, and distribution of mangroves worldwide. This study aimed to examine the influence of changing salinity on the carbon stock capacity for Rhizophora mangle and Laguncularia racemosa forests, and the distribution of biomass in each species relative to salinity in …

Evidence Of Competitive Release Following Overstory Mortality In A Semi-Arid Piñon-Juniper Woodland, Corrie D. Gonzalez

Biology ETDs

Extreme temperatures and severe drought events have led to widespread tree mortality worldwide. In semi-arid regions of the Southwest United States, these events pose a significant threat to piñon-juniper (PJ) woodlands. We studied the effects of piñon and juniper mortality on the growth and physiology of existing saplings in PJ woodlands by analyzing water status, photosynthetic activity, and tissue chemistry to gain insights into these impacts. Juniper saplings exhibited improved water status and water use efficiency in response to overstory mortality, whereas piñon saplings did not. Additionally, both piñon and juniper saplings exhibited increased photosynthetic rates, increased photosynthetic capacity, and …

Do Species Matter? Examining The Niche Of White Ash (Fraxinus Americana L.) And Estimating Potential Subcanopy Effects Of Its Loss In North-Temperate Forests, Elizabeth Anne Studer

Dartmouth College Ph.D Dissertations

To understand the downstream consequences of the extinction of a species, we must understand its role in an ecosystem. With the impending extirpation of ash (Fraxinus spp.) due to the invasive emerald ash borer (Agrilus planipennis), understanding the role of ash trees is critical to predicting whether its loss will precipitate further species declines and/or ecosystem functions. We evaluated whether subcanopy microbial, invertebrate, and floral communities under four tree species (white ash, American beech, yellow birch, sugar maple) and on two soil hydropedological types (Bh podzol and Typical podzol) varied in species richness, composition, and functional traits in a factorial …

Animal Communication And Sentience, Catia Correia-Caeiro, Katja Liebal

Animal Sentience

Segundo-Ortin & Calvo (S&C) argue for sentience in plants on the basis of several studies of what they describe as "cognitive abilities" in plants. As other commentaries (e.g., Brooks Pribac, 2023; Damasio & Damasio, 2023; ten Cate, 2023) have pointed out, however, there is some misuse of several concepts, and a lack of evidence for sentience. We try to clarify three questions in S&C’s discussion: (1) How is communication defined and conceptualised in animal research? (2) Is plant communication comparable to animal communication? (3) Is communication (or the process we see in plants) a good basis for inferring sentience in …

Fluidity And Inconstancy: Australian Bush Tomatoes As An Exemplar Of Non-Normative Sex Expression, Christopher T. Martine

Faculty Journal Articles

Solanum, a genus of ~1500 global species, is one of the more interesting plant groups in which to study reproductive biology and ecology. Overwhelmingly, species in this group express full cosexuality, where individual plants have flowers containing both fully-functioning “male” (staminate) and “female” (carpellate) organs. However, there have been multiple and widespread evolutionary transitions within the genus to non-normative variations on this ancestral condition. Australian bush tomatoes (ca. 40 species) are especially diverse in this regard, with uncommon variation and combinations of unisexuality and cosexuality -- including, most notably, two sexual systems known as dioecy (unisexual male or female …

Reaction-Diffusion System On Irregular Boundaries Reproduces Multiple Generations Of Petal Spot Patterns In Monkeyflower Hybrids, Emily Simmons

Biology and Medicine Through Mathematics Conference

No abstract provided.

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

Patterns And Sources Of Variation In Heterospecific Pollen Deposition In Flowers Of The Native Blue Cardinal Flower (Lobelia Siphilitica), Allie Drinnon

Undergraduate Honors Theses

Plants species interactions via pollinators are a model system to understand the mechanisms that generate plant diversity in nature. However, most studies have focused on plant-plant interactions via pollinator attraction while ignoring the role of plant-plant interactions via pollen transfer. Heterospecific pollen transfer (henceforth HP) can be common and have negative fitness effects. Negative HP fitness effects may prompt the evolution of adaptive strategies to minimize them. However, the extent of spatial variation in HP load size within and among populations, a tenet for natural selection, remains unexplored. Such knowledge would hence constitute a first step in advancing our understanding …

Sensing Is A Far Cry From Sentience, Antonio Damasio, Hanna Damasio

Animal Sentience

The hypothesis that plants might be sentient confuses the notion of sentience (or consciousness) with that of sensing. Sentience/consciousness implies feeling, experience, and subjectivity. Sensing does not. Plants can sense/detect and even respond appropriately in the absence of any sentience/consciousness.

Plant Sentience: A Hypothesis Based On Shaky Premises, Carel Ten Cate

Animal Sentience

Plants may produce fascinating behavioural phenomena for which the label ‘cognitive process’ may be applicable, at least by some definitions. Segundo-Ortin & Calvo (2023) base their hypothesis that plants might be sentient on the premise of demonstrated presence of cognitive complexity. However, the way phenomena are ascribed, and how the term ‘cognitive’ is used by Segundo-Ortin & Calvo, deviates from the common practice in studies of animal cognition, implying greater complexity than seems justified. It thus provides a questionable basis for attributing sentience to plants.

The Bellarmine Bee Bed: Organizing A Native Plant Garden Using Feedback From The Local Community, Kate Moran

Undergraduate Theses

Animal pollinators are the cornerstone of healthy ecosystems. Their survival is essential for the persistence of entire food chains: from the flowers they cross-pollinate directly, to the animals who depend on those plants for nutrition. The establishment of pollinator gardens—particularly ones that consist of native plants—is an effective way to enhance their biodiversity, abundance, and well-being.

The main goal of this thesis is to construct a pollinator garden that maximizes the benefits for animal pollinators using feedback from local gardeners. A survey was used to gather information about the popularity and preferences of 40 flowering plants, and after analyzing the …

Plants Detect And Adapt, But Do Not Feel, Paul C. Struik

Animal Sentience

Plant sentience is a hot topic in scientific and popular media. There are moral reasons to respect both the service of plants to humanity and their natural integrity as creatures playing their own significant role in a complex ecosystem. However, to infer that plants have certain cognitive capacities that are present also in certain human and nonhuman animals calls for scientific rigor beyond mere analogy. The unique capacities of plants identified by Segundo-Ortin & Calvo are not necessarily linked to sentience. Nor is it likely that sentience is an evolutionary trait that is present to some extent in all living …

Senesced Leaves Of An Invasive Species (Lonicera Maackii) Alter Community Composition And Ecosystem Function In Experimental Wetlands, Cy Mott

2023 Midwest Ecology & Evolution Conference

Secondary compounds produced by terrestrial invasive plants can cross terrestrial-aquatic boundaries via senesced leaves, leading to altered patterns of aquatic biodiversity and ecosystem functioning. Prior attempts to examine the impacts of invasive leaves on wetland communities have primarily employed the use of leaf leachates and focal taxa inhabiting relatively low trophic positions, and additional studies are needed to examine impacts on higher-order consumers and potential additive/synergistic effects of leachates and leaf decomposition. Using cattle-tank mesocosms across multiple experiments, we observed that the addition of senescent leaves of Amur Honeysuckle (Lonicera maackii) to native leaves resulted in mass mortality …

Investigating Pollinator Mismatch In Cardamine Concatenata And Claytonia Virginica, Nada Elgousi

2023 Midwest Ecology & Evolution Conference

Global warming is gradually affecting the local climate causing pollinators and plants to change their emergence and flowering times. This can potentially cause a phenology mismatch between pollinator activity and open flowers leading to limitation in seed production in plants. However, other factors such as intense predation or competition can also shift phenology. As part of a preliminary study exploring the mechanisms of phenology mismatch, Cardamine concatenata and Claytonia virginica, were observed to determine if there is a phenology shift due to competition with an invasive plant that flowers early and overlaps these two native species. In early spring, …

How Accurately Structure Can Identify Hybrids When Comparing Different Numbers Of Species And Marker Types And Numbers, Chloe Hendrikse

2023 Midwest Ecology & Evolution Conference

Hybridization is a common problem in conservation. It can be difficult to identify hybrid individuals but doing so is often necessary in order to make conservation recommendations. For example, botanical gardens and seed banks want to identify if individuals are hybrids of two or more species to determine if offspring could be used for conservation or restoration, and to analyze the risk of possible extinction via introgression. Our project looks at how well the program STRUCTURE can detect and cluster hybrids, their parent species, and other pure species, which we created using simulations. We build on past studies, which typically …

Variation In Synthetic Floral Microbiome Composition Is Largely Ignored By Foraging Bumblebees, Nevin P. Cullen

2023 Midwest Ecology & Evolution Conference

Most flowers are occupied by diverse communities of microbes, which can alter floral attractiveness to key pollinators and floral fitness by interacting with floral traits. Different species of flower often acquire unique communities of microbes. Consequently, pollinators are frequently forced to choose between two flowers with distinct floral microbiomes while foraging. However, it is currently unknown whether pollinators have an inherent preference for flowers containing one floral microbiome over another, and whether microbial preference is modified by variation in floral traits. We investigated this knowledge gap using distinct bacteria and yeasts cultured from a nickel-hyperaccumulating plant and its non-accumulating relative. …

Quantifying The Relationship Between Arbuscular Mycorrhizal Fungi And A Native And Invasive Thistle, Nicole Baker, Lucia Vera, Ian Rosales

2023 Midwest Ecology & Evolution Conference

Arbuscular mycorrhizal fungi (AMF) associate with 80% of vascular plant roots and are an important part of nutrient exchange. Our research quantified the relationship between (AMF) and native Pasture Thistle (Cirsium discolor) and invasive Canada Thistle (Cirsium arvense). We hypothesized that Pasture Thistle would have a stronger relationship with AMF than Canada Thistle because of the degraded mutualism hypothesis, which states that invasive species have reduced relationships with AMF. For our experiment, we grew inoculated and non-inoculated plants at 10 different levels of soil phosphorus concentrations. Pasture Thistle and Canada Thistle were both facultatively dependent upon …

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 …

Spatial Variation In Flowering Age In Cirsium Pitcheri: Does This Imperiled Dune Thistle Hedge Its Bets?, Lucas A. Priemer

2023 Midwest Ecology & Evolution Conference

For perennial plants, the optimal timing of flowering is a tradeoff between survivorship and fecundity, a classic example of bet-hedging. For many monocarpic perennials, there is an advantage in delaying flowering until the plant reaches a larger size and is thus capable of a higher fecundity. However, in delaying flowering, there is a risk that the plant will die before reproducing at all. Here, we investigate this fitness trade-off in the imperiled dune thistle, Cirsium pitcheri. Using a long-term, spatially-explicit demographic data set with yearly censuses, we found that C. pitcheri individuals on the foredune flowered at a younger …

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 …

Biology Of Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) On Rice And Different Corn Varieties, Anthony S. Agravante, Karen B. Alviar, Analiza Henedina M. Ramirez, Sheryl A. Yap

The Philippine Agricultural Scientist

Rice and corn are one of the most important crops in the Philippines. Several insect pests contribute to the losses and low yield of these crops. The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), was recently reported to cause economic damage to corn. Also, this insect consists of two genetically differentiated strains namely, the corn strain and the rice strain. This study was conducted in a laboratory conditions to evaluate the biological parameters of FAW on rice and corn varieties. Newly hatched larvae were fed such as the open pollinated variety (OPV), traditional variety, Macho F1 (hybrid), NK 6410 (genetically …

Natural Variation In Temperature-Modulated Immunity To Pseudomonas Syringae Pv. Tomato (Pst Dc3000) In Arabidopsis Thaliana Plants, Christina A. M. Rossi

Theses and Dissertations (Comprehensive)

Studies conducted on the model plant-pathogen system Arabidopsis thaliana-Pseudomonas syringae pv. tomato (Pst) showed that elevated temperature suppresses the pathogen-induced production of salicylic acid (SA), which is a key plant defence hormone. This increased host vulnerability at higher temperatures is due to downregulated expression of CALMODULIN BINDING PROTEIN 60-LIKE G (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1), which encode master regulators of SA production. Collectively, these previous studies only focused on one natural accession of Arabidopsis called Columbia-0 (Col-0). However, the intraspecific variation in Arabidopsis immunity phenotypes under elevated temperature remains unknown. To fill this critical knowledge gap, my …