Biology Commons^™

Characterizing Leaf Endophyte Composition In The Dune Grass Ammophila Breviligulata, Nabaa Majeed, Sarah Hobbs, Sarah Emery, Connor Morozumi, Natalie Christian

Undergraduate Research Events

Microorganisms living within plants play crucial roles in their health and function, yet these diverse communities that make up the plant microbiome remain poorly understood. The dune grass Ammophila breviligulata. is an ecosystem engineer which helps to build and stabilize dune ecosystems effectively acting as a buffer against storms to coastal communities. It is currently unknown whether the Ammophila microbiome plays a role in this plant species’ ability to transform dune ecosystems.. In this study, we assessed fungal diversity of endophytes—microbes living within plant tissues— in Ammophila leaves collected from Leelanau State Park, MI along the eastern shores of Lake …

The Foreign Earth: An Exercise In Speculative Biology, Aidyn Ruf

WWU Honors College Senior Projects

Speculative Biology is the practice of examining hypothetical scenarios about the potential evolution of life. This project explores one such perspective timeline, utilizing scientific illustration, scientific information, and creative writing to estimate what the organisms of Earth might look like 250 million years into the future. Basic parameters were established, examining our current knowledge about geology and the environment to determine how the Earth itself might look. This included examining factors such as tectonic movement, adjusted ocean currents, and planetary heat cycles. Then, I studied mass extinctions and the animals which survived them, creating a baseline of ancestors the future …

Comparative Genomic Analysis Of 31 Phytophthora Genomes Reveals Genome Plasticity And Horizontal Gene Transfer, Brent A. Kronmiller, Nicolas Feau, Danyu Shen, Javier F. Tabima, Shahin S. Ali, Andrew D. Armitage, Felipe Arredondo, Bryan A. Bailey, Stephanie R. Bollmann, Angela Dale, Richard J. Harrison, Kelly Hrywkiw, Takao Kasuga, Rebecca Mcdougal, Charlotte F. Nellist, Preeti Panda, Sucheta Tripathy, Nari M. Williams, Wenwu Ye, Yuanchao Wang, Richard C. Hamelin, Niklaus Grünwald

Biology

Phytophthora species are oomycete plant pathogens that cause great economic and ecological impacts. The Phytophthora genus includes over 180 known species, infecting a wide range of plant hosts, including crops, trees, and ornamentals. We sequenced the genomes of 31 individual Phytophthora species and 24 individual transcriptomes to study genetic relationships across the genus. De novo genome assemblies revealed variation in genome sizes, numbers of predicted genes, and in repetitive element content across the Phytophthora genus. A genus-wide comparison evaluated orthologous groups of genes. Predicted effector gene counts varied across Phytophthora species by effector family, genome size, and plant host range. …

Sprouting Systems, Abaigeal Aydt, Cassidy Smith

Honors Expanded Learning Clubs

After taking a class at UNL about environmental awareness, two honors students paired up to start a hydroponics club at a local Lincoln school. In reaching out to the LPS director of sustainability, they were paired up with Prescott Elementary School. Over the course of a semester, they developed a club that got a hydroponic grow tower functioning for the school and taught students about nutrition and sustainability. This club is only in its beginning stages, but the impacts that it is making around the school can already be seen.

Partnering With Archivists To Process The Manuscript Collection Present At The Marshall University Herbarium, Pamela Puppo, Lori Thompson

Biological Sciences Faculty Research

The Marshall University Herbarium (MUHW) is located on the third floor of the Science Building at Marshall University in Huntington, West Virginia, United States. It was founded in the 1930's by Dr. Frank A. Gilbert when Marshall was still Marshall College. Today, MUHW is the second largest herbarium in West Virginia with about 50,000 specimens, including 20 types. Mostly composed of vascular plants, the herbarium also contains small collections of non-vascular plants, fungi, algae, fossils, and some ethnobotanical material, mainly brought from Ecuador by one of the former curators, Dr. Dan Evans between the 1980's and 2000's. Apart from these …

Living Shorelines Achieve Functional Equivalence To Natural Fringe Marshes Across Multiple Ecological Metrics, Robert Isdell, Donna M. Bilkovic, Amanda Guthrie, Molly Mitchell, Randolph M. Chambers, Matthias Leu, Carl Hershner

VIMS Articles

Nature-based shoreline protection provides a welcome class of adaptations to promote ecological resilience in the face of climate change. Along coastlines, living shorelines are among the preferred adaptation strategies to both reduce erosion and provide ecological functions. As an alternative to shoreline armoring, living shorelines are viewed favorably among coastal managers and some private property owners, but they have yet to undergo a thorough examination of how their levels of ecosystem functions compare to their closest natural counterpart: fringing marshes. Here, we provide a synthesis of results from a multi-year, large-spatial-scale study in which we compared numerous ecological metrics (including …

A Review Of Plant-Soil Feedbacks And Their Importance For Palouse Prairie Restoration And Management, Rachael Sv Pentico

2020 Symposium Posters

A plant-soil feedback (PSF) is the process in which plants alter both the biotic and abiotic characteristics of the soil they grow in. These changes in the soil composition alter which plants can grow and survive there in the future. Negative PSFs occur when plants struggle to grow in soil that was previously inhabited, due to a buildup of soil pathogens. Positive PSFs, however, provide benefits to the plants due to an abundance of soil microbes, such as AMF. Understanding the effects that PSFs have on plant communities and dynamics could be vital for restoring damaged ecosystems, like the Palouse …

Biogeochemical Recuperation Of Lowland Tropical Forest During Succession, Benjamin W. Sullivan, Rachel L. Nifong, Megan K. Nasto, Silvia Alvarez-Clare, Camie M. Dencker, Fiona M. Soper, Kevin T. Shoemaker, F. Yoko Ishida, Joana Zaragoza-Castells, Eric A. Davidson, Cory C. Cleveland

Biology Faculty Publications

High rates of land conversion and land use change have vastly increased the proportion of secondary forest in the lowland tropics relative to mature forest. As secondary forests recover following abandonment, nitrogen (N) and phosphorus (P) must be present in sufficient quantities to sustain high rates of net primary production and to replenish the nutrients lost during land use prior to secondary forest establishment. Biogeochemical theory and results from individual studies suggest that N can recuperate during secondary forest recovery, especially relative to P. Here, we synthesized 23 metrics of N and P in soil and plants from 45 secondary …

Student Misconceptions About Plants – A First Step In Building A Teaching Resource, April N. Wynn, Irvin L. Pan, Elizabeth E. Rueschhoff, Maryann A B Herman, E Kathleen Archer

Biological Sciences Research

Plants are ubiquitous and found in virtually every ecosystem on Earth, but their biology is often poorly understood, and inaccurate ideas about how plants grow and function abound. Many articles have been published documenting student misconceptions about photosynthesis and respiration, but there are substantially fewer on such topics as plant cell structure and growth; plant genetics, evolution, and classification; plant physiology (beyond energy relations); and plant ecology. The available studies of misconceptions held on those topics show that many are formed at a very young age and persist throughout all educational levels. Our goal is to begin building a central …

Interaction Of Shading And Cytokinins In The Sun-Shade Foliar Adaptation Mechanism, Oleg S. Gross

Honors College

Plants, being sessile, address environmental changes and resource constraints by means of developmental plasticity. For example, plants maximize photosynthesis driven carbohydrate production by undergoing physiological and structural changes in response to their environmental conditions. This plasticity to light environment has several potential regulatory pathways that may include light intensity and light spectral quality. Hypotheses advanced to associate foliar plasticity to light intensity include sensing products of photosynthesis and regulation by the phytohormone cytokinin. In this study, we examined the interacting roles of the cytokinin 6-Benzylaminopurine (BAP) and light intensity in the regulation foliar plasticity. Exogenous application of BAP was used …

Plant Distribution Data Show Broader Climatic Limits Than Expert-Based Climatic Tolerance Estimates, Caroline A. Curtis, Bethany A. Bradley

Environmental Conservation Faculty Publication Series

Background

Although increasingly sophisticated environmental measures are being applied to species distributions models, the focus remains on using climatic data to provide estimates of habitat suitability. Climatic tolerance estimates based on expert knowledge are available for a wide range of plants via the USDA PLANTS database. We aim to test how climatic tolerance inferred from plant distribution records relates to tolerance estimated by experts. Further, we use this information to identify circumstances when species distributions are more likely to approximate climatic tolerance.

Methods

We compiled expert knowledge estimates of minimum and maximum precipitation and minimum temperature tolerance for over 1800 …

Testing Dose-Dependent Effects Of The Nectar Alkaloid Anabasine On Trypanosome Parasite Loads In Adult Bumble Bees, Winston E. Anthony, Evan C. Palmer-Young, Anne S. Leonard, Rebecca E. Irwin, Lynn S. Adler

Dartmouth Scholarship

The impact of consuming biologically active compounds is often dose-dependent, where small quantities can be medicinal while larger doses are toxic. The consumption of plant secondary compounds can be toxic to herbivores in large doses, but can also improve survival in parasitized herbivores. In addition, recent studies have found that consuming nectar secondary compounds may decrease parasite loads in pollinators. However, the effect of compound dose on bee survival and parasite loads has not been assessed. To determine how secondary compound consumption affects survival and pathogen load in Bombus impatiens, we manipulated the presence of a common gut parasite, …

Effects Of Buckthorn (Rhamnus Cathartica And Rhamnus Frangula) On Native Flora Functional Traits, Alexandra Perry

Honors College

Invasive plant species are currently a threat to native species and communities,

and two major challenges facing scientists today are trying to figure out how to deal with the invasive plants and trying to pinpoint their effects on the native communities. While some methods of removal have been effective, it is still unclear how the invasive plants affect the natives. Two species of the shrub buckthorn are invasive in the United States and both are causing problems in the state of Maine. I studied the native plants in areas with and without buckthorn to determine the effects of buckthorn on …

Elevational Gradients In Β-Diversity Reflect Variation In The Strength Of Local Community Assembly Mechanisms Across Spatial Scales, J Sebastián Tello, Jonathan A. Myers, Manuel J. Macia, Alfredo F. Fuentes, Leslie Cayola, Gabriel Arellano, M Isabel Loza, Vania Torrez, Maritza Cornejo, Tatiana B. Miranda, Peter M. Jørgensen

Biology Faculty Publications & Presentations

Despite long-standing interest in elevational-diversity gradients, little is known about the processes that cause changes in the compositional variation of communities (β-diversity) across elevations. Recent studies have suggested that β-diversity gradients are driven by variation in species pools, rather than by variation in the strength of local community assembly mechanisms such as dispersal limitation, environmental filtering, or local biotic interactions. However, tests of this hypothesis have been limited to very small spatial scales that limit inferences about how the relative importance of assembly mechanisms may change across spatial scales. Here, we test the hypothesis that scale-dependent community assembly mechanisms shape …

Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira

All Faculty Scholarship for the College of the Sciences

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7 …

Beta Diversity Of Urban Floras Among European And Non-European Cities, Frank A. La Sorte, Myla F.J. Aronson, Nicholas S.G. Williams, Laura Celesti-Grapow, Sarel Cilliers, Bruce D. Clarkson, Rebecca W. Dolan, Andrew Hipp, Stefan Klotz, Ingolf Kühn, Pter Pyšek, Stefan Siebert, Marten Winter

Scholarship and Professional Work - LAS

Aim- Cities represent an ideal study system for assessing how intensive land-use change and biotic interchange have altered beta diversity at broad geographic extents. Here we test the hypothesis that floras in cities located in disparate regions of the globe are being homogenized by species classified as invasive (naturalized species that have spread over a large area) or as a European archaeophyte (species introduced into Europe before ad 1500 from the Mediterranean Basin). We also test the prediction that the global influences of European activities (colonization, agriculture, commerce) have supported this outcome.

Location- One hundred and ten cities …

Reduced Ability Of Drought-Effected Plants To Assimilate Carbon Dioxide, Adrian Alvarado, Francisco De Mendiola, Julia Namkoong, Yunni Zhai

Featured Research

As a group, we hypothesized that plants affected by the drought will absorb less CO2 compared to those that are irrigated regularly by Pepperdine University. In order to test this out we used the Carbon Dioxide CO2 transmitter which analyzed the carbon dioxide levels and conduction of three leaves that are under the drought and three leaves that are fully irrigated. The results were outstanding. As we hypothesized, the irrigated leaves had significantly higher CO2 and photosynthesis values than the leaves that were in the drought. The results are clearly reflected in the data, and consistent with the initial hypothesis. …

Coreopsis Gigantea And Ice Plant Relationship On Point Dume, Lizzie Fichtner, Mccartney Ruff, Sean Hanson

Featured Research

This study looks to determine the affects of the non-native ice plant on the native Coreopsis gigantea located at Point Dume in Malibu, California. After examining the size of the Coreopsis we were able to identify that they were smaller in height when growing next to the ice plant and greater height when farther away. We concluded that the Coreopsis does survive next to the ice plant, however its growth is restricted. Through our research we discovered many factors that could attribute to the growth difference, yet further research is necessary to decipher the main one.

What You Can Do About The Negative Effects Of Methane, Jb Maza, Laurel Rodewald, Ashley Thurmond

Featured Research

Our central objective was to investigate the apparent rise in methane emissions and whether or not they are having a negative effect on the environment. By themselves, methane emissions are natural and self-regulating (and thus do not cause damage to the atmosphere), but our thesis is that a build up of methane emissions as a result of increased human activity/negligence poses a threat to the environment, and needs to be addressed in the quest to live sustainably. In our research, we chose to focus specifically on one source of methane emissions: permafrost, both because there is a significant amount of …

A Selected Surveyo F Ocean Acidifcation's Effect On Coccolithophore And Other Marine Ecosystems, Taylor Zaw, Joel Wood, Anthony Gonzalez

Featured Research

With it's rapid rate of generation, the coccolithophore was expected to adapt to the altered pH levels relatively quickly. By analyzing several scientific studies concerning this algae's interaction with various water qualities, the species' response is clarified. These findings are compared to rudimentary data concerning pH levels taken along the coast of Malibu.

Leaf Foliar Absorption In Pentagramma Triangularis And Polypodium Californicum, Justin Choe, Carlos Larios, William Prorok, Emily Rose Pierce

Featured Research

In Riparian and moist zones of the Santa Monica Mountains of Southern California, ferns flourish. However, the Mediterranean climate they live in is subject to drought, and the area is currently facing the worst drought it has ever seen. With little moisture in the ground and streams drying up, these ferns are running out of sources of water. However, being on the coast, the area is subject to fog nightly. This research was done to see if ferns can do leaf foliar absorption, getting their water source from the air rather than the ground. We hypothesized that ferns do leaf …

Comparison Of Photosynthetic Ability In Single And Double Palisade Parenchyma Leaves In Southern California, Vincent Quach, Ryan Sauer, Haley Smith, Christian Wright

Featured Research

Melaleuca quinquenervia is a myrtle (family Myrtaceae) with a propensity for invasiveness. The leaves feature an isobilateral orientation: vertically aligned with a layer of palisade parenchyma on both the adaxial and abaxial sides. Quercus agrifolia (Fagaceae) is a native evergreen with one layer of palisade parenchyma. Due to this structural difference, it was hypothesized that Melaleuca would have a higher rate of photosynthesis (Pn) and less reflectance (NDVI) of green light than Quercus. These two variables were compared using an unpaired t-test, yielding p-values of 0.1366 for NDVI and 0.04428 for photosynthetic rate. No significant difference was found between the …

Initial Post-Fire Resprout Success Of Q. Agrifolia, J. Californica, And P. Racemosa In Sycamore Canyon, Frida Morales, Sawyer Mcgale, Drew Bowers, Zahra Madraswala, Michael Mori

Featured Research

Resprouting after fire and during a drought can be one of the greatest challenges a plant faces. This phenomena was observed and recorded in three different species of trees: P. racemosa, Q. agrifolia, and J. californica, all located in the Sycamore Canyon study site in Pt. Mugu State Park. P. racemosa was hypothesized to initially be the most successful post fire resprouter. The rationale for this is that the DBH and deciduous factor would cause the tree's vascular system to survive and possess usable starches to power resprouting. The data was analyzed and found to support the hypothesis.

Drought-Induced Mortality In Malosma Iaurina And Ceanothus Megacarpus In Response To California's Changing Climate, Stefano Berrios, Stefani Francisco, Olivia Kim

Featured Research

The hypothesis of this research and experiment is that Malosma laurina is better adapted to drought than Ceanothus megacarpus due to its adaptation of deep roots. This addressed the question of which plants are better adapted to drought and by which adaptations are they superior. We decided to choose these two types of chaparral due to their differences in adaptations: Malosma laurina having deep roots and Ceanothus megacarpus utilizing cavitation resistance. Our method of investigation was to study the findings of scientific journal articles and to conduct our own experiment involving the mortality of Malosma laurina on the Pepperdine University …

Measuring Performance Of A Weedy Species (Nicotania Glauca) Vs. A Native Species (Venegasia Carpesioides) On The Pepperdine Campus, Emily J. Blair, Zach G. Coffman, Celina Y. Jones

Featured Research

This study investigated four different mechanisms of growth performance of a native chaparral species, Venegasia carpesioides, and a weedy species, Nicotiana glauca. The research group hypothesized that one or more of the following variables would be higher for the weedy species than the native species: photosynthetic rate, conductance, fluorescence, and electron transport rate (ETR). This hypothesis was formulated in order to provide a plausible explanation for why weedy species often outcompete native species when grown in proximity to each other, especially in a chaparral environment experiencing drought conditions. This hypothesis was tested by obtaining two groups of each species and …

Relationship Between Canopy Location And Tensile Strength Of Leave Of Heteromeles Arbutifolia In Malibu, Ca, Elena Witham, Melinda Marchiano, Danielle Reynolds

Featured Research

Our hypothesis is that canopy location has an effect on the characteristic tensile strength of leaves, with the leaves on the top of the canopy having greater strength than the leaves on the bottom. We tested our experiment by sampling leaves from the top and bottom of three H. arbutifolia specimens, obtaining raw measurements of size, and testing the tensile strength of each leaf using the Instron. We performed t-tests on the data to determine if the average length, width, thickness, and tensile strength were statistically different depending on if our p values were < 0.05 when top and bottom leaves of the same tree were compared. We chose a chapparral stand removed from heavy human traffic and influence, eliminating as many extraneous variables as possible by taking leaves from the same tree of the same age from the same position on the branch and chose three trial specimen of similar height in the same area to reduce the possibility of varying sunlight exposure or water supply from affecting leaf morphology in a way that canopy position would not. The results show that blade length between top and bottom is statistically significantly different, while blade thickness and lateral strength at midsection were not statistically different. From our analysis of the data, it is clear that leaves on the bottom of the plant were longer and broader than leaves on the top, but we determined that canopy location does not have a major effect on tensile strength or thickness, supporting a null hypothesis.

Community Structure And Differential Mortality Of Chaparral During Extreme Drought, Keb Doak, Allison Hubbard, Alawna Jamison

Featured Research

We have set out to find, in extreme drought, which species of chaparral are dominant and why they are dominating. We thought that the indicator species of chaparral, Adenostoma fasciculatum, would have highest relative density, relative frequency, and dominance in our research area. Additionally, plants with higher water potential values would have lower percentages of mortality. Chaparral with stronger ability to fluoresce (higher Fv/Fm value) would have lower mortality percentages due to their ability to dissipate excess energy, and therefore reduce water loss. By analyzing our vegetation area using point-quarter sampling system, we were able to record data that show …

The Effects Of Higher And Lower Co2 Levels In The Atmosphere On The Photosynthetic Rates And Stomatal Conductance Of Malosma Laurina In The Santa Monica Mountains, Victoria A. Thorsen, Maverick E. Turner, Colby P. Harriman

Featured Research

We hypothesize that higher CO2 levels will lead to a change in photosynthetic performance in the Malosma laurina population of the Santa Monica Mountains. We used one Malosma laurina that is across the street from university’s theme tower. We chose this specific plant because it was in the sun and it was in a well irrigated area. We selected a plant that is in non-shaded areas at 12:00 pm and then dark adapt them for 20 minutes. We selected an adult plant that was between four and six feet tall. We took the measurements from the upper leaves of the …

Relationship Between Canopy Location And Tensile Strength Of Leaves Of Heteromeles Arbutifolia In Malibu, Ca, Elena Witham, Melinda Marchiano, Danielle Reynolds

Featured Research

Our hypothesis is that canopy location has an effect on the characteristic tensile strength of leaves, with the leaves on the top of the canopy having greater strength than the leaves on the bottom. We tested our experiment by sampling leaves from the top and bottom of three H. arbutifolia specimens, obtaining raw measurements of size, and testing the tensile strength of each leaf using the Instron. We performed t-tests on the data to determine if the average length, width, thickness, and tensile strength were statistically different depending on if our p values were < 0.05 when top and bottom leaves of the same tree were compared. We chose a chapparral stand removed from heavy human traffic and influence, eliminating as many extraneous variables as possible by taking leaves from the same tree of the same age from the same position on the branch and chose three trial specimen of similar height in the same area to reduce the possibility of varying sunlight exposure or water supply from affecting leaf morphology in a way that canopy position would not. The results show that blade length between top and bottom is statistically significantly different, while blade thickness and lateral strength at midsection were not statistically different. From our analysis of the data, it is clear that leaves on the bottom of the plant were longer and broader than leaves on the top, but we determined that canopy location does not have a major effect on tensile strength or thickness, supporting a null hypothesis.

Elevation’S Effect On Malosma Laurinais Leaf Size, Callyn E. Shelley, Nathan R. Gehring

Featured Research

Our hypothesis was that the average leaf size of Malosma laurinais would be different at high and low elevations due to the variance in temperature and solar radiation. This is especially relevant considering the severe drought conditions of California. Testing the factors of growth for chaparral may help ecologists to better understand how the plants cope with abnormalities in the ecosystem. Our study examined variance in Malosma laurinais leaf length, width, area, curvature, and thickness at high elevation (610 meters to 629 meters) and low elevation (27 meters to 53 meters) located along Sycamore Canyon. Differences were only significant in …