Life Sciences Commons^™

Root Hydraulic Conductance In Laurel Sumac Experiencing Severe Dieback In The Santa Monica Mountains, Natalie M. Aguirre, Avery N. Davis, Sarah B. Nelson

Featured Research

Malosma laurina (laurel sumac) is a dominant species in coastal chaparral ecosystems, extending its roots down to an average of 40 feet in rocky, sandy soils. The deep root systems of M. laurina provide structural support for the steep Santa Monica Mountains. The roots also allow M. laurina to draw from the deep water table, increasing its drought tolerance. M. laurina dieback is prevalent in coastal exposures of the Santa Monica Mountains presumably due to historic drought predisposing plant tissues to infection by the fungal pathogen Botryosphaeria dothidea. In ecosystems that experience annual dry periods, a high hydraulic conductance …

Extensive Dieback In Malosma Laurina In Coastal Exposures Of The Santa Monica Mountains Associated With Unprecedented Drought In California, Gina S. Gilderman, Kaitlyn E. Sauer, Gabriella N. Palmeri

Featured Research

Throughout coastal exposures of the Santa Monica Mountains (SMM) there is a recent emergence of widespread dieback in Laurel Sumac (Malosma laurina). M. laurina is a keystone species of chaparral that dominates the SMM. A significant trait of M. laurina is an extensive root system exceeding 12 m in depth. We hypothesized that M. laurina was weakened by unprecedented drought in California (2013-2015) and predisposed to fungal pathogens. An initial study conducted in the summer of 2015 revealed all stem samples taken from dieback adult M. laurina plants were infected with Botryosphaeria dothidea, while zero stem samples taken …

Recent Dieback In A Keystone Chaparral Species Is Caused By A Fungal Pathogen, Botryosphaeria Dothidea, Frida Morales, Mariah Taylor

Featured Research

Due to the recent drought in Southern California, the abundance of a keystone species within the Santa Monica Mountains (SMM) has been dwindling. This species, Malosma laurina, has an average root depth of 40 feet, so it has little difficulty tapping into the watershed. Recently, this species has undergone extensive dieback, which is potentially attributed to the unprecedented drought and the introduction of the fungus B. dothidea. While this fungi appears to be innocuous to M. laurina when the plant is healthy, it is more susceptible to invasion under water stress due to the dry heated conditions of …

Premature Seed Germination And High Seedling Mortality In A Chaparral Shrub (Adenostoma Fasciculatum) Caused By Severe Drought In Calfiornia, Lexe Evans, Teal Speece, Stephen D. Davis

Biology

The Santa Monica Mountains (SMM) represents one of five Mediterranean-type environments in the world. With sustained summer droughts, this ecosystem is prone to frequent wildfires, a phenomenon that has affected the SMM with regularity once every 32 years. Adenostoma fasciculatum (chamise), is a chaparral shrub well adapted to wildfire cycles because typically its seeds are triggered to germinate by high fire temperatures, smoke, and charate. In the winter of 2015, we were surprised to discover seedlings of A. fasiculatum emerging at an unburned chaparral site without the occurrence of fire. We hypothesized that drought induced canopy dieback at some microsites, …

Recent Dieback In A Keystone Chaparral Species Is Caused By A Fungal Pathogen, Botryosphaeria Dothidea, Adriana Borges, Frida Morales, Emily Pierce, Mariah Taylor

Biology

Due to the recent drought in Southern California, the abundance of a keystone species, Malosma laurina, within the Santa Monica Mountains (SMM) has been dwindling. This species has a rooting depth that exceeds 13 m, so it typically has little difficulty tapping into the water table. Recently, this species has undergone extensive dieback, which might be attributed to the unprecedented drought in California and predisposition fungal pathogen Botryosphaeria. dothidea. While this fungi appears to be innocuous to M. laurina when the plant is healthy, it is more susceptible to invasion under water stress due to the dry and …

Extensive Dieback In Malosma Laurina In Coastal Exposures Of The Santa Monica Mountains Associated With Unprecedented Drought In California, Gina S. Gilderman, Kaitlyn E. Sauer, Gabriella Palmeri

Biology

Throughout coastal exposures of the Santa Monica Mountains (SMM) there is a recent emergence of widespread dieback in Laurel Sumac (Malosma laurina). M. laurina is a keystone species of chaparral that dominates the SMM. A significant trait of M. laurina is an extensive root system exceeding 12 m in depth. We hypothesized that M. laurina was weakened by unprecedented drought in California (2013-2015) and predisposed to fungal pathogens. An initial study conducted in the summer of 2015 revealed all stem samples taken from dieback adult M. laurina plants were infected with Botryosphaeria dothidea, while zero stem samples taken …

Natural Gardening, Lisa Karen Miller

DLPS Faculty Publications

This presentation features methods of natural and organic gardening that preclude the use of harmful pesticides and herbicides.

Novel Seed Germination In Response To California’S Historic Drought May Deplete Soil Seed Banks, Amanda M. Burns, Victoria M. Lekson, Helen I. Holmlund, Stephen D. Davis

Biology

We observed novel seed germination, without a fire cue, in an obligate seeding species of chaparral (Ceanothus megacarpus) during historic drought in California (2014). We hypothesized that premature germination was promoted by drought-induced canopy dieback among adults that allowed high radiation loads to reach normally shaded soils, cracking seed coats, facilitating water uptake. We hypothesized that because premature seed germination was late in the season (April, when December is typical) roots would not have time to penetrate deep moisture resources before the onset of summer drought, leading to excessive mortality and eventual depletion of soil seed banks. We …

Comparative Foliar Water Uptake And Leaf Hydrophobicity In Island Versus Mainland Ferns, Victoria M. Lekson, Helen I. Holmlund, Nicole A. Nakamatsu, Amanda M. Burns, Stephen D. Davis

Biology

In 2014, Southern California experienced the worst drought in the last 1,200 years. In this study, the mechanisms of drought tolerance for eight species of ferns in the Santa Monica Mountains were assessed with a focus on foliar water uptake and hydrophobicity of frond (leaf) surfaces. We measured gravimetric foliar water uptake and angle of contact for a drop of water on a frond. Seasonal shifts were tracked as a method of following drought response patterns.

Fog is becoming more important due to limited ground water. Fog is far more common on Santa Cruz Island off the coast of California …

How Does The Exploitation And Degradation Of Finite Natural Resources By Industrial Oil Producers Effect Our Future Planetary Environment?, Zachary J. King Mr.

Symposium of Student Scholars

Zachary King

Dr. Tu

26 March 2015

GEOG 3700

Abstract

The purpose of this presentation is to communicate content of the reports given by credible institution on the degradation and exploitation of finite natural resources by corporate institutions, for short term financial gain, and how it will effect the future planetary environment. Methods used in obtaining this research range from point source observation directly from oil spills in the Gulf or pipe leaks in the Mid-West, to analytical and numerical data quantifications gathered over a period of two decades. This presentation encompasses a wide scope of information concerning the way …

Effects Of High Light Exposure On Photosynthetic Rate And Fluorescence Of Eucrypta Chrysanthemifolia, Alec Flores, Gina Gilderman, Hannah Dario

Featured Research

In this experiment, we examined how a partial shade plant, Eucrypta chrysanthemifolia, found in the Santa Monica Mountains, responded to predictive models of higher light intensities created bydrought. We hypothesized that, with higher levels of light, Eucrypta chrysanthemifolia would respond with a decreased photosynthetic rate, light-adapted, and dark-adapted fluorescence. This was performed by comparing control plants grown in an artificial shade environment to plants exposed to a series of high light intensity treatments. These partial shade plants were found on Piuma Trail in the Santa Monica Mountains. Our data supported our null hypothesis, indicating the photosynthetic rates and light-adapted …

Seedling Resprouts Of Adenostoma Fasciculatum Between Wildfire Cycles Are Promoted By Environmental Conditions That Mimic Fire-Like Environments, Lexe Evans, Teal Speece, Stephen D. Davis

Featured Research

The Santa Monica Mountains represent one of the largest Mediterranean-type environments in the world. With sustained summer droughts, this ecosystem has become prone to frequent wildfires, a phenomenon that has affected the area with regularity (approximately 21 years apart). Naturally, this cycle of wildfires has had a great effect upon the mortality and survival of the diverse chaparral varieties that inhabit the Santa Monica Mountain region. This includes the Adenostoma fasciculatum (chamise), which is the most commonly-found form of chaparral shrub in California. (Redfeldt & Davis, 1996) This species of chaparral is particularly well-adapted to survival in a climate that …

Morphological Changes In Malosma Laurina Due To Prolonged Drought In The Santa Monica Mountains, Grace S. M. Bae, Majie C. Foster, Maryelizabeth S. Stein, Mariah K. Taylor

Featured Research

Observations of Malosma laurina seedlings in Sycamore Canyon, Malibu, CA, exhibit abnormally small and wrinkled leaves. We propose that the prolonged drought in California’s Santa Monica Mountains has lead to physical malformations indicative of water strain in the leaves of M. laurina plants. In this experiment, we tested water relations of six M. laurina plants found on Pepperdine University’s Malibu campus showing similar leaf patterns to those found in Sycamore Canyon. Six M. laurina plants devoid of the abnormal leaf growth patterns functioned as our control group. Stomatal conductance, water potential, and leaf mass to area data was gathered using …

Possible Fungal Infection Leading To Malosma Laurina Dieback, Gabriella N. Palmeri, Braden S. Olsen, Kaitlyn E. Sauer, Stephen D. Davis

Featured Research

There is a significant and apparent dieback of Malosma laurina in the Santa Monica Mountains, some which is found near Pepperdine University. Other areas near Pepperdine show a flourishing growth of M. laurina and our objective was to determine why this difference in M. laurina health exists. We initially hypothesized that in addition to water stress, the unhealthy M. laurina was effected by a pathogen. Under further inspection, the unhealthy plants contained hyphae in some of their xylem vessels, while the healthy ones did not. We sought to determine whether the existence of hyphae in the unhealthy plant’s xylem affected …

Effects Of Drought On Malosma Laurina Leaves, Suk Ho (Josh) Chang, Jingyi Chen, Sarah B. Nelson

Featured Research

Drought induced deformations in the chaparral plant Malosma laurina were observed following the lack of water availability during the years of 2013 and 2014. We hypothesized that the middle leaves grown during the drought would have the lowest productivity, the top post-drought leaves would have the highest productivity, and the bottom pre-drought leaves would have an intermediate level of productivity. We used a sample size of n = 6, representing 6 unique M. laurina plants. To obtain our data, we used the LI-6400 gas exchange system. In our comparisons of photosynthetic rate, stomatal conductance, and photosynthetic quenching of the top, …

Fitness Parameters In Malosma Laurina Seedlings Growing Near And Away From Invasive Brassica Nigra, Natalie M. Aguirre, Agustin Vargas, Phoebe Shin

Featured Research

In this study we aim to assess the photosynthetic rate of native Malosma laurina (M. laurina) seedling, in comparison to M. laurina seedlings growing amongst several hundred B. nigra invasive plants. We predicted that there will be a difference in the stomatal conductance of each population. We measured photosynthetically active radiation (PAR), seedling height, and stomatal conductance of two isolated populations of M. laurina seedlings. One population grows near B. nigra, an invasive specie, and the other only grows amongst native plants. We found that M. laurina seedlings growing near weeds …

Difference In Chaparral Species Population On The North And South Aspect On Pepperdine University Campus, Alexandra N. Lozano, Drew N. Rasmussen, Ashlyn L. Rawls

Featured Research

In this experiment, we analyzed the difference in population frequencies of chaparral plants along the north and south aspect of a slope on Pepperdine University campus in the Santa Monica Mountains in Malibu, CA. We began the experiment by hypothesizing the south aspect would receive the most sunlight, and thus would hold the most amount of plants. By using the Point Quarter Sampling Method, we were able to determine if our hypothesis was correct. After analyzing our data, we found no significant difference between the north and south aspect in terms on frequency. During our experiment we also measured the …

Correlation Between Hydration And Reflectance Of Yellow Petals On Encelia Californica, Jayci M. Givens, Kaylee A. Nussbaum, Caitlin R. Kawata

Featured Research

It is known that the NDVI can be used as a measure of hydration in plants because of the variation in pigments due to xanthophyll cycling (Schmitz et al., 2013). Flower petals can also exhibit variations in petal reflectance invisible to the naked eye (Fam & Espinoza, 2013). It was hypothesized that overall hydration levels of a plant would correlate to a difference in the pigments produced for petal color, and thus differences in hydration levels would correlate to differences in petal reflectance. To test this hypothesis, three flowers and two stems were collected from ten different E. californica plants, …

The Effects Of Salinity On The Photosynthetic Rate Of Limonium Californicum, Adriana J. Borges, Elizabeth S. Chau, Justine M. Mckitrick

Featured Research

Halophytic plants, unlike most plants, are able to survive in stressful saline environments. Halophytes possess adaptations to osmoregulate, which gives them a competitive edge in saline environments such as coastal salt marshes. Our group analyzed the responses to salinity of the halophytic plant, Limonium californicum, which is present in California’s coastal salt marshes. We hypothesized that the photosynthetic rate of the Limonium californicum plants would decrease with increasing saline water treatments. In order to test this hypothesis, we watered L. californicum plants with solutions of varying salinity over the course of four days. We measured the photosynthetic rates using …

Correlation Between Hydration And Reflectance Of Yellow Petals On Encelia Californica, Jayci M. Givens, Kaylee A. Nussbaum, Caitin R. Kawata

Featured Research

It is known that the NDVI can be used as a measure of hydration in plants because of the variation in pigments due to xanthophyll cycling (Schmitz et al., 2013). Flower petals can also exhibit variations in petal reflectance invisible to the naked eye (Fam & Espinoza, 2013). It was hypothesized that overall hydration levels of a plant would correlate to a difference in the pigments produced for petal color, and thus differences in hydration levels would correlate to differences in petal reflectance. To test this hypothesis, three flowers and two stems were collected from ten different E. californica plants, …

Differential Survival Of Chaparral Shrub Species In Response To Severe Drought, Hannah Dario, Stephen D. Davis

Biology

In this experiment, we examined how the plants in the Santa Monica Mountains are responding to the driest period in recorded history for California. Our hypothesis was that plant species with the deepest roots would have highest survivorship. We thought this because deep-rooted shrubs will have greater access to soil moisture. This hypothesis was tested by collecting data on plant survival, in a mixed chaparral stand, containing eleven species, growing in the Green Valley Preserve off of Stunt road, in the Santa Monica Mountains. The chaparral stand was 21 years old, having last burned in 1993 (Old Topanga Canyon Fire). …

The Folklore Of Herbs, Lisa Karen Miller

DLPS Faculty Publications

Take a walk through the herb gardens of history and find out what our ancestors knew (and thought they knew) about herbs and their uses for medicine, beauty, and even love. The presentation compares ancient beliefs to current scientific evidence and reveals the places where they intersect.

Fl-Friendly Container Gardening, John J. Pipoly Iii

Marine & Environmental Sciences Faculty Reports

No abstract provided.

Fl-Friendly Container Gardening, John J. Pipoly Iii

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.

Florida-Friendly Butterfly Gardening, John J. Pipoly Iii

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.