492 Works

Plant morphology and behavior of Simmondsia chinensis in the Colorado Desert

Sarah Eskander, Kayla M. Kettmann, Jeramy Ott & Sarah Payne
At the edges of its range in the Colorado Desert, jojoba (Simmondsia chinensis) has been known to exhibit local morphological adaptations not found elsewhere in its distribution. In this study, we expand upon jojoba’s known sexually dimorphic adaptations and examine its behavioral adaptations to a xeric environment. Specifically, we investigate how jojoba avoids intense solar radiation through leaf orientation. We found that jojoba does not exhibit paraheliotropic leaf tracking but instead orients its leaves to...

An ancient forest on the move: Range shifts in bristlecone pines

Angela Delos Santos, Katherine Pratt, Grace Rosburg-Francot, Linnea Schaefer & George Sidarous
Recent changes in global climate are causing many species to shift their ranges towards higher elevations. The rate at which species can shift their ranges may determine whether or not they will be able to persist in light of such rapid environmental change. In this study, we examined the effect of elevation on recruitment, mortality, and intraspecific competition in Great Basin bristlecone pines (Pinus longaeva, BC), a long-lived subalpine species whose upper limit is often...

Alpine wet meadows: soil properties’ effect on plant diversity

Madeline Castro, Fidel Machado-Perez & Rebecca Raven
Alpine ecosystems are a harsh environment with little nutrients and the abiotic effect that the soil has on the plant community is relatively unknown. The focus of this study is to illuminate the role that soils play in the plant diversity of alpine wet meadows. In doing so we investigated the function of clay and root content, organic matter, pH and soil moisture in determining plant diversity in three meadows in the White Mountains, California....

Seed preference in a desert harvester ant, Messor pergandei

Tonia Brito-Bersi, Emily Dawes, Richard Martinez & Alexander McDonald
Optimal foraging theory states that foragers maximize their energy intake by minimizing the energy expended to collect their food. The harvester ant, Messor pergandei, provides a model system to study foraging energy expenditure due to their dependable group foraging behavior. Exploring seed preference could give us further insight into how their harvesting affects the surrounding vegetation and ecosystem as a whole. Choice trials were conducted on M. pergandei using three native seeds and one non-native...

The impact of shallow landslides on primary productivity

Addison Eftekhari, Carly Lam, Francesca Penny & Ian Silberstein
Shallow landslides provide us with a closer look at succession in response to disturbances and their long-term impact on a landscape. Shallow landslides are commonly found in low hills of coastal California, and while research has been conducted on the impacts to human infrastructure and habitation, effects on plant communities and subsequent succession has not been well researched. This study looked at the effect of shallow landslides on vegetation in the grasslands of UC Santa...

Long-term changes in composition of old-growth mixed evergreen forests in Mendocino County

, Charlie Schiebl, Gabriel Perez & John Salib
Abiotic factors have caused changes in old-growth California forests. These changes may be indicators of environmental stressors such as decreases in precipitation, increases in temperature, and changes in historic fire regimes. We aim to examine these changes by doing a 40-year follow-up study on Ashley Boren’s 1981 undergraduate thesis, conducted at Angelo Coast Reserve in Mendocino County, California. The purpose of this study is to examine whether or not the predictions made in 1981 would...

Herbivory defense and growth tradeoffs along a moisture gradient in Lupinus latifolius var. columbianus

Lilly Boiton, James Powers & Jordan Waits
Hypotheses such as the plant stress hypothesis, apparency theory, and the resource availability hypothesis provide contrasting predictions to how plants respond to abiotic stress and their interactions with herbivores. In this paper we examined the effects of a water availability gradient on the morphological characteristics and herbivory of Lupinus latifolius var. columbianus. We measured the abundance of the leaf beetle, Galeruca rudis, and Aphididae as well as the amount of leaf herbivory damage on lupine...

Factors affecting woodrat abundance over 70 years

Wolfgang Abad, Jose Morales-Doo, Carly Pomeroy & Adrienne Ung
Woodrats are ecosystem engineers that can increase biodiversity by physically changing the environment. In doing so, they alter landscapes and increase the number of microhabitats for other organisms. In order to better understand woodrats’ role in their ecosystem, we surveyed big-eared woodrat (Neotoma macrotis) houses in Hastings Natural History Reservation located in Monterey County, California. For each house, we determined its usability and measured its size. We found a 26 percent increase in population density...

Competition between exotic honey bees (Apis mellifera) and native pollinators on late-blooming desert scrub

Janelle M. Osteen, Alexis M. Necarsulmer, Jessica J. Fan Brown & Nhung H. Nguyen
Pollinators are essential to worldwide biodiversity. This study focuses on pollinator communities on Isocoma acradenia, a late blooming shrub in the Colorado desert. We hypothesize that late in the flowering season, exotic honey bees and native pollinators experience increased competition for floral resources. We surveyed pollinator species richness, abundance, and competitive interactions. Our results reveal that honey bee presence does not have effects, competitive or otherwise, on native pollinators. Continuing to research exotic and native...

The effects of sunlight and slope on the lichen community of the Sweeney Granite Mountains reserve

Kha Cung, , & Samantha Spiegel
Lichen communities are essential to their ecosystems as they provide a means of nitrogen fixation, suitable growing conditions, and resources to other organisms across diverse environments. Their community structure can be impacted by changes in abiotic factors such as temperature, pollution, precipitation, and sunlight. It is widely assumed that lichen prefer to grow on the northern faces of their substrates because it is believed they experience less desiccation and UV radiation from sunlight exposure. This...

Habitat preference and species interactions of the desert woodrat (Neotoma lepida) in the Mojave Desert

Becca Cosmero, Emily Fieberling, Katherine Marlin, Ricardo Ruiz, & Lara Volski
Ecosystem engineers often have cascading impacts on the ecosystems in which they occur. Understanding the factors that contribute to their habitat selection can provide valuable information on how ecosystems function. Our study investigates the habitat distribution of desert woodrats (Neotoma lepida) in the Eastern Mojave Desert. We show that there is a difference in desert woodrat abundance among habitats, and found that specific aspects of these environments are associated with woodrats. These aspects include grass...

Data from \"Quantification of major particulate matter species from a single filter type using infrared spectroscopy – Application to a large-scale monitoring network\"

Ann Dillner, Bruno Debus, Andrew T. Weakley, Satoshi Takahama, Kathryn George, Bret Schichtel, Scott Copeland & Anthony Wexler
This data set contains FT-IR data obtained from spectra of PTFE filters routinely in IMPROVE network during the time period 2015-2017, as well as the corresponding routine IMPROVE data for all ( ~160) IMPROVE sites except Korea. The data include PM2.5 aerosol concentrations measurements for organic carbon (OC), elemental carbon (EC), total carbon (TC), sulfate, nitrate, silicon, aluminum, calcium, titanium, iron, mass and light absorption. The data are in ug/m3. Some samples are excluded based...

Bacteria isolated from bengal cat (Felis catus × Prionailurus bengalensis) anal sac secretions produce volatile compounds associated with animal signaling

Mei Yamaguchi, Guillaume Jospin, Holly Ganz, David Coil, Jonathan Eisen, Adrienne Cho, Thant Zaw, Mitchell McCartney & Cristina Davis
Anal sacs are an important odor producing organ found across the mammalian Order Carnivora. Secretions from the anal sac may be used as chemical signals by animals for behaviors ranging from defense to species recognition to signaling reproductive status. In addition, a recent study suggests that domestic cats utilize short-chain free fatty acids in anal sac secretions for individual recognition. The fermentation hypothesis is the idea that symbiotic microorganisms living in association with animals contribute...

Soil Water Content at MMWD

Peter Hartsough
These data were collected using Decagon (Meter) GS1 sensors at two different depths, 30cm and 60cm. Data were collected hourly and these are mean values at the three different sites.

A microbial survey of the International Space Station (ISS)

Jonathan Eisen, David Coil & Jenna Lang
Background Modern advances in sequencing technology have enabled the census of microbial members of many natural ecosystems. Recently, attention is increasingly being paid to the microbial residents of human-made, built ecosystems, both private (homes) and public (subways, office buildings, and hospitals). Here, we report results of the characterization of the microbial ecology of a singular built environment, the International Space Station (ISS). This ISS sampling involved the collection and microbial analysis (via 16S rDNA PCR)...

Signatures of Environmental Adaptation During Range Expansion of Wild Common Bean (Phaseolus vulgaris)

Paul Gepts
Landscape genomics integrates population genetics with landscape ecology, allowing the identification of putative molecular determinants involved in environmental adaptation across the natural geographic and ecological range of populations. Wild Phaseolus vulgaris, the progenitor of common bean (P. vulgaris), has a remarkably extended distribution over 10,000 km from northern Mexico to northwestern Argentina. Earlier research has shown that this distribution represents a range expansion from Mesoamerica to the southern Andes through several discrete migration events and...

Incipits for the Catalogue of the Works of Hector Berlioz, Second edition, digital

Jonathan Minnick & D. Kern Holoman
This collection of PDFs contains all of the incipits for the Catalogue of the Works of Hector Berlioz, Second edition, digital, edited by D. Kern Holoman and Jonathan Minnick. Contents used with permission from Bärenreiter-Verlag / Kassel-Basel-London-New York-Praha / www.barenreiter.com

Data associated with manuscript \"Predicting wave-induced sediment resuspension at the perimeter of lakes using a steady-state spectral wave model\"

Derek Roberts, S. Geoffrey Schladow, Simon Hook, Shohei Watanabe & Patricio Moreno-Casas
This repository includes data associated with the manuscript, "Predicting wave-induced sediment resuspension at the perimeter of lakes using a steady-state spectral wave model," currently in press at Water Resources Research as of January 2019. Following American Geophysical Union standards, this repository serves to publically share all data associated with the manuscript. Plain lanuage summary of the manuscript: A tool that describes lake-wide wave conditions as a function of combinations of wind speeds and directions is...

Heterotrophic N2-fixation contributes to nitrogen economy of a common wetland sedge, Schoenoplectus californicus

Eliska Rejmankova, Dagmara Sirova, Stephanie Castle, Jiri Barta & Heather Carpenter
These data sets document environmental characteristics of sampling locations of Schoenoplectus californicus, california bulrush, throughout its range in the Americas. In addition, the data on nif gene in rhizomes and roots of Schoenoplectus are provided.

Vibrational Neutron Scattering Spectra for Undoped and Doped P3HT

Thomas Harrelson, Jun Li & Adam Moule
Doped semiconducting polymers have garnered vast research interest in photovoltaic, transistor, thermoelectric, and sensor applications. P3HT is a canonical semiconducting polymer that self-assembles into a mixture of crystalline and amorphous domains. Doping P3HT can increase the observed conductivity by several orders of magnitude. The vibrations of the polymer are sensitive to the local morphology of the film, and the morphology of the film changes upon doping. Vibrational neutron spectroscopy is a method for identifying vibrational...

Regional and disease-related differences in properties of the equine temporomandibular joint disc

Derek Cissell
Temporomandibular joint (TMJ) disorders are increasingly recognized in animals. The articular disc plays a major role in TMJ disorders in people, but its role in the pathogenesis of TMJ disease in animals is not well understood. This study characterizes properties of the equine TMJ disc, including regional variation within discs as well as differences in properties associated with naturally-occurring TMJ osteoarthritis.

Caltrans PEMS highway sensor average flows by occupancy

Clark Fitzgerald & Michael Zhang
This data summarizes average vehicle flow as a function of occupancy for traffic sensor data available from CalTrans Performance Management System (PEMS). It's useful because it shows the behavior of traffic in congested regimes, without requiring the preprocessing of several hundred GB of the raw data. Open the pdf files to see what this data looks like.

Defining hydrogel properties to instruct lineage- and cell-specific mesenchymal differentiation

Kent Leach
The maintenance and direction of stem cell lineage after implantation remains challenging for clinical translation. Aggregation and encapsulation into instructive biomaterials after preconditioning can bolster retention of differentiated phenotypes. Since these procedures do not depend on cell type or lineage, we hypothesized we could use a common, tunable platform to engineer formulations that retain and enhance multiple lineages from different cell populations. To test this, we varied alginate stiffness and adhesive ligand content, then encapsulated...

Channel types predictions for the Sacramento River basin

Hervé Guillon, Colin F. Byrne, Belize Arela Albin Lane, Samuel Sandoval Solis & Gregory Brian Pasternack
Hydrologic and geomorphic classifications have gained traction in response to the increasing need for basin-wide water resources management. Regardless of the selected classification scheme, an open scientific challenge is how to extend information from limited field sites to classify tens of thousands to millions of channel reaches across a basin. To address this spatial scaling challenge, we leveraged machine learning to predict reach-scale geomorphic channel types using publicly available geospatial data.

Effect of stressors on the carrying capacity of spatially distributed metapopulations

Bo Zhang, Donald DeAngelis, Wei-Ming Ni, Yuanshi Wang, Lu Zhai, Alex Kula, Shuang Xu & David Van Dyken
Stressors such as antibiotics, herbicides and pollutants are becoming increasingly common in the environment. The effects of stressors on populations are typically studied in homogeneous, non-spatial settings. However, most populations in nature are spatially distributed over environmentally heterogeneous landscapes with spatially-restricted dispersal. Little is known about the effects of stressors in these more realistic settings. Here, we combine laboratory experiments with novel mathematical theory to rigorously investigate how a stressor’s physiological effect and spatial distribution...

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