Resource management is necessary for the success of a species. Optimal foraging theory states that a species will attempt to minimize the energy spent obtaining resources, whilst maximizing the resources collected. Optimal foraging theory can be examined through the lens of ant colony behavior. Formica obscuripes utilizes role specialization and resource partitioning in each colony to minimize its energy use while maximizing its nutrient reserve. However, nutrient preferences within roles have been largely unstudied. In...

Oak woodlands are in decline due to failed oak recruitment in California. Oak recruitment is heavily impacted by vertebrate herbivory and insect infestation of acorns. Oaks have developed chemical defenses such as tannins to protect acorns from attack. Studies have explored infestation differences in red oaks but have not compared infestation between red oaks and white oaks. We explored how Cydia latiferreana (filbertworm) infestation, Curculio occidentalis (filbert weevil) infestation, and Sciurus griseus nigripes (western gray...

Parasitic plants must rely on their hosts to survive. However, the distribution and survival of parasitic plants often depends on other organisms in addition to the host. Desert mistletoe (Phoradendron californicum) has a unique interdependent relationship with its preferred host, honey mesquite (Prosopis glandulosa), and its primary disperser, Phainopepla (Phainopepla nitens). We sought to study this relationship by testing the effects of honey mesquite size and distribution on the likelihood of infection by mistletoe. At...

Deserts are changing rapidly due to urbanization and climate change. Although human development can destroy habitat, it can also create novel environments that organisms may use or adapt to. In this study we compared artificial ponds to natural oases to determine whether artificial water sources differ in the odonate communities they support, as odonate species are indicators of aquatic habitat quality. We found that odonate community composition differed markedly based on water source characteristics such...

Predation is a potent ecological and evolutionary force, shaping the behavior of animals to minimize risk. Behavior itself can therefore provide clues into the predation pressure experienced by a population. We investigated anti-predator vigilance behavior in a California coastal population of black-tailed deer in response to vocal cues from three predator species of varying current and historical risk: grey wolf, coyote, and red-tail hawk. Vigilance was measured as the proportion of a herd alerting to...

Grazing has been documented to have widespread effects on flora and fauna in a variety of ecosystems. However, research has yielded conflicting results on determining the impact of grazing on ants; some have found that grazing increases ant abundance and alters composition while others have found the opposite pattern. It is critical to accurately survey the consequences of grazing in order to understand the implications of this widespread land management practices on ecosystems especially on...

Fluctuating flowering patterns affect an environments floral abundance, impacting the spatial structure of nectar and pollen resources, ultimately influencing floral visitor foraging behavior. We examined the effect of reducing floral resources on floral visitors of Monardella odoratissima, commonly known as the mountain coyote mint. Isolated patches of M. odoratissima were created by removing all surrounding resources, in order to test its effect on floral visitor communities. Exploring how the resource-richness of a habitat affects this...

Drylands are prone to desertification as human disturbances degrade desert ecosystems and limit their capacity to bio-produce. Biological soil crusts, a specialized community of lichen and cyanobacteria, are particularly vulnerable to these disturbances. To gauge the effects of anthropogenic disturbance on soil particle size and soil crust growth, Collema, a widely-distributed genus of soil lichen, was used as an indicator of overall ecosystem health. We used the visual percent cover method in four “low disturbance”...

Road disturbance can facilitate the establishment and growth of invasive plant species and herbivorous insects in adjacent ecosystems. The hydrological and atmospheric impacts of roads are especially important to understand in arid desert environments that are highly sensitive to water stress and dust pollution. In this study, we looked at how impacts of road disturbance change among different road types within the Mojave Desert. Specifically, we observed how three types of roads (paved road, dirt...

Streams and rivers represent less than 0.0001% of the planet's water, but are support up to 10% of its biological diversity and are fundamental to human life. As sources of drinking water, transportation, recreation, and energy, streams are both highly valuable and highly vulnerable to us. Humans have obvious imperative to protect stream ecosystems, but many effects are likely to be unintentional and unseen, incidental to our existing in a place. We sampled stream macroinvertebrate...

Disturbance often increases local-scale (α) diversity by suppressing dominant competitors. However, widespread disturbances may also reduce biotic heterogeneity (β diversity) by making the identities and abundances of species more similar among patches. Landscape-scale (γ) diversity may also decline if disturbance-sensitive species are lost. California’s vernal pool plant communities are species-rich due in part to two scales of β diversity: (1) within pools, as species composition changes with depth (referred to here as vertical β diversity),...

The force-dependent bond lifetime of a T Cell Receptors (TCR) to 17 peptide-Major Histocompatibility Complexes (pMHCs) was simulated using Steered Molecular Dynamics. Physiochemical descriptors of the TCR-pMHC interaction during simulation were then filtered and selected to understand the best feature sets that predict bond lifetime. This methodology sets precedence on the rational design of TCRs via force-dependent bond lifetime enhancement.

Selection for crop cultivars has largely focused on reproductive traits, while the impacts of global change on crop productivity are expected to depend strongly on the vegetative physiology traits that drive plant resource use and stress tolerance. We evaluated relationships between physiology traits and growing season climate across winegrape cultivars to characterize trait variation across growing regions and elucidate the mechanisms that adapted grapevines to hot, dry conditions. We compiled values from the literature for...

Dockless bikeshare systems show potential for replacing traditional dock-based systems, primarily by offering greater flexibility for bike returns. However, many cities in the US currently regulate the maximum number of bikes a dockless system can deploy due to bicycle management issues. Despite inventory management challenges, dockless systems offer two main advantages over dock-based systems: a lower (sometimes zero) membership fee, and being free-range (or, at least free-range within designated service areas). Moreover, these two advantages...

Maternally inherited Wolbachia transinfections are being introduced into natural mosquito populations to reduce the transmission of dengue, Zika and other arboviruses. Wolbachia-induced cytoplasmic incompatibility provides a frequency-dependent reproductive advantage to infected females that can spread transinfections within and among populations. However, because transinfections generally reduce host fitness, they tend to spread within populations only after their frequency exceeds a critical threshold. This produces bistability with stable equilibrium frequencies at both 0 and 1, analogous to...

Evolutionary comparisons between major environmental divides, such as between marine and freshwater systems, can reveal the fundamental processes governing diversification dynamics. Although processes may differ due to the different scales of their biogeographic barriers, freshwater and marine environments nevertheless offer similar opportunities for diversification in benthic, demersal, and pelagic habitats. Here, we compare the evolutionary patterns and processes shaping teleost diversity in each of these three habitats and between marine and freshwater systems. Using specimens...

Around 90 percent of natural oak habitats have been cleared due to the development of agriculture, cattle ranching, and urbanization. This study focuses on the legacy of coast live oaks (Quercus agrifolia) and how they influence their surrounding environment through testing soil moisture, plant biomass, and plant percent cover. We located areas containing dead and living coast live oaks trees along two valleys at Sedgwick Reserve, examining trees that were living, recently dead (<15 years),...

MISSION STATEMENT: The UC Natural Reserve System is a network of protected natural areas throughout California. Its 39 sites include more than 756,000 acres, making it the largest university-administered reserve system in the world. Most major state ecosystems are represented, from coastal tidepools to inland deserts, and lush wetlands to Sierra Nevada forests. The reserves also serve as a gateway to more than a million acres of public lands. Founded in 1965 to provide undisturbed...

MISSION STATEMENT: The UC Natural Reserve System is a network of protected natural areas throughout California. Its 39 sites include more than 756,000 acres, making it the largest university-administered reserve system in the world. Most major state ecosystems are represented, from coastal tidepools to inland deserts, and lush wetlands to Sierra Nevada forests. The reserves also serve as a gateway to more than a million acres of public lands. Founded in 1965 to provide undisturbed...

MISSION STATEMENT: The UC Natural Reserve System is a network of protected natural areas throughout California. Its 39 sites include more than 756,000 acres, making it the largest university-administered reserve system in the world. Most major state ecosystems are represented, from coastal tidepools to inland deserts, and lush wetlands to Sierra Nevada forests. The reserves also serve as a gateway to more than a million acres of public lands. Founded in 1965 to provide undisturbed...

MISSION STATEMENT: The UC Natural Reserve System is a network of protected natural areas throughout California. Its 39 sites include more than 756,000 acres, making it the largest university-administered reserve system in the world. Most major state ecosystems are represented, from coastal tidepools to inland deserts, and lush wetlands to Sierra Nevada forests. The reserves also serve as a gateway to more than a million acres of public lands. Founded in 1965 to provide undisturbed...