Elsa Calderon, Environmental Studies
Environmental Justice and the Threat to Black Farm Ownership in the Mississippi
Calderon’s research focuses on the fertile and water-rich Mississippi Delta, an area attracting investor interest that is also home to a large Black farming community. As the number of large and corporate-owned farms grew, so did agricultural technology and crop production. The changing landscape pressured Black farmers to often turn to the US Department of Agriculture (USDA), whose loan agencies were designed to provide financial assistance for farmers facing setbacks with yield production and natural disasters. However, Black farmers seeking USDA support often faced discrimination by local USDA agents and received more letters of rejection than assistance. She is seeking to uncover the intersections between the influx of investment capital into Southeastern farmland markets and the preexisting landscape of racial inequality. In her research, Calderon asks, “What are the lived experiences of Black farmers regarding corporate land grab practices?” From a natural science perspective, the Mississippi Delta is a hotspot for monoculture farming, and the environmental impacts from large agribusiness should be further explored. Calderon also therefore examines intersections with soil health.
Vidi Castro, Ecology and Evolutionary Biology
Developing Climate-Resilient Crops: a multi-trait analysis of the dry-farm tomato Solanum lycopersicum
Dry-farming is a method for growing crops under minimal water in clay soils located in areas with summer-time marine influence. While dry-farming does not maximize yields, it increases crop flavor intensity, growers using dry-farming methods can increase crop prices, and it also allows extending the regular growing season. The goal of Castro’s project was to capture the physiology of organic dry-farmed tomatoes. Her experiments interrogated two of California’s most popular varieties of organic tomatoes, the New Girl slicer variety and the dehybridized, dry-farm Dirty Girl variety, when grown under irrigated and dry-farm conditions. Castro found differences in how tomato varieties respond to dry-farmed conditions. Specifically, photosynthetic carbon assimilation did not differ for Dirty Girl tomatoes between irrigated and dry farm plots, whereas the New Girl slicer tomatoes had lower photosynthetic carbon assimilation in the dry-farm plots. Her ongoing research is exploring other physiological and trait responses to the dry farm conditions.
Charlie Chesney, Environmental Studies
Cactus-Electricity Demonstration Plot
One potential way to alleviate our current energy crisis is to generate renewable energy and produce crops on the same plot of land. One candidate crop, the prickly pear cactus, is a drought-tolerant, climate-change-resilient plant that bears two agricultural products: nopales (cactus pad) and tuna (prickly pear fruit). The prickly pear cactus may also generate electricity from cacti photosynthesis. Because prickly pear occur in hot, dry environments, they only open their pores at night when temperatures are low. This means they can absorb CO2 while minimizing water loss. Cacti store CO2 as an acid during the night, and during the day this acid breaks down to make sugars. Because cactus stems are opaque, each side of the cactus undergoes this process independently, meaning the sun-facing side of the cactus breaks down the acid and photosynthesizes more rapidly than the other side. This results in a difference in acid concentration between the stem sides, creating a pH gradient, which is measured as a voltage. Chesney established the Cactus Electricity Demonstration Plot at the UCSC farm to examine how to (a) harvest electricity and monitor power production of prickly pear cactus stems and (b) understand how power production varies with planting orientation and weather conditions. Chesney built devices to remotely and continuously monitor cactus pH, voltage, current, and light interception and also built an electricity harvesting prototype. Chesney’s electrode design increased voltage production over previous models, and results in a voltage and current high enough to power a small electronic device.
Bo Huey Chiang, Microbiology and Environmental Toxicology
Metabolic Interactions among Human Gut Bacteroides that Co-Adhere to Dietary Plant Fiber Particles
The prevalence of inflammatory bowel disease (IBD), including Crohn’s disease and Ulcerative colitis, are on the rise globally, and suffering from IBD may lead to increased risk of colorectal cancer in IBD patients. Thus, there is an urgent need to understand the causative and exacerbative factors of IBD. IBD is likely related to both host and environmental factors. Dysbiosis, or abnormal abundance of bacterial species in the gut microbiota, is a common feature in IBD patients, but a diet high in non-digestible plant fibers may change the composition of the gut microbiota. Professor Michael Patnode’s lab has developed an artificial food particle technology to study bacterial adhesion to non-digestible plant fibers and interactions between co-adhering bacteria. Chiang used this technology to isolate defined food particle-associated bacterial communities in the intestine. Chiang’s work is aimed at providing information on bacterial interactions that can be used to predict the effects of dietary changes on gut bacteria and how these may exacerbate or ameliorate intestinal diseases.
Sanya Cowal, Environmental Studies
Ant-Mediated Biocontrol for Hawaiian Coffee
Hawaiian coffee is a culturally and economically significant crop. However, Hawaiian producers have experienced significant financial losses due to the 2010 introduction of the coffee berry borer (CBB), the most damaging coffee pest. The CBB bores inside coffee fruits where it completes its entire lifecycle, destroying the fruit from the inside out; since the invasion, Hawaiian farmers have reported CBB damage in up to 90% of their coffee. The CBB is commonly controlled with chemical pesticides, which can leach into water systems with significant consequences on human and ecosystem health. Biological pest control, the use of natural enemies to control pests, is one agroecological and economically accessible alternative to chemical pesticides. The goal of Cowal’s research is to investigate ant-mediated biocontrol as a sustainable pest control strategy for Hawaiian coffee. Cowal conducted ant surveys and experiments to test how well ants control the CBB in Hawaii. She found 20 ant species across the 16 coffee farms in Kona, Ka’u, and Puna areas of Hawaii. She also found that CBB damage ranged from 0.4% to 34.08% of fruits damaged in sampled coffee farms. Lastly, she found that ants removed CBB from coffee plants on 13 out of 16 farms, demonstrating an important potential for biological control of this pest.
Meg Decoite, Coastal Science and Policy
Marine Debris Assessment of the Channel Islands National Marine Sanctuary: Protecting Seafood Stocks
In collaboration with Commercial Fishermen of Santa Barbara, DeCoite worked with fishers from the spiny lobster fishery to conduct a targeted marine debris assessment and removal effort within the Channel Islands National Marine Sanctuary. Their boats, which are especially well-suited for handling larger debris, allowed DeCoite to focus on removing abandoned lobster traps from shorelines. This partnership was instrumental in making these some of the most effective debris removal efforts ever conducted in the area. Together, DeCoite and the fisherman developed new techniques for trap recovery and worked to streamline removal processes. Over the course of the project, they successfully removed a total of 162 traps from two critical beach areas, significantly reducing the impact of ghost fishing on local seafood stocks. Additionally, DeCoite worked with other researchers to centralize other datasets on lost underwater lobster traps and their removal and/or presence of ghost fishing.
Piyush Gandhi, Economics
Extinguishing the Blaze: Reducing Crop Residue Burning in India
Air pollution is a major concern in many Indian cities exposing millions of people to extremely toxic air. Crop residue burning contributes up to 40% of the air pollution in winter, often pushing the air quality index far over the safe limit. Various factors contribute to crop residue burning including credit constraints, a narrow time frame to prepare soil for the next crop, and a lack of information about sustainable crop residue management. Relatively new early maturity seed varieties could shorten the time needed between rice harvest and wheat sowing, reducing the pressure to burn crops, and lowering air pollution. Using a randomized controlled trial research design, Gandhi evaluated the impact of seed subsidies for early maturity variety and technical training about sustainable residue management on burning outcomes. Their preliminary results show that treatment farmers are approximately 31% more likely to adopt an early maturity variety of paddy seeds. In terms of acres, the treatment farmers sow the early variety seeds on about 4 additional acres compared to the control group of farmers.
Hannah Jayanti, Film and Digital Media
Topography
Topography is a multi-format documentary project. For several years, Jayanti has spent time in public lands, researching and collecting material for films and interactive works. From the Badlands, to Death Valley, to Fire Island and Zion, Topography unearths historical conflicts that have shaped the American landscape while exploring paths to environmental justice and ecological restoration. In the Badlands of South Dakota, a seemingly barren landscape is revealed to be teeming with life, buried histories, and crucial lessons about stewardship. Grounded in documentary footage, the project weaves together archival material and virtual landscapes. The land is cast as the protagonist and the narrative visits with humans and non-humans who have impacted the Badlands throughout its past, present and potential futures. Topography not only depicts ecological systems, but is an ecology of storytelling in itself. The Badlands portion includes a documentary feature film, a short film, a live-edited documentary performance, an immersive installation, and community projects. Similar to South Dakota, California’s public lands are stratifications of settler colonialism, indigenous dispossession, conservation, militarization, and preservation. The future can feel hopeless, and yet there are extraordinary practices of stewardship happening around the country. The Badlands provides a compelling case study for how the history of land use informs contemporary ecological approaches, and how communities are working towards sustainable futures.
Danielle Klawitter, Environmental Studies
Integrated Aquaculture-Agriculture for Nutrient Source and Soilborne Pathogen Suppression in Strawberries
Aquaculture systems generate large amounts of waste which may be beneficial to agricultural systems by supplying water and nutrients and by suppressing pathogens. Aquaculture effluent has high amounts of nitrogen, phosphorus, and potassium, the main nutrients supplied by typical synthetic fertilizers. The effluent is also rich in microorganisms, which suppresses plant root colonization of pathogens in tomatoes and may suppress common soilborne diseases in strawberries. Klawitter’s research investigated the use of aquaculture effluents for fertilization and disease suppression of strawberries, as well as the opportunity to implement sustainable, on-site, closed loop systems via Integrated Aquaculture-Agriculture (IAA) Systems. Klawitter conducted an in vitro study and a field study at the UCSC Farm to evaluate the potential for aquaculture wastewater to suppress soilborne pathogens in agriculture.
Edith Lai, Ecology and Evolutionary Biology
Hyperparasites in Plant Disease Control
Powdery mildew fungi are widespread pathogens affecting thousands of plant species, including many of agricultural and conservation importance. In California alone, powdery mildew management costs exceed hundreds of millions of dollars per year. While current control methods include breeding resistant cultivars, physical management, and chemical fungicides, these options are not always completely effective. One alternative is using the fungal hyperparasite, Ampelomyces quisqualis, as a biological control of powdery mildew. This hyperparasite grows inside powdery mildew structures to absorb nutrients, reducing growth and survival of the plant pathogen. Ampelomyces appears to have a broad host range, but we do not know much about how its impact varies across powdery mildew species. Understanding when and where Ampelomyces infection is more severe is a necessary step in designing a disease management tool targeting powdery mildew species. Lai investigated the ecological and evolutionary patterns underlying host specificity. She went on regular survey walks to collect leaf samples infected with powdery mildew throughout Santa Cruz County. She was then able to identify, collect, and culture pycnidia (flask-shaped structures bearing spores) from a handful of Ampelomyces-infected samples to create a small culture collection. In this initial survey, Lai found the hyperparasite only in the first half of the summer, and only in urban sites.
Jack Lin and Firouz Vafadari, Electrical and Computer Engineering
Greener Greenhouses
Greenhouses and hoop houses are becoming increasingly common as technology evolves to allow for optimization of growing conditions in a myriad of environments. The ability to create and manage a microclimate via sensors and actuators is essential for the success of greenhouse operations. The imminent bottleneck, however, is that current monitoring technologies employed in greenhouses are expensive, energy-demanding, and require frequent human intervention. In order to combat the unavoidable costs incurred by traditional agricultural sensing architectures, Lin and Vafadari investigated an ultra-low-power sensing node that leverages the existing supplemental LED lighting commonly found in indoor agriculture for both communication and power. Their Greener Greenhouses Project introduces a Visible Light Communication system, FIAT LUX, aimed at enhancing wireless data transmission for the Internet of Things (IoT) in noise-prone settings like greenhouses. They designed, simulated, and implemented a proof-of-concept prototype, validating FIAT LUX’s superior robustness and efficiency in high-noise conditions. FIAT LUX enables efficient, low-power data communication, positioning it as a viable alternative with potential applications in protected agriculture, precision agriculture, and smart IoT networks.
Suzanne Lipton, Environmental Studies
How Does Management Affect Dung Beetles and Cascading Impacts on Nutrient Cycling in California’s Central Coast?
Two of the largest and intertwined environmental crises we face today are massive loss of biodiversity and climate change. Agriculture, and in particular animal agriculture, is a salient example of how these crises interconnect. The largest sources of animal agriculture-based carbon dioxide emissions are from land use change when land is cleared to create pastures or crop fields for animal feed and from overgrazing. But grazed pasture systems can either be sources or sinks of greenhouse gases or may mitigate emissions by increasing soil carbon sequestration depending on ranch management. Whether a grazed pasture is a source or sink depends on emissions from dung, biological activity of insects and microbes that decompose dung, and any subsequent soil carbon storage. Lipton examined how management and landscape factors affect dung beetle diversity and abundance and whether dung beetle diversity and abundance influence microbial composition and carbon (C) and nitrogen (N) in soil organic matter. She found that wetland cover in the surrounding landscape boosted dung beetle abundance and species richness, forest cover had a positive effect on diversity, and grassland cover had a positive effect on species richness and diversity. She also found that grazing management, including the number of days cattle were grazed, and the animal density influenced abundance and species richness of dung beetles. She also found that the presence of different types of dung beetles influenced soil fungal communities, but not soil bacterial communities.
Siyu Luo, Environmental Studies
Enhancing California Farms and Water Resources: Growing Solar on Fallowed Land as a Drought Resilience Strategy
Luo’s research focuses on navigating contractual dynamics of on-farm solar development in the San Joaquin Valley. The goal is to better understand the potential challenges and opportunities to develop solar energy generation as a drought resilience strategy in response to the Sustainable Groundwater Management Act (SGMA). To gain insight into the contractual framework governing water rights and land use, Luo conducted a case study on the Westlands Water District (WWD). Through site trips in the water district and its office, she obtained detailed information about their land ownership practices. In addition, she observed how these policies have evolved, particularly in relation to farmers’ obligations to comply with property use and water supply agreements. Luo also developed a multinomial probit model to examine the likelihood of changes in crop selection by farmers, including fallowing, as a response to the adoption of solar energy. The study aims to predict how agricultural producers might engage in net metering programs. Understanding this engagement is crucial for assessing the impacts of fallowing linked with groundwater restrictions and for enhancing policy development in both groundwater and renewable energy planning in the agricultural sector.
John Madden, Electrical and Computer Engineering
Power measurement hardware to study microbial fuel cells as real-time soil carbon sensors
Soils have the capacity to sequester three times more carbon than above-ground vegetation. Leveraging this potential, however, is hindered due to the lack of real time sensing providing insight into the carbon cycle. The soil microbe community plays a key part in the soil carbon cycle, and monitoring microbial behavior may give us a window into the soil carbon cycle. A promising class of devices, known as microbial fuel cells, generate electricity in response to the activities of naturally-occurring exoelectrogenic microbes. The electrical response of these microbes over time are likely linked to the soil carbon cycle, but datasets to support this hypothesis are scarce. To address this, Madden is working to design a large scale and affordable monitoring system to progress the study of microbial fuel cells and their surrounding environment. This research is focused on correlating the output power signal from microbial fuel cells with the manual measurements of the carbon cycle, ideally creating a new model that would let us infer soil carbon solely from microbial signals in the future.
Morgan Masters, Electrical and Computer Engineering
Creating 3D Semantic Land Use Models with Agricultural Robotics
Though farmers have shown desire to adopt Artificial Intelligence (AI) technologies, implementation remains a hurdle due to technical barriers, fears of labor displacement, and issues on data ownership, security, and privacy. To address some of these concerns, Masters is working to create an AI-equipped camera system designed to be modular and easy to use, free to access, and provides users with complete control over their data. Their goal is to provide AI tools for land managers to use at a fraction of the cost, which could especially benefit smaller-scale growers. Users will be able to use these tools to create their own custom AI models, or, alternatively, use (or adapt) a model pre-created by the UCSC team. By providing a modular system with working examples of functionality and the possibility to customize, they expect to initiate broader interest in AI tools within the agriculture community.
Summer Sullivan, Environmental Studies
Leafy Greens and Digital Dreams: California Agriculture, Racial Capitalist Landscapes, and the Future of Farm Work
California’s Salinas Valley is known as the “salad bowl of the world” for its prolific and highly valuable leafy green production. As its lettuce growers face pressing environmental sustainability challenges and labor shortages, they are turning toward automated harvesting machines to increase efficiency, decrease their reliance on farmworker labor, and enter into the future work. However, unlike sturdier, more uniform crops that have long been mechanized, specialty crops like lettuce are perishable, fragile, and reach maturity at different rates. Despite “labor-saving” innovations, most lettuce varieties remain manually harvested by a predominantly Mexican immigrant workforce facing immigration challenges and discrimination. These unique circumstances have informed the lettuce industry’s desire to attract what one prominent lettuce grower called “a new type of worker” who can “marry this technology with the human touch.” But who is this new farmworker? Sullivan’s research is focused on (1) understanding agricultural industry perceptions regarding labor, workforce development, sustainability, and the future of work, (2) broadening academic and popular understandings of “digital laborers” and bring agricultural concerns regarding labor and sustainability to the fore of discussions surrounding the future of work, and (3) supporting farmworker communities in holding industry players accountable to creating safe environments as they introduce automation.
Tashina Vavuris, Environmental Studies
Connecting Leaders4EARTH with Agroecology and NEXTGEN Fellows
Vavuris’ dissertation research intersects environmental justice, anticolonial pedagogy, agroecology, and participatory practices. She embraces the approach of agroecology, which is conceptualized as a science, practice, and social movement that draws on non-Western relationships to land, seeks to involve all stakeholders, values all forms of knowledge, and is participatory and action-oriented. Additionally, agroecological research can emphasize the importance of understanding already present agricultural knowledge through more participatory methods, which is central in my work and fosters youth perspective to enhance environmental science learning. In work with UCSC’s People of Color Sustainability Collective (PoCSC), Vavuris forged a robust collaboration with a Salinas Valley-based, youth-led Environmental Justice organization, Leaders for Environmental Activism Reclaiming Their Health (Leaders4EARTH). The Environmental Justice Youth Leadership Academy (EJYLA), a multi-week, experiential learning program, is a mainstay of Leaders4EARTH programming. This research, conducted alongside Leaders4EARTH, aimed to (1) teach agroecology and science learning through embodied and relational pedagogies and (2) foster a critical sense of belonging through mentorship with Salinas Valley youth.
Giovanni Vega, Microbiology and Environmental Toxicology
Studying the biology of diet-induced antibodies that target plant glycans
Each person harbors hundreds of bacterial species in their intestine, and humans have evolved mutualistic relationships with gut bacteria. Dietary fiber in the plant-based foods we eat supplies these bacteria with their main source of nutrients. In return, bacteria provide our cells with metabolic byproducts of fiber breakdown. Gut bacteria can block incoming pathogens from colonizing and causing infection. Yet, the bacterial community in the gut can become imbalanced, a state called dysbiosis that has been linked to diseases such as inflammatory bowel disease, irritable bowel syndrome, and diabetes. Dietary plant fiber is a promising natural and non-invasive means for altering bacterial composition in the gut to favor configurations that promote health. However, the direct effects of plant fiber on the mammalian host are poorly characterized, making it hard to predict the overall outcome of these efforts to modulate gut bacteria with fiber. Vega’s research goal is to characterize the potential of dietary fiber as a natural and non-invasive means for altering gut bacterial compositions to favor configurations that promote health. Vega examined whether fiber-specific antibodies inhibit microbial growth using growth assays and germ-free mono-colonization experiments. In the case that these antibodies don’t inhibit microbial growth, future research could be done to determine if the function of these antibodies is meant to benefit the host through other means instead of altering the microbiota composition.
Connie Zheng, HAVC/Visual Studies
All The Food We Can and Cannot Find: A Visual Culture of Foraging 2001-2022
All the Food We Can and Cannot Find” examines different visual representations of foraging — from contemporary art projects to YouTube influencers — over the past two decades and across geographic regions. Anchored around four case studies, Zheng’s project works to connect spatial knowledge production and democratized modes of visuality with food sovereignty, land use, and agroecological diversity amidst worsening climate change. The research thus considers how foraging can work as a conceptually expansive practice that addresses overlapping political, ecological and aesthetic concerns; and enters into visual representation amidst conditions of climate breakdown and industrialized agriculture. Zheng conducted archival research at the New York Public Library, The Asia Art Archive in Hong Kong, and the Korean Film Archive in Seoul, Korea.