The Land Repurposing Research Round-Up is a quarterly speaker series designed to keep the land repurposing research and implementation community connected and informed. Our goal is to highlight the latest science, data, tools, and strategies driving land repurposing efforts. This series is a space where we can collectively create interdisciplinary dialogue, foster collaboration and ground research in real-world applications and needs.
The speaker series is orgnaized by Environmental Defense Fund, supported through funding from the Agriculture and Food Research Initiative of the USDA National Institute of Food and Agriculture (#2021-69012-35916) and the Water Resources Research Act 104(b) program administered by the US Geological Survey.
Dr. Amy Quandt is an Assistant Professor in the Department of Geography at San Diego State University. She is an environmental social scientist and human ecologist whose work focuses on agroforestry, natural resource management, and rural livelihoods, particularly in East Africa and California. Amy also explores the use of mobile technologies in agricultural development and studies community perceptions of drought and climate change.
She earned her Ph.D. in Environmental Studies from the University of Colorado Boulder, an M.S. in Resource Conservation from the University of Montana Missoula, and a B.S. in Biology from the University of Puget Sound. Before joining SDSU, Amy was the global coordinator for the Land-Potential Knowledge System Project, which helps smallholder farmers access biophysical information through the LandPKS mobile app.
Fluent in Swahili, Amy has spent five years living and working in East Africa with organizations including the World Agroforestry Centre, Kenya Red Cross Society, Peace Corps Tanzania, and USAID. Her research has been published in leading journals such as Environmental Science and Policy, Climatic Change, and World Development.
Perspectives on Land Repurposing: Insights from Farmers, Stakeholders, and Newspaper Analyses
Dr. Amy Quandt, Associate Professor of Environmental Geography, San Diego State University
The seminar will draw from three recent publications:
Quandt, A., Larsen, A.E., Bartel, G., Okamura, K., and D. Sousa. 2023. Sustainable groundwater management and its implications for agricultural land repurposing. Regional Environmental Change 23:120. Doi: 10.1007/s10113-023-02114-2
Quandt, A., Sousa, D., Bartel, G., Dunbar, W., Keiser, J., Marschalk, S., Perez, A., Williams, M., Larsen, A.E., and A.J. MacDonald. 2025. Groundwater recharge as an adaptive response to flood events in the San Joaquin Valley, California. Water Policy 27 (8): 785–803. Doi: 10.2166/wp.2025.188
Bartel, G., Quandt, A., Larsen, A.E., and D. Sousa. 2025. Identifying producer perspectives on groundwater management and repurposed land strategies in Kern County, California. Water Policy. Accepted.
Sarah Sarfaty Epstein is a Master of Science candidate in the Energy and Resources Group at the University of California, Berkeley. Her research focuses on landscape-scale climate resilience and decision-making in California’s agricultural sector, with an emphasis on the intersections of water, energy, and food systems.
Before graduate school, Sarah worked as an Associate at Ross Strategic, supporting projects in food systems, rural development, and energy resource planning. She is passionate about advancing environmental and social justice through collaborative, science-based solutions. Born and raised in the East Bay, Sarah is dedicated to fostering resilient and equitable futures for California’s communities and ecosystems.
Agrivoltaics Suitability: Multi-Criteria Decision Making in a Repurposing Context
Sarah Sarfaty Epstein, UC Berkeley Energy & Resources Group
California’s agricultural regions are rethinking land and water use to meet groundwater sustainability goals. This presentation examines agrivoltaics, the combined use of land for solar energy and crop production, as a strategy to build climate resilience across the food, energy, and water sectors. Using a multi-criteria decision-making framework, Sarah Sarfaty Epstein identifies where agrivoltaic systems are most suitable in California and how stakeholder input shifts those patterns. The research also explores connections between agrivoltaics, managed aquifer recharge, and other groundwater conservation efforts, offering insights for basin-level planning and the Multibenefit Land Repurposing Program. The findings show that thoughtful integration of environmental, technical, and social criteria can advance both agricultural and energy transition goals across the state.
Dust and Heat from Fallowed Agricultural Fields in California
Adeyemi Adebiyi, Assistant Professor, University of California Merced
Dr. Adeyemi (Yemi) Adebiyi is an Assistant Professor in the Department of Life and Environmental Sciences at UC Merced. His research focuses on understanding the impacts of atmospheric aerosol particles, such as dust and smoke, at the regional and global scales. In California, these include the implications of these aerosol particles on crop production, air quality, public health, precipitation, and droughts, among others. Before joining UC Merced, Dr. Adebiyi was a UC President's Postdoctoral Fellow at UCLA. He obtained his Ph.D. in Meteorology and Physical Oceanography from the University of Miami, Florida, and his M.Sc.-equivalent diploma in Earth System Physics at the International Center for Theoretical Physics in Trieste, Italy.
Abstract: Farmers often fallow their fields for various reasons, including soil degradation and nutrient depletion, water management and availability issues, economic factors and market dynamics, government policies, and environmental factors related to climate change. In California, previous studies have suggested that to achieve the goals of the Sustainable Groundwater Management Act (SGMA), which aims to bring groundwater basins into balance within the next two decades, farmers would have to fallow between 0.5 and 1 million acres of irrigated agricultural lands. While some of the reasons to fallow irrigated lands have inherent benefits, the practice of fallowing may also result in potential consequences for the health of farm workers. During this presentation, we will explore two of those consequences, associated with dust and heat in Central Valley - a region that accounts for more than 50% of all U.S. crops, like fruits, nuts, and vegetables, and contain 75% of the irrigated land and about 77% of fallowed agricultural lands in California. We will show that fallowed fields dominate anthropogenic dust sources in California, contributing to the worsening air quality in the Central Valley. In addition, we will also show that, because of surface exposure of these fallowed fields, absorption of solar radiation can result in cropland heat island effect – a concept similar to urban heat island – with outward radiating heat of about 3.5 oC from the fallowed lands that can influence nearby cropland up to about 500 meters – that is about the size of five baseball fields. Furthermore, the cropland heat island effect from fallowed fields can impact evapotranspiration and crop water demands of nearby croplands, with significant consequences for crop yields.
There's a path forward in the San Joaquin Valley to benefit farmers, communities, and nature—but only if we plan...and plant
Daniel Toews, Strategic Project Manager, The Nature Conservancy
Dr. Daniel Toews is the Strategic Restoration Project Manager for The Nature Conservancy in California’s San Joaquin Valley. Born and raised in Merced, Daniel has deep roots in the Central Valley and a driving passion to conserve its rich biological diversity and cultural heritage. Growing up in a farming family on the outskirts of Merced, Daniel saw the effects of unsustainable farming practices on the environment, and the impacts it can have on small family growers. Daniel earned his Ph.D. in vernal pool plant evolutionary ecology from UC Merced, where his research focused on the unique and threatened ecosystems of California’s valley and foothill grasslands. He has worked as a consulting biologist and now leads efforts to conserve rare species and restore critical habitats across the San Joaquin Valley. In his current role, Daniel combines scientific expertise with strategic planning to implement large-scale restoration projects that support both ecological resilience and community well-being.
Abstract: The San Joaquin Valley was once a vast mosaic of rivers, floodplains, oak savannahs, and expansive desert oases with a rich diversity of wildlife. Years of urbanization and intensive groundwater-dependent agriculture have led to substantial habitat loss, putting some species on a path toward extinction—especially in the San Joaquin Desert. Today, chronic water scarcity and other environmental concerns are forcing a fundamental rethinking of this landscape. To meet groundwater sustainability goals of California’s 2014 Sustainable Groundwater Management Act, an estimated 500,000 acres of irrigated farmland may need to be retired by 2040. Rehabilitating land at this scale is a daunting challenge, and without strategic planning, land fallowing could worsen air quality, harm local economies, and create uninhabitable lands. This transition, however, also presents a once-in-a-lifetime opportunity to restore wildlife habitat in the Valley. Building on past San Joaquin Desert restoration efforts, The Nature Conservancy (TNC) and partners developed a vision for large-scale habitat restoration on retired farmland, prioritizing areas with the highest potential to support 25 imperiled San Joaquin Desert species. In 2022, TNC and the Tule Basin Land & Water Conservation Trust launched the Capinero Creek project in Tulare County to explore scalable, sustainable restoration. Adding topographical complexity, seeding native forbs and non-native grasses to suppress weeds, and managing vegetation through grazing and harvesting have already produced ecological benefits, including increased pollinator activity and the return of endangered species like the blunt-nosed leopard lizard. Capinero Creek demonstrates that with strategic planning, restoration can support groundwater sustainability, improve air quality, and create vital wildlife habitat, offering a replicable model for the broader San Joaquin Valley.