Karlie is a third-year Cognitive Science undergraduate at UCLA with a double minor in English and Environmental Systems and Society. With an interdisciplinary background, Karlie is interested in the impact of human behavioral choices on sustainability, communicating environmental information to decision makers, and the intersection of data and the environment. Outside of the Corporate Partners Program, Karlie is a Zero Waste Ambassador with UCLA Facilities Management, where she works with a team to develop programming to support UCLA’s Zero Waste target. She’s especially excited about “Think Outside the Landfill”, an education and outreach campaign, and the Surplus Stop, a space for UCLA students and staff to donate or take excess items, thus diverting waste from the landfill. She also is a part of the Energy team with Sustainability Action Research; her team’s project analyzes the energy use of dorm buildings to guide energy efficiency recommendations. If you check in with Karlie outside of the classroom, she will probably be on a run, drinking coffee, or eating an everything bagel. After graduating, she hopes to work in corporate sustainability.
Brad Smith
Brad is a communications management specialist (APMP certified) with more than ten years of experience at world-class institutions and industry-leading companies. For over 20 years, he has served as a professional writer and editor, including in journalism, media relations, and corporate communications (internal and external, including digital media and social media) positions, and multiple management assignments.
Cynthia Lee
Justin Dunnavant
Dr. Justin Dunnavant is an Assistant Professor in the Department of Anthropology at UCLA. His current research in the US Virgin Islands investigates the relationship between ecology and enslavement in the former Danish West Indies. In addition to his archaeological research, Justin is co-founder of the Society of Black Archaeologists and an AAUS Scientific SCUBA Diver. In 2021, he was named a National Geographic Emerging Explorer and inducted into The Explorers Club as one of “Fifty People Changing the World that You Need to Know About.” He is also a member of the Board of Trustees of the National Marine Sanctuary Foundation. His research has been featured on Netflix’s “Explained,” Hulu’s “Your Attention Please” and in print in American Archaeology and Science Magazine.
Francisco Spaulding-Astudillo
Francisco hails from a small farm in the Illinois countryside, where he developed a deep appreciation for nature in his youth. He received a B.S. in Geophysical Sciences from the University of Chicago in 2017 and a M.S. in Geophysics and Space Physics from UCLA in 2021. He is currently finishing his PhD in Planetary Science at UCLA’s Department of Earth, Planetary, and Space Sciences. His primary research focus is how the availability of moisture at the surface and in the atmosphere affect the climate and clouds of terrestrial planets. He is passionate about giving science demonstrations to young audiences that make the big ideas easy to understand. Francisco enjoys visiting the beach, working with new recipes in the kitchen, playing tennis and weightlifting, dabbling at the harmonica, and consuming science fiction and fantasy in movies, television, and video games.
Kyle Callahan
Samantha Catella
Samantha Catella is fascinated by the causes and consequences of spatial variation in plant communities. As a La Kretz Postdoc, she collaborated with The Nature Conservancy, California Botanic Gardens, Pomona College, and multiple natural resource agencies throughout the city of Los Angeles to bring a spatial perspective to urban ecology. Specifically, her research investigated how spatial heterogeneity in multiple anthropogenic disturbances has affected the population structure and local adaptation of California buckwheat (Eriogonum fasciculatum) at the urban-wildland interface.
Samantha received her PhD in 2019 from Case Western Reserve University, and completed her first postdoc at the University of Pittsburgh in 2021. Samantha is currently resident in Ohio, where she is continuing her work on La Kretz conservation projects while exploring new options in the Buckeye State.
Colin T. Kremer
I am a quantitative ecologist, studying how plasticity and evolution mediate the response of populations and communities to natural and anthropogenic environmental change. I both develop and test ecological and evolutionary theory, using empirical data and modern computational statistical approaches. I explore these ideas in the context of studying how changes in temperature, nutrients, and light affect phytoplankton (globally important photosynthetic microbes) over time scales from hours to centuries, and in habitats from beakers to oceans. This emphasis allows me to advance basic ecology while addressing applied questions, including predicting the effects of climate change on communities and ecosystems.
Zachary MacDonald
Zachary MacDonald is broadly interested in ecological and evolutionary mechanisms that structure biodiversity in space and time. Throughout his Ph.D. at the University of Alberta, much of Zac’s work focused on conservation applications of theoretical ecology, evaluating relationships between habitat loss, habitat fragmentation, and emergent patterns of species diversity and genetic diversity. During his La Kretz Center Postdoctoral Fellow in the Shaffer Lab, Zac focused on evaluating effects of habitat and climate changes on a reduced number of species, but in greater detail. This involved equal parts of: (1) forward-in-time landscape and environmental modelling, to map habitat suitability and connectivity, and predict how they will change under different climate change scenarios; and (2) population genomics, to quantify population structure, genetic diversity, and inbreeding depression within species. This has proven valuable for conserving many endangered and at-risk butterfly species throughout western North America, often working closely with regulatory agencies to develop adaptive management strategies that translate science into policy.
In 2025, Zac joined UC Riverside’s Department of Entomology as an Assistant Professor of Conservation Genomics and Biodiversity.
Ariana Hernandez
Ariana Hernandez is a second year Master’s student in Urban and Regional Planning concentrating in Environmental Analysis and Policy. In addition to her coursework, she works as a Graduate Student Research at the Luskin Center for Innovation on projects focusing on drinking water safety, trust, and affordability, and also on sanitation access issues. Ariana received her Bachelor’s in Environmental Policy Analysis and Planning from UC Davis. Ariana came to UCLA to better understand the influence urban planning has on the distribution of environmental benefits and burdens (access to safe drinking water and adequate sanitation) in vulnerable communities.