California's changing climate continues to influence weather events from extreme rainfall to outbreaks of high winds that have fueled some of our most destructive wildfires. This session focuses on the influence of weather events on our state's ecosystems and how land management is also affected.
Moulton Niguel Water District, Laguna Hills, CA, USA
Lindsey Stuvick
Moulton Niguel Water District
Lindsey is the Sustainable Resources Officer at Moulton Niguel Water District and supports water resource, energy optimization, digital innovation, and operational efficiency projects. Her career has been dedicated to developing sustainable, data-driven efficiency solutions and customer engagement strategies that can be replicated and adapted across the industry. She has a Master’s Degree in Urban and Regional Planning from the University of California, Irvine and a Bachelor’s Degree in Political Science from California State University, Fullerton. She is the Co-Chair of SWAN’s Digital Twin Working Group and the recipient of the Switzer Fellowship from the Robert & Patricia Switzer Foundation.
Julie Schrock
Moulton Niguel Water District
Julie Schrock is a Landscape Architect passionate about creating joyful, practical, and water-wise solutions in urban environments. During her decades as a designer, horticulturist, and arborist, she has managed complex projects for clients including HOAs, Cities, and residents throughout Southern California. She is most proud to have led high-performing, cohesive teams and mentored junior staff to achieve their professional goals. Her work as a Senior Water Efficiency Specialist at Moulton Niguel Water District blends her technical expertise with a deep commitment to education, environmental stewardship, and people-centered design. She believes in transforming the world through small, intentional acts of goodness one landscape at a time.
24.1 What Drives Plant Heat Tolerance? Trait Coordination, Temperature Acclimation, and Evolutionary History Across California’s Plant Species
Dr. Georgia G. Hernández, Maisey M. Rew, Kekoa C. Nelson, Dr. Jennifer Funk, Dr. Gary Bucciarelli, Dr. Justin M. Valliere
University of California Davis, Davis, CA, United States
Description Understanding the predictors of plant heat tolerance is critical for conservation strategies for California's diverse flora in a warming climate. Across 14 sites and over 100 native species, we investigated how heat tolerance is shaped by leaf morphology, evolutionary history, and local climate, testing whether it aligns more with "carbon economic" traits for long-term growth or "energy balance" traits for short-term thermoregulation. We found that heat tolerance is strongly conserved phylogenetically, meaning closely related species exhibit similar thermal limits. Higher heat tolerance was consistently associated with greater leaf structural investment (higher LMA and LDMC), indicating that durable, resource intensive leaves are a key strategy for surviving extreme heat. In addition to these long-term strategies, we found evidence for rapid acclimation, where heat tolerance increased in response to high temperatures in the preceding days. Our findings support a framework where tolerance to lethal temperatures is achieved through investment in durable leaf structure, while tolerance to initial damage is linked to a separate strategy involving rapid thermal dynamics. These findings have direct conservation implications, suggesting that vulnerability is concentrated in specific evolutionary lineages and that simple leaf traits can be used to rapidly assess heat tolerance.
Presenter Bios
Dr. Georgia G. Hernández
University of California, Davis
Georgia Hernández is a postdoctoral researcher at UC Davis. She is interested in understanding the effects of climate change on plants, from the leaf level to communities. Her research aims to identify potential species’ capacity to tolerate climate stresses and how communities will eventually fluctuate on time and space.
24.2 Rapid Evolution Leads to Demographic Recovery After the 2012-2025 Extreme Drought
Daniel N. Anstett1, Seema Sheth2, Loren Rieseberg3, Amy Angert3
1Cornell University, Ithaca, NY, United States. 2North Carolina State University, Raleigh, NC, United States. 3University of British Columbia, Vancouver, BC, Canada
Description Anthropogenic climate change is generating more extreme environments, contributing to the biodiversity crisis by threatening native plant populations and species. Populations declining due to extreme climate change may require adaptive evolutionary change in order to recover, a process known as evolutionary rescue. While there is strong evidence from theory and microbial studies for evolutionary rescue, its relevance to the persistence of native plant populations facing climate change remains largely unknown. Here we document range-wide patterns of rapid evolution and evolutionary rescue after the exceptional 2012-2015 drought event in scarlet monkeyflower, Mimulus (Erythranthe) cardinalis. We leverage 9 years of range-wide demographic field monitoring with whole-genome sequencing across 55 populations throughout California and Southern Oregon prior to the exceptional drought, and sequencing across 11 populations throughout the drought. We establish that population decline during the drought is predictable by genetic variation and rapid evolution at climate-associated SNPs (single nucleotide polymorphisms). These findings demonstrate evolutionary rescue in a Californian wildflower, showing that populations can leverage evolution to recover from climate-change induced population decline, and that conservation genomics can have an important role in predicting population recovery.
Presenter Bios
Daniel N. Anstett
Cornell University
Daniel Anstett is an Assistant Professor at Cornell University, where he is the principal investigator of a lab focusing on adaptation to climate change. He uses a combination of long-term ecological surveys, plant growth experiments and spatiotemporal genomic approaches to understand the potential for contemporary evolution. He seeks to find solutions to the biodiversity crisis by leveraging spatial-based science to inform biodiversity conservation.
24.3 The Status of California’s Champion Trees in a Time of Record Fires and Changing Climate
Dr. Matt Ritter
Cal Poly, SLO, San Luis Obispo, CA, United States
Description Understanding California’s 95 native tree species is essential for interpreting the state’s ecosystems, biodiversity, and ecological history, as well as guiding sustainable management and restoration. Since 1940, the California Big Tree Registry has documented the largest known individuals of these species, though many champions have been lost to fire and drought in recent decades. As state coordinator of this 85-year-old program, I will present the current status of California’s native tree species, the condition of their largest representatives, and their prospects for long-term survival and conservation.
Presenter Bios
Dr. Matt Ritter
Cal Poly, San Luis Obispo
Dr. Matt Ritter is a professor of ecology, conservation biology, and botany in the Biological Sciences Department at Cal Poly, San Luis Obispo. He is an internationally recognized expert on tree ecology, California’s native flora, and urban forestry. He has published numerous scientific articles and authored seven books, both non-fiction and fiction. He currently serves, or has served, on the boards of several major conservation organizations in California and the western United States.
24.4 Developing a Sequoia sempervirens-Specific Vitality Index to Evaluate and Monitor Effects of Drought and Heat Stress in Coast Redwoods
Dr. Michelle E. Geary1,2, Melanie Zarza1, Lucy West1, Harte Thomas3, Tucker McCarthy1, John Adams2, et al.
1West Valley College, Saratoga, CA, United States. 2West Valley Redwood Team, San Jose, CA, United States. 3University of California, Santa Cruz, Santa Cruz, CA, United States
Description Coast redwoods demonstrate extraordinary resilience after fire and flooding, but little is known about how/if they recover from drought. Their range in California is limited to the coastal band where fog provides summer moisture and cooler temperatures, but as climate changes, higher temperatures and drought are challenging the species’ physiological limits. In the geological past, redwood relatives disappeared from much of their range, yet we do not know which environmental conditions triggered these losses.
In 2018, planted coast redwoods in parts of California were showing stress linked to ongoing drought. These effects eased with high rainfall in 2022-3, but by early 2025 stress effects returned and accelerated. To track the health of individual trees, we created a rapid coast redwood vitality assessment that would be usable by scientists and non-scientists alike.
Index components include needle color; canopy volume; needle pattern; and treetop health. Components are scored on a 0-3 scale (3 indicates highest stress); a 12 overall indicates low tree vitality. Visual supplements provide assistance with the qualitative evaluations. Our analyses show that structural/physiological factors - changes in xylem function and needle characteristics that affect water uptake - correlate with overall tree vitality index.
This index could be used to create baselines to monitor change. We are already seeing vitality downshifts in wild populations. Property owners might use this tool to determine if stressed redwoods are at recovery tipping points; in wildlands, ecologists and land managers could anticipate ecological state changes and use this information in restoration and management decisions.
Presenter Bios
Dr. Michelle E. Geary
West Valley College
Michelle Geary earned her PhD in Environmental and Integrative Plant Biology from UC Davis in 1999. Since 2000, she has been teaching (primarily plant biology and environmental biology) at West Valley College in Saratoga, CA. In 2014, she formed a community college based research team to study the effects of climate change on coast redwoods with a focus on areas in the fringes of the species' range.
24.5 Monitoring California jewelflower (Caulanthus californicus) Demography in the Context of Pollinator Networks, Plant Communities, and a Federally Endangered Herbivore
Dr. Isabela Borges, Dr. Sarah Cusser, Dr. Heather Schneider
Santa Barbara Botanic Garden, Santa Barbara, CA, United States
Description California jewelflower (Caulanthus californicus, Brassicaceae) is a federally endangered annual wildflower. In 2022, the Santa Barbara Botanic Garden initiated a study in collaboration with the Bureau of Land Management to increase our knowledge of jewelflower demography at Carrizo Plain National Monument. Focusing on three remnant jewelflower populations, we are interested in finding whether these populations are stable, increasing, or decreasing, as well as the biotic and abiotic factors driving these dynamics. We have collected jewelflower demographic data from over 400 individual plants across three consecutive years, which have spanned a wide range of precipitation in California, and will continue to monitor these populations for at least three more growing seasons. Concurrently, we collected annual data on the pollinator and plant communities interacting with our jewelflower populations to better understand the species’ ecology and its effects on demography. Here, we present preliminary results on the effects of local conditions on jewelflower survival and reproduction. We find effects of climate and local plant communities on jewelflower, and we see that herbivory on these plants is widespread, with the primary vertebrate herbivore being the federally endangered giant kangaroo rat (Dipodomys ingens). Once plant demographic data collection is complete, we will compile data across years to build an integral projection model to understand how biotic and abiotic factors drive jewelflower population dynamics. Those results will substantially increase our understanding of Caulanthus californicus at Carrizo Plain National Monument and point to potential management actions to bolster populations of this endangered plant across its range.
Presenter Bios
Dr. Isabela Borges
Santa Barbara Botanic Garden
As the rare plant conservation scientist at Santa Barbara Botanic Garden, Isabela Lima Borges, Ph.D., works to understand and conserve California’s rare plants. She earned her doctorate in integrative biology from Michigan State University, working at the W.K. Kellogg Biological Station. Prior to that, Isabela studied the ecology and evolution of a diverse array of organisms, doing fieldwork in Brazil, Costa Rica, the Dominican Republic, Canada, and various locations in the U.S. Isabela is interested in how rare plants interact with their environments, and passionate about integrating research and conservation action.
Thank you to our 2026 sponsors!
Giant Sequoia
Special thanks to Esri, our 3-time Giant Sequoia Sponsor, for making this movement stronger than ever!
The mission of the California Native Plant Society is to protect California’s native plants and their natural habitats, today and into the future, through science, education, stewardship, gardening, and advocacy.
DateFriday, February 6
