Ahart Herbarium

Ahart Herbarium presents
All Things Botanically Related (Series)

Annual Meeting

Featuring talks on "Evolution of the Fire-Adapted California Flora" and "2023 Jokerst Student Award Winner: Priority effects of foliar fungal endophytes in leaf litter decomposition"

Thurs, October 16, 2025, 6:30pm-8pm

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Evolution of the Fire-Adapted California Flora

Presented by Jon E. Keeley

Over the past century much has been written on the evolution of the California flora. Drivers of change have focused on the role of climate, topographic relief, and substrates, however the role of fires as a selective force has largely been ignored. Macrofossil data provide convincing evidence that fires have been a regular feature of California landscapes throughout the Cenozoic. Understanding how fire has shaped plant adaptations requires recognition of the different fire regimes in a range of ecoregions in the state. In this presentation I will explore fire regimes in herbaceous, shrubland and forest types throughout the state and how different regimes have selected for different fire-adaptations. Some traits such as vegetative resprouting from burned skeletons appear to be quite ancient and not always associated with fire. Others such as the basal burls (lignotubers) that give rise to postfire resprouts in a few genera, as well as smoke-stimulated seed germination of soil stored seed banks evident in both woody and herbaceous taxa, date to the Miocene and are associated with the rise of the Mediterranean climate, which increased fire predictability. Looking forward I will discuss how global changes are likely to alter fire regimes and their impact on different fire response types.

Jon E. Keeley, is an adjunct professor at UCLA, research associate with the California Botanic Garden, former program director at the National Science Foundation, recipient of a Guggenheim Fellowship and is an Ecological Society of America Fellow. The California Botanical Society dedicated their 2025 volume of Madroño to him and this same year the Southern California Horticultural Society awarded him (with his wife Melanie) Horticulturist of the Year. He has spent sabbaticals in all five Mediterranean climate regions of the world. His research has focused on the evolution of fire-adaptive traits, ecological life history strategies of plants and role of global changes in climate and population growth on management of fire-prone ecosystems. In addition, he has done extensive research on photosynthetic pathways in vernal pool plants and is co-author of the The Jepson Manual treatments for Isoetes and Arctostaphylos. He has over 400 publications, which have garnered more than 47,000 citations. He is senior author of a 2012 Cambridge University Press book Fire in Mediterranean Climate Ecosystems: Ecology, Evolution and Management.

2023 Jokerst Student Award Winner: Priority effects of foliar fungal endophytes in leaf litter decomposition

Tawny Bolinas, 2023 Jim Jokerst Field Botany Grant Award Winner

Priority effects of foliar fungal endophytes in leaf litter decomposition

Foliar endophytic fungi live inside plant leaves and are invisible to the unaided eye. These fungi can defend against pathogens and help plants retain water in arid environments, but many of their ecological roles remain unclear. We hypothesized that certain endophytes persist in leaves as dormant commensals, becoming active upon senescence to initiate decomposition and influence subsequent fungal community assembly via priority effects. We tested this through a 36-week field experiment using Quercus lobata leaf litter in mesh bags exposed to different fungal treatments. Using high-throughput sequencing, we tracked fungal community shifts and found that while distinct taxa were associated with each treatment, decomposition rates were similar. Site-level effects and stochastic processes played a larger role in shaping community composition than endophyte presence. Our findings suggest that endophytes exert weak priority effects under natural conditions and highlight the complexity of fungal interactions in litter decomposition.

Tawny Bolinas

Tawny Bolinas is a first-generation immigrant from the Philippines, now based in California. She holds a B.S. in Cellular and Molecular Biology and an M.S. in Biological Sciences from California State University, Chico. Under the mentorship of Dr. Gerald M. Cobián, her graduate research in fungal ecology explored the ecological roles of foliar fungal endophytes, with a particular focus on how the order of their arrival influences leaf litter decomposition in Quercus lobata (valley oak) leaves. Tawny probably ranks among the top earners of merit scholarships, awards, and honors during her baccelaureate and graduate programs at Chico State.

High Elevation Ephemeral Geophytes: Fire & Other Disturbances at Snowline

Presented Hal Mackey

Thurs, November 20, 2025
7pm - 8pm

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Ephemeral geophytes at high elevations are only available for study for five to six weeks after snowmelt and therefore are rarely investigated. From 2009 to 2021, Hal Mackey and Rob Schlising collected life history data on the closely related Dicentra uniflora Kellogg and Dicentra pauciflora S. Watson (Papaveraceae) in the Cascade Range of northeastern Butte County, California, through field surveys and plantings. The field data were supplemented with CCH2 herbarium records from the late 1890’s to the mid-2020’s. These combined data provided a baseline to assess the effects of Dixie Fire in the summer of 2021, which burned to varying intensities in three of their study sites and multiple plots within each site. Post-fire surveys from 2022 through 2025 showed fire responses that ranged from slight to catastrophic, depending on the fire intensity. There were also unexpected post-fire consequences from other plants and animals. In addition to Dixie Fire impacts, another Dicentra study location near Butte Meadows was impacted by fire line construction during the Park Fire in the summer of 2024. These 16 years of data, both pre- and post-fire, have provided insights into recovery times and persistence after major forest fires.

Hal Mackey received his PhD from the University of Tennessee and has worked on environmental projects for the past 54 years. As a professor teaching environmental sciences at the University of Pittsburg in Johnstown, he researched American chestnut regrowth in forests of western North Carolina and Pennsylvania. Earning a second degree in Public Health at the University of North Carolina at Chapel Hill, he became a senior environmental scientist with a federal government contractor at the Savannah River Site in SC, where he coordinated environmental assessments, and used satellite, multispectral and lidar data to map and evaluate wetlands on the 300-square-mile site. He was also instrumental in developing foraging ponds for the endangered American wood stork, and in mapping previously unknown nuclear waste sites from 1950s historical photographs for cleanup and closure. Since retiring and moving to Chico in 2008, he has worked with Rob Schlising to explore the natural history of two Northern California geophytes and their responses to snow patterns and climate change, work summarized in two publications in Madroῆo. When he’s not pursuing science, he enjoys working in his organic vegetable and fruit tree garden in his backyard and would be happy to give tours.

All Things Botanically Related - Past Presentations:

Kyle holding a mighty harvest of the sacred mugwort (Artemisia douglasiana) plant.

Fire History and Use in Butte County, California

Presented by Kyle Mason

Thurs, September 18, 2025
7pm - 8pm

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A brief overview of the history of fire in Butte County, how it's been used, and why. Kyle will follow-up with a discussion of how fire management might look in the future.

Kyle Mason is a California Climate Action Corps fellow at CSU Chico's Office of Tribal Relations and an employee with the Big Chico Creek Ecological Reserve, where he is in the process of finishing a comprehensive ethnography report about fire in Butte County at the reserve. He also helps manage and process data for an eddy covariance flux tower that is on the Reserve. He enjoys connecting with the land and life however he can.

PHOTO: https://www.cnps.org/biodiversity-initiatives/horticulture-science

Landscaping Paradigms, 
Wildfire, & Habitat

Presented by Adrienne Edwards  & Rachel Schleiger

Thurs, August 21, 2025
7pm - 8pm

Recording coming soon!
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Join the authors of Firescaping Your Home: A Manual for Readiness in Wildfire Country to explore paradigms that get in the way of landscaping for defensible space or supporting native biodiversity.  We will focus on psychological conventions in landscaping that often complicate the adoption of firesafe strategies, including foundation plantings, fences, wind patterns, and habitat fragmentation.   We will wrap up with a discussion on support for biodiversity and fire insurance challenges.  

PHOTO: https://www.cnps.org/biodiversity-initiatives/horticulture-science

Rachel Schleiger, MS, is a plant ecologist who specializes in restoration ecology. She has lived in the Sierra Nevada Foothills most of her life.  Her family and property survived the 2018 Camp Fire.  She has developed curricula to teach about wildfire, both in-person and online through Butte College.  She is currently a faculty lecturer at both Butte College and California State University, Chico.

Adrienne Edwards, PhD, is a botanist, plant ecologist, garden designer, and environmental consultant.  She began her botanical odyssey in the Southeast, spent time botanizing in the Midwest, and since 2006 has lived and worked in northern California.  With over 35 years of experience teaching, researching, and consulting, plants continue to inspire her passion.  She is currently a faculty lecturer at California State University, Chico.

Check out more previous presentations in the All Things Botanically Related Series >>(opens in new window)

California Phenology Thematic Collections Network

Ahart Herbarium is actively photographing specimens in the collection and linking the images to the collection information for each species. This information is accessible through the California Phenology Thematic Collections Network (www.CCH2.org(opens in new window)). Through a National Science Foundation grant, the Herbarium will be imaging over 30,000 specimens in the collection which will be similar to the one here. Collectively, over 23 different herbaria and collections across California will be located on CCH2. Check out the website!(opens in new window)