Speaker Series

Everyone is welcome to attend membership meetings in the Recreation Room of the San Francisco County Fair Building (SFCFB) at 9th Avenue and Lincoln Way in Golden Gate Park. The #71 and #44 buses stop at the building. The N-Judah, #6, #43, and #66 lines stop within 2 blocks.
Before our programs, we take our speakers to dinner at Chang’s Kitchen, 1030 Irving Street, between 11th and 12th Avenues. Join us for good Chinese food and interesting conversation. Meet at the restaurant at 5:30 pm. RSVP appreciated but not required. If you wish to notify, please call Jake Sigg at 415-731-3028.

October 4, THURSDAY, 7:30 PM

Re-Oaking Silicon Valley

Speaker: Erica Spotswood

In this report, we investigate how integrating components of oak woodlands into developed landscapes — “re-oaking” — can provide an array of valuable functions for both wildlife and people. Re-oaking can increase the biodiversity and ecological resilience of urban ecosystems, improve critical urban forest functions such as shade and carbon storage, and enhance the capacity of cities to adapt to a changing climate.



November 1, THURSDAY, 7:30 PM

Northern California Black Walnut: A tree with many stories

Speaker: Heath Bartosh

Despite previous research and study, the original distribution, subsequent radiation, and genetic identity of the northern California black walnut (Juglans hindsii) remains a source of considerable perplexity and debate. This confusion is confounded by the perception that some northern California black walnut trees may be hybrids with other native or non-native Juglans species. To get a clearer understanding of the northern California black walnut’s historic and current distribution as well as the rate of hybridization throughout a larger portion of its range, researchers, including our speaker Heath Bartosh, inventoried specimens in a number of counties and performed genetic testing on the trees. With information from the study, an informed decision can be made on the future conservation status of this native tree, which is currently recognized as rare. Heath will summarize what we know about northern California black walnut’s past, present, and future, focusing on work done by a collaborative group of people interested in this mysterious native tree.

Heath Bartosh is co‐founder and Senior Botanist of Nomad Ecology, based in Martinez, California, as well as a Research Associate at the University and Jepson Herbaria at UC Berkeley. After graduating from Humboldt State University, Heath began his career as a professional botanist in 2002 and has been an earnest student of the California flora for the past 15 years. In 2009, he also became a member of the Rare Plant Program Committee at the state level of CNPS. His role on this committee is to ensure the rare plant program continues to develop current and accurate information on the distribution, ecology, and conservation status of California's rare and endangered plants, and help promote the use of this information to influence plant conservation in California.

February 2019, THURSDAY, 7:30 PM

Title: TBD

Speaker: Tom Bruns

At UC Berkeley, Tom Bruns, a researcher and fungus expert, or mycologist, has spent decades studying the hidden world of fungi in the wild, and their relationships with living plants.

“There’s a lot we don’t know,” he said, “but we now estimate 90 percent of all plant species live in association with fungal partners. They’re absolutely everywhere.”

And, without their fungal partners, it’s now known, many seedlings and trees will simply not survive.

The mycorrhiza fungi send their filaments out into the surrounding soil, gathering water and essential nutrients like nitrogen and phosphorus, which they transport back to the tree. Their branching mycelia are so incredibly fine that a cubic inch of soil can contain a mile or more of them. As a result, they extend the tree’s reach to critical food and water by ten to 1,000 times.

In exchange, Bruns explained, the tree provides them with sugars and carbon, which the growing fungus can’t produce themselves.

“Up to 20 percent of the sugar energy and fixed carbon produced by tree leaves using sunlight, is transported to the fungal mycorrhiza,” Bruns said, adding that individual types of trees and plants can each have their own particular fungal partners.


June 6, 2019, THURSDAY, 7:30 PM

Mosses are from Mars, Vascular Plants are from Venus

Speaker: Brent D. Mishler

The bryophytes are the most diverse set of land plants aside from the flowering plants.  The group includes three quite distinct lineages (i.e., mosses, hornworts, and liverworts), some familiar species frequently encountered in mesic forests and along streams, as well as a number of less familiar species of tropical rain forests, arctic tundra, and desert boulders.  The bryophytes have an ancient history; they are remnant lineages surviving today from the spectacular radiation of the land plants in the Devonian Period, some 400-450 million years ago.  Yet despite their diversity, phylogenetic importance, and key roles in the ecosystems of the world, study of many aspects of the biology of bryophytes has lagged behind that of the larger land plants, perhaps because of their small size and the few scientists specializing on them.  This talk summarizes what we do know about their biology, as an encouragement for you to get to know them better.

One might assume to start with, that bryophytes are biologically like their larger cousins, just smaller versions.  But, in what ways does bryophyte biology different from that of the larger vascular plants?  The short answer: in almost every way possible!   The groups didn't evolve on different planets, but their differences could almost make you think they did.  They certainly adopted very different approaches to being a land plant on this planet.  Many aspects need much more study, but what is known about bryophyte biology suggests that in general the bryophytes differ in most ways in their genetics, physiology, ecology, and evolution from vascular plants.

Brent D. Mishler is Director of the University and Jepson Herbaria at University of California, Berkeley, as well as Professor in the Department of Integrative Biology, where he teaches phylogenetic systematics, plant diversity, and island biology.  He received his Ph.D. from Harvard University in 1984, then was on the faculty at Duke University for nine years before moving to UC Berkeley in 1993.  His research interests are in the systematics, evolution, and ecology of bryophytes, especially the diverse moss genus Syntrichia, as well as in the phylogeny of green plants.  He is also interested in more general topics involving the theoretical basis of systematic and evolutionary biology, such as phylogenetic methods and the nature of species.  He has been heavily involved in developing electronic resources to present plant taxonomic and distributional information to the public, and for research applications of these data including to the California flora.  He is one of the founders of, and incoming President Elect for, the CNPS Bryophyte Chapter.