- A state-funded survey has sampled and collected fungi species from across California, identifying hundreds of new-to-science species.
- It’s part of a statewide effort to protect biodiversity, which has yielded thousands of specimens and is the first of its kind in North America.
- Fungi are often neglected compared to the attention given to plants and animals, yet they play an important role in maintaining ecological health by supporting plant growth and storing carbon.
- Understanding fungi’s role in nature has implications for conservation and for forest restoration as wildfires grow larger and more frequent. Other researchers in California are working on putting fungi to use cleaning up polluted areas.
Getting to The Cedars, an ecological preserve in California’s Sonoma county, is a slog. Multiple rivers and creeks must be crossed, and it can be tough going on an often storm-destroyed road. But it’s home to a rich diversity of species found nowhere else on Earth that are uniquely adapted to serpentine soil, composed of decomposed rock and rich in heavy metals.
If you’re a fungi collector, it’s well worth the trip. Over the past two years, a dedicated team of mycologists — specialists in the study of fungi — and experienced mushroom collectors have combed California’s forests, rivers and mountains in often remote locations such as this, searching for and collecting fungi. Those making the arduous journey out to The Cedars have identified more than 100 new species, 25 of which are only known from the area.
They snapped photos, which were then uploaded with all pertinent data to iNaturalist, a citizen scientist biodiversity database. Collections have been sent to labs where scientists extracted DNA for sequencing. Dried specimens are stored for safe keeping at California State University, East Bay, and the University of California, Los Angeles.
This is part of an expansive effort to map the state’s fungal diversity, which has yielded thousands of specimens and is the first of its kind in North America, says Harte Singer, who heads genetic research at the California Fungal Diversity Survey (CA FUNDIS).
Since 2022, this nonprofit, comprised of more than a dozen experienced collectors, has gathered and sequenced the DNA of more than 10,000 California fungi. The goal: to build a comprehensive database. More than 2,000 may be new-to-science species.
It’s not known exactly how many fungi species are in California, but Singer estimates it could easily be as many as 15,000. Certain areas, such as The Cedars, likely have many more species to “mine,” he says.
Globally there may be as many as 3 million species, with only around 5% described thus far.
This effort is funded with government support and contributions by the California Institute for Biodiversity and others.
“[This] should set a benchmark for other states, other jurisdictions, that we should be surveying fungi, and we should be using public funding to that end,” Singer says.
A neglected kingdom
Fungi are an oft-forgotten kingdom in the world of conservation. They comprise a vast range of mosses, mushrooms and microscopic species found in soils. Up until the mid-20th century, they lived within the botanists’ domain. Unlike plants, they can’t photosynthesize sunlight into energy, and in fact are more closely related to animals than plants. They now occupy their own niche, neither plant nor animal.
Considered “keystone organisms,” they’re vital to the healthy functioning of ecosystems. Scientists have long known that fungi help plants uptake nutrients such as nitrogen and phosphorus through symbiotic relationships. And as fungi break down decaying organic matter, they play a vital role in maintaining soil health. They also help slow climate change, acting as an integral part of the carbon cycle.
Amid a global biodiversity crisis, fungi face many of the same threats as plants and animals: deforestation, pollution and warming climate with more frequent extreme weather events.
Scientists suggest we may be losing fungi species faster than we’re discovering them. “There’s a real importance in describing new species, because you can’t conserve rare species if you don’t know that they exist,” Singer says.
One newly described species, a type of gilled Psilocybe mushroom (yes, a hallucinogen) dubbed “CA01,” looks like a newly sprouted seed with a tendrilled root. Another, named “Pillbug Fluff” from the Ascomycota group, looks like puffy orange dots; it grows on the exoskeletons of dead pill bugs.
Restoring scorched forests
The CA FUNDIS team says it hopes its efforts are helping put the state’s fungi in the limelight. The survey isn’t just about finding and naming new species. It will have implications for research, conservation and ecosystem restoration efforts.
Laura Meredith Bogar, an assistant professor of plant biology at the University of California, Davis, is focused on understanding the symbiotic relationships between plants and fungi. In her view, an expanded database of fungal genes across Californian landscapes could enable researchers to pinpoint the range of species in soil samples.
Dustin Lower, a doctoral student in Bogar’s lab, is exploring how fungi species could help restore forests devastated by climate-driven wildfires, which are growing larger and more frequent in California. In the aftermath of wildfire, certain fungi — known as pyrophilous (or fire-loving) species — kick-start ecosystem recovery by helping both soils and trees regenerate. Lower notes that science is just beginning to understand how fire affects fungal diversity.
One goal of the ongoing research is to provide a healthy microbiome for trees being grown in a nursery setting by introducing ectomycorrhizal fungi. These fungi colonize plant roots, providing nutrients and water in exchange for plant carbon. Lower’s hope is that introducing beneficial fungi will improve reforestation efforts.
An estimated 8.8 million trees have been planted to restore fire-impacted areas in California, according to the nonprofit One Tree Planted. However, seedling survival rates can be low.
By taking soils from an area burned by low-intensity fire in the Sierra Nevada and then applying them to conifer seedlings, Lower has documented healthier trees and increased richness of fungi species. His experiments show that regrowth in soils from high-intensity fires is poor: More intense heat likely penetrated deeper into the soil, killing off beneficial fungal communities.
An important finding is that seedlings grown in low-intensity fire soils have higher tolerance to drought conditions, suggesting that higher fungal diversity helps reduce stress responses.
“Going forward, I want to try to take soils that have been burned at a low severity or part of a prescribed fire and use those fungal communities to inoculate seedlings — and see how that impacts a reforestation effort,” Lower says.
His adviser, Bogar, is optimistic about this approach, noting that “it has the potential to be a relatively low-cost and low-effort intervention that could move the needle at least a little bit on seedling survival.”
Other researchers are exploring the use of fungi species to help remediate polluted areas, sites impacted by toxic ash from widespread fires, or soil contaminated by industrial chemicals. Known as mycoremediation or bioremediation, the idea is to use native species of fungi and plants in contaminated areas to soak up polluting chemicals and heavy metals. A pilot project in Los Angeles has shown some success.
Saving redwoods
A deeper understanding of fungi could also aid in restoring California’s iconic redwood forests. Only around 5% remain intact and free from logging.
Research published earlier this year in the journal Biological Conservation found that these old-growth forests host larger diversity of important soil microorganisms — called arbuscular mycorrhizal fungi — than secondary-growth forests. These species form a close relationship with plants, helping them absorb water, nitrogen and phosphorus, and provide protection against pathogens that can kill off these trees.
Past efforts to rapidly replant pine trees in logged redwood forests through aerial seeding — dropping “seed balls” wrapped in soil and nutrients from above, usually from a plane, helicopter or a drone — altered the forest composition. These secondary-growth forests have more ectomycorrhizal fungi, which could negatively affect redwood restoration, says David Bañuelas, who studied these forests as a graduate student at University of California, Irvine.
“We’re barely beginning to scratch the surface of how redwood trees and fungi are working together,” he says. “We need to think about removing the non-redwood trees, but we also need to think about how the developing understory may restore fungal diversity indicative of old-growth forests.”
He says this could take the form of a “fungal inoculum.” It would involve growing trees for reforestation in concert with specific fungi cultivated from old-growth forests: arbuscular mycorrhizal. “I definitely advocate for going back into a forest and restoring it … and I think the fungi can help us do that.”
That research, however, is still in its infancy. So, too, are studies understanding how climate change will impact redwoods’ fungal diversity, including potentially harmful fungi.
“We’ve always thought of redwoods as being rather resistant to fungal pathogens,” Bañuelas says. But some species can infect and rot trees. Though this is an important part of their role in maintaining ecosystem health, climate change could upend the traditional balance. For example, Phytophthora ramorum, a microscopic pathogen, causes sudden oak death, has decimated coastal forests in California and Oregon and can also affect redwoods.
“With climate change, some of these fungal pathogens could actually increase, so we need to do these big restoration projects,” Bañuelas says. “But we also need to monitor future fungal pathogens and get ahead of them before they wreak havoc in these ecosystems.”
From mycophobia to mycomania
The CA FUNDIS project is now shifting gears to target less “charismatic” fungi that were missed during the first two years of the survey. These include species under the Ascomycota phylum, a broad range of fungi that are often barely visible to the naked eye. Collectors plan to search for visible varieties, looking out for telltale “bumps and dots” among rare plants, dead wood and leaves that act as hosts for these species, Singer says.
The group says it hopes its efforts can push fungi research forward in California and elsewhere. Gabriela D’Elia, former director of the Fungal Diversity Survey, already sees a shift from a “mycophobic” culture to a form of what she calls “mycomania,” spurred by interest in citizen science both in California projects and in other states.
Even policymakers are beginning to understand fungi’s importance. In 2023, the golden chanterelle (Cantharellus californicus) joined the California grizzly bear and California poppy as a designated state symbol: It’s now the state mushroom. The state legislator’s intent was to highlight the mushroom’s pivotal role in nourishing forests and grasslands.
That, for D’Elia, who is now a FUNDIS board member, is emblematic of this shift, and a wider appreciation of the role that fungi play in maintaining ecosystem health. “We’re hoping that every state can see the results and look at the success of understanding fungal biodiversity as a whole entire kingdom of life,” she says.
“When we understand more about the fungal biodiversity of a given place, we understand more about how our ecology functions,” she adds. “We understand more, I think importantly, about the interconnectedness of our planet.”
Singer says that beyond the clear ecological knowledge that can be gained from this research, there’s a host of human-centered potential in mapping out and understanding California’s fungi. One example is a curious new psychedelic species that the team found, tentatively named Psilocybe gandalfiana, named after the wizard Gandalf from J.R.R. Tolkien’s Lord of the Rings. With some psychedelic substances now being used in medical treatment, this points to the unknown potential of these species.
“So many different medicines and chemical compounds have been isolated from fungi, whether it be for drug treatments or enzymes to create biofuels,” Singer says. “If these species disappear for whatever reason, whether it’s climate change or human intervention, we’re going to lose everything that this very specialized evolution has created within them … and if we don’t collect it before it’s gone, we won’t have access to that incredible library of evolution that we can take advantage of.”
Banner image: A fungi in the family Hygrophoraceae. This fungi, which may represent a new genus, is rare and restricted to California’s coastal regions, says Harte Singer, who heads genetic research at the California Fungal Survey. Image by Harte Singer via iNaturalist (CC BY-NC 4.0).
Citations:
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