Metro’s Native Plant Center is full of visible life – after all, it’s where Metro grows plants it uses to restore and maintain its parks and natural areas. But tucked into a shady spot of the small forest near the garden beds, a very different form of growth is taking place. It doesn’t look like much – just patches of dirt and wood chips surrounded by stumps and logs.
Metro Parks and Nature staff are a year into a pilot project on mycology, the scientific term for the study of fungi. And much like the organisms they’re cultivating, to truly understand their work, you need to go deep beneath the surface. The project started in spring of 2023, when a few alder trees were removed at Borland. Alder, as it happens, is a great medium for growing fungi.
Jeffrey Lee, a natural resource technician at Metro, saw an opportunity. He and two colleagues – natural resource specialist Kristina Prosser and plant scientist Hannah Schrager – set up seven fungi-growing test beds. They implanted – “inoculated” is the technical term – fungal spawn into chips, stumps and logs. The spawn came from seven types of native fungi including oyster, turkey tail and Oregon reishi.
It might be years before any mushrooms appear. But growing mushrooms is not the goal. Instead, Lee, Prosser and Schrager are interested in what’s happening deep within the inoculated wood. There, threadlike fungal strands are spreading, forming an ecologically valuable, ever-expanding network. They see all sorts of potential for fungi to help native plants and animals thrive, prevent soil erosion, reduce wildfire risk, build healthy soil, promote forest diversity, provide medicine and food, and connect people to the land in culturally meaningful ways.
First, though, they have to better understand these potentially powerful partners.
Coral fungi peek through the forest floor at Gabbert Butte Natural Area.
Following the fungal clues
Prosser – who, like Lee, is on Metro’s land management team – is always looking out for fungal species when she’s in the field, both to record their quantity and diversity and to increase fungus literacy among conservation staffers. She’s also attuned to what’s going on from an ecological standpoint. Fungi, she explains, have beneficial relationships with many plants and animals and help to promote ecological diversity.
Schrager, who primarily works at the Native Plant Center, has also developed an interest in fungi.
“People like me who work in a related realm, like with plants, are realizing that fungi play an essential role in how plants function,” she says.
For these reasons, Metro Parks and Nature is considering how to incorporate fungi into site conservation plans. These policy documents set out a vision for conserving natural areas based on historical and current habitat as well as other factors like equity and climate change. Right now, they focus mainly on plants and animals.
Fungi – which are neither plant nor animal, but their own separate kingdom – can show what may have been on a site before it was farmed or logged.
“Fungi offer clues to what we are restoring to,” Schrager adds.
“There’s a mushroom that I am very fond of: the Laricifomes officinalis or quinine conk,” Prosser adds. “It’s rare and primarily grows in old growth forests. Occasionally, I’ll find it on sites like in the East Buttes. When I see it, I look up and imagine what was once there.”
Mycorestoration – the potential of partnering with fungi to heal the land
Mention fungi, and many people think of mushrooms. Mushrooms are actually the fruiting body or reproductive part of fungi. The web of threads that spreads within the fungi’s food source (soil, wood or other organic matter) is called the mycelium. It’s usually out of sight. You may have seen it as a green or white fuzz on a lemon left too long in a fruit bowl. This mycelial network takes nutrients from the soil or wood or other food source and releases other nutrients into it.
“The mycelium is where the magic happens,” Prosser says. “The water-holding capacity, the erosion control, the nutrient exchange.”
This is what the test beds are all about. “We want to learn the mechanics of dealing with fungi. The potential uses are so exciting.”
In Colorado, Prosser says, “they are chipping and inoculating logging slash [debris] with oyster mushrooms. They are finding that it decomposes significantly faster than wood not treated with fungi. This reduces fire risk and puts nutrients back into the soil. They’re finding that, in areas that have been hammered by heavy logging equipment, they can reestablish plants much faster. The mycelium also holds moisture, so it provides water to the new plants.”
Fungi could also help to stabilize riverbanks and to clean up decommissioned roads. “A web of mycelium in the soil is like throwing a net over the riverbank to hold it,” Prosser says. And mycelium can uptake pollutants, she explains. “Oyster mushrooms break the hydrocarbon bond in oil,” offering possibilities for cleaning up roads and other sites.
But before any of that, the team must master the basics: Where do they source mycelium? Can they get the mycelium to spread? What types of materials do they need to grow it? How do they prepare them? What are the costs and logistics of larger-scale projects out in natural areas? How do they measure success?
The seven test beds are starting to provide some answers.
Kristina Prosser works to create fungal test beds at Metro's Native Plant Center.
Putting mycorrhizal fungi to work
Land restoration often involves replacing invasive weeds with native plants, but those plants can sometimes struggle.
“We use best practices for mowing and herbicide spraying, but we are looking deeper into the soil, to look at fungi, at the microbiome of life in the soil,” says Prosser. “How can we promote that to help plants flourish and forests be more diverse?”
Mycorrhiza may hold an answer. Mycorrhizal (“fungus-root”) fungi partner with the roots of plants and trees, growing within and among them and exchanging nutrients in relationships that are beneficial to both.
“There is concrete evidence that plants and forests are connected underground by mycelia and mycorrhizae,” Schrager says. “A Douglas fir might be connected to all its neighbors through these networks exchanging phosphorus and nitrogen.”
These plant-fungus partnerships may offer clues why certain native plants, such as red huckleberry, can’t be grown in nurseries.
“We know that in nature it grows on decaying wood, which is a moisture and fungi sink,” Schrager says. “So at this point we are hypothesizing that there is a mycorrhizal connection that might allow us to put that on our landscapes more effectively.”
“We are doing a small experiment with Portland Bureau of Environmental Services,” Schrager says, “to see if we can propagate or replicate the root-connected mycorrhizal fungi that does those beneficial nutrient exchanges at the plant root level. We went out and scooped up native soil from four of our natural areas where we are going to do future plantings. We put it in a sterile environment and then put a fast-growing crop on it to build lots of biomass. What you end up with in the soil is spores from the mycorrhizal fungus. The idea then is to treat the new plants with something beneficial from the site you’re about to plant it on.”
The end result: A sort of site-specific fungal supplement for the plants. The supplement can be a powder sprinkled on plants or a slurry that a plant’s roots can be dipped in. The mycorrhizal supplements will be used on plants this coming winter, with the aim of boosting planting success.
“It lets us connect a bit more with the ecological complexity,” Lee says. “It gives us the chance to be more intentional with how we plant.”
Lee, Prosser and Schrager hope these projects are just the start of a program to incorporate fungi into their work.
“Fungi are so obviously important to ecology,” Schrager says. “They offer another way to understand the systems we are tasked with managing.”
Bringing people into the picture
Jeffrey Lee
“There are a lot of communities around like my own,” says Jeffrey Lee, who is a second-generation Chinese American. “I grew up with traditional East Asian medicine. I was used to my Grandma giving me soups with reishi and turkey tail mushrooms. It has made me think a lot about the stigma surrounding fungi. That can put up barriers for folks who want to access mushrooms for food and medicine.”
Recently, Lee was inoculating logs with mycelium at Glendoveer Golf Course. “At that site, you get a lot of trail users, many of them Vietnamese or Chinese,” he says. “A lot of them were very interested in what I was doing. They knew about turkey tail, they knew about reishi – it’s called the ‘mushroom of immortality,’ it’s good for the immune and circulatory systems and many other things.”
Lee reached out to Metro’s community engagement and stewardship team, which runs events for community members at Metro parks and natural areas. The fungi work resonated with them, and they are now planning to host some log inoculation workshops with community groups.
“Not necessarily to harvest mushrooms on the property,” Lee explains, “but with the idea that it’s an opportunity for people to connect with nature in a way that is culturally relevant to their lives and experiences.”