Lichenology 101


Bright green letharia and pale green usnea are two of the lichen species that adorn branches in the Cascade-Siskiyou National Monument.

Where we live now, clumps of what appears to be bright green-yellow lace adorns every visible conifer, as if tatted by an obsessive grandmother who makes surprising color choices. Our daughter, Magdalena, collects handfuls of the intricate, lacy strands and discovers that, when wetted, it makes a wonderful sculpting material. She moulds enough fingers to craft a human-like hand with this wonderful macrolichen, letharia, that thrives in the Pacific Northwest. Viewed up close, I see the fibers are arranged in a branching pattern. The fibers appear delicate, but feel tough and durable.

Special thanks to lichenologist John Villella who allowed me to interview him for this post. Any errors are undoubtedly my own.

Good news: the world holds 15,000 described species of lichens!!!

Why is this good news? 

Lichens are important components of the ecosystem, and I will delineate how so in just a moment. But first, what exactly is a lichen?

Perhaps you may remember from high school biology class that a lichen is composed of two different organisms working together in symbiosis: a fungus with an algae, or a fungus with a cyanobacteria (both algae and cyanobacteria perform photosynthesis). These lichens, along with their pals, mosses, form a crusty film over nearly everything outside: rocks, tree trunks, sidewalks, fallen branches, decaying plant matter. If you are like me, perhaps you appreciate lichens for the rich colors and textures that they form on hard surfaces– greens, blues, yellows, oranges, reds, and pinks painted on rock and bark. Even urban sidewalks are inscribed with subtle, blue-green circles of living pattern.

Lichen, Southern Oregon

But beyond their aesthetic value, the lichen crust also performs three vital functions for the ecosystem.

First, lichens moderate moisture. During foggy or misty days, the lichens and mosses on trees will puff up, absorbing water from the air and retaining it like a sponge. Then on drier days, the lichens release that moisture gradually, creating a microclimate.

Second, lichens are nitrogen-fixers. Trees and plants need nitrogen to grow. The more nitrogen, the bigger they get. Where does a forest procure enough nitrogen for all those large flora like redwood trees? Well, surprisingly, salmon is the primary source for Pacific Northwest forests. Salmon begin life small, in forest streams, then swim out to sea where they bulk up on the ocean’s nutrients. Then they swim back to their home rivers, importing all that accumulated nitrogen in their bodies. Other animals, such as birds and bears, eat the salmon, then deposit nitrogen-rich scat inland and upland. After salmon, the next nitrogen source is alder trees. Alders have root nodules, wart-like infestations of cyanobacteria that make nitrogen for the alder trees to consume. Alders, when they die, fall and feed other tree species. But another important source of nitrogen for forest food is . . . lichens, which absorb nitrogen from the air and create nitrates and nitrites. So, lichens are basically a vitamin pill for plants, hanging onto the tree and gradually leaking nitrogen.

Third, lichens serve as nesting material for birds and mammals. In fact, some species, including some hummingbirds, build their nests almost exclusively from lichens, using spiderwebs to hold them together. When Magdalena used lichens for a hand-shaped sculpture, she was acting on an impulse she shares with the hummers.

When I first visited the Pacific Northwest, the most striking feature I noticed in the landscape were the masses of fluorescent green material clumped along the trunks and branches of nearly every evergreen tree. Close up, it appeared to be formed of delicate networking strands, so intricate. Was it a moss, a lichen, or a fungus? Was it parasitic, I wondered? John Villella, a lichenologist, informed me that it is letharia, a macrolichen commonly known as “wolf lichen.” A poisonous species, it was christened “wolf lichen” because of the traditional trapper practice of combining it with glass shards and hiding the mixture inside meat, in order to kill wolves. Vulpinic acid lends letharia its bright green color. A charismatic and plentiful lichen, it makes a good natural dye, producing a dark red to purplish color.


Now when I hike outside or peer out my windows at lace-festooned branches, I will know what I am seeing. I will think of grandmothers, of textile artists using natural dyes, of trappers and wolves, of my daughter and her sculptures. I will exhale in wonder with the thought that this letharia is just one of the 15,000 different lichen species that share this blue-green world with us, adorning nearly every hard surface on the spinning planet.

What is a lichenologist?

John Villella, whom I interviewed on Wednesday this week, is the first lichenologist I ever met in my life. He’d met Steven this past fall on a hike, and the two of them quickly discovered their mutual fondness for small, obscure woodland creatures such as salamanders. They agreed to meet again before long. This week, John invited us to his home to discuss lichens, salamanders, and his work as a biosurveyor. He welcomed us in to his warm kitchen, where he made places for us at the table, and quickly brewed a pot of red chai tea. The tea pot was lime green, like some stunning species of lichen.

John appeared to be about my age, maybe early- to mid-thirties, with dark hair and a medium build. He had an introvert’s gentle demeanor, and a field biologist’s sense of wonder. He spoke with both clarity and exuberance about the flora and fauna he’d surveyed in the Cascade-Siskiyou National Monument in 2007. He brought out a couple of lichen books and showed us a few of his favorite species.

At John’s kitchen table, with indie music softly playing from a small speaker resting on the bench where I sat, I asked him how had I missed this as a career option? Was this a very rare niche, or had I simply not been paying attention?

Proposed logging area near Cascade-Siskiyou National Monument

John Villella and his family explore an old growth grove adjacent to the Cascade-Siskiyou National Monument. Stands like this are still at risk of being logged.

He said, “Oh, lichenology’s not that rare; there are about 35 of us in the Pacific Northwest.” Oh, thirty-five. And apparently, this is not a viable field outside the Pacific Northwest. No wonder I’d missed this, having lived most of my life on the East Coast or Middle West. The biosurvey industry is fairly new, too, having materialized in the 1990s around the time that the spotted owl controversy was raising havoc among loggers and environmentalists in the Northwest.

John filled us in on his industry’s backstory. In the 1990s, while loggers were shooting spotted owls to display on their car grills and tick off the tree-huggers, and environmentalists were physically camping in old growth tree canopies to prevent timbering, the Clinton administration decided to come up with some kind of plan to allow all parties to get something of what they wanted. The government-mandated Survey and Manage plan allowed for scientific studies and protections for endangered species while allowing timbering activities to take place in lower-risk areas.

The idea was to figure out which animal and plant species were dependent exclusively on old growth forests for survival, and then, through ecosystem management plans, to ensure that those species retained adequate habitats to prevent extinctions. The spotted owl was a popular poster child for this effort, but other, less charismatic, species benefited too–say, specklebelly lichen and jumping slugs. Instead of protecting isolated species, an ecosystem management plan recognizes that all these  organisms are intricately linked together. For example, each plant species benefits from a specific community of microorganisms (fungus and cyanobacteria) that live at its root base, funneling nutrients into the root hairs. Without the right mix of microorganisms, plants and animals are negatively affected. So, if we want to save the spotted owl, we must protect the owl’s preferred trees, which in turn necessitates protecting the tree’s preferred lichens and fungi, which might also mean protecting the associated slugs and salamanders and tree frogs.

Pileated woodpecker and lichen, Lincoln, Oregon

Pileated woodpecker and letharia

The survey and manage program allows for scientists to evaluate and monitor logging sites to ensure the conservation and preservation of important species that cannot survive elsewhere. Logging can still happen, but it’s supposed to occur in a managed, responsible manner.

In response to the need to evaluate management strategies and to survey which species most need to have their ecosystem protected, a mini-industry has sprung up, biosurveying. Lichenology is one component of this mini-industry.

Just at the right time, when this biosurveying was budding, John was a college student, enrolled in a course called “Lichens and Mushrooms.” During that semester, there came a call for people to go out and survey old growth areas for lichens and other species. John took the timely job opportunity, finding field work observing lichens, mushrooms, mosses, and rare and threatened plants. He has since taught the Lichens and Mushrooms course, and become a certified lichenologist (certification is necessary to ensure that qualified, knowledgeable people are recording accurate data). John now performs biosurveys throughout the Pacific Northwest and in Alaska.

John Villella even named his second daughter after his favorite kind of lichen, Ahtiana. John picks up a twig that has lain on the kitchen table throughout our conversation, and passes it to us to inspect. For Ahtiana’s birthday, one of her pre-school friends presented this stick to her, covered with lichens. At first glance, I notice two shades of green lichen–one like celadon glaze, another more blue-green like juniper. But John says, “Look closely. You can see about ten different kinds on there.” I look again, and notice a flatter, rust-colored texture, specks of bright reddish-orange, a bit of day-glow yellow, something chalky white, and flecks of brown. Here, a color I knew in kindergarten as “spring green,” here, threads of salmon pink. A diversity of lichens, going about their quiet work of regulating moisture, procuring nitrogen, and waiting to be built into a nest.

 Anna Maria Johnson

Photos © Steven David Johnson (All Rights Reserved)

3 Responses

  1. April Moore says:

    I loved this post! Wonderful photos and fascinating information about lichens. If your site is one I can ‘subscribe’ to, I would like to.

    Anna Maria, I was sent this post by your mother. My husband Andy Schmookler and I met Anieta during Andy’s campaign for Congress. In viewing your post, I realize I’ve had contact with you both before. Steven, I remember that you generously donated some of your excellent photos to Friends of the North Fork for a ‘user’s guide’ I created to the flora and fauna of the North Fork. And Anna Maria, I think I have spoken to you on the phone.

    BTW, I encourage you to take a look at my website, I think you’ll find we’re kindred spirits.

    Best to you both! And keep up the good work.–April

    • SJ & AM says:

      Thank you, April, for your comments and for your beautiful and inspiring posts on your website. The post about the bird flyway was especially interesting since the same birds come up to the Klamath Basin Refuge that we posted about here on our blog. When we return home to Virginia, we will be sure to connect with you in person and perhaps we can work together on more conservation efforts there as well.

  2. Pingback: Parsnip Lakes and the Oregon Spotted Frog | A Season in the Cascade-Siskiyou National Monument

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