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Lichenologist John Villella examines lichens on a rock on the Upper Table Rock Trail Monday. Villella is one of the leaders in the annual weekend spring hikes on the Table Rocks that begin Saturday. - Jim Craven

Take a hike

Most folks hike the Table Rocks each spring to ooh and ah over the colorful carpet of wildflowers.

Not John Villella.

It isn't that the botanist doesn't appreciate the beautiful fawn lilies and buttercups now attracting hikers to the rocks like bees to a flower bed.

"With flowers, you only have a season," he explained during a hike on Upper Table Rock on Monday. "But with lichens and bryophytes (mosses), you can go out any time of the year and see them. They are everywhere."

With that, he pulled a small branch of a white oak down to eye level. Half a dozen lichens, from slate green to dark brown, live on the small branch barely two feet long.

"They are ubiquitous — you find them on trees, soil, rocks, fences, roofs," said the certified lichenologist and member of the American Bryological and Lichenological Society. "Anything out there for very long that doesn't move, chances are it is going to have a lichen growing on it."

Villella is a hike leader for the guided annual weekend spring interpretive hikes that kick off Saturday on the Table Rocks, offered by the U.S. Bureau of Land Management and The Nature Conservancy. His tour will focus on lichens and mosses growing on Upper Table Rock.

Hailing from the moss-covered Olympic Peninsula, Villella, 35, of Ashland, began studying lichens in college.

"When I finally figured out what they were, I realized I had been seeing them all my life and had been kind of glossing over them," he said. "Once I learned about the symbiosis between algae and fungus (creating lichens), I got more and more intrigued by them."

A botanist with Siskiyou Biosurvey, he now does contract work for the BLM and U.S. Forest Service.

"The Table Rocks are especially interesting places for lichens and bryophytes," he said, adding that he made a point of stopping at the Table Rocks last year while leading a West Coast tour of lichenologists from the world over. "There are several rare species that are found here," he added.

Although mosses are not lichens, they are often discussed together because they are found in the same habitat such as a tree trunk or rock, he said. Moss is commonly found on all sides of a tree, not just the north side, incidentally.

Moss is commonly dark green while lichen tends to be every color from light green to orange, he explained. If you use a magnifying glass, you can actually see tiny leaves on moss, he added, noting lichens don't have leaves.

"Mosses are very old plants," added Leah Schrodt, a naturalist with the BLM's Medford District who joined him on the hike. "It has an ability to completely dry up as it does every year here, then, instead of dying, goes through a stage of dormancy and comes back to life."

Same with lichen, Villella said. When they were watered, lichens and mosses collected by Darwin sprang back to life more than 100 years after he collected them while traveling the world in the HMS Beagle, he noted.

Contrary to popular myth, lichens are not harmful to trees, he said.

"Lichens aren't parasites — they are not getting nutrients from the tree," he said. "Lichens mostly live on nutrients brought in by fog, rain and deposition of dust.

"There is actually benefit to trees by having them covered by lichens and mosses," he added, noting they slowly release water they absorb. "There is also speculation the lichens form a protective barrier against insects because they have acids that are functionally insecticides."

A lichen known as old man's beard — the Latin term is usnea — commonly found on oaks has medicinal properties, Schrodt said.

"In a lot of natural deodorant, lichen is included as an antimicrobial," she said. "It is also an antibiotic."

Some birds look for specific lichen to feather their nests, Villella said.

"They are actually pretty good lichenologists — they pick the usnea and bring those back to the nest to make the lining," he said. "When their chicks hatch, they have this antimicrobial barrier."

He pulled some dark lichen off an oak branch. The lichen has Velcro-like attachments on the bottom, he said.

"Hummingbirds will take this lichen and Velcro it to the outside of their nests for camouflage," he said.

Some lichens, including a gray form that appears to be painted on rocks, has the ability to produce chemicals to break down rocks, creating soil in a process that takes eons.

Another form, known as cyano lichen, has the unique ability to absorb nitrogen from the atmosphere and release it for use by plants, he said.

"I think of these nitrogen fixers as a nitrogen pill growing on the tree," he said. "When the rainwater comes through, that nitrogen becomes available to the trees."

As for the fact lichens attach themselves to just about anything, a dawdling Table Rock hiker needn't worry, he said, although noting the giant tortoises in the Galapagos Islands have been known to have lichen growing on their shells.

"You just have to go a little faster than a tortoise," he said.

Reach reporter Paul Fattig at 776-4496 or e-mail him at pfattig@mailtribune.com.

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