Observers take a liking to lichen while hiking

Just about everyone has seen lichens. They are the ubiquitous greenish or gray crusts that are plastered to tree bark or festoon branches. Some species grow on rock, or even headstones.

Although largely ignored, lichens are interesting on multiple levels, including their fascinating multi-species structure. Symbiosis refers to different organisms that closely interact, and lichens epitomize this term.

A lichen is a collective of an alga and a fungus, living together and creating a composite species. The fungus provides structure (the “house”) and the alga manufactures the food. The individual identities of the symbionts — fungus and alga — are lost, and their combined identity becomes the lichen.

Why do lichens matter? Animals from insects to mammals eat them or use lichens for shelter. Hummingbirds shingle their nests with them. They help in soil formation by breaking down rock, and they enrich soil with nitrogen secretions.

Lichens are sensitive to airborne pollutants and serve as an early warning system for toxins in the environment. People make showy dyes from chemicals infused in lichens.

Finally, diverse, showy and ubiquitous lichens visually enhance the world around us.

On Feb. 1, I participated in an epic lichen expedition with two outstanding lichenologists, Tomas Curtis and Shaun Pogacnik, along with teacher Chelsea Gottfried. We visited Conkles Hollow State Nature Preserve in the Hocking Hills, a gorgeous site that is loaded with lichens.

Curtis, 21, attends the University of Akron and Pogacnik, 24, is a student at Ohio University. Both are fanatical about biology and have made unbelievable strides in helping to expand lichen knowledge in Ohio and beyond.

Gottfried and I quickly realized we were on a rocket ship ride on the learning curve of lichens. We hadn’t made it 20 feet up the trail before Curtis and Pogacnik had found a dozen species or more.

We slowly advanced, with the guys — whose powers of observation are far beyond average — constantly calling out new species.

Although some lichens are big, ornate and can’t be missed, far more are the definition of obscurity. Some so much so that even when presented with an aggregation of various tree crusts, Curtis and Pogacnik would literally have to put a finger on the species in question so we could pick it out.

It was impressive to hear them identifying scores of species, by scientific name: Dimelaena oreina! Imshaugia aleurites! Lepraria finkii! We sometimes would ask for common names, and they knew those, too: golden moonglow lichen! salted starburst lichen! fluffy dust lichen!

I think my mind finally blew when Curtis called us over to see a truly Lilliputian species, the Sulphur pin lichen, growing deep within the furrows of tree bark. Even a woodpecker would have missed it.

The day’s total was in excess of 100 species. Fewer than 700 species are known in Ohio, and we visited only one site.

Both men have made many notable finds, including new species for Ohio, rediscovery of extirpated lichens not seen in decades, and even species new to science.

Curtis has thus far found about 200 species of microlichens — really tiny ones — new to Ohio, a jaw-dropping accomplishment.

Curtis and Pogacnik represent the very best of a new generation of field biologists. They are keen observers, possess endless intellectual curiosity, have an infatuation with unraveling the mysteries of the natural world, and a passion for protecting it. I wish we could clone them.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.