Lichens Alive

Along with Ray Showman and Brian Gara, I made an expedition into southeast Ohio's rugged hill country today. We had a great time, and made many interesting observations and finds, until the snow and ice forced us out. Today brought the worst winter weather yet, and in many areas the roads were ice sheets.

But our main targets were lichens, and for the tree-dwelling species at least, snow and winter are not obstacles to observation. They look just fine at this time of year.

Along the banks of Handley Branch, a small stream in Lawrence County. The multi-trunked Silver Maple, Acer saccharinum, in the foreground was liberally festooned with lichens, including a very rare species. We walked as much of this habitat as we could before increasing snowfall started us worrying as to whether we'd be able to navigate back out the hilly gravel lane that brought us here.

Several factors probably conspire to create an Eden for lichens at this spot. The slight difference in micro-climate caused by the narrow, low-lying stream valley and increased humidity due to water from the creek is one. The Silver Maples seem to provide an excellent substrate for growth.

And, maybe, the active presence of that giant paddle-tailed rodent the beaver.

I had never tied lichens and beaver together until today. But lichens flourish where there is lots of sunlight penetration, and one of the big, furry fellows had an active slash and skid operation going on here. It's possible that as beavers fell streamside trees and create a more open grovelike situation, the increased sunlight penetration to the remaining timber creates a dreamland for the lichens. At least that's what it looked like and the scattered maples were thickly encrusted. In places where the forest was denser and less beaver-manipulated, lichen abundance dropped noticably.

This maple trunk is heavily laden with six or eight species, including the very rare beard lichen Usnea substerilis. This species is new to Ohio and these trees support the only known Ohio population thus far found. Ray, Dan Boone, Jim Decker and I had found it here back in April. Or more accurately, Ray found it and recognized it while the rest of us looked on in semi-ignorant awe. This trunk also supports Green Shield Lichen, Flavoparmelia caparata, Ruffle Lichens, genus Parmotrema, and some species in the genus Hypnotrachyna and Punctelia. And more.

In this video, Ray Showman briefly explains the workings of a lichen. They are fascinating organisms, the result of a pairing between an alga and a fungus. The fauna associated with lichens is poorly known, and if someone wanted to describe new species of insects they'd probably do well to study lichens. Who knows what all creatures have evolved a specialized lifestyle attached to lichens. There is no doubt that lichens are often heavy in bugs, and bark-creeping birds pick through them seeking prey.

This is Bushy Beard Lichen, Usnea strigosa, one of three species in this distinctive genus at the Lawrence County site. The specimen in the above photo is in reproductive mode; it sports apothecia, or fruiting bodies. They are the slightly concave round appendages, two of which are especially prominent at the bottom of the lichen.

This is the heavy hitter, Usnea substerilis, of which this specimen and the others at the site - about a dozen in all - make for the first Ohio record. There is no question that lichens are obscure and overlooked. Few people seek them out, and few people can identify them. However, there have been enough authorities looking around the state over the decades to paint a somewhat accurate picture of their status. And these beard lichens are among the most conspicuous of the group, and with only ten or so species to be concerned with in these parts, it's not like one will be overloaded trying to master Usnea.

Yet no one had reported this one. I suspect it will prove to be a localized rarity, but I'd bet other populations await discovery. Indeed, while driving back we passed along a very similar habitat, and a quick scan of some large creekside trees through binoculars revealed more beard lichens. By then, it was snowing pretty good and the roads were skating rinks so we forged ahead. I'm sure Ray will be back there next year, though, and add to our database of lichen knowledge.