Hey, are you algae? Because I’m a fungi and I’m lichen you!
What is lichen, you ask? It is a composite organism; an alga and a fungus living together in a symbiotic relationship. The algae are able to photosynthesize while the fungi provide structural support. Amazingly, lichens can live in some of the most extreme environments on Earth and also some of the most common. Worldwide, there are more than 14,000 species of lichens (Walewski, 2011).
It’s not every day that you have a lichen expert, or lichenologist, on campus. But, when we hosted the Residential Environmental Learning Conference, we were fortunate to meet Joe Walewski, Director of Naturalist Training for Wolf Ridge Environmental Learning Center and author of “Lichens of the North Woods.” This guy knows his lichens!
On a tree branch, right outside our White Pines Campus Dorm, Joe found a species of lichen that had not yet been recorded on our list of species in the Cuyahoga Valley National Park. Though common in many parts of United States, Usnea strigosa did not yet appear on the lichen portal list for Cuyahoga Valley.
Usnea strigosa, commonly known as the “strigose bearded lichen,” will soon be added to our biodiversity tally. The genus Usnea refers to the group of lichens resembling gray or greenish hair. Usnea strigosa has the large apothecia, or discs, at the end of the branches. The apothecia can vary between yellow and pale orange, depending on the chemical race of the species.
In a biodiversity count compiled in 1917, Cuyahoga Valley housed 172 species of lichens. Today, in 2013, we have only 72. (For a complete list, check out the lichen portal website!) Just as macroinvertebrates are bioindicators of stream health, lichens are considered bioindicators of air quality. Certain lichens can only exist in clean air; therefore, if you find lichens in an area, the air in that area is most likely clean. So, adding Usnea strigosa to our lichen list is a positive sign for our environment!
Still curious about lichens, or wonder what lichens exist in other National Parks? Check out the list of lichen species at the lichen portal website!
Walewski, J. 2011. Lichens of the North. Collath + Stensaas Publsihing, Duluth, MN.
Usnea strigosa, Consortium of North American Lichen Herbaria. http://lichenportal.org/portal/taxa/index.php?taxon=54697