Log Off… Shut Down… Get Outside!


Do you know what a lichen is? Whether you’ve heard the name or not, you’ve probably seen a lichen before!

Have you ever noticed differently colored patterns on trees, rocks, wooden posts, etc.? Lichens can grow on natural materials, as well as many man-made materials. Lichens are composed of both a fungus and an algae or cyanobacteria. The differing species combination of both produce different types of lichens.



Lichens are so common that only bacteria are more widely distributed on the planet. This means that lichens are found in more places than any other group of organisms, including plants and animals! They can even grow in the Artic and Antarctic! There are over 15,000 species of lichens in the world, and Butler County is estimated to have 80 of them. Southern Ohio typically has more lichen diversity than northern Ohio, due to greater habitat variety.

Lichens are an incredible indicator of air quality. They cannot live in areas where air pollution is too great, and in the past have even been completely eliminated from areas where coal-burning factories were common, up until the Federal Clean Air Act was put into law in 1972. Since then, lichens have nearly, if not completely come back to their original population numbers.



There are many other creatures that have adapted to living around lichens. Many types of moths, whether in their juvenile caterpillar stage or in their adult winged stage, have excellent camouflage with lichens. The Gray Treefrog that is common in Ohio can also blend in with lichen-laden trees. With this camouflage, these frogs can be very difficult to find! Many bird species, especially Ruby-throated Hummingbirds, use lichen as a nesting material. This helps the nest to hide in plain sight in the trees.



The pictures used here were taken around the Administration office at Forest Run MetroPark. Have you ever seen these organisms growing in nature? All of these lichens were found during a 5-minute walk around the building.

We challenge you to see how many different types of lichens you can find within a 5-minute walk around your house, neighborhood, or in a MetroPark!