Getting to Know Us!
Lichens are complicated little organisms. It’s incredibly easy to get lost in the little details of lichens, so I like to tell a story to help illustrate what they are and why they are so special.
Joe Walewski, a well known lichenologist, tells the story of Freddy the fungus to people of all ages at Wolf Ridge Environmental Learning Center in Northern Minnesota. Freddy Fungus had a spacious home to himself and all the necessary life skills except cooking. Alice Algae was a master cook and lived alone. Freddy and Alice met, took a "lichen" to each other and decided to live together, cohabitating together in symbiosis. Walewski’s story becomes more complicated as he introduces Cybil Cyanobacteria, who occasionally cohabitates with Freddy and Alice. (Waleski, 2007). This story illustrates the complexity of what a lichen is and its basic functioning.
While this story hints at what lichens are, a more thorough explanation is needed. Lichens consist of at least two partners, a fungus and a green algae. The fungi never exists outside of the lichen and the algae can occasionally be found outside the lichen. The fungus provides the habitat and protection for the algae while the algae provides the food. Some people say that lichens are simply, "a fungus that has discovered agriculture" (Waleski, 2007).
Lichens can be found almost everywhere on Earth, ranging from tropical rain forests and deserts to Arctic plains and central Iowa. Since lichens can live nearly everywhere, it’s no surprise that it has been estimated that they cover six percent of the land on Earth (Gadd, 2010). Lichens are pioneer species. This means they are the first to come into an area that has been recently disturbed by events including lava flows, glaciers, and other natural disasters. Pioneer species help the area recover and, ultimately, create a more stable ecosystem. Lichens often use rocks as their substrate, and start to break down the rocks, creating soil in new environments. Lichens that contain cyanobacteria often fix nitrogen, increasing the amount of nitrogen in the soil and improving soil quality.
Despite their enormous geographic area and vast number of species (between 14,000 and 20,000 species), lichens go unnoticed every day. Lichens live on the trees, buildings, rocks, and even the sidewalks here at Iowa State. Lichens are permanent residents of their substrate. Lichens have a long lifespan ranging from 30 to over 4,500 years (Waleski, 2007). This makes them easy to study over a long period of time, and helpful for the tour you’re about to embark on!
Identifying lichens is incredibly tricky, but no worries! I’ve gathered all the pertinent information you’ll need to start! Learn more about identifying lichens here!
Gladd, Geoffery Michael. "Metals, Minerals and Microbes: Geomicrobiology and Bioremediation." Microbiology 156 (2010): 609-43. Print.
Waleski, Joe. Lichen of the North Woods. Canada: Kollath+Stensaas, 2007. Print.