By Michele McDonald
When George Mason University doctoral student Manuela Dal-Forno goes for a hike, she’s on the hunt for inconspicuous lichens, which make their home on trees, rocks and leaves. She’s helped find more than 100 new species and suspects there are hundreds more in what used to be considered a single species.
Lichens are the result of a symbiotic relationship between fungus and a photosynthetic partner such as algae or cyanobacteria. They can be a key indicator to the ecological health of an area and also can be a future source for new drug treatments.
Until recently, scientists lumped many lichens into a handful of species in this group. To Dal-Forno, they are beautifully diverse. Lichens range in color from camouflage brown to turquoise, vary in shape from ignored flat to gorgeous fronds, and can be any size from a 50-cent piece to a dinner plate. These organisms also “fix” nitrogen gas in the air so plants can use this essential element as a nutrient.
Dal-Forno is working with George Mason’s Environmental Science and Public Policy professors Jim Lawrey, Pat Gillevet and Masi Sikaroodi, as well as Robert Lücking from the Chicago-based Field Museum. They’re looking at lichens that were categorized as a single species of lichenized basidiomycete called Dictyonema glabratum, also known as Cora pavonia.
Whether the lichens were found in Florida or South America, they previously received the same name. It didn’t help that much of the assessment was done by studying dried specimens; the brilliant colors dimmed and the extravagant fronds shriveled so they all looked similar, much like dried mushrooms, and lost some of their distinctive characteristics. But no longer—the team is now looking at the lichens at the molecular level, and discovering entirely new species based on their genetic makeup, Lawrey says.
They’re also getting a close look at them in the wild. Dal-Forno, a native of Brazil, has traveled to the Galapagos Islands, Brazil’s rain forest, Puerto Rico, Costa Rica and Ecuador in search of these lichens. In person, these lichens have noticeable differences, she points out: “Why does this one have hairs and this one doesn’t? This lichen is green, and this is brown.”
New discoveries of mammals and birds may get most of the attention, but lichens deserve some fanfare too. They’re models of symbiosis and show how two different organisms can bond together, Lawrey says. Plus, they can thrive in the high Andes Mountains, which may look like a wasteland to the casual observer.
Lichens are everywhere, Dal-Forno says, adding, “I challenge you to go on a hike and not spot some.”
Dal-Forno came to Mason specifically to study lichens with Lawrey and his team. She first learned about them during a three-hour course as an undergrad in Brazil. She was hooked. “I immediately fell in love and thought ‘this is what I want to do with my life.’”