Here’s why you should care about these organisms scattered throughout the Southern Utah desert

ST. GEORGE — These alien-like organisms that cling to rocks, earth or trees are something humans frequently walk past – but what exactly are they?

Red lichen making up biological crust at White Dome Nature Preserve, St. George, Utah, Oct. 2, 2022 | Photo by Alysha Lundgren, St. George News

Lichens are composite organisms, which means they’re actually made up of two distinct organisms, said Dr. Jacqualine Grant, an associate professor in Southern Utah University’s geosciences department. One of the organisms is fungi and the other is cyanobacteria, which also bears the common name blue-green algae.

Despite bearing the name “algae,” cyanobacteria are part of the bacteria kingdom Monera, according to the United States Forest Service’s website about lichen.

“The ‘blue’ in the common name refers to the fact that they need to live in water, and “green algae” refers to their photosynthetic abilities.”

Cyanobacteria are typically single-celled but are occasionally multicellular. The organisms can photosynthesize, which means they create their own sugars, a feat the fungi are not capable of, Grant said.

Lichen found at Snow Canyon State Park, Utah, Sept. 23, 2022 | Photo by Alysha Lundgren, St. George News

Additionally, a lichen might also contain green algae, or both green algae and cyanobacteria, according to information provided by the U.S. Forest Service. Green algae can survive in fresh and saltwater and in “any environment when part of a lichen relationship.”

There is some debate among researchers whether cyanobacteria and fungi in lichens have formed symbiotic relationships or if the fungi have “enslaved” the blue-green algae,” Grant said.

“For the longest time, everyone thought, ‘Well, the fungus is making a home for the cyanobacteria, and then the cyanobacteria are producing the sugars for the fungus,’” she said. “But some recent evidence has come to show that in some cases, it might be that the fungus has actually enslaved the cyanobacteria, sort of forcing it to live there against its will. Not that it has a will, but it might have been able to live on its own without the fungus.”

Red lichen making up biological crust at White Dome Nature Preserve, St. George, Utah, Oct. 2, 2022 | Photo by Alysha Lundgren, St. George News

These odd-looking organisms are found in a wide variety of environments and climates and can survive in extreme conditions, according to a 2007 study.

Lichens respond “incredibly rapidly” to moisture, particularly in the dry environments found in Southern Utah and can remain active throughout the winter, Grant said.

“Of course, it’s going to slow down for them if it’s really, really cold, but as long as the cyanobacteria have enough light and it can be warm enough to have all its metabolic processes working (and) have all the chemical reactions inside of it going, it’ll still be active, especially on warm winter days,” she added.

Lichens are one of the first colonizers of harsh environments, Grant said. They are known to break down rocks into soil and open crevices so other organisms, like plants, can begin to grow.

Lichen found at Snow Canyon State Park, Utah, Sept. 23, 2022 | Photo by Alysha Lundgren, St. George News

“And then we find a succession of bigger and more complex organisms are able to move in after lichens provide that first foothold,” she said.

They also serve as a “good indicator” of air pollution. If lichens are dying in an environment, it could be due to pollutants, Grant said.

Lichens absorb “everything in their environment,” according to the forest service, and provide researchers with valuable environmental information.

“Scientists can extract these toxins and determine the levels that are present in our atmosphere,” it states.

Lichens also may form a biological crust, or biocrust, which can consist of cyanobacteria, mosses and other organisms. Because it keeps soil “stuck together,” biocrust helps control erosion, so sediment isn’t washed or blown away, according to the National Park Service’s website.

Lichen and moss found in Dixie National Forest, Utah, Sept. 9, 2022 | Photo by Alysha Lundgren, St. George News

Additionally, biocrusts retain water, which plants can use to survive hot and arid desert conditions, and convert nitrogen from the air into the “kind of nitrogen plants need,” the National Park Service states.

And because these crusts control dust, they also prevent humans from being exposed to chemical compounds or spores that can be found in the underlying soil, Grant said.

For instance, Valley Fever spores, which cause a fungal disease, can be found in Southern Utah’s dust. While the Center for Disease Control and Prevention states that most who breathe in the spores will not become sick, higher-risk individuals can become “severely ill.”

“So the lichens and mosses, they hold all that dust down, and every time we walk on them or drive on them, we’re opening up and exposing ourselves to more of this dust that could cause us health problems later in the future,” Grant said.

Lichen under ultraviolet light, Cedar City, Utah, Oct. 3, 2022 | Photo by Alysha Lundgren, St. George News

These crusts are fragile and easily destroyed. Impacted lichens and mosses can take centuries to fully recover, according to the National Park Service. And some may never return.

“Vehicle tracks, bicycles, and footprints are extremely harmful – even a single footprint can kill the soil crust immediately below,” the site states. “Continuous pressure can break up the crust. Then, rain or wind can scatter the pieces.”

Similarly to scorpions, some lichens fluoresce under ultraviolet light, and the glow patterns are dependent on the chemicals they produce. Those interested in seeking out these glowing organisms can do so with a UV flashlight.

To learn more about lichens, click here.

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