February EcoQuest: Looking for Love(ly Lichens)

As Valentine's Day warms our hearts, let's explore the forest's most romantic residents—lichens! Imagine a love story where fungi and algae join forces, creating the ultimate power couple—that’s a lichen. Lichens are a symbiotic relationship between two or even three different species—one or two fungi paired with an algae or even cyanobacteria! These partnerships give lichens structure through the fungi and energy through the photosynthetic algae (you could say they’re a bit co-dependent).

In addition to being biologically fascinating, they are also ecologically important. They provide food, shelter, and even habitat for various other species. For example, birds will use lichens for building their nests—and tiny tardigrades (aka water bears) live within lichen like a real bear might live in a forest. Lichens perform ecosystem services like carbon capture, nutrient cycling, and can act as pioneer species, able to obtain nutrients from sheer rock and sunlight.

Beard lichens are a specific genus of lichens called Usnea. Although lichens are notoriously challenging to identify, this genus is quick to spot—look for tangled masses of silvery-green threads hanging from tree branches and bark. This genus is prolific in its range and grows from the Arctic to the tropics. Usnea is often confused with Spanish moss (which actually isn’t a moss or a lichen and doesn’t grow in Colorado). To identify Usnea, pull apart the outer sheath of its main stem. If there is tiny, white central cord inside, with the pull of an elastic thread—it’ll be Usnea. If not, it’ll likely be a different genus.

Usnea, and other lichens are known for their valuable benefits to humanity. For example, they are known for their usefulness in traditional medicine. The species in Usnea aren’t edible but are widely regarded for their medicinal uses, especially for their antibacterial and antifungal properties. Lichens are also known as bioindicators, meaning they can be used to monitor changes in environmental health. Some lichens, such as the beard lichen, are sensitive to common air pollution contaminants, like sulfur dioxide. This means that they can only thrive in areas with good air quality.

We still have a lot to learn about lichens. Learning more about where they grow can help us better understand air quality in the Front Range. In February, get more acquainted with this romantic fellow and contribute to our understanding of beard lichens by searching for these fascinating forest lovebirds and posting your findings on iNaturalist.

Usnea hirta by @phyllisholst

Usnea hirta by @bolmstead42

Posted on February 2, 2024 09:33 PM by alissa_iverson