The Bridges, a newsletter from the Natural Resources Foundation of Wisconsin, featured a good article about lichens by Jaime Kenowski. (Fall 2021)
As Dr. James Bennett, who is an emeritus professor of botany of UW-Madison, once said. “Lichens, you’ve probably spent your life overlooking them, but they’re all around us — growing on rocks, trees, and even cars, clotheslines, telephone poles, or tombstones.”
Many lichens are unique organisms consisting of a symbiotic growth of fungi and algae. They grow on trees, often forming colorful and interesting patches on trunks and twigs. They grow on shaded tree trunks, but the best habitat on a tree for many lichens is on high branches where they have access to full sunlight. The lichen communities found on high branches are normally out of our reach, but they can be seen when those branches break.
Indicator of Unpolluted Air
Lichens are an indicator of fresh, unpolluted air, and they struggle to thrive in highly urbanized environments. They play a role in creating soil by breaking down rocks. Small songbirds use them for nests, and some animals, including snails, deer, and even flying squirrels, eat lichens. Like everything else in Wisconsin’s interconnected natural world, lichens are being impacted by habitat loss and our changing climate. (Bridges)
“Our northern species are moving up and out of the state, seeking the colder temperatures they need. There are species that we can no longer find up north anymore that we know used to be there,” says Bennett. “Lichens are very sensitive, so the health and presence of lichens, or lack thereof, reflects the bigger picture health and biodiversity of an ecosystem.”
Next time you walk in the woods, take a good look where you find the lichens, and see how beautiful and varied lichens really are.
Transmittal photo courtesy of EPA.