Although you will not see a great abundance of lichen on the trunks of redwood trees, high up in the canopy the branches are covered with a rich variety of lichen species, adding to the complex habitat the redwoods are known for.
In March 2014, our scientists explored the epiphyte community in a coast redwood and Douglas fir tree at Muir Woods National Monument as part of the National Parks Service bioblitz. During this study they found 103 different species of lichen, from the forest floor to the tops of the trees.
These lichens can play an important role in the forest ecosystem. Lichens are often the first to enter an area, breaking down bare rock and sand into rich soil. Some lichen species will take nitrogen from the air and add it to the soil; they also provide food and nesting material to many animals.
Maybe most importantly, they can be indicators of air pollution. Many lichens are sensitive to changes in the environment, making their presence or absence in an area a clear sign of the health of the surrounding ecosystem.
Soon, everyone who visits Muir Woods will be able to learn about the rich lichen community present in the park through a new interpretive display in the visitor’s center. As part of the display, there will be intricate, carefully hand-knitted lichen samples for all to examine and touch. These impressive specimens were created by a local resident who artistically shares the natural world with others through her handiwork. You can see more of Celeste Woo’s knitted works here.