Feature Life

Lichens are an early warning system for forest health

Scientists tap symbiotic lichens as sentinels of air quality, and now, climate problems

Fairy barf lichen

SENTINELS OF FOREST HEALTH  Aptly named “fairy barf” lichen (Icmadophila ericetorum) clings to bark in the Great Smoky Mountains of Tennessee. Lichens are useful for sensing threats to ecosystems, including air pollution and climate change.

Jason Hollinger/flickr (CC BY 2.0)

By Amy McDermott

- More than 2 years ago

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Ecologist Linda Geiser works her way through thick undergrowth on the steep hills of the Bull Run Watershed just outside of Portland, Ore.