As fires continue grow larger, hotter and more frequent in California, an overlooked organism essential to forest health isn't always returning.
Lichen forms leaflike layers over bark and rocks. Animals like deer consume it, and it sometimes is the only food for flying squirrels (which spotted owls eat).
A recent UC Davis study suggests that today's increasingly dry forests, severe wildfires and climate change are impacting the organism. And, if lichen continues to disappear, it could alter the food chain in forests.
"If the lichens start disappearing off the landscape, which is what we're seeing, it could have this ripple effect and ultimately change the ranges or the abundance of animals in the forest,” said UC Davis researcher Jesse Miller.
He sampled 104 spots across the Sierra Nevada in places like Tahoe and Yosemite where fire's burned in the last 16 years. Miller found that fewer lichens survive in large, hot blazes and then have a slimmer chance of re-colonizing.
"We're seeing that the lichens just aren't coming back, even up to 16 years after fire,” Miller said. “What we think is going on is that climate change may be interacting with the altered environmental conditions that naturally occur after fire."
He says the lichens’ recovery is dependent on when mature trees regrow in burn areas, which he says could be exacerbated by climate change.
“If the species could keep pace with the rate of climate change, the effects of fire might not be so bad,” Miller said. “But the concern is they might not. These fires happen so quickly and in such a large area, they could cause species ranges to contract faster than they are expanding.”
Because of this, Miller points to the need for prescribed burns in cooler months in areas with lots of fuel on the ground. In turn, he says that could prevent large destructive fires in the future.
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