新澳门六合彩内幕信息

Lichens Are Losing to Wildfire, Years After Flames Are Gone

Wildfire Is Reshaping Forests and Lichen Communities

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LIchen
Lichen on a Napa County oak tree. (Jesse Miller/新澳门六合彩内幕信息 Davis)

Quick Summary

  • Lichens are mostly unaffected by low-severity fires.
  • In severely burned areas, nearly all the lichen were gone, even 16 years after a fire.

As increasingly hot and severe wildfires scorch the West, some lichen communities integral to conifer forests aren鈥檛 returning, even years after the flames have been extinguished, according to a study from scientists at the University of California, Davis.

Lichen, an often overlooked organism that forms fuzzy, leaflike layers over tree bark and rocks, is an unsung hero in forest ecosystems. It provides food for deer, caribou and elk, and is sometimes the only food source for flying squirrels, which are key prey for threatened spotted owls. Birds and insects use it to eat and nest. An important contributor to the nutrient cycle, it also helps fix nitrogen in forest soils.

鈥淟ichens are beautiful, ecologically important, are all around us and tell us important things about the environment,鈥 said lead author Jesse Miller, a postdoctoral scholar in the Department of Environmental Science and Policy at 新澳门六合彩内幕信息 Davis. 鈥淏ut even if you don鈥檛 notice lichens, you would notice the consequences in ecosystems when they are lost.鈥

Lace lichen
Lace lichen, or Ramalina menziesii, is California鈥檚 state lichen. These drape across blue oaks in Napa County, which is outside the study area. (Jesse Miller/新澳门六合彩内幕信息 Davis)

Lichen loss and fire severity

For in the journal Global Change Biology, researchers sampled lichen communities in about 100 study plots across California鈥檚 Sierra Nevada region. Five wildfires had burned, at varying levels of severity, in and around the plots between four and 16 years before the study鈥檚 sampling.

The results show that lichen communities were largely unaffected by low-severity fires. This suggests that prescribed fires and natural wildfires under moderate weather and fuels conditions are compatible with lichen diversity.

But areas that experienced higher severity wildfires had significantly lower abundance and diversity of lichens.

In severely burned areas where most of the trees died, nearly all the lichens were gone, even 16 years after the fire.

Post-Fire Warner Mountains
This post-fire landscape in the Warner Mountains remains deforested 16 years after the Blue Fire. (Jesse Miller/新澳门六合彩内幕信息 Davis)

Recovery race

The lichens鈥 recovery is likely held back by the loss of tree canopy after the fire, the researchers said. The hot, dry microclimate left in the forest post-fire is not conducive to lichen growth. This indicates that lichen communities burned in Sierra Nevada forests likely won鈥檛 recolonize until mature trees regrow and the forest canopy is restored. This may exacerbate the effects of climate change that already threaten lichens.

鈥淚f the species could keep pace with the rate of climate change, the effects of fire might not be so bad,鈥 Miller said. 鈥淏ut 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.鈥

Lichen
This lichen community is typical of the study area. The bright chartreuse lichen is wolf lichen (Letharia), which is poisonous and is said to have killed wolves historically in Scandinavia. (Jesse Miller/新澳门六合彩内幕信息 Davis)

The study also indicates that the trend of and hotter, bigger and could cause broad impacts to lichen diversity across the landscape, which could impact nutrient cycling and multiple food-chain interactions among wildlife.

The study areas included:

  • Yosemite, in areas burned by the Rim (2013) and Grouse (2009) fires
  • Greater Lake Tahoe Basin, in areas burned by the Showers (2002) and Long (2009) fires
  • Warner Mountains, in northeastern California, in areas burned by the Blue Fire (2001).

The study鈥檚 co-authors are Hugh Safford of 新澳门六合彩内幕信息 Davis and the USDA Forest Service, Pacific Southwest Region; and Heather Root from Weber State University in Utah.

The research was funded by the USDA Forest Service, Pacific Southwest Region. A link to the lichen research can be found .

Media Resources

Jesse Miller, Environmental Science and Policy, jedmiller@ucdavis.edu

Kimberly Hale, 新澳门六合彩内幕信息 Davis News and Media Relations, 530-752-9838, klhale@ucdavis.edu

Kat Kerlin, 新澳门六合彩内幕信息 Davis News and Media Relations, 530-750-9195, kekerlin@ucdavis.edu

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