Once thought to be impervious to fire, the trees, which grow only within a limited band on the western slopes of the Sierra, have become increasingly vulnerable to California's bigger, hotter blazes.
With forest fires burning longer and larger due to climate change, more research is needed to understand the long-term health effects of prolonged exposure to smoke, a new international report concludes.
The State of California is a six-part series that explores the history of California's forests, as well as the increasing threat of catastrophic wildfires.
