In 22 years since the Hayman fire on Colorado’s front range burned 182 square miles (471 square kilometers) of forest, there has been almost no tree regeneration in the most severely burned areas, researchers and the Forest Service said.
In California’s Sierra Nevada, where
up to 20% of the world’s mature giant sequoias and their seeds have been killed by fire in recent years, there are
massive openings without seedlings. A U.S. Geological Survey study concluded some groves will never recover without replanting.
But researchers say the odds of forests growing back will worsen regardless of fire intensity because of more heat and drought.