BRIAN MELLEY, Associated Press
Lightning-triggered forest fires killed thousands of giant sequoias this year, causing a staggering death toll in two years, accounting for nearly a fifth of the largest trees on earth, officials said Friday.
Fires in Sequoia National Park and the surrounding National Forest, which is also the name of the trees, ripped through more than a third of the groves in California, setting off an estimated 2,261 to 3,637 sequoias, the largest trees by volume. Fires in the same area last year killed an unprecedented 7,500-10,400 of the 75,000 trees native to only about 70 groves dotted along the west side of the Sierra Nevada.
Intense fires that burned hot enough and high enough to kill so many giant sequoias – trees that were once considered almost fireproof – put an exclamation mark on the effects of climate change. The combination of a warming planet that has resulted in hotter droughts and a century of firefighting that smothered forests with thick underbrush has fueled fires that have rung the death knell for trees dating back to ancient civilizations.
“The sobering reality is that within a finite population of these iconic trees that are irreplaceable in many lifetimes, we have experienced another great loss,” said Clay Jordan, superintendent of Sequoia and Kings Canyon National Parks. “As spectacular as these trees are, we cannot take them for granted. To ensure that they are there for our children and grandchildren and great-grandchildren, some measures are needed. “
California has seen its largest fires in the past five years, with the last year setting a record for the most areas burned. This year the second largest land area so far has been burned.
After the fires at the castle and the SQF complex last year surprised officials by wiping out so many sequoias, extraordinary measures have been taken this year to save the largest and oldest trees.
The General Sherman tree – the largest living creature on earth – and other old trees that are the backdrop for photos, which often do not capture the splendor of the giant sequoia trees, have been wrapped in a foil blanket.
A type of fire retardant gel, similar to the one used as an absorbent in baby diapers, has been dripped onto tree tops, which can be 60 meters high. Sprinklers watered down tree trunks and combustible material was raked from trees.
The measures spared the giant forest, the park’s first jungle grove, but could not be used everywhere.
Much of the Suwanee grove in the park burned in an extreme fire in the marble fork of the Kaweah River drain. The grove of the Starvation Complex in Sequoia National Forest has been largely destroyed based on estimates of how much was burned at high severity.
In 2013, the park had performed climate modeling that predicted extreme fires would not endanger the sequoias for another 50 years, said Christy Brigham, director of resource management and science at the two parks. But that was the start of a five-year punitive drought that essentially broke the model.
In the midst of the drought in 2015, giant sequoias were burned in the park for the first time. Two fires in 2017 killed more giant sequoias. Just over 200 giant sequoias were killed in the fires, which served as a warning of what was to come.
“Then the castle fire happened and it was like, ‘Oh my god,'” Brigham said. “We went from the warning sign to hair on fire. Losing 7,000 trees in a fire is crazy. “
A full mortality count from last year’s fire is still not available as forest crews were confirming how many trees died when lightning struck on September 9, setting off the Windy Fire in Sequoia National Forest and the SQF complex in the park. said Brigham.
Not all of the news in the park’s report of the fires was dismal.
While 27 groves were burning and many trees were burned, much of the low intensity fire that sequoias need to thrive will clear the vegetation and the heat from the flames will open cones for them to spread their seeds.
There has also been less damage in many of the groves where the park routinely used mandatory fire to clear accumulated vegetation in cooler, wetter conditions to control the fire. The fires underscored the need to expand this work and, where too risky, start thinning the forests, Jordan said.
However, areas where the fire was so hot that seeds were killed and trees cannot regenerate may need additional help. For the first time, the park is considering planting seedlings to preserve the species.
“I’m not ready to give up giant sequoias,” said Brigham. “This is a call to action to better protect the remaining old growth and make our forests in the Sierra Nevada more resilient as the fire is coming.”