WASHINGTON (NYTIMES) - Three wildfires in California in the past 15 months killed or mortally wounded thousands of mature giant sequoias, accounting for an estimated 13 per cent to 19 per cent of the world's population of the majestic trees, officials said.
A National Park Service report last Friday (Nov 19) estimated that two fires in September, sparked by a lighting storm, caused 2,261 to 3,637 mature giant sequoias - or between 3 per cent and 5 per cent of the population of mature giant sequoias - to be killed or so severely burnt that they were expected to die within five years.
Mature giant sequoias have a diameter of more than 1.2m.
Giant sequoias, which are found on the western slope of the Sierra Nevada in California, can live thousands of years on their way to dwarfing most everything around them. These trees include iconic national treasures such as the General Sherman Tree, which is considered the world's largest tree, standing at 83.8m tall with a diameter of 11m at the base.
The death of the trees in staggering numbers is the product of a deadly combination of unnaturally dense forests caused by fire suppression that began about 150 years ago and increasingly intense droughts driven by climate change, said Mr Clay Jordan, superintendent of Sequoia and Kings Canyon National Parks.
"That becomes a recipe for a catastrophic fire that threatens our sequoia groves, the health of our forests and, at the same time, threatens our communities," he said. The mortality rates in the sequoias are unprecedented, he added.
KNP Complex, one of the September fires, burned mostly within Sequoia and Kings Canyon National Parks. The other, the Windy fire, burned in the Sequoia National Forest, the National Park Service said.
The Castle fire, which began in August last year, destroyed 7,500 to 10,600 large sequoias, park officials said, representing an estimated 10 per cent to 14 per cent of the entire Sierra Nevada population of large sequoias.
Sequoias evolved to survive, and even thrive, in fires. But the ever-increasing intensity of fires in California has become too much for them.