US firefighters race to protect Yosemite's giant sequoia trees

NEW MEXICO • Hundreds of firefighters scrambled on Monday to prevent a wildfire from engulfing an area of rare giant sequoia trees in California's Yosemite National Park.

The Washburn fire, in the renowned Mariposa Grove of Giant Sequoias, was first reported last Thursday and doubled in size over the weekend to 946ha, according to a park report.

Yosemite's fire management service said 545 firefighters were battling the blaze, including proactively protecting the grove - the largest group of sequoias in Yosemite, with over 500 mature trees.

The previously out-of-control blaze is now 25 per cent contained, but the weather is expected to remain hot and dry for the next few days - conditions that do not help efforts to curb the flames.

"We are doing everything we can to put this fire out," said Yosemite Fire Information spokesman Nancy Phillipe, adding that measures include deploying air tankers and helicopters.

At the Mariposa Grove - which remains closed to the public due to the fire - crews worked to remove quick-burning leaves, sticks and branches, and to drench the ground and giant sequoias. Large plumes of grey-white smoke were seen over the imposing trees.

The Yosemite fire service posted on Twitter footage of emergency sprinklers set up specifically to douse the grove's Grizzly Giant - the second-largest tree in Yosemite at 64m, and one of the oldest.

Giant sequoias are the world's largest trees by volume. Their relatives, the California redwoods, can grow taller - well over 100m - but are not as wide.

Both species are adapted to fires, with thick bark that protects them from heat and flames. But longer, hotter and more aggressive fires can damage them, sometimes irreparably.

AGENCE FRANCE-PRESSE