Yosemite National Park: Forest fire threatens some of Earth's oldest trees

The forest fire that had been raging since Thursday expanded over the weekend. By Sunday, the flames had destroyed almost 650 hectares of wood and brush in Yosemite National Park. The park on the West Coast attracts tourists with its extensive landscapes, waterfalls and sequoia trees. Some of the oldest giant trees in the world can be found in the park.

The fire is also raging around the largest sequoia grove in the park. Here, a firefighter protects a giant tree threatened by the flames. Firefighters are taking special measures to protect the grove. Scrub that could worsen the fire has been cut down. In addition, sprinklers set into the ground are intended to increase humidity and protect the trees.

The flames also threaten humans. According to a spokeswoman for the national park, 1,600 residents in the community of Wawoma, which borders the park, have been evacuated, as has a campsite inside the park. The evacuations are happening at the height of the summer tourism season and the southern entrance to the park has been closed.

The Mariposa Grove, which has more than 500 mature sequoias like this one, was closed immediately. So far, none of the sequoia trees, some of which are more than 3,000 years old, have fallen victim to the flames. According to the authorities, no people have been injured either so far. The cause of the fire is still under investigation.

Many of the park's most famous attractions, including Yosemite Valley, remain accessible. Here, visitors enjoy the view of the valley as best they can. The view is clouded by thick smoke. The US Federal Forest Service warned on Sunday that particulate pollution had reached unhealthy levels in large parts of the park.

Not all sequoias, native to only 70 groves on the western slopes of California's Sierra Nevada, have been so lucky. Here, a firefighting plane flies over Yosemite Park during a major fire in 2018. In the past six years, fires have destroyed up to a fifth of the estimated 75,000 sequoia trees, the largest trees on Earth by volume.

Temperatures are expected to rise to more than 30 degrees Celsius (86 degrees Fahrenheit) in this area in coming days. At least there are no strong winds, which should help the emergency services fighting the fire. "We are confident about the plan to protect the sequoia trees," Nancy Phillipe, a spokeswoman for the park, told Reuters news agency.

In ecosystems such as this one, experts say fires are important for the natural balance of healthy forests. The trees are adapted to fire; the cones of the redwoods need strong heat to break open and release seeds, for example. At the same time, redwoods stricken by drought as a result of climate change are now becoming more vulnerable to increasingly frequent extreme fires.