By Dan Joling

The Associated Press

ANCHORAGE, Alaska — More than 75 U.S. and Canadian scientists have sent a letter to President Barack Obama asking for a policy to preserve what remains of America’s old-growth forest.

The scientists include two former chiefs of the U.S. Forest Service, Jack Ward Thomas and Mike Dombeck.

They say less than 10 percent of the old-growth forest before European settlement is still intact.

Only fragments remain in the eastern United States, and the largest trees in the Pacific Northwest were targeted more than a century ago.

About 21 million acres of Washington state is forested, according to the state Department of Natural Resources, which estimates that 13 percent to 14 percent of forest land in Western Washington is old-growth forest.

The largest extent of remaining old-growth forest is in southeast Alaska’s Tongass National Forest but faces the threat of logging, the scientists said.

“As far as I know, the Tongass is the only national forest where they are still clearcutting old growth,” said John Schoen, a former state of Alaska research biologist.

Owen Graham, director of the Alaska Forest Association, said the Forest Service has been carefully planning appropriate timber sales and should be left to do its job.

“I presume those scientists’ salaries don’t rely on timber harvest or any other sort of resource development,” he said.

Old-growth forests vary greatly but are distinguished by old trees, accumulations of dead woody material and diversity of plant life.

Gordon Orians, professor of biology emeritus at the University of Washington, acknowledged that part of the motivation for protecting old growth is the powerful, emotional relationship with towering old trees.

“They’re like cathedrals when you walk in them,” he said.

However, the world has a major climate change problem, and old-growth forests retain more carbon than any other ecosystem.

They offer plants, animals, fungi and microorganisms found nowhere else and provide protection of salmon streams.

“There’s a biodiversity element to this,” he said.

A national policy would help re-establish old-growth forest in the Lower 48 states, which can take 120 years or more, while balancing timber needs, he said.