EUGENE, Ore. — Thousands of people may be prevented from joining the fall mushroom harvest after an abrupt change in U.S. Forest Service policy that resulted from a California lawsuit.

The policy shift also may restrict the availability of Christmas trees on Forest Service land, disappointing up to 65,000 families expected to hunt for trees during the coming holidays.

Forest Service officials say they have no choice after a California court ruling that says the agency has to grant appeal rights to the public on nearly every project or activity the forest allows or undertakes.

Environmental attorneys who filed the lawsuit say the Forest Service is overreacting by including noncontroversial activities such as Christmas-tree cutting and mushroom hunting.

Brookings mushroom buyer Tom Way has been frantically calling congressional offices and Forest Service officials, but no one has given him any hope of reprieve, he said.

"They're not sympathizing," he said. "They're not saying, we'll allow a public review of the decision. They just terminated it, and that's the way it is."

Way said he gets mushrooms from 500 pickers who harvest in the woods between Brookings, Ore., and Crescent City, Calif. He paid out $10.8 million to them last season, he said.

"If I don't hand that money out, that's $10 million in revenue they're going to lose," he said. "That's a major economic disaster for this community."

Wholesaler Casey Jonquil said he couldn't believe that the agency would halt permitting without contacting people in the wild-mushroom business. "They don't seem to understand that this is a multimultimillion-dollar business that pumps cash into very depressed small local economies," said Jonquil, president of a major Portland-based wholesale company, Alpine Forager.

The wild-mushroom industry is likely worth somewhere between $10 million and $100 million annually in Oregon, said David Pilz, a forest mycologist at Oregon State University. But that's only a guess.

The fall season includes golden chanterelle mushrooms that are shipped to Europe and to fine restaurants all over the United States, Pilz said. Others go to Japan.

Much of the harvest comes from residents of Southern Oregon who work part time and rely on mushroom picking to add a couple of thousand dollars to their annual income.

Permit prices range from $20 for a five-day permit to an average of $250 for a seasonal pass. Last year, the Forest Service collected $309,124 in those permit fees.