WASHINGTON - Agriculture Secretary Tom Vilsack issued a temporary order yesterday governing development in "roadless" areas of national forests, requiring all new projects to be approved by him personally.

Vilsack's order, which will be in effect for a year, is the latest turn in an eight-year-old battle over 58.5 million acres of pristine woods. President Bill Clinton made these areas off-limits in 2001, but President George W. Bush effectively reopened some in 2005. That led to a series of court cases that ultimately replaced the national policy with a patchwork of regional rules.

Vilsack, whose purview includes the U.S. Forest Service, did yesterday what environmental groups had been urging: call a "timeout."

Agriculture Department officials said that while the temporary order is in effect, the Obama administration and Congress would try to create a permanent policy on roadless regions. They said Vilsack's caseload was not expected to be large: Over the last eight years, one official estimated, 30 to 40 projects have been proposed in these areas.

"We're raising the level of scrutiny," said Chris Mather, a spokeswoman for Vilsack. "From this moment ... we are going to make sure that our forests are protected in all projects we approve."

USDA officials said the order was not an outright ban: One said projects aimed at protecting watersheds, planting trees, or stopping forest fires might be allowed. The official said it was unclear whether projects with a strictly commercial aim, such as logging or mining, would be allowed.

The order does not apply to national forests in Idaho, which recently developed its own policy on roadless areas.

The Forest Service's inventory of roadless regions includes about a third of the country's national forests. About 97 percent of them - often never-logged old-growth forests - are in the West. The ones in the East include small pockets of New Hampshire and the Appalachians that in most cases have regrown after being logged in past centuries.

Environmental groups say these areas serve as crucial natural filters for rivers and streams, key habitats for fish and animals such as grizzly bears, and "sinks" that take carbon dioxide out of the atmosphere. Several applauded Vilsack's decision.