BOISE, Idaho — An 11-judge panel of the 9th U.S. Circuit Court of Appeals has ruled it’s improper for federal judges to act as scientists when weighing in on disputed U.S. Forest Service timber projects.

Timber industry lobbyists and Forest Service officials called the unanimous ruling overturning a challenge to a northern Idaho logging sale significant, partly because it emerged from a court often seen as favorable to environmental groups.

In the ruling released Wednesday, the judges dumped a July 2007 decision by a three-judge 9th Circuit panel that halted the Mission Brush timber sale in the Idaho Panhandle National Forest. Environmental groups The Lands Council, based in Spokane, Wash., and the Wild West Institute, in Missoula, Mont., contended the Forest Service’s logging plan exceeded what was needed to restore the forest’s historic character and claimed logging would harm the region’s ecosystem for species including small, migratory owls.

The ruling also overturns a 2005 9th Circuit decision in which judges concluded the Forest Service’s approval of logging in burned areas of western Montana’s Lolo National Forest was based on an arbitrary and capricious environmental analysis.

U.S. Agriculture Department Undersecretary Mark Rey, who oversees the Forest Service, called this “the most important decision involving a Forest Service environmental case in the last two decades,” saying it restores the ability of federal agencies, not meddling judges, to exercise discretion over timber sales.

“The judges established a much more limited framework for judicial review of Forest Service decisions — a framework that’s much more consistent with the standard use by other circuits,” Rey told The Associated Press on Thursday.

 “The court says its role is not to act as a panel of scientists. They wanted to move back to a more appropriate role.”

Timber industry representatives said this will help stop judges from asserting their opinions over the decisions of Forest Service managers.

“We think it’s a landmark case,” said Tom Partin, president of the Portland, Ore.-based American Forest Resource Council. “It speaks volumes that 11 judges out of the 9th Circuit came up with this decision ... saying that the panel screwed up and that the judges aren’t supposed to second-guess the forest managers.”

Earth Justice, a nonprofit environmental law firm that’s monitored this case but didn’t represent the plaintiffs, contends claims by logging advocates and Rey are premature that this decision will radically shift the balance of power toward the agency and away from environmental groups.

“I don’t know that it changes the law at all, frankly,” said Todd True, from the group’s Seattle office. “Environmental groups or anyone else asking the courts to review government action have always had the burden to show that the government acted arbitrarily and that it failed to consider some factor that’s important. I don’t think this decision says that these agency scientists get a free pass and can do whatever they want to, and the courts have to accept it.”

The logging projects on 3,829 acres in the Bonners Ferry region will likely now move forward, a victory for the cities of Bonners Ferry and Moyie Springs that had said blocking the work could hurt the region’s timber-based economy. Some logging in the area had already begun before becoming entangled in the courts.

The logging is meant to bring a dense, Douglas fir-packed forest closer to its historical composition of open ponderosa pine and Douglas fir stands and to reduce the risk of insect infestation and devastating wildfire.

The judges’ decision this week affirms a 2006 ruling by U.S. District Judge Edward Lodge rejecting an injunction.

Environmentalists had asked the court “to act as a panel of scientists that instructs the Forest Service how to validate its hypotheses regarding wildlife viability, chooses among scientific studies in determining whether the Forest Service has complied with the underlying Forest Plan, and orders the agency to explain every possible scientific uncertainty,” Judge Milan D. Smith, Jr., wrote. “This is not a proper role for a federal appellate court.”

Smith was on the three-member panel last July that overturned Lodge’s original decision, but wrote then he did so only reluctantly because he was bound by the precedent of the 2005 Montana ruling.

That case, Ecology Center v. Austin, was an example of an “over-broad court injunction” that had ignored well-established standards that governed the court’s limited role in reviewing laws and slashed employment in logging communities in the Pacific Northwest, he wrote then, adding he’d gladly overturn it if the occasion arose.

“Today, we correct those errors,” Smith wrote this week, concluding that wildlife viability isn’t the Forest Service’s only consideration when developing logging plans for public land. Other considerations are outdoor recreation, range, timber and watershed protection — and federal law doesn’t dictate just what methodology the agency must use when doing its environmental analysis, Smith wrote.

The environmental groups still plan to pursue their case in U.S. District Court. No hearing date is set.

Mike Petersen, executive director of The Lands Council, contends a more complete scrutiny of the arguments will work out in the environmentalists’ favor — if not in Lodge’s court, then with another 9th Circuit appeals panel.