In a woodlands dispute involving red-cockaded woodpeckers, southern pine trees and voracious pine beetles, a federal judge here has tried to split the difference.

U.S. District Court Judge Gerhard A. Gesell, ruling in a suit by the Sierra Club, has blocked the U.S. Forest Service from cutting down pine trees in four wilderness areas in the South to stop the spread of the southern pine beetle.

But the judge said the government could cut down some trees that the pine beetle has infested if colonies of the woodpecker, which is listed as an endangered species, are directly threatened.

"This case poses an environmental Catch-22," Gesell wrote. "Concern for preservation of pristine wilderness conflicts with concern for the red-cockaded woodpecker whose habitat may be threatened unless the government cuts down infested wilderness trees."

According to court papers, when the beetles arrive, thousands of pine trees can turn yellow and die, killing the woodpeckers that live in the trees.

To try to stem the contagion the government has been cutting infested trees for several years and creating "buffer zones" by cutting uninfested trees around the infested areas.

Gesell said thousands of acres of pine trees have been cut. Some of the buffer zones extend for miles.

But the Sierra Club maintained that by cutting the trees themselves, the Forest Service is improperly destroying the forests while providing "no scientific proof" that the tactic is effective in deterring the persistent beetle.

Gesell ruled that under the National Environmental Policy Act, the government can only cut down the trees after it completes a proper environmental impact statement, instead of the three more limited assessments it has conducted.

The assessments conclude that controlling the pine beetle by cutting the pine trees would have "no significant impact on the environment." But Gesell rejected that finding. "One could not rationally conclude," he said, "that cutting thousands of acres of pine trees in a wilderness forest will not have any effects that may be major."

Gesell's injunction applies to the cutting program in four wilderness areas -- two in the DeSoto National Forest in Mississippi and one each in Ouchita National Forest in Arkansas and the Kisatchie Hills National Forest in Louisiana.

Gesell noted that an environmental impact statement on the cutting program is scheduled to appear in draft form in October. Once it is completed, Gesell said, he will reconsider his ban.

But despite the Sierra Club's concerns, Gesell said he would permit pine trees to be cut down "immediately around a colony" of red-cockaded woodpeckers.

Even though it has not been "scientifically" shown that the cutting works, Gesell said "common sense would seem to suggest" that it "must have some effect" on the beetles that attack the birds' homes.

He said even this cutting must be strictly limited by guidelines set by the Fish and Wildlife Service.

But Gesell added, "As the government points out, the beetle is voracious and will not obey a court injunction."