MONTPELIER, Vt. (AP) _ A group of environmentalists sued the U.S. Forest Service on Thursday, claiming it is ignoring evidence that forests generate more income when left alone than when logged.

The environmental groups, which include Friends of the Earth and Forest Guardians, accuse the Forest Service of violating federal law requiring it to consider the economic and social benefits of a standing forest before cutting the trees.

The lawsuit is unusual, since environmental groups normally claim economics should have no bearing in the forestry debate.

But it plays into a new legal theory gaining hold in some circles that asserts that standing forests are worth more than the value of the timber sold and jobs created through logging.

``The goal of the lawsuit is to compel the proper accounting,'' plaintiff lawyer Brian Dunkiel said.

Uncut forests generate income through recreation, hunting, fishing and tourism, according to the lawsuit. The Forestry Service must consider these values, as well as the economic costs of logging such as damage to water resources, and weigh them against the value of the timber industry, according to the suit.

``This case is really about jobs versus jobs,'' Dunkiel said. ``There's a certain amount of jobs and economic activity that's created by logging public lands and there's a certain amount of jobs and economic activity that's created by unlogged public lands, and we want to find out how the scales balance out.''

Underscoring the uniqueness of the lawsuit is its list of plaintiffs.

Among them are the former mayor of Oakridge, Ore., a town that blames logging for its having to spend millions of dollars on a water filtering system; the owner of a medicinal herb company in Indiana whose income depends on standing forests; an Arizona hunter who claims to lose hunting opportunities when forests are logged, harming the income of guides, outfitters, equipment suppliers and others.

There are 191 million acres of national forest lands in 43 states. Less than half is available for logging.