WASHINGTON — A Bush administration spending plan that would slash money for the Forest Service could lead to massive layoffs at the agency charged with managing 193 million acres of national forests, Democratic lawmakers said Wednesday.

Spending for the Forest Service would be cut by nearly 8 percent next year, to $4.1 billion, in a budget plan submitted by President Bush.

The plan could mean the loss of more than 2,700 jobs — nearly 10 percent of the agency’s work force — as well as reductions in dozens of non-fire related programs, from road and trail maintenance to state assistance, land acquisition and recreation, lawmakers said.

Rep. Norm Dicks, D-Wash., chairman of the House Appropriations Interior subcommittee, called the budget plan “an unmitigated disaster” that “would cause real harm to our 193-million acre national forest system.”

The only bright spot in the budget was a request to increase spending to fight wildfires by about $148 million to just under $1 billion, Dicks said.

The figure based on the 10-year average of firefighting costs and responds to a frequent complaint by lawmakers that firefighting costs typically exceed the amount budgeted. The Forest Service spent $1.4 billion fighting fires nationwide last year, according to the National Interagency Fire Center. The Interior Department spent an additional $450 million.

Even the increase for firefighting comes with a catch, Dick said. The plan would cut spending for fire prevention and preparedness — an approach Dicks said “would guarantee large, expensive wildfires again next year.”

Forest Service Chief Gail Kimbell acknowledged the budget request was “challenging,” but told Dicks, “I can report to you the state of the Forest Service is sound.”

The president’s budget reflects his priorities, including support for U.S. troops in Iraq and Afghanistan, strengthening homeland security and promoting economic growth, Kimbell said.

Within that framework, spending for the Forest Service is focused on core responsibilities — most especially fighting wildfires, Kimbell said. Wildfire-related spending accounts for 48 percent of the proposed budget, she said, a sharp increase that reflects the agency’s actual spending in recent years.

“The responsibility to protect people and property from wildfire is one the Forest Service performs professionally and honorably,” Kimbell said. Kimbell did not challenge Dicks’ prediction of as many as 2,700 jobs lost in the spending plan, but said most or all of the reduction could take place through attrition and retirement.

“We are not using the word ‘layoff’,” said Forest Service spokeswoman Allison Stewart.

Last October, nearly 2,200 homes in California were destroyed in simultaneous wind-driven blazes that charred about 800 square miles from north of Los Angeles south to the Mexican border. The fires caused more than $2.2 billion in private insurance claims and killed 10 people.