SILVERDALE, Wash. — About 80 million acres of national forests are ripe for burning up, so the U.S. Forest Service will have to be smart about picking which ones to thin, the agency’s chief, Vicki Christiansen, says.

A native of Washington state, Christiansen attended the annual meeting of the Washington Farm Forestry Association, a group that represents small forest landowners. In an interview, Christiansen said that the agency needs to do more to head off catastrophic fires.

“Quite frankly, the scale is not big enough,” she said. “We’re not reducing the risk. America’s forests are in crisis.”

Christiansen was elevated to interim Forest Service chief in March 2018. USDA Secretary Sonny Perdue eliminated the “interim” label in October, making Christiansen the Forest Service’s 19th chief in its 105-year history and the first since the 1930s to not have spent most working years with the federal agency.

She had a 26-year career with the Washington Department of Natural Resources, beginning in 1983. Her first job was overseeing reforestation around Mount St. Helens. She eventually became the Washington state forester.

Later, she was the Arizona state forester and joined the Forest Service in 2010. She was deputy chief for state and private forestry when picked to replace Tony Tooke, who resigned amid allegations of sexual misconduct.

Under Christiansen, the Forest Service has adopted a fire-prevention strategy that stresses working with states and private landowners.

She notes that she, Perdue and Under Secretary for Natural Resources and Environment Jim Hubbard all have backgrounds in state government. Perdue was governor of Georgia, and Hubbard spent 35 years in the Colorado State Forest Service.

The state experience, Christiansen said, “gives me, I think, a different perspective than many of our, at least, modern chiefs.

“These national forests are not just islands,” she said. “We’re all in this together.”

In a budget plan submitted to Congress, the Trump administration has proposed spending $450 million on thinning forests and controlled burns in the fiscal year that begins Oct. 1.

That would be $20 million more than the current year, even as the administration proposes trimming the Forest Service’s overall budget by $815 million to $5.7 billion.

With $450 million for fire prevention, the Forest Service estimates it could reduce fire-fueling vegetation on 3.4 million acres, an increase of 200,000 acres over the last complete fiscal year.

The Forest Service will concentrate on places where big fires would endanger communities, sources of drinking water and habitat, according to the budget plan.

To spend the money effectively, the Forest Service will have to look beyond just the number of acres thinned, Christiansen said.

“We have a rough idea that more acres treated is good progress, but I tell you there are 80 million acres just in the national forest system that are at least moderate to high risk of catastrophic wildfire, insects and disease and just working harder to treat more acres, well, we’ve been working on that for 15 years, and we’re not making the progress we need,” she said.

The Trump administration also proposes to increase spending on timber harvests by $11 million to $375 million. The Forest Service projects harvesting 3.7 billion board feet. Federal timber harvests have been on the upswing under the Trump administration, and Christiansen said she expects that to continue as a product of thinning fire-prone forests.

“We need to create better forest health conditions and timber harvest is a part of that,” she said.