The U.S. Forest Service, an agency with a long history of prioritizing timber production, has taken a first step toward protecting the nation’s most ancient forests from logging.

The agency on Tuesday announced plans to amend management plans for all 128 national forests and grasslands across the country to better conserve carbon-rich “old-growth” forests, typically defined as those at least 150 years old and largely undisturbed by human activity.

“Old-growth forests are a vital part of our ecosystems and a special cultural resource. This proposed nationwide forest plan amendment — the first in the agency’s history — is an important step in conserving these national treasures,” Agriculture Secretary Tom Vilsack said in a statement. “Climate change is presenting new threats like historic droughts and catastrophic wildfire. This clear direction will help our old-growth forests thrive across our shared landscape.”

The proposal, if finalized, would restrict commercial logging across the approximately 25 million acres of old-growth timber that the Forest Service manages, but stops short of limiting harvest in “mature” forests, those that are decades old but haven’t reached the old-growth stage.

The move comes after months of the Forest Service seemingly dragging its feet on the issue, as HuffPost previously reported.

The Climate Forests Campaign, a coalition of more than 120 environmental groups, applauded Tuesday’s announcement as “an important first step” but called on the Forest Service to also take action to safeguard mature trees. Together, mature and old-growth forests form a key natural climate solution, sequestering a massive amount of planet-warming greenhouse gasses.

“Our ancient forests are some of the most powerful resources we have for taking on the climate crisis and preserving ecosystems,” Alex Craven, forests campaign manager at the Sierra Club, said in a statement. “We are pleased to see that the Biden administration continues to embrace forest conservation as the critical opportunity that it is. This amendment is a meaningful step towards averting climate catastrophe, safeguarding vulnerable ecosystems, and fulfilling President Biden’s commitment to preserve old-growth and mature trees across federal lands.”

This is a developing story. Check back for updates.