Donald Trump and U.S. Agriculture Secretary Sonny Perdue are planning to roll back Bill Clinton-era logging restrictions in Alaska’s 16.7-million-acre/6.75-million-hectare Tongass National Forest, exposing more than half of the world’s largest intact temperate rainforest to logging, fossil, and mining projects.

The so-called “roadless rule” protecting the forest has withstood a couple of decades of legal assault, the Washington Post reports, but may not survive the former reality TV star’s self-declared personal interest in “redefining” the term “forest management” while he occupies the White House.

“Politicians have tussled for years over the fate of the Tongass, a massive stretch of southeastern Alaska replete with old-growth spruce, hemlock, and cedar, rivers running with salmon, and dramatic fjords,” the Post recalls. “President Bill Clinton put more than half of it off limits to logging just days before leaving office in 2001, when he barred the construction of roads in 58.5 million acres of undeveloped national forest across the country. President George W. Bush sought to reverse that policy, holding a handful of timber sales in the Tongass before a federal judge reinstated the Clinton rule.”

The area has now become the U.S. Forest Service’s biggest holding, and agency officials had laid plans to phase out old growth logging in the Tongass within the decade. Trump’s decision to intervene, after prodding from Gov. Mike Dunleavy (R) and Sen. Lisa Murkowski (R), could affect 9.5 million acres, after setting aside the 5.7 million acres the U.S. Congress has designated as wilderness.

Citing Murkowski, the Post says Alaska’s entire congressional delegation and its governor want the roadless rule blocked. “It should never have been applied to our state, and it is harming our ability to develop a sustainable, year-round economy for the Southeast region, where less than 1% of the land is privately held,” she said. “The timber industry has declined precipitously, and it is astonishing that the few remaining mills in our nation’s largest national forest have to constantly worry about running out of supply.”

But “it is unclear how much logging would take place in the Tongass if federal restrictions were lifted, because the Forest Service would have to amend its management plan to hold a new timber sale,” the Post explains. A plan developed in 2016 “identified 962,000 acres as suitable for commercial timber and suggested no more than 568,000 acres of that should be logged.”

Another study, produced in 2013 by retired wildlife ecologist John Schoen, determined that “roughly half of the forest’s large old-growth trees had been logged last century,” the news story adds. “The remaining big trees provide critical habitat for brown bears, Sitka black-tailed deer, a bird of prey called the Northern Goshawk, and other species.”

The failed New York real estate magnate’s sudden interest in forestry apparently traces back to last year’s devastating Camp Fire, in which the town of Paradise, California burned to the ground and Trump was mocked for suggesting the U.S. could get wildfires under control by “raking and cleaning and doing things”, as he falsely claimed they do in Finland. Since then, Trump “has peppered Perdue with questions about forest management and has indicated that he wants to weigh in on any major forestry decision,” The Post writes, citing current and former aides. “One former Trump staffer, who spoke on the condition of anonymity to avoid retaliation, said forest policy has become ‘an obsession of his’.”

But in Alaska, local business owners, conservationists, and outdoor organizations are urging the Forest Service to adopt more limited changes to the roadless rule. “They need to keep the trees standing in order to keep the fish in the creeks,” said Chris Wood, president of Trout Unlimited, who explained that a more dramatic shift could mean trouble for the area’s commercial, sport, and subsistence salmon industry.

“About 40% of wild salmon that make their way down the West Coast spawn in the Tongass,” the Post says, and “the Forest Service estimates that the salmon industry generates US$986 million annually. Returning salmon bring nutrients that sustain forest growth, while intact stands of trees keep streams cool and trap sediment.”

Over time, agency officials have “realized the golden goose is the salmon, not the trees,” said Wood, a former Forest Service staffer who worked on the original Clinton rule.