Biden forest plan stirs dispute over what counts as "old"

BILLINGS, Mont. (AP) — President Joe Biden's order to protect the nation’s oldest forests against climate change, wildfires and other problems devastating vast woodlands is raising a simple yet vexing question: When does a forest grow old?

Millions of acres are potentially on the line — federal land that could eventually get new protections or remain open to logging as the administration decides which trees to count under Biden's order covering "old growth” and “mature” forests. Underlining the urgency of the issue are wildfires in California that killed thousands of giant sequoias in recent years.

Experts say there’s no simple formula to determine what's old: Growth rates among different tree types vary greatly — and even within species, depending on their access to water and sunlight and soil conditions.

Any definitions for old-growth or mature trees adopted by the Biden's administration are “going to be subjective,” said Mark Ashton, a forestry professor at the Yale School of the Environment.

Already disagreement is emerging between the timber industry and environmentalists over which trees to count. That's likely to complicate Biden's efforts to protect older forests as part of his climate change fight, with key pieces stalled in Congress.

“If you were looking at ecological and academic definitions of old growth, it’s going to be very different from what the White House is thinking about,” Ashton said. “Even the word ‘mature' is difficult to define.”

Groves of aspen, for example, can mature within a half century. For Douglas fir stands, it could take 100 years. Wildfire frequency also factors in: Ponderosa pine forests are adapted to withstand blazes as often as once a decade, compared to lodgepole pine stands that might burn every few hundred years.

There's wide...