"BILLINGS, Mont. — 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."
Matthew Brown and Matthew Daly report for the Associated Press May 19, 2022.