Definition of ‘old’ at heart of debate on Biden forest order
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.
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. Douglas fir stands could take 100 years.
There’s wide consensus on the importance of preserving the oldest and largest trees — both symbolically as marvels of nature, and more practically because their trunks and branches store large amounts of carbon that can be released when forests burn, adding to climate change.
Global wildfires last year emitted the equivalent of about 7.1 billion tons of carbon dioxide, according to the Copernicus Atmosphere Monitoring Service. That’s equal to about 18% of global carbon dioxide emissions from coal, oil and other energy sources recorded last year by the International Energy Agency.
Concerns that warming temperatures, fires and disease could doom the dwindling number of ancient trees in federal forests drew a bipartisan group of lawmakers to California this month. They pitched planned legislation to preserve perhaps the most iconic old growth in the U.S.: stands of massive sequoias that can tower almost 300 feet.
Lightning-sparked wildfires killed thousands of giant sequoias last year, adding to a two-year death toll that accounts for up to nearly a fifth of Earth’s largest trees.
But the unity behind saving rare sequoias quickly fades when it comes to “mature” forests — a term that White House climate adviser David Hayes said could apply to stands at least 80 years old.
Biden’s order calls for the Forest Service and Bureau of Land Management over the next year to define and inventory all mature and old growth forests on federal land. After that, the agencies must identify the biggest threats those forests face and come up with ways to save them.
Threats could include fire, drought, competition with younger trees, insect infestation and timber harvests, agency officials said in a statement. How those rank won’t be known until after the inventory.