Image: delfi de la Rua delfidelarua7 via Wikimedia Commons

by Amy Lupica, ODP Staff Writer

A study published in the Journal of Archaeological Science: Reports has uncovered one of New York City’s best-kept secrets. Researchers took a peek into the cracks of the iconic city’s foundations and found that wood from the region’s original old-growth forests can still be found in the walls and beams of many NYC buildings. Now, they’re trying to reconstruct the history of these forests and see what they can tell us about deforestation today.

Why This Matters: The world’s old-growth forests are crucial to fighting climate change, sequestering billions of tons of carbon each year. The U.S.’s largest old-growth forest, the Tongass National Forest in Alaska, sequesters about 8% of the nation’s carbon emissions.

• Unfortunately, these forests are declining rapidly as human development and devastating natural disasters take their toll.
• The world is already witnessing the consequences; the Amazon is predicted to shift to a Savannah in the coming years.

Investigating how the destruction of old-growth forests 200 years ago impacted climate and biodiversity could help scientists fight back against similar changes we face today.

Building Up, Chopping Down: A team from the Tree Ring Laboratory at Columbia University’s Lamont-Doherty Earth Observatory observed growth ring patterns in the old building blocks of NYC buildings like the Terminal Warehouse. There, they found discarded beams with more than 150 growth rings and determined they belonged to old-growth longleaf pine, which builders valued for its strength and resistance to rot. These rings don’t just age the trees but show scientists what climate conditions led up to their chopping down. Thicker growth rings signify wetter years with good growing conditions.

The researchers determined that most of NYC’s old-growth trees had been felled in 1891 or just a bit earlier and that most of them dated back to the early 1600s to the mid-1700s. The oldest tree they found would have sprouted in 1512. “There is a lot of history locked up in those timbers. It’s really difficult to find living old growth in the eastern United States now,” said Caroline Leland, one of the study’s lead authors. “If we can get enough samples, it may allow us to develop a better understanding of the long-term climate in the regions these trees come from.”

The researchers are now working with New York entrepreneur and Preservationist Alan Solomon to create a non-profit dedicated to preserving old-growth timbers in NYC. They plan to lobby the city for an ordinance to identify old-growth timbers uncovered in demolitions and require companies to contact salvagers like them. “I’d like to see information from a big network of buildings,” said Leland. “We could develop a sort of history of the urban forest.”