One of the world’s most highly regarded scientific journals, Nature, reported in January that forest ecologists with the U.S. Geological Survey have discovered that trees continue to grow rapidly as they age, dispelling the traditional belief that bigger trees grow more slowly than younger trees or stop growing once they mature. Thirty-seven researchers from around the world provided long-term data.

The finding has important implications for forest management and carbon capture because it shows that the oldest trees in a forest are doing the most work to pull carbon dioxide out of the air and store it as carbon in their wood.

This dynamic presents one of the strongest arguments for preserving old-growth forests because their carbon-pulling process continues to take carbon out of the atmosphere and not contribute to increasing atmospheric CO2 levels. The study is based on repeated measurements of 673,046 trees of 403 species across every continent except Antarctica.

The value of old trees will be the topic of a public lecture hosted by Virginia Tech’s Department of Forest Resources and Environmental Conservation. Joan Maloof, founder and executive director of the Old-Growth Forest Network, will speak in Fralin Auditorium on the Blacksburg campus on Friday, April 4, from 12:30 to 2 p.m.

A Professor Emeritus of Biological Sciences at Salisbury University (part of the University of Maryland System), Maloof founded the Old-Growth Forest Network to preserve, protect, and promote the nation’s few remaining stands of old-growth forest.

She is the author of “Teaching the Trees: Lessons from the Forest” (2007) and “Among the Ancients: Adventures in the Eastern Old-Growth Forests” (2011). Her books will be available for signing following the presentation.

In her talk, “Old-Growth Forests: Understanding the Big Picture,” Maloof will define old growth and explain the uniqueness of this forest type. She will describe the quantity and quality of forests on Earth, in the United States, and particularly in Virginia.

Maloof will share her work preserving ancient forests through the Old-Growth Forest Network and her efforts to assist with their recovery. She will expand the discussion to include the importance of Virginia Tech’s own old-growth forest, Stadium Woods.

While in Blacksburg, Maloof will also present her talk at the Blacksburg Public Library on Thursday, April 3, at 7 p.m.

Jeff Kirwan, Professor Emeritus of Forestry at Virginia Tech and a co-author of the popular “Remarkable Trees of Virginia” book, explained, “The U.S. Geological Survey study gives us one more reason — carbon capture — to value and preserve old-growth forests.”

The research indicates that large, ancient trees are not just storing carbon, they are adding a little more mass to their trunks, limbs, and leaves each year. While the amount of mass a tree adds per unit of leaf area does decline with age, the old trees have much more leaf area than younger trees.

“The study also shows that trees do not suffer growth rate decline as they grow larger, as commonly believed,” Kirwan added.

A large tree may add three times as much biomass per year as a tree half its diameter. This means that giant trees are much more effective at removing carbon dioxide from the atmosphere than younger trees.

Specific research in Stadium Woods conducted by John Seiler, The Honorable and Mrs. Shelton H. Short Jr. Professor of Forestry and Alumni Distinguished Professor, and his colleagues found that older trees are now growing faster than at just about any time in their lives.

Earlier studies only looked at forests as a whole until a 2010 study now validated by this wider Nature report measured the actual carbon value of individual old-growth trees and found that trees reach their adolescent growth spurt and never stop growing.

Parking information

The Fralin Auditorium is located in Fralin Hall at 360 West Campus Drive. With a visitor’s pass, parking is available in the Wallace, Hillcrest, and Litton Reaves Lots, which can be accessed from Washington Street or Duck Pond Road. A visitor’s pass may be obtained Monday through Friday from 8 a.m. to 5 p.m. at the Visitor’s Information Center located at 965 Prices Fork Road, near the intersection of Prices Fork and University City Boulevard next to the Inn at Virginia Tech and Skelton Conference Center. Find more parking information online or call 540-231-3200.