CRC Woods has surprising history
Undergraduate research uncovers diversity in tree populations
Ethan Fray (at left) and Olivia Dean (at right) worked on tree core samples from CRC Woods while undergraduates. They discovered there are very old trees in that forest. A white oak dates to 1787 and a pignut hickory is 164 years old, despite being only four inches in diameter.
An undergraduate research project produced unexpected results that shed new light on the history of the forested area near Virginia Tech’s Corporate Research Center.
CRC Woods, which is bifurcated by Pratt Drive and abutted by buildings and parking lots in the center, has a population of trees older and more diverse than expected.
Professor Carolyn Copenheaver of the College of Natural Resources and Environment said this raises an interesting question: “How do you age a forest? Is it by the oldest tree? That’s a really hard question.”
The CRC Woods is a forest long thought to be just a stand of woods that grew on land that was farmed at some point in the past. Turns out, that might not be right. Copenheaver’s student, Olivia Dean, made a stunning discovery when she counted the rings in a core sample of a pignut hickory tree that was only four inches in diameter.
The tree is 164 years old.
Copenheaver says this discovery illustrates the principle that tree age and trunk size is not necessarily correlated.
“You cannot tell age from diameter,” Copenheaver said. “It’s about availability of water and competition for light.
That pignut hickory has been surviving in the understory of the forest and received no direct sunlight.
“The soils are good at this site and water is available, but it is clear this tree has been shaded out by other trees for its entire life,” said Copenheaver, who teaches in the Department of Forest Resources and Environmental Conservation (FREC) “Thus, the cause for such slow growth: competition.”
These core samples are both from pignut hickory trees that are the same age and growing in the CRC Woods, on Pratt Drive in the Virginia Tech Corporate Research Center. They both grew slowly, in shade, until the tree on top was able to reach the overstory, likely because trees around it were felled, and it grew more vigorously.
The core of the 4 inch hickory tree
Research from a noteworthy program
Dean took the core of the old hickory when she was an undergraduate student at Virginia Wesleyan University in 2021, while taking part in the Multicultural Academic Opportunity Program (MAOP). The program, which partners students conducting individual research projects with faculty members, is designed to bring undergraduates from underrepresented groups to Virginia Tech for a summer research internship. Dean’s project – overseen by Copenheaver – looked at pignut hickory trees in CRC Woods.
Other hickory trees within the woods also date back to the same era, but they grew larger. Looking at the cores of two trees of the same age, one has a two-inch radius and one has a 10-inch radius where some rings are significantly thicker. Many of the hickory trees experienced a growth spurt as a result of being left in place when most of the surrounding trees were cleared in 1951, a date that’s verifiable from aerial photographs showing that much of the forest was felled. Many of the remaining trees were no longer shaded.
Dean finished her research and then came to Virginia Tech as a graduate student. She graduated with her masters in forestry earlier this month.
The research at CRC Woods was picked up by Ethan Frye, who finished the project and earned two semesters of undergraduate research credit through its completion. He graduated earlier this month with a degree in environmental conservation and society and will soon pursue of a master’s degree in FREC. Ethan dated the oldest tree in CRC Woods, a white oak that started growing in 1787.
A tumultuous history
The core samples Frye took found no other trees in the stand that sprouted prior to the mid-1800s, when suddenly there is a significant population. From roughly 1850-1951, new trees sprouted. Many of the white oaks in this group are significantly larger than the oldest tree. The 1787 tree is only about 24 inches in diameter while some of the trees that sprouted more than half a century later are significantly larger.
Just like the case of the pignut hickory, the white oak grew for many years in the shade of other trees. Those trees, were likely more valuable to loggers, were harvested while the oak that remains has flaws that would have made it unappealing, so it was left standing where it is to this day.
"There were really interesting competition signals, meaning the stand has a lot of interesting things going on that I wasn’t expecting. I thought it was just an old field stand that grew in and boom, there we had a forest,” Copenheaver said.
The research conducted by Dean and Frye showed that there are two significant reforestation events in the stand now called CRC Woods. The mid-nineteenth century growth period and another after the cut in 1951.
Copenheaver, Dean, and Frye are now finishing a manuscript about the research that will soon be sent for review and publication.
--Chris Moody