Longwood professor reconstructs history of trees

BY JAMIE C. RUFF
Times-Dispatch Staff Writer
Published: August 26, 2008

When Dan Druckenbrod looks at trees he sees trees, but he also sees history — lots of it.

A Longwood University assistant professor of environmental science, Druckenbrod is leading research projects at two of the most historic homes in America — Monticello and Mount Vernon.

“Much of my research is about tree rings and forest change in an effort to understand

landscapes,“ Druckenbrod said. “In both projects, I’m interested in how the surrounding forests have changed over time, which is largely in response to how Jefferson and Washington used the environment two centuries ago.“

Druckenbrod is using tree rings, geographic information systems and other documentary evidence, such as maps, to reconstruct the forest histories of the two historic sites.

“There are lots of woods you can look at in Virginia, but it’s fun to get to work at Mount Vernon and Monticello,“ Druckenbrod said. “It’s not only environmental history but the history of our country.“

Druckenbrod started working with Monticello in 2002 as a University of Virginia graduate student. A large part of the Monticello project, sponsored by the Thomas Jefferson Foundation, is to determine what Montalto, the large hill behind Monticello, looked like during Jefferson’s time.

Montalto, also called Brown’s Mountain,

had plans for the site, but it is unclear whether any were realized before his daughter sold the tract in 1832 — six years after Jefferson’s death — to pay off his debts. The Jefferson Foundation was worried about the land being developed and purchased the 330-acre tract in 2004.

“Hopefully this research will help to shed some light on the timing of the field-clearing, since the foundation wants to reconstruct the appearance to that of Thomas Jefferson’s retirement years,“ Druckenbrod said.

The Mount Vernon Ladies’ Association is funding Druckenbrod’s work at Mount Vernon. The association invited Druckenbrod to submit a proposal based on his work at Monticello and earlier, similar research at Montpelier, James Madison’s home in Orange County.

Dennis Pogue, associate director of preservation at Mount Vernon, said researchers have been conducting a number of projects over the past several years aimed at learning more about George Washington’s home.

Establishing the ages of the trees has been problematic because researchers depended on subjective sources, such as the opinions of visitors, earlier managers and outside specialists, Pogue said. Testing a select group of 40 trees confirmed that 11 are at least 200 years old. The results prompted them to expand their search, including conducting a multiyear project to sample more trees from throughout the estate.

“The goal of his work is to reconstruct the history of the development of the forested areas, about 60 to 70 percent of the estate,“ Pogue said.

“Those results will be significant in terms of adding to . . . historical evidence that we have available to interpret the site, but they will have management applications as well. We are committed to preserving all of Mount Vernon’s significant cultural and natural resources.“

Two weeks at Mount Vernon yielded enough samples for analysis through the fall and into the spring. “And this is just the first of three summers we are going to spend up there,“ Druckenbrod said.

Heather Carty, a senior biology major at Longwood, and Michael Thorogood, a rising junior who is majoring in anthropology and minoring in earth science, have been working with Druckenbrod on the Mount Vernon research.

There are numerous core samples and some cross-section segments of trees in his lab in Longwood’s science building. “Cross-sections are nice because they are great visible features, but we would fill up that lab pretty fast,“ he said.

At both sites, Druckenbrod and his students take core samples from selected trees. “It doesn’t really injure the tree,“ he said. At his lab in the Longwood science building, Druckenbrod and his students use specialized sandpaper to smooth the cores so the rings can be read better.

Druckenbrod uses the computer to analyze the temporal pattern of the rings and physical features of the trees in an area. The research involves counting tree rings and measuring their widths to see how environmental conditions for the tree changed over time.

Two lessons: The center of a tree is not always in the middle, and the largest tree might not be the oldest. Less fertile soil and the lack of light influence growth.

Druckenbrod points to a sample from a Monticello white oak tree growing in 1728 — years before Jefferson was born — and another that started growing in 1830, shortly after his death.

“We’re learning there are 200-year-old trees at these settlements today, which is exciting,“ Druckenbrod said. “There are trees that remain from early in the lives of these presidents.“

Ultimately, Druckenbrod said, the question is how our forests have responded to changes in the past and are likely to respond to changes in the future.

“You can find some old trees, but you can also tell the story of how people have interacted with the woods, with the forests, and how these forests have responded to environmental change — how [people] have used the trees and used the land going back to the Colonial period.

“Instead of saying, ‘This tree is 210 years old,‘ we can say, ‘Ah, this tree grew really well this period; not so well that period — why is that?‘ And that is really a science question,“ Druckenbrod said.

Contact Jamie C. Ruff at (434) 392-6605 or .