Under Dr. Daniel Druckenbrod’s advisement, Nicole Chakowski ’12 used cross dating to determine whether two trees from Monticello were planted by Thomas Jefferson.
Meaghan Haugh

Dr. Daniel Druckenbrod and Nicole Chakowski ’12 hold a segment of the tulip poplar.

Thomas Jefferson, the third U.S. president, who penned the Declaration of Independence, was also an avid gardener who recorded detailed observations of his Monticello plantation in Virginia. Trees were among Jefferson’s favorite garden plants and he was committed to forestry preservation. In his Garden Book, Jefferson often wrote about the tulip poplar trees growing on his land. He once dubbed the east coast’s tallest hardwood species as “The Juno of our Groves.”

Recently, the Thomas Jefferson Foundation had to remove two large tulip poplars because there were concerns that the trees could fall and damage the house at Monticello. Researchers wondered if Jefferson, who died in 1826, had planted the two trees, and turned to Dr. Daniel Druckenbrod, assistant professor of Environmental Sciences at Rider, to investigate.

Last semester, under Druckenbrod’s advisement, Nicole Chakowski ’12, an Environmental Sciences major, used standard dendrochronological techniques of cross dating to determine the ages of the trees. This painstaking process involved coring and sanding the tree samples sent from Monticello before using a stereoscopic microscope to examine the tree cores and count the rings. She repeated this process with 10 other tulip poplar trees from Monticello and combined the results, along with data from local oak trees, into a master skeleton plot in order to compare tree-ring patterns. What she found was indeed historical.

“The tree on the north side was a Jefferson tree,” she said.

In fact, Chakowski was able to date the tree back to 1822 — four years before Jefferson’s death. The result of the tree from the south side of the house was inconclusive because the section was only from an upper branch. Though they dated the tree to 1852, Chakowski and Druckenbrod believe it could be older because of an entry from Jefferson’s Garden Book. In 1807, Jefferson wrote about how he planted a tulip poplar “in margin of S.W. shrub circle from the nursery.” The Jefferson Foundation recently sent another cross-section of the north side tree in a wooden crate, and Chakowski plans to study the cross section before she graduates in May.

Chakowski will present her findings so far during a poster session of the New Jersey Academy of Sciences 57th Annual Meeting at Seton Hall University on Saturday, April 21. The lab experience and an opportunity to present at a professional conference will certainly help Chakowski as she pursues a career in environmental consulting and later pursue a graduate degree.

Druckenbrod said he has been impressed by Chakowski’s dedication to the Monticello research project. She has been able to apply the dendrochronological skills she acquired during a field experience at George Washington’s Mount Vernon last summer to her independent research.

“Nicole is a hard-working, determined and studious student. She has done well. A project like this, there’s no guarantee that it will be an easy project. This analysis was complicated by the fact that the trees were hollow at their base,” Druckenbrod said. “Nicole’s research can help us learn more about the history of Jefferson’s formal grounds. Tree rings can tell you a lot about an area, including its climate at a particular point in time.”