A million little rings

Doctoral student uses dendrochronology—the study of tree rings—to explore the ancient environment, constructing a 5,177-year chronology of the Georgia coast, the longest in eastern North America:

Kat Napora didn’t plan to study trees. The UGA grad student originally worked on shell middens, or ancient trash piles. She’d planned to continue researching them in Ireland, but a tip from a colleague led her to a site much closer to campus—and an opportunity too good to pass up.

It was a trove of bald cypress trees buried and preserved in the marsh near Darien in southeast Georgia. Like shell middens, the trees allowed her to explore the ancient environment and human relationships with coastal resources.

“I’m broadly interested in how we can use that information to try and improve the future, on both sides of the Atlantic,” said Napora, who’s earning a Ph.D. in anthropology. “It’s really similar research to what I’ve done in Ireland. It’s just using a different data set, from trees instead of ancient shells, to look at past changes in the environment.”

Napora is an environmental archaeologist, and the primary tool she’s employing for her dissertation work is dendrochronology, the study of tree rings.

Dendrochronology provides a high-resolution paleoclimate indicator, particularly of rainfall and droughts, according to Victor Thompson, professor and director of UGA’s Laboratory of Archaeology as well as Napora’s advisor. He expects that her work will illuminate climatic changes and help explain how people responded to them.

“When you have a tree ring sequence, it tells you what that past climate was like, how people experienced rainfall, droughts—the same sorts of things that we are experiencing right now,” he said. “It helps you grasp what life was like on a day-to-day basis, on a year-to-year basis.”

Four years after shifting from shells to cypress, Napora is putting the finishing touches on her tree-ring chronology, which spans 5,177 years and covers the period from 3161 B.C.E. to 2016 C.E. It’s the longest chronology in eastern North America, providing a localized look at what happened on the Georgia coast.

“It’s not only important for learning about the past,” she said, “but it’s important for knowing what’s within normal fluctuations of the environment, to help us try to prepare for the future and make our use of resources more sustainable.”

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