Graduate student Sanpisa Sritrairat studies how and why wetlands change by examining pollens, macrofossils, and geochemical tracers found in cores from the marshes of the Hudson River estuary. Originally from Thailand, Sritrairat began her wetlands studies at Rensselaer Polytechnic Institute in Troy, New York. She came to Columbia in 2004, moving down-river to Lamont-Doherty Earth Observatory to work with Adjunct Professor Dorothy Peteet on her decade-long mission to reconstruct the ecological history of the Hudson River estuary. The materials in the wetland cores provide a record of changes in vegetation cover, climate, and sea level, which Sritrairat and Peteet decipher using tools such as mass spectrometry and X-ray flourescence spectroscopy.

Comparison of the vegetation and sediment types deposited prior to anthropogenic influence on the environment with the present environment, helps develop better management strategies for restoring these wetlands.

Of her experiences in the department and at Lamont, Sritrairat says:

"Like most earth and environmental studies, my research interest requires multidisciplinary approach. Lamont-Doherty Earth Observatory and the Department of Earth and Environmental Sciences is the perfect place for such study as there are so many top-notch researchers and state-of-the-art facilities from various fields all together in one place. The atmosphere is very informal. Every time I need help, regardless of the topics-- biology, climatology, oceanography, geochemistry, or solid geology, in regional or global scale, there always are some friendly and easy-to-approach people here willing to assist. The opportunity to interact with researchers from other fields also broadens my perspective."

Read more about Sritrairat's research in her graduate student profile, and below in an article from the 2006-2008 Biennial Report of Lamont-Doherty Earth Observatory

Digging Deep Into the History and Ecology of the Hudson River

Sanpisa Sritrairat grew up on the coast of Thailand, which was rich with lush, fascinating and ecologically essential mangrove swamps and estuaries. But she lacked scientific instruments to study them as she yearned to do.

With a scholarship from the Royal Thai Government, she came to Rensselaer Polytechnic Institute (RPI) in Troy, N.Y., on the banks of a world-famous estuary. “The Hudson River became my classroom and laboratory,” she said, and she studied it from as many scientific angles as she could, earning two B.S. degrees with three majors in hydrology, environmental science and biology, and a minor in economics.

Sritrairat worked on Hudson River research with Richard Bopp, an environmental geochemist at RPI who earned his Ph.D. at Columbia. Then she moved downriver to graduate school at Columbia in 2004, where she dug deeper—literally—into the Hudson estuary, by analyzing cores of sediments extracted from wetlands along the length and breadth of the river. The cores also span time—more recent sediments accumulate atop those from times gone by.

Sritrairat leapt into the decade-long mission of her adviser, Adjunct Professor Dorothy Peteet, to reconstruct the Hudson estuary’s ecological history and determine how and why it has changed, especially with increasing use.

The scientists used a wide range of analytical tools, including mass spectrometry, gas and liquid chromatography, and X-ray fluorescence spectroscopy, to extract clues from the cores. Fossilized pollen, spores, seeds, needles and stems indicated how plant life shifted over time, which, in turn, told the story of changes in climate and sea levels, invasions of non-native species, and the clear-cutting of trees by Europeans.

Charcoal fragments yielded evidence of fires and periods of drought. Sand and pebbles revealed changes in erosion and river flow patterns. At the core tops, pollutants conveyed a history of industry.

“You use one tool to determine one part of the story and the next tool for another,” Sritrairat said. “We want to make all the stories come together to broaden understanding of how nutrients, sediments, toxins, climate change and biology—from microbes to humans—affect the ecosystem. Such baseline knowledge is essential for making decisions on how to maintain and restore wetlands.”

Sritrairat’s career goals also include “teaching to produce more quality scientists to work in the environmental field,” she said. She taught undergraduate and graduate classes at RPI and Columbia and in 2007 won the Department of Earth and Environmental Science’s “Best Teaching Assistant Award.”

“She’s great with students,” Peteet said. “She always volunteers for the Lamont-Doherty Open House and she’s always up for going with us on River/Summer,” an eight-week educational program for high school teachers and students who travel by boat up and down the Hudson River.

Somewhere in there, Sritrairat also found time to take care of another ecosystem: Lamont’s community garden.