Elliot Chang, 2016, Civil and Environmental Engineering

Working with a team of other undergraduate Princeton students, I studied water distribution among competing oak and pine trees in the Silas Little Experimental Forest. Using four sheltered and irrigated plots linked to large tanks of isotopically labeled water, we were able to label the water applied to the territory around one focal tree. This label allowed us to determine how much water neighboring trees “stole” from this focal tree. Sampling soils, tree stems, and roots, I learned how to use cryogenic vacuum distillations to collect the water from these samples. Using a Picarro isotopic analyzer to study isotopologues of water, including HDO and H218O, we examined which competing tree obtained the isotopic water. On a sub-project, I assembled a Decagon Hyprop device to study the volumetric water content of soils across varying water potentials. I plan on continuing my research with the Hyprop device to attempt long periods of data collection. The troubleshooting of the Hyprop software and hardware was highly rewarding, and I was able to learn how engineers work on a day-to-day basis. My summer research helped me learn more about isotopic hydrology and inspired me to do research in ecohydrology for my junior independent work.