Cody's (Environmental Resource Management major) undergraduate research project focused on understanding the relationship between soil volumetric water content and soil water isotopic signature at the Shale Hills Critical Zone Observatory.
Shallow soil water is thought to be an important water source for trees. However, it is difficult to sample shallow soil water during the dry part of the season with traditional methods (suction lysimeters, centrifuge), and those methods may neglect a portion of soil water that trees are able to access that is tightly bound to soil particles.
Cody used cryogenic vacuum distillation to extract this tightly-bound water from soil samples, which will then be analyzed for stable isotopes of oxygen and hydrogen. Since volumetric water content (VWC) is simpler to measure, and data are readily available for the study site, Cody will then work to determine the relationship between VWC and soil isotopes to better understand the sources of water that trees are using during the driest part of the year (mid-summer). Cody's work is part of a larger effort to characterize the sources of water used by vegetation at Shale Hills.
