USGS Student Intern Takes Tree-Core Samples

The water we drink, air we breathe, and soil we come into contact with have the potential to adversely affect our health because of contaminants in the environment. Environmental samples can characterize the extent of potential contamination, but traditional methods for collecting water, air, and soil samples below the ground (for example, well drilling or direct-push soil sampling) are expensive and time consuming. Trees are closely connected to the subsurface soil and water, and sampling tree trunks can indicate subsurface pollutants, a process called phytoforensics. Scientists at the Missouri Water Science Center were among the first to use phytoforensics to screen sites for contamination before using traditional sampling methods, to guide additional sampling, and to show the large cost savings associated with tree sampling compared to traditional methods.

Small teams of one or two people can collect as many as 100 tree-core samples per day, tree cores are analyzed for contaminants in a laboratory, and results are typically provided within two weeks. Missouri Water Science Center student intern Rahel Pommerenke is shown in the process of obtaining a tree-core sample. Tree-core samples may cause local scarring to tree trunks, but trees are able to repair any scarring within two to three years (Vroblesky, 2008).