A HIDDEN SPIDERWEB: MAPPING THE LATERALLY EXPANSIVE TREE ROOT SYSTEM OF AN OAK TREE WITH GROUND PENETRATING RADAR

Trees have become part of our daily lives but we do not think much about their root systems that are hidden within the subsurface. Although they are hidden by soil, these roots have a large impact on the critical zone and many geologic systems. Trees are not only a key component of many biomes but also regulate many of Earth’s systems above and below ground. Understanding where roots are in the subsurface can lead to insights on how they interact with bedrock and groundwater. I am utilizing ground penetrating radar (GPR) to image the laterally extensive root system of an oak tree on Clemson’s campus. Tree root maps are not only important for monitoring the health of trees themselves, but they also give insight into the depth of tree roots and how far they expand away from the tree trunk which can be useful for subsurface biomass estimations. Tree root maps have already been created for laterally extensive root systems but the processing of the data is not well published and the root maps that are created are not always clear in what they are representing from the original raw GPR data. Using a 500 MHz GPR a survey was conducted for one side of an oak tree. For the oak tree a root map will be created along with a velocity full analysis to confirm the EM velocity of the soil around the oak tree. The roots picked up by the GPR were approximately 3 cm in diameter or bigger and extended 4 m away from the base of the tree. This is a tool that could be utilized by forest managers, geologists, and those studying carbon storage in forest ecosystems.