Non-Invasive Assessment of Tree Roots in a Suburban Environment.

A tree can only be as healthy as its system of roots, and a tree’s root system is approximately 15-35% of the overall mass of the tree. In suburban settings shallow disturbance or trenching can damage a tree’s root system, potentially severely stressing a tree and predisposes the tree to abiotic, insect, or pathogen interactions and may, ultimately, result in death. Traditional excavation methods of locating tree roots are themselves invasive and may damage a tree. Consequently, guidelines for cut and fill, and trenching are based on crown characteristics. It is assumed that roots are radially distributed around the trunk, although this assumption of radial distribution is seldom reasonable in commercial and residential settings. If a reliable non-invasive technique can be developed, it could greatly simplify planning for cut and fill, trenching, and other construction activities in a way that minimizes root damage. Previous research. As such, the objective of this research was to use electrical resistivity tomography (ERT) and electromagnetic induction (EMI) in conjunction with field excavation to evaluate prediction of large lateral root locations. ERT and EMI measurements were taken around six trees at the Bartlett Research Laboratory in Charlotte, NC under both dry and wet soil conditions. After the second measurement a 8x8 meter section was excavated with an airspade to expose the upper 20 cm of roots. Correlation with EMI and ERT images indicate some correlation.