Tree Root Morphology Mapping by Non-Invasive Ground-Penetrating Radar.

Ground-penetrating radar (GPR) has the potential to become a non-invasive technology used to detect and map tree roots.  However, efforts to create maps that show the root layout, density and extent have had limited success.  The root architecture is often very complex, including roots that can bifurcate, merge and graft, or overlay.  Although GPR could become a superior alternative to current destructive and labor-intensive sampling methods used for root detection, significant technical challenges need to be resolved before GPR can be widely used for this application.  Prior experiments have demonstrated that GPR can be successfully used as a non-invasive root mapping tool for trees growing in highly sandy soils or under artificial conditions, but signal processing algorithms need to be developed for root mapping of trees growing in more challenging environments such as urban or forest soils, including under covered soils.

 This paper presents a new approach to using GPR that greatly enhances tree root detection and morphology mapping.  Examples of real cases will be presented that demonstrate the application of signal processing algorithms to significantly improve the signal-to-noise ratio from difficult (e.g., high clay) soils and enable root cluster radar returns to be separated into the individual roots of the cluster.  The talk will discuss the steps used to produce accurate morphology maps and to detect and monitor root health.