Applied DC Resistivity for Tree Trunks

B020 APPLIED DC RESISTIVITY FOR TREE TRUNKS 1 Summary We present a geoelectric technique for investigating the electric interior of cylindrical bodies and apply it to trunks of various European tree-species. Healthy trunks always show a concentric central maximum of resistivity decreasing to the outside corresponding to an increase of moisture from the inner dry heartwood to the outer wet ring of sapwood. Any anomalies are interpreted by infections or influences of branching or the direction of sunshine and wind. Introduction It is well known that various geoelectric and electromagnetic methods including ground-penetrating radar (GPR) extend the range of geophysical