Evaluation of internal wood condition in tree trunks using sonic tomography and electrical resistance tomography

ABSTRACT Backgrounds: There are still uncertainties on how the data obtained from tomographs can affect tree failure risk evaluations. The aim of the study was to evaluate the internal trunk condition of Spathodea campanulata using sonic and electrical resistance tomographies. Forty-three sidewalk-planted, mature-stage individuals were assessed using PiCUS 3 and TreeTronic 3 tomography. Results: Sonic tomographies detected internal wood decay in 27,9% of the individuals and the Electrical resistance ones detected 30,2%, due to sensitivity to different types of anomaly, explained by different operating principles. Five individuals showed differing results between the two types of equipment. Collectively, the tomographies revealed the following results: 55.8% of the trees had good internal conditions, 6.3% demonstrated decay, 16.3% demonstrated early stages of decay, and 11.6% demonstrated advanced stages of wood decay. Conclusion: In conclusion, both tomographies provided significant information for diagnosing the internal condition of the trunk though their correct interpretation relies on the operator’s level of expertise.