Assessment of urban tree condition using sonic tomography technology

Abstract

Trees are an important biodiversity component in urban landscapes where their performances have to be monitored regularly in order to secure public safety as well as to avoid damages on humans and properties. Tree risk monitoring and assessment are conducted based on visual tree inspection as the principal method. However, in certain cases, the results from tree inspection still require supporting information generated from special equipment in order to clearly determine the internal condition prediction of assessed trees. We have investigated more than 300 trees of about 15 species located in several public areas in Jakarta. The objective of this study was to determine the internal condition of the main trunk of the tree main at 1.3 m height using PiCUS® sonic tomography. We categorized the status of the tree trunk condition based on the percentage of solid wood from the tomogram image. The results showed that about 80% of the main trunks of the tree were in sound condition, 12% were in moderate condition, and the rest was in worst condition. The final evaluation of the tree condition should have also considered the result of the visual condition.