Oleoresin prospection in Copaifera sp. trees by using impulse tomography

Abstract

Background: Copaiba oil (Copaifera L.) is a raw material used by pharmaceutical, cosmetic, and
energy industries. However, the difficulty in locating the oleoresin reservoirs, is an obstacle to its continued supply, affecting the sustainable commercialization of the product. So, the potential of impulse tomography for prospecting oleoresin reservoirs in the trunk of 18 Copaifera sp. trees was tested, in cross-sections at heights levels 0% (DBH), 25%, 50%, 75%, and 100% (1st fork). The impulse tomography prospections (ITP) were performed only at the 0%, in others 12 trees, because of the risk associated with climbing hollow trees. In total 30 trees were tested. Altogether 102 tomograms were analyzed obtaining: average mechanical wave propagation speed (aMPS), minimum mechanical wave propagation speed (minS) and maximum mechanical wave propagation speed (maxS), prospecting height (Hp%) and total tree height (Ht), diameter at the Hp% (Dhp), and low speed mechanical wave propagation percentage areas (LSa%). These variables were analyzed using multivariate analysis.
Results: The reservoirs were located exclusively at DBH and confirmed by borer prospection increment
in 26.7% of the trees. ITP resulted in 37.3% of correct answers and 62.7% of errors, considering the 99
tomograms. However, it was found that the ITP is efficient to indicate sections for which no significant
reservoir or hollow presence is expected to be found. The analysis of the main components showed
that, except for Ht, the components are good indicators for the location of the reservoirs.
Conclusion: We were able to use tomography to search reservoirs with a significant amount of oleoresin, identify hollow trees, and indicate the exclusion of trees that do not have reservoirs or other alterations.