Original scientific paper
https://doi.org/10.31298/sl.146.1-2.2
Acoustic tomography assessment of decay in sessile oak trees
Vinko Paulić
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Tomislav Škarica
; Drniš
Damir Drvodelić
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Milan Oršanić
; Sveučilište u Zagrebu, Fakultet šumarstva i drvne tehnologije
Abstract
Urban trees and forests contribute to citizens’ wellbeing and provide a wide range of benefits. Yet in the urban environment, trees are exposed to a range of abiotic and biotic factors that can impair growth. Wood decay fungi are a major cause of tree failure. Devices supported methods that measure certain wood properties are often used in addition to visual assessment of urban trees. Acoustic tomography is a device that measures the velocity of sound wave propagation through wood in the radial and tangential directions and is used to assess internal defects in trees. The aims of this study were to determine the size and position of healthy and decayed wood and to define the accuracy of acoustic tomography on ten old sessile oak trees in the Maksimir Forest Park, Zagreb. Results of acoustic tomography images (tomograms) were compared with photographs of tree cross sections after felling to confirm decay. The visual assessment indicated the presence of decay on ten trees, and this decay was visible on eight of ten tomograms. Decay was further confirmed in seven cross-sections after felling. Of these, three trees had incipient wood decay, while four had active wood decay with cavity formations. The shape of tomograms and position of decay were similar to the cross-section photographs for eight and nine trees, respectively. The area of decayed wood in different wood condition categories was correctly shown on the tomograms in comparison with the cross-section photographs in six of the trees. Acoustic tomography underestimated the area of sound wood and overestimated incipient wood decay in comparison with the actual state of cross-sections, while the area of active degraded wood and cavities was accurately represented.
Keywords
sessile oak; urban forest; arboriculture; acoustic tomography; decayed wood
Hrčak ID:
273389
URI
Publication date:
28.2.2022.
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