Extensively damaged trees tested with acoustic tomography considering tree stability in urban greenery
Damaged area of five tree species was determined by acoustic tomography. Final accuracy of 83% was found as satisfactory and proven suitability for overall tree stability assessment.
Objectives of study were to assess the accuracy and reliability of the acoustic tomography technique for detecting internal structural defects compared to visual assessment on extensively damaged trees of five species in urban greenery. Tomography was realized by Fakopp 3D acoustic tomograph tool. Several types of structural defects were determined, such as heartwood and sapwood decay, internal and lateral cracks, ring shake and hollow. Acoustic tomography inspection revealed correct detection of damage in all disc samples involved in study. Accuracy of damaged area determination reached 90%. Total accuracy determination for both area and location of damage was 83%. Overestimation of damaged area was observed in eight samples, contrary to seven underestimated samples. Difference in estimated false-positive area in comparison to false-negative area was minimal. Irregularity of cross section shape does not affect the final accuracy of tomograph. Accuracy is not influenced by diameter of tree trunk. We determined strong positive correlation between real area of damage and results of tomography (r = 0.75; p = 0.001). Acoustic tomography provides satisfactory accuracy in damage area determination inside tree trunk and for overall tree stability assessment on even extensively damaged trees in urban greenery.
KeywordsAcoustic tomography Tree stability Visual assessment
Supported by the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences—VEGA, Grant Nos. 2/0071/14 and 2/0143/15. Authors thank the Municipality of the city of Nitra for providing wood logs for analysis.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Anon (2015) Fakopp 3D Acoustic Tomograph - User’s Manual. Fakopp Bt., Agfalva, HungaryGoogle Scholar
- Divos F, Divos P (2005) Resolution of stress wave based acoustic tomography. In: Proceedings of the 14th International Symposium on Nondestructive Testing of Wood, Shaker Verlag, Eberswalde, pp 307–314Google Scholar
- Divos F, Szalai L (2002) Tree evaluation by acoustic tomography. In: Proceedings of the 13th International Symposium on Nondestructive Testing of Wood, Berkeley, pp 251–256Google Scholar
- Gilbert EA, Smiley ET (2004) Picus sonic tomography for the quantification of decay in white oak (Quercus alba) and hickory (Carya spp.). J Arboric 30:277–281Google Scholar
- Johnstone D, Moore G, Tausz M, Nicolas M (2010) The measurement of wood decay in landscape trees. Arboric Urban For 36:121–127Google Scholar
- Juhásová G, Adamčíková K, Kobza M, Hrubík P, Serbinová K, Hanzel E (2007) Horticultural evaluation of woody plants in the National Cemetery Martin, Slovakia. Folia Oecologica 34:9–15Google Scholar
- Liang S, Wang X, Wiedenbeck J, Cai Z, Fu F (2008) Evaluation of Acoustic Tomography for Tree Decay Detection. In: 15th International Symposium on Nondestructive Testing of Wood. Forest Products Society, Duluth, pp 49–54Google Scholar
- Nicolotti G, Socco LV, Martinis R, Godio A, Sambuelli L (2003) Application and comparison of three tomographic techniques for detection of decay in trees. J Arboric 29:66–78Google Scholar
- Pellerin RF, Ross RJ (2002) Nondestructive Evaluation of Wood. Forest Products Society, MadisonGoogle Scholar
- Pokorny J (2003) Urban Tree Risks Management: A Community Guide to Program Design and Implementation. USDA Forest Service, St. PaulGoogle Scholar
- Rayner ADM, Boddy L (1988) Fungal Decomposition of Wood. Its Biology and Ecology. Wiley Ltd., ChichesterGoogle Scholar
- Schubert S (2007) Acousto-Ultrasound Assessment of Inner Wood-Decay in Standing Trees: Possibilities and Limitations. Dissertation, Swiss Federal Institute of Technology ZurichGoogle Scholar
- StatSoft, Inc. (2011) STATISTICA (data analysis software system), version 10. http://www.statsoft.com. Accessed 27 Jan 2015
- Wang X, Allison RB (2008) Decay detection in red oak trees using a combination of visual inspection, acoustic testing, and resistance microdrilling. Arboric Urban For 34:1–4Google Scholar
- Wang X, Wiedenbeck J, Ross RJ, Forsman JW, Erickson JR, Pilon C, Brashaw BK (2005) Nondestructive evaluation of incipient decay in hardwood logs. General Technical Report FPL-GTR-162. USDA Forest Service, MadisonGoogle Scholar
- Wang X, Allison RB, Wang L, Ross RJ (2007) Acoustic tomography for decay detection in red oak trees. Research Paper FPL-RP-642. USDA Forest Service, MadisonGoogle Scholar
- Wang X, Wiedenbeck J, Liang S (2009) Acoustic tomography for decay detection in black cherry trees. Wood Fiber Sci 41:127–137Google Scholar