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Tree Health Ultrasound Assessment |
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Abstract. Much of a tree's timber value resides in
the first log (lower 16 feet). Current timber inventory procedures assess
that log's quality and value using traditional tree grading methods. These
methods include examining the tree stem for indicators of decay and other
degrades. These indicators are not always readily apparent, however, and
even when present, do not provide any useful quantitative measure of extent.
Furthermore, certain types of bacterial infection can reduce log quality
substantially, and yet exhibit no external signs. The quality of the lower
tree stem is also indicative of overall tree health. Therefore, both
assessing impacts of silvicultural practices on tree quality and conducting
forest inventories (and health) rely heavily on knowing lower stem
soundness.
We have conducted preliminary assessments with a commercially available, and inexpensive, ultrasonic device for detecting the extent of decay in standing trees. An extensive test to detect wetwood in standing trees was also conducted (Leininger). This apparatus is small, light, and easy to use. It is limited, however, by the manner in which measured ultrasound signals are used to indicate decay. The limitation in its electronics means that small bark plugs must be removed prior to measurement (and later replaced). Bark removal and replacement is both time-consuming and extremely difficult. We feel that by modifying the device's electronics we can eliminate the need for bark removal and additionally distinguish between voids, decay, and wetwood infection. This modified device should prove extremely useful to inventory and forest health personnel, silviculturalists, and extension foresters. Daniel L. Schmoldt, Theodor D. Leininger (USFS), Matthew F. Winn, and Donald E. Yuhas (Industrial Measurement Systems)
Current and Future Work
Last Modified:
06/13/07
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