Relationship between acoustic emission characteristics generated with water conductivity of xylem and wood anatomy

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The acoustic emission from seedlings and adult trees was detected to relate to the transpiration or anatomical structure of vessels. There was significant relationship between AE events and amount of transpiration that is water flow through the vessels. Small specimens were cut from xylem of adult trees, and used for the water conductivity testing. Results were discussed hydrodynamically. The flow rate was determined by the pressure difference, the diameter of a vessel and number of vessel based on the Hagen-Poiseuille's law. There was relationship between AE events and the number of vessel. The AE generation was observed proportionally to the flow rate when the water flow velocity was over a certain value.The AE generation from seedlings and trees was depended on the climate and the water condition of the plants. It is possible to apply the AE technique to detection of the water stress of plants and to tree diagnosis. The AE generation occurred by not only the transpiration but also the shoot glowing, then the technique would be able to use for the research of tree phenologyIt is necessary to study ultrasonic properties propagating in the wood for the application of the ultrasonic to the tree diagnosis such as the AE and ultrasonic CT. The scanning acoustic microscope (SAM) was used for the measurement of isotropic wave velocity on the cell wall of tracheids. The wave velocity depended on the micro-fibril angle. The transverse wave velocity measured with a pulsar-and-receiver of the acousto-ultrasonic was depended on the anatomic wood structure.