Low-decibel ultrasonic acoustic emissions are temperature-induced and probably have no biotic origin

摘要

The detection of ultrasonic acoustic emissions (UAEs) in plants is one of the rare methods applicable to field-grown trees without causing any disturbance to the objects investigated. The sensors are weatherproof, are easy to mount, use little energy and produce highly reproducible signals in a range between 20 and 300 kHz (Tyree & Sperry, 1989; Laschimke et al., 2006).