According to https://www.popsci.com/environment/article/2013-04/sound-thirst trees make a sound when they cannot transport enough water to their body. This sound generated in the xylem is when cavitation is formed. At the recent meeting of the American Physical Society, scientists from Grenoble University in France presented research that not only were they able to determine that drought-stressed trees make noise, they were also able to show exactly which process created the sound. To really grok the research, it's helpful to understand how trees transport water. Trees draw ground water up through specialized tubes called xylem, relying on intermolecular forces between water molecules and themselves, and water molecules and the sides of the tubes, to create a single column of unbroken water in each xylem tube. But as groundwater dries up, the trees must pull harder on the remaining water; if the pressure is greater than the strength of the intermolecular forces, the column of water breaks and an air bubble forms. This process is called cavitation. Too many air bubbles can mean death for the tree.To ensure that these air bubbles were the culprits behind the acoustic signature of drought-parched trees, the researchers mocked up a tree in the lab.
They placed a thin piece of pine wood, complete with its xylem intact, into a capsule filled with a gel. As the researchers evaporated the water out of the gel -- a test "drought" -- they simultaneously recorded video and sound of the cavitation in the xylem. The researchers discovered that about half of the sounds made by a tree are due to cavitation and that the process has its own unique acoustical signature. Acoustic monitoring already allows for the identification of individual species through environmental audio recordings. The Stevens Institute of Technology, working with CBP, sought to use acoustic sensors (piezoelectric sensors, lasers Doppler vibrometers – also applicable to wood, ultrasound microphones) to monitor rodents and insect pests in grain shipments In laboratory settings, off-the-shelf laser vibrometers detected Asian longhorned beetle larvae (Anoplophora glabripennis) in wood samples. (https://static1.squarespace.com/static/56047ac1e4b0612d66a56646/t/59888d6da5790a7d30e560db/1502121330871/federal_capacities_for_edrr_through_technology_innovation_prepub_8.7.17.pdf ) In our case since the ROD infected Ohia tree can transport less water than it needs, it is obvious that cavitation will occur at the upper part of the tree. By using this ultrasound microphones and vibrometers integrated with AI-assisted software that can ignore other sounds, we can trace this cavitation sound and the ambrosia beetles sound and this will be used for early warning mechanism.
I am assuming that Ohia tree is no different than other trees that the research is conducted on. But it needs to be proven that the 'ohi'a tree actually has the same effect as the other trees.
I am assuming that ultrasound microphones, vibrometers and the AI will trace the sound of cavitation and the ambrosia beetles.
The inability of land managers to detect the ROD fungus at early stages of infection in trees and elsewhere in the environment presents a unique challenge. This challenge is compounded by the vast landscapes on which ʻŌhiʻa trees reside, including remote and often steep areas not easily accessible by foot or vehicle. To address this challenge head on, it is critically important to develop tools that enhance the detection of ROD.
Currently, I have managed to come up with a good solution and the next step will be testing the theory.
I need collaboration and funding to test the theory.