Remote Continuous Monitoring of Tree Physiological Activity using Four-point Electrical Resistance Measurement

A system and application for remote and continuous monitoring of tree physiological activity using four-point electrical resistance measurements are presented. To overcome traditional visual, qualitative observations of tree health, ShigometerTM was developed that uses the electrical resistance of trees. The ShigometerTM is a portable device that allows only one-time measurement with user intervention, and has a large error due to the 2-point measurement method. To overcome the shortcomings of the ShigometerTM, the world's first remote continuous measurement tree physiological activity monitoring (TPAM) system adopting the four-point measurement method was developed and validated. The TPAM system harvests energy using sunlight, simultaneously measures ambient temperature and light intensity, and transmits wirelessly using Zigbee. The developed TPAM system was applied to Zelkova trees, and as a result, it was verified that the repeatability error was improved by 8 times and the accuracy error was improved by 5 times compared to the previous ShigometerTM method. The tree resistance measurement results during the day showed a 12% variation, which means that continuous measurement monitoring for 24 hours is necessary because measurement data at any one point in the day does not represent the tree's health status. KCI Citation Count: 0