Low-cost, high-resolution stemflow sensing

Abstract

This study develops and evaluates a sensing system capable of measuring stemflow at high temporal resolutions. Leveraging affordable hobbyist grade electronics has allowed for the development of a system which is low-cost, easy to reproduce and adaptable. Eschewing classic stemflow measurement techniques, the system demonstrated herein utilizes a sensing payload which includes a wetness sensor and ultrasonic rangefinder. Combined, these sensors are capable of determining precise stemflow initiation and cessation times as well as capturing high temporal resolution stemflow volume measurements at 10 s intervals. A case study focusing on stemflow data collected by the sensing system from an isolated green ash (Fraxinus pennsylvanica Marshall) during a May 2016 rainfall event in Kamloops, British Columbia is used to evaluate the performance of the sensing system, demonstrating the accuracy of the collected data and the potential research questions that can be addressed by large scale deployment of the sensor system.