High Tech Puts Tree Research Within Reach
The center’s mission is to create the scientific knowledge and technical expertise needed to sustain trees and help them meet the challenges of the future. “That includes creating the tools and the research platforms for the experimental sites we have on the grounds,” says the center’s director, Chuck Cannon, PhD. “It’s been my longtime dream to increase our ability to understand trees through technology.”
Studying trees has special challenges. “They’re very big, they’re half underground, and most of the rest is way overhead,” Cannon says.
Not long ago, research teams measured and examined trees just once a year. It could involve using a bucket truck or even climbing a tree to reach into its high canopy of branches and leaves. Between annual health checks, subtle evidence of a tree’s decline could go undetected. Today, Arboretum scientists can outfit trees with automated solar-powered sensors that gather data 24 hours a day.
“Trees are very dynamic,” Cannon says. “They act differently each day according to environmental conditions.” For example, a tree’s trunk expands when sap flows beneath the bark, so measuring its daily expansions and contractions can reveal if the tree is drought-stressed. “We’re building a set of tools that can give us a fine-tuned, high-resolution understanding of a tree’s growth, health, and vigor in real time,” he says. “That helps us make a fast, early-stage diagnosis of any problem.”
Several years ago, Cannon began using camera-carrying drones to gather canopy data, but he knew these digital dragonflies had more potential. In 2019, he hired Colby Borchetta, a PhD candidate in mechanical engineering, as his research assistant and tech advisor. The same year, working with area universities, he enlisted engineering students to help develop specialized tools for the center as their senior class projects.
Cannon has a project wish list, and he also consults with his scientists for challenges to give the students. One year’s project can build on a previous year’s effort. For example, in 2019, Northern Illinois University students developed a drone mount that could carry a sensor, camera, or other tool, either for aerial monitoring or for precise placement in a tree’s canopy. In 2020, an environmental engineering class at Loyola University Chicago built an air-quality sensor for use with the drone mount. That’s what Cannon calls developing “a whole data pipeline.”
Northwestern’s product design class developed a prototype for a tree “fitness tracker”—a sap-flow monitor to track what is essentially a tree’s heartbeat. The following year’s class created an app for a researcher to interpret the sap-flow data.
Borchetta works closely with the student teams. “It’s a good way to get our projects started and have an impact with the schools,” he says.
Much of Borchetta’s everyday work involves analyzing data from drone-deployed cameras and laser scanners to build 3-D models of study trees. Cannon says a future student project might be developing an automated image-analysis system.
“There aren’t enough of us plant scientists to gather and analyze all this data,” he says, “so we have to think of ways to apply the technology that’s becoming available.”
He adds, “The canopy is just over our heads, and we haven’t had access to it before. There’s tons going on up there.”