NASA engineers, world scientists work at Arboretum to find new ways to save trees
By David Sharos For The Beacon-News September 17, 2012 2:08PM
From left: French scientist Thierry Fourcard and NASA scientists Justin Littell and Matt Melis study data and digital images from 3D cameras surrounding an Ash tree trunk at the Morton Arboretum on Wednesday, September 12, 2012. | Jeff Cagle~For Sun-Times Media
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Updated: September 17, 2012 3:45PM
Losing a special tree in your yard can be a tough thing for a homeowner.
A group of scientists working at the Morton Arboretum hopes to find ways to make sure those episodes are very few and far between.
The goal of their research is to find out how much stress trees can take, to make sure that damaged trees that can make a comeback aren’t cut down prematurely.
A lot of work
Painting polka dots on trees sounds like a cruel prank against one of nature’s most majestic things. However, it’s one of the steps necessary for NASA aeronautical engineers and Morton Arboretum scientists to discover more about the life and death of trees.
This month, a team of local scientists and colleagues from France, England and Germany, as well as NASA aerospace engineers, have been conducting field tests at the Arboretum in Lisle in order to collect data that may someday help arborists evaluate trees for individual consumers.
While the day of funneling down the data to the consumer level may be a few years away, the technology to make that outcome a reality is already here.
“We actually started this two years ago when I attended a research week that was held in Ohio,” said Gary Watson, senior scientist at the Arboretum. “A group known as the Davey Tree Expert Company was conducting some biomechanical research and I was there to help out. Through talking with one of their customers, I got connected with some people from the NASA Glenn Research Center, who already had better equipment to conduct research on the composition of trees.”
Stress on trees
Using what are called “strain gauges,” Watson, 61, has studied the outer surface of trees in order to better evaluate stress and compression points that make them vulnerable to winds and the potential destruction of uprooting.
The gauges, Watson said, are cumbersome and large in diameter, while the NASA gear evaluates the stress and compression points using digital photography based on the dots painted on trees.
“Given the cameras we are using and the software, every pixel becomes a strain gauge as we are able to see areas of the tree where compression and expansion occurs as the tree bends,” Watson said. “We’ve marked trees here that were scheduled to come down, either because of replanting or disease, and using a wench that generates up to 8,000 pounds of force, we bend the trees and evaluate the stress and strain.”
Dots were painted on 10 trees and were used by the cameras to localize points to test. A similar test involved attaching coded “targets” on trees in order to evaluate what Watson called “the root plate.”
“This is where a tree is uprooted and you’ll see the root system as well as the soil that is attached to it,” he said.
NASA connection
Matt Melis, 53, of Cleveland, was on hand to help coordinate the tests that have basically been going on “from sun-up till sundown.”
A NASA aerospace engineer for the past 30 years, Melis said the technology being used at the Arboretum has been employed over a number of years to test the surface of the space shuttles.
“We have 10 field centers, and many of them have this same equipment in their labs,” Melis said. “When digital photography finally came out, there was a lot of pent-up technology waiting to happen. We have collected a lot of data here we can bring back to the table.”
Justin Littell, another research engineer with NASA, said tests at the Arboretum have gone well, thanks to equipment that has functioned properly.
“The first time you do a test on a tree, things go a little slow, but after a while, the pace picks up,” he said. “At this point, it takes about a half an hour to get the wench attached and conduct the tests.”
Using the wind stress data scientists are collecting, Watson said the end game is to someday add to the knowledge of local arborists who might be called in for consultations with homeowners about the condition of their trees.
“My emphasis with this is on safety and preservation,” Watson said. “We’re trying to learn more about how the tree responds to stress. These are living organisms and their surface and patterns adapt and change.
“Unfortunately in society today, people err on the side of liability, and a lot of trees come down unnecessarily. Our objectives here are to collect data for science and to test how the technology works in order to predict when a tree remains useful.”
