Cassian Humphreys, a technical arborist from Australia, walks through a stand of trees as he prepares to collect tree samples for the research project he is working on in Ravenna, Ohio.

By Paula Schleis



It’s a treasure box, in the eyes of an arborist — a 40-acre outdoor research lab filled with surprises waiting to be discovered.
Visionaries at the Davey Tree Expert Co. in Kent, Ohio, planted hundreds of trees here some 60 years ago, 14 species in neat rows, some of them genetic clones of each other.
It’s pretty rare to find more than three or four people doing work here on any given day, but early last month, 80 scientists, academics and environmentalists in yellow hard hats were invited to play in this forest off state Route 303.
Some came from as far as Australia, Germany, Hong Kong and the Czech Republic for the rare opportunity to demolish trees in the hopes of learning how to preserve them.
Every participant had to submit a research idea and be accepted to the second Tree Biomechanics Symposium, where they could work out their theories, share ideas and add to the industry’s knowledge of why trees fail.
“They’re sharing labour and brain power,” said Janet Bornancin, CEO of the Illinois-based Tree Fund, which co-sponsored the event with Davey Tree, International Society of Arboriculture, and half a dozen other supporters.
On one end of the property, Anand Persad of Davey Tree explained his own work in understanding the unique dangers to taking down an ash tree that has been infected with the emerald ash borer. The beetle, which is on a course to making ash trees extinct in Ohio, bores into a tree and effectively kills it before the tree’s death is evident on the outside.
There was a rash of instances where experienced tree cutters were injured from falls when infected ash trees broke in unexpected ways.
Persad’s research showed the trees are splitting at the union of branches, a place that is usually among the strongest points on a tree, and doing so with just a third of the pressure it takes to break a typical tree.
“Knowing this has changed how we take trees down,” Persad said.
Elsewhere on the lot, Ken James, who works for an environmental inspection company in Victoria, Australia, has attached a “tree motion sensor” he invented to the bottom of a red maple.
His expertise is in how winds affect the movement of trunks and branches. But the real value of this event is that his device can be placed next to a NASA-invented system for recording the tension and compression on the roots of the maple as it is pulled out of the ground.
The side-by-side comparison will give James a rare opportunity to check on the accuracy of his equipment.
“I could never have done this anywhere else,” he said.
Behind him, other researchers are dropping different sizes of branches from 80 feet in the air onto a device that measures the force of the fall. The experiment is being funded by the Electric Power Research Institute, which wants to know how much abuse its power lines and other equipment can take from trees that come apart in a storm.
The week-long symposium was the second that Davey Tree has hosted, the first taking place in 2010 after a group of arborists at a convention bemoaned that there were few opportunities for collaboration.
Ward Peterson, Davey’s manager of urban resources, said it makes sense to space the events three years apart because researchers can then study the effects of what was done to trees in past symposiums.
Peterson kneeled to check on a maple that was cut down earlier in the day. Three years ago, it had two-thirds of its roots removed, but it survived. The tree’s resourcefulness is now a new opportunity for research.
In spite of the destruction around him, Peterson said the point of all research is to save trees.
Research has helped experts identify trees capable of surviving storm trauma, where in the past, those same trees would have been chopped down to prevent future failure.
Among other nuggets of knowledge, researchers have learned that trees that are battered a lot are stronger than trees that have never been tested or trees that have been staked to prevent them from moving. Not unlike the way human bone and muscle gets stronger if they are used, trees that move develop “reactive wood” that can keep them from breaking.
Still, there is plenty more to be learned.
Along the only road that weaves through the forest lab, a tree with a man-size cavity is decorated with slips of bright pink, blue and orange tags.
For fun, the researchers have each waged a dollar and placed a bet on where the tree will break when it is pulled down later in the day.
The fact that some slips have been tacked far above the cavity, in the cavity, or at ground level to signify the tree will be uprooted before it breaks, shows there is not always a consensus about how a tree will act.
“It will probably be about two years before the things we learn this week will be analysed and published,” Peterson said.
By then, the planning stages for the next symposium in 2016 will be well underway. — Akron Beacon Journal/MCT


Related Story