I have known Professor Tom Worthley at UConn for many years.
I read this story with great interest and will continue to keep tabs on the Stormwise project.
UConn Researchers Go Into The Woods In Search Of New Ways To Protect Power Lines
By BRIAN DOWLING
STORRS- Two professors, a master’s candidate and a research assistant walked into a forest.
Their boots crunching in the snow, the research team made it to their experiment, a young stand of sugar maples and other species that has been thinned out and wired with sensors.
“They are swaying more,” said Jenna Klinck, the master’s candidate, who analyzes how trees react to forest thinning and build up strength afterward.
The group has monitored this site for more than a year as part of its efforts to learn how managing the deeper section of roadside forests could reduce outages from major storms.
Tree management plans from the state’s two electric utilities largely ignore this slice of the state’s forest — from about 10 feet to 100 feet in — even though researchers and the state’s top forester say a significant number of outages are caused by trees falling into the lines from farther in the forest.
“When the big storms come, these trees get a big gust and they can’t withstand it,” said Mark Rudnicki, assistant professor of forest ecology at UConn. “We want to then change that forest edge structure so that doesn’t happen as much.”
Trees just inside the forest are generally weaker than the ones along the road that are adapted to wind because they are not regularly exposed to it. To fix this, the team is focusing on thinning out the forest, giving the choice remaining trees more room to grow, which will slowly make them stronger.
The research, though in its initial stages, hopes to offer a management plan, called Stormwise, that mirrors the type of in-depth community-centered approach to tree risk that led to the Firewise program to address wildfire risk.
And the snowy patch of forest might hold some answers to how this could work.
In August 2012, researchers attached sensors to the trees, measuring how they sway back and forth in the wind. A year later, foresters thinned the trees, exposing them to more wind. Though the initial thinning exposes the trees to more wind, the stress pushes them to get stronger and the swaying should lessen.
Just feet inside the forest, many trees lack wind strength because their growth is focused vertically to reach sunlight. When stronger storms blow through the usual protections of the outer forest, the inner, less stable trees topple.
“If you expose a tree to more wind, it will respond by changing its growth strategies, its priorities,” Klinck said. “Instead of focusing on trying to grow taller, it will increase woody growth to the stem, the bowl and to the root structure, really wherever it is feeling most stress from the wind it is going to strengthen those areas.”
Rudnicki said the stress changes the shape of the trees and the properties of the wood itself. The trees develop thicker rings and the tree becomes more flexible. “Trees do phenomenal things when you start to acclimate them to the wind.”
He has researched how trees collide into one another to absorb wind energy during storms.
“There’s a lot of wind energy absorbed by collisions,” he said. “Until you get a sudden burst, and you’re all alone and you can’t rely on your neighbors anymore. We want trees to be more independent, more self-stable.”
One difficulty to this process is it requires more time and resources. The forest would need to be examined, rather than merely trimmed back. Towns would need planning. And homeowners would need to sign off on any work. But the process would not need to keep pace with the five-year trimming plan. Rudnicki said the deeper forest management would operate on a 20- to 30-year cycle.
When the forests are thinned, the researchers plan to arrange that the wood be milled on-site, when possible, for lumber to be sold to support the program or to compensate the land-owner whose trees were cut.
Stormwise has two other experiment locations — one in Portland and another in Litchfield — where the trees have been thinned to stimulate growth and strengthening. They hope to establish two more sites wired with sensors in coming months.
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