FOND DU LAC, WI (WTAQ) – You’ve probably noticed leaves changing colors this time of year, but if you drive along Birch Tree Lane in Fond du Lac, you’ll see a few trees wrapped in foil.
“The foil is basically insulation and underneath that foil is a sap flow sensor it’s essentially, it injects a pulse of heat and then it has two temperature sensors above and below that,” said Bill Selbig, a research hydrologist with the U.S. Geological Survey.
He tells FOX 11 those sensors track how much water the tree’s absorbing.
The focus of this urban tree study is to observe the quality of stormwater along with how much of that water trees collect and keep out of storm drains.
“The best way to do that is to measure or characterize an area with the trees and then follow it up without the trees,” Selbig said.
Jordan Skiff, Fond du Lac Public Works director, tells FOX 11 they plan to remove the trees because of encroaching Emerald Ash Borer.
“We’ve actually treated those ash trees for this year just to make sure they’d have a leaf canopy for this year and next year but they would be dying relatively soon without that treatment.”
On Birch Tree Lane, the measuring process for the foiled trees is powered by a battery that has to be replaced on a weekly basis.
Selbig says a separate study in this neighborhood will focus on leaves from the trees.
“Leaves are falling and they’re in the gutters and when a storm moves through, water percolates through those leaves and removes phosphorous and that phosphorous makes its way into some receiving water body”.
Whether it’s leaves or something else, Selbig says when too much phosphorous makes its way into lakes and streams it can cause algae blooms.
“One-way cities can address this is through leaf collection but what nobody knows is does leaf collection do any good to remove phosphorous from stormwater.”
As for the urban tree study, it will continue over the next two years.
Fond du Lac plans to eventually replace the trees.


