Stressed pines in area concern property owners, DNR experts
Previous weather conditions may have caused stress to pine trees in the area and apparently promoted a die-off. Throughout the Hudson area pines are turning up brown and lifeless this spring.
"We are concerned about the dying pines in Hudson, Troy and other areas of the county," said Dahn Borh, DNR Forester in Baldwin, in an email conversation last week.
"DNR plant and pest disease specialist Todd Lanigan's preliminary finding is that it may be due to the drought conditions in the past few years," he said.
"I observed the hardest hit trees are on pine plantations that have high tree density," said Borh.
"When pines are stressed as a result of drought, fierce competition or other conditions. The potential threats that may further stress or kill them included fungus and insect outbreaks. Stressed pine trees may be more susceptible to fungus diseases, insect outbreaks and fire," he said.
"The trees are likely affected by a combination of issues and some may trigger others," Borh said.
Lanigan plans to be in St. Croix County on June 25 to conduct further field investigations to ascertain what is going on, Borh said.
According to the Wisconsin DNR's website, one of the culprits could be a bark beetle. Southern pine engraver and other bark beetles attack stressed trees from drought, flooding, loss of leaves due to insect feeding and other conditions.
Dan Sitz, a St. Croix County zoning technician, cautioned property owners who live within the portion of the St. Croix Riverway District under county zoning to contact the St. Croix County Zoning Department before removing any stressed or diseased trees.
"Typically, Dahn Bohr and I inspect properties before we allow trees to be cut," Sitz said in an email message to the Star-Observer.
He said the Zoning Department can provide advice on what trees to replant with that are more resistant to beetles.