'Explosive' Disease Progression Threatens Mendham's Tree Canopy

MENDHAM, NJ — A beetle infestation is spreading in Mendham Township.

At the July 24 township committee meeting, Brian Hays, a representative of the Mendham Township Tree Protection Committee, stated that the township's infection rate has been steadily increasing over the years.

Hays warned against increased activity from the emerald ash borer beetle and asked residents to check their trees for this destructive infestation. This invasive species kills ash trees by tunneling through the bark, disrupting the tree's vascular system, and preventing nutrients from reaching the leaves.

According to tree care professionals, the ash trees killed by the emerald ash borer across the township will not only become an eyesore, but the trees that remain could be dangerous.

Infested ash trees can quickly deteriorate and become dangerous, with limbs falling on your personal property, your neighbor's personal property, sidewalks and roadways.

The New Jersey Department of Agriculture said the emerald ash borer was first discovered in the state in May 2014, when it was located in Somerset County. "Infestations throughout the U.S. and Canada have killed tens of millions of ash trees since 2002," the department said.

"As a result of this, we applied for and received a grant four or five years ago to inventory the right of way of all the roads in Mendham Township for ash trees. The total, when we finished the survey, was approximately 5,000. Because of the scope of the problem and the number of trees, the township committee passed an ordinance, placing the responsibility of removing the dead or hazardous trees in the township right of way on the property owner," Hays said.

In Mendham Township, the ash tree currently makes up around 10 percent of the tree canopy, and the disease is forecast to wipe out all of those trees over time as the disease spreads.

Hays explained that while there is a known cure for clearing the disease from a tree, the cost would be prohibitively expensive for the township to support given the large proportion of ash trees in the canopy.

"Each year since the beginning of this problem, I would describe the increase from year to year as arithmetic. But from last fall until this spring, I would describe it as geometric; it's been explosive. There's a progression: the dieback of some leaves, the loss of all the leaves, the dropping of the little branch ends, the dropping of large limbs and eventually the collapse of the entire tree," Hays said.

The plan of action right now, according to Hays, is that the tree protection committee has created a forest management plan, which is pending approval, that will help them apply for grants to remove trees from municipal properties.

However, the approval process is taking longer than expected, which is causing concern among the committee due to the rapid progression of ash tree disease.

"My concern is that while we're waiting, trees are going to fall. What's happened in the last year? Trees are going to fall on trails and in the roadway. Considering the potential liability in the event of an injury or death, it makes sense to address the trees with advanced deterioration as soon as possible," Hays said.

The tree protection committee is counting on the township and the county to cut down all infected ash trees in the township to stop the spread of the disease.

"If the county won't take these trees down, I think we have to consider doing it," Hays said.