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Battle to Preserve Ash Trees
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Little by little, due to development and disease, Montgomery County is fighting a losing battle to preserve large trees. Landscaping architects and engineers say this puts a strain on local habitats and creates headaches for humans, like higher energy bills and flash flooding.
PBS39 News Reports

Battle to Preserve Trees in Montgomery County


Montgomery County is fighting a losing battle to preserve large trees.

HUNTINGTON VALLEY, Penn. (WLVT) - If you walk into the ash tree plantation in Pennypack Preserve natural area, you’ll find a standing graveyard. Every one of the 1,000 ash trees planted 20 years ago is dead or dying.

Chris mendel, exec. Dir. Pennypack ecological restoration trust: “We’re going to have to knock down the ashes that we have and start over,” said Chris Mendel, executive director of the Pennypack Ecological Restoration Trust.

The Pennypack Ecological Restoration Trust works to protect the Pennypack Preserve natural area and restore local habitat. When the trust planted the trees in the mid-1990s, ash was considered a suitable tree for forest regeneration.

But in 2002, the emerald ash borer, an invasive species, was detected in Michigan, according to the United States Department of Agriculture (USDA). They have since spread to 31 states and Canada, and were identified in Montgomery County, Penn. in 2013.

Rob nagy, arborist representative giroud tree and lawn: “It’s everywhere,” said Rob Nagy, arborist representative for Giroud Tree and Lawn tree service. “If I come up to an ash tree now, the two variables are: either we’ve had it on a treatment program and the treatment program is being successful, or it’s a removal operation.”

Giroud Tree and Lawn is called to cut down infected ashes all the time, Nagy said. He also sees the symptoms all the time: thinning canopy, sprouting near the base, bark splitting and small D-shaped holes in the bark.

“In this area in particular, as I drive around and see a woodlot, I’ll see dead tops of trees everywhere,” Nagy said. “I of course notice that, but those are all ash trees.”

The infestation trend isn’t like to slow, according to Mendel: “We’re probably going to see upwards of a 90 percent knockdown in ashes over our generation.”

As ash borers chew through the trunk, they cut off water and nutrient flows to the branches. They can kill small trees in one to two years, and large ones in three to four years. And they have no natural predators in North America.

The problem, Mendel said, is that most biosystems can’t support a new organism without time to adapt.

“These systems have grown up over millions of years, and their components are dropping off in simply decades, and all the animals that come to depend on it can’t react in time,” he said.

Blight isn’t unique to ash trees. American chestnut, once the dominant tree in the Mid-Atlantic region, was almost completely wiped out by a fungal blight in the early 20th century. Ameriacn elm, a popular tree along northeast streets, virtually disappeared after another fungal blight in the ‘50s and ‘60s.

Once infected and showing damage, the only choice is to cut the ash trees down.

“We can’t leave a standing hazard near somebody’s house where there are wires, where there are walkways, where there are roadways, where you sleep every evening,” Nagy said.

But if you have ash trees on your property, there are steps you can take to protect them.

“For lack of a better analogy, it’s like a flu shot,” Nagy said. “You have to get it pre-being infested.”

Arborists treat the ashes by injecting insecticide into the truck. Eventually, the insecticide travels throughout the tree, waiting for any emerald ash borers. Then, when the ash borer larvae hatch, they try to eat the wood.

“It will come in contact in the cambium layer with the insecticide, and it dies,” Nagy said. “The effectiveness of it is terrific.”

When applied correctly, the insecticide is 85 to 95 percent effective. For the best results, you’ll need to treat your trees every two years, Nagy said.

And if you do have to cut down an ash, Mendel suggested replacing it with another tree, which can play an important role in residential habitats and save homeowners a lot of money. Trees increase property values by an average of 10 percent, according to the U.S. Forest Service. A shade tree can cut up to half off a home’s cooling bill in the summer. Trees can also prevent flash flood damage by absorbing rainfall on their leaves and stormwater through their root system.

Mendel suggested choosing another native tree, like elm, oak, birch, chestnut, sassafras, sycamore, maple or tulip poplar.

One of the most effective ways people can affect environment change is to grow trees,” he said.

But until ash borers find a natural predator, it may be best to choose a different tree.

“Until you have that insect or disease contained, what you want to do is bring in a different species that isn’t susceptible to it,” Nagy said.

“I wouldn’t bother with ashes right now,” Mendel said.

The Pennypack Ecological Restoration Trust is now installing another tree plantation, this time with a mixture of different native trees.