TERRE HAUTE —
Vigo County park officials are planning to take pre-emptive action this fall to remove ash trees in county parks that could be potential safety hazards after dying from a predicted infestation of the emerald ash borer.
The emerald ash borer, a beetle from Asia, first likely came to the United States in 1992 in solid wood packing material for cargo, but it was not until 2002 that the impact of the beetle that kills ash trees was known, said Cliff Sadof, professor of entomology at Purdue University.
Currently, Vigo County is about 80 miles from the closest known population of the emerald ash borer in Indiana. Some sites in Indiana already infected include South Bend, Fort Wayne and Indianapolis.
The closest site to Terre Haute is south of Bloomington in Monroe County. That means Vigo County will likely become infested with the emerald ash borer within five years, Sadof said.
“Once the beetle arrives, five years after its arrival you will start seeing massive [ash] tree die-off. So, [Vigo County] probably has, at the maximum, about 10 years before you start losing trees,” Sadof said.
Once a tree dies, its limbs or even the entire trunk can topple within a year, said Keith Ruble, superintendent of the Vigo County Parks Department.
“We want to be proactive. A tree can fall across a road and kill somebody or across a utility line,” Ruble said.
Ruble said the largest concentration of ash trees is in Fowler Park, about 7 miles south of Interstate 70. The 462-acre park includes a 300-acre wilderness area.
“We would look at areas that are potentially hazardous around shelters and camp areas,” Ruble said. “We will also plant trees, so we don’t lose our shade. If an ash tree is in a place that is not near a trail or camp area, we will leave it alone and let the bugs have it.”
One other option Ruble said he is considering is a timber harvest. Ruble plans to assess the volume and board feet of ash trees in the parks. If a harvest is done, the park department would seek bids on removing and selling the trees, with the bid amount paid to the park department.
Ruble said removing ash trees may be done in the county parks over a span of several years. Ruble met with county commissioners Tuesday, asking them to also consider steps to remove ash trees along county roads.
Terre Haute has many ash trees that could be infested. However, City Forester Bill Kincius said the city is not yet prepared to take a pre-emptive approach.
“We realize that we will have an issue,” Kincius said. “Certainly we don’t want to wait until we have many ash trees that are dying. However, if the tree is still healthy and is not otherwise a safety hazard, it is probably not something in the next couple of years that we will look at removing.
“We’ve only got so many resources available and we always have hazard trees out there” that need to be removed immediately, Kincius said.
Terre Haute, Kincius said, is now conducting a new city tree inventory, which is about 70 percent complete. The city’s previous complete tree inventory was done in 2003. At that time, the city had 988 ash trees.
Kincius said while the city has not yet enacted a formal plan, he expects the city’s efforts to include phasing out of ash trees over several years. Kincius said currently the city has healthy ash trees that continue to provide shading of homes and streets, stormwater interception and reduction of air pollution.
“It will be hard to remove a healthy tree when there may or may not be a backlog of trees that could be hazardous in their current condition,” Kincius said.
The city, Kincius said, could look at ash trees that are the most stressed now, as the emerald ash borer will attack those ash trees first.
The city’s budget to remove damaged trees, funded from a state cigarette tax, is $180,000 this year. The budget also covers tree plantings and tree maintenance.
“We have to prioritize our money. If we have trees we are aware of that are causing safety problems now, regardless whether they are ash trees or not, that has to be our highest priority. Safety first,” Kincius said.
The Indiana Department of Natural Resources already has several purple-colored boxes in ash trees throughout Terre Haute in an attempt to detect the insects.
Sadof said municipalities can save costs by protecting some ash trees using an insecticide. Ruble said it costs about $10 per diameter of a tree to treat with insecticide. Sadof said a homeowner could protect a 12-inch-diameter tree with about a quart of insecticide for about $25 a year.
“They [cities] don’t have to remove every last tree,” Sadof said. Purdue has established a cost calculator on its Web site, www.entm.purdue.edu/eab, that can be used to project costs as far out as 25 years and project the size of an ash forest over time.
Replacement trees can be planted near ash trees and allowed to grow for several years before cutting down ash trees, to help keep a city forest canopy constant, Sadof said.
“We are trying to protect the services the trees provide. They reduce air pollution, they soak up groundwater, reduce carbon and provide shading, reducing the amount of energy needed to cool a home,” Sadof said.
Howard Greninger can be reached at (812) 231-4204 or firstname.lastname@example.org