Campus plan aims to remove ash trees, head off emerald ash borer

Staying one step ahead of an aggressive, wood-boring beetle that is threatening ash trees in several states is the aim of a plan that will gradually remove many ash trees at the University of Wisconsin–Madison.

Officials have begun selectively removing ash trees and scouting for the emerald ash borer, which has yet to be found in Wisconsin. The beetle has been found in Michigan, Maryland, Indiana, Ohio, Virginia — and most recently in Illinois.

“We hope to gradually remove many of the ash trees on the developed parts of campus and replace them with more diverse varieties of trees before the beetle is found here,” says Gary Brown, director of planning and landscape architecture.

That plan will give the campus more time and flexibility in dealing with the problem, because the state’s plan is to remove all ash trees within a half-mile of any confirmed infestation to help eradicate the voracious pest.

“In addition to removing ash trees, we’ll take steps to educate the public about the emerald ash borer and actively scout for the beetle on campus,” says Ellen Agnew, campus arborist.

There are about 550 ash trees on the developed part of campus, with many more in the adjacent Lakeshore Nature Preserve.

Agnew’s crew in Environmental Services has begun removing about 160 of the campus ash trees. They were selected based on their location and poor health status. Appropriate replacements will be planted within a year of their removal, and about 40 of the ash trees already have a variety of younger tree replacements planted nearby.

In addition, about 30 ash trees will be designated as “detection trees” that are girdled in May. The trees are monitored for the emerald ash borer until the fall, when they will be felled and removed.

About 72 ash trees in the developed part of campus have been designated for preservation — including two high-value trees that will be chemically treated to protect them from the pest, in the event that they are not in a state-designated eradication zone. The other 70 trees are in places that may not be able to support future tree growth, and some provide needed shade in parking lots, are healthy or are of a desirable species.

Another 160 ash trees are likely to be removed as a result of future construction activity on campus. And about 130 trees surrounding the campus are shared with the city of Madison, and campus officials will work with city foresters to determine how to deal with them.

Additionally, the campus will no longer allow the movement of firewood into picnic areas. Visitors requesting reservations will be notified beforehand and approved firewood will be provided, if requested. Informative posters regarding the emerald ash borer will be also be posted around campus and at the entrances of both Frautschi Point and Picnic Point.

Officials have also begun using campus tree pruners and volunteers to scout for the beetle, which is native to China and eastern Asia.

“In order to be successful, we have to be watchful and proactive,” says Brown. “Although the removal of ash trees will change the campus landscape, we hope the diverse new plantings will provide an equally attractive setting for many years to come.”