Office of the Vice President for Global Communications

Thursday, May 10, 2012

Elm trees being removed due to disease, safety concerns

Two American elm trees on Central Campus are being removed this month due to disease and structural issues that have raised concerns over pedestrian safety.

One of the trees — located at State and William streets — suffered from Dutch elm disease and was nearly dead. A crew from Grounds Services removed it Wednesday.

    Left, this diseased American elm was removed from Central Campus near Angell Hall on Wednesday. Below, Paul Cox (left) and Rob Miller of Plant Buildings and Grounds Services maneuver a tree limb. (Photos by Austin Thomason, Michigan Photography)

The second tree — located in the Law School's main courtyard — is structurally unsound, raising concerns over pedestrian safety. With the renovation of the Lawyer's Club scheduled to begin this month, representatives from Grounds Services have recommended its removal prior to that work beginning.

"As with all of our trees on campus, we are actively managing our elm tree inventory to make sure they are kept healthy and properly maintained," says Marvin Pettway, senior supervisor for Plant Buildings & Grounds Services. "With these two trees, one is diseased and the other has been determined to be unsafe structurally which could create safety problems for pedestrians."

The Ann Arbor campus has 220 trees in the elm family, including 134 that have been planted during the last two decades. Pettway says the newer elms that have been planted are of disease-resistant varieties, and he and his team proactively monitor the insect population looking for the beetle that transmits the Dutch elm fungus. As part of the maintenance program, elm trees are injected with a fungicide making them more resistant to the disease.

In assessing the structural integrity of the tree in the Law School courtyard, Pettway and his team consulted with James Kielbaso, professor emeritus of urban forestry and arboriculture at Michigan State University. Kielbaso is an expert in the field of urban tree evaluation and specializes in the assessment of shade trees and trees that have been affected by storms.

A third elm tree on campus, located near West Hall, also will undergo some changes this spring, including the removal of major limbs due to structural problems and potential safety concerns. Pettway said a determination on the long-term plan for that tree will be made following the limb removal. The university consulted with a certified board-certified master arborist from the International Society of Arboriculture on the state of this tree.