The University Record, April 8, 2002

Trees topple to winter’s wrath

By Joanne Nesbitt
News and Information Services

The U-M Forestry Crew: (from left) Michael Stoker, Arthur Grissom, Robert Miller and Laura Bowman (Photo by Marcia Ledford, U-M Photo Services)
Harsh winter weather did permanent damage to tree collections on campus says Robert Grese, director of the Nichols Arboretum and associate professor in the School of Natural Resources and the Environment.

Among the areas damaged were the Nichols Arboretum (the Arb), the Matthaei Botanical Gardens, and parts of Central Campus. “We had a lot of damage from the ice and wind storms of late,” says Brian Klatt, interim director of the Botanical Gardens. “In fact, we have so much damage that it is way beyond our internal resources, and we have enlisted the help of the University Forestry Crew.”

Forester Marvin Pettway, who heads the Forestry Crew, says the Arb experienced more damage than anywhere else on campus. According to Pettway, a program of intensive management kept other areas of campus from being more severely damaged. Yet despite these precautions, Central Campus still experienced some unexpected branch damage and upturned trees. “I would not have predicted the fall of some of those trees,” Pettway said. “They were in protected areas.”

The cleanup procedure of damaged areas varies in both the Arb and the Botanical Gardens. “We do a thorough clean up of our display areas and those areas that are readily visible from visitor areas or Dixboro Road,” says Klatt. “But those trees and branches that come down in the natural areas and that are not blocking a trail, or damming Fleming Creek, are for the most part left alone.”

“The majority of the Gardens, 350 acres, are natural acres that fend for themselves,” says Mike Hommel, superintendent of the Gardens. “But the five miles of hiking trails that traverse the property require clearing and the removal of dangerous limbs that hang precariously above the trails.”

The white pines along the main entrance to the Botanical Gardens suffered the most extensive damage and will require cosmetic and prophylactic pruning to minimize the risk of infection, Hommel says. “Our most traumatic loss was a landmark oak at the edge of our prairie. It was split in half and came to rest across a trail.”

At the Arboretum, the crabapple and hawthorn collections were particularly hard hit. “This is a great loss to us,” Grese says, “and we’ll have to think hard about how we rebuild these historic collections. We’re used to accounting for the loss or damage to things that are easily replaced, but what do we do about specimen trees that were key parts of our collection or to natural areas? What exactly is the value of a hawthorn tree planted nearly 100 years ago, most likely as part of O.C. Simond’s original plan for the area?”

The challenge at the Arb is to complete the removal of trees still blocking some trails. “Some trees are cracked and will continue to fall,” Grese says. Crews from the Arb, volunteers, crews from the Washtenaw County Sheriff’s Department and University foresters will continue to clean up much of the debris in the open areas and in major collections. “But,” Grese says, “we will probably leave many of the downed trees in the natural areas of the Arb where they don’t pose hazards to our users. Those downed trees provide important wildlife value and other functions in the ecosystems where they’re found.”