These trees won't last forever

By Emily Howland

There is no telling how much longer the canopy of shade over the quad will remain. One thing is for sure, though—it is bound to eventually disappear.

For decades, Dutch Elm disease has been destroying the once abundant elm tree population nationwide. Two signature trees of the quad in front of the Campus Center have escaped this disease for years, but like the remaining elms in the Twin Cities, their time is limited.

The disease, which entered the U.S. in the 1930s on diseased logs from Europe, is a non-native fungal infection that compromises the vascular tissue, tubes that carry water up the tree. After the trees are infected their leaves become brown and wilted and the tree then withers and dies.

None of the existing 20 elm trees on campus are infected with Dutch Elm disease but Director of Facilities Management Mark Dickinson said, “realistically, the future doesn’t look great.”

In the last 30 years the college has lost about 100 Elm trees, Dickinson said.

No estimates have been made as to how long the trees will remain uninfected and Facilities Management has no plans to remove any existing elms.

The college has decided to increase the frequency of antifungal treatments for its elm trees from every three years to every two years to prevent the disease from reaching some of the oldest and largest trees on campus.

This antifungal treatment costs $6,000 every time Rainbow Landscaping Company treats the Elm trees on campus.

Despite the college’s efforts to protect the trees, some see their death asyears to prevent the disease from reaching some of the oldest and largest trees on campus.

This antifungal treatment costs $6,000 every time Rainbow Landscaping Company treats the elm trees on campus.

Despite the college’s efforts to protect the trees, some see their death as inevitable.

“I wouldn’t be surprised if eventually [the elm trees] die,” Biology professor Mark Davis said. The cost to remove an 80-or 90-year-old elm would be approximately $5,000, according to Grounds Manager Gerald Nelson.

The disease has killed over half of the elm trees in the northern United States and threatens the remaining elms.

“We are lucky to still have elm trees,” Davis said.

Dickinson described the giant elm trees by the Campus Center, the oldest trees on campus, as priceless.

Wes Roberts ’08 agreed. “[The elms] are some of the biggest part of the landscape and people would miss them. But of course we don’t appreciate what we have until it’s gone.”

The disease began spreading through St. Paul in the early 1970s, killing some 10,000 elms each year. Before the disease hit, elm trees made up a good portion of the trees on campus and in most St. Paul communities.

“In the 1940s and 1950s there were elms on either side of the street,” Davis said. “When I arrived in 1981 all the elms were gone.”

Elm trees are prime for urban landscapes because they can grow in harsh environments and produce a large canopy for shade and aesthetics, Nelson said.

Bark beetles transmit the disease when they get the spores of an infected tree attached to their body and carry them to another tree. The disease also spreads when the roots of two trees connect underground.

The high temperatures and dryness of St. Paul summers add stress on trees, which makes them more susceptible to contracting the disease. Dickinson also hypothesized that the warmer winter may have contributed to the spread of the disease.

While Nelson said the college is doing everything it can to maintain the elm trees, he tries to plant a variety of tree types, such as oak, linden and ash trees.

But all tree species are susceptible to some disease. “Oaks could get Oak Wilt. Maples can have Maple Decline,” Nelson said. “The key is to have trees.”

The college plants trees each year and plans to plant more elms of a variety that is resistant to Dutch Elm Disease.