Decades of neglect exploded into the biggest plague in 26 years
Thirty years ago this fall, the Minnesota Shade Tree Advisory Committee held its first meeting to combat Dutch elm disease.
After a generation of containment, Park Board Forestry Director Ralph Sievert said more elms have been lost in 2004 than in all but two years dating back to the mid-'70s.
From early June to Labor Day, 75 Park Board arborists and 20 machine operators crews worked 10-hour days, Monday through Saturday, removing diseased trees, Sievert said -- adding that "there is definitely a lag" in getting them down. Crews have now cut back to 40-hour weeks.
"People were getting tired, and we were having a few injuries," he said. "The other is a budget reason."
Michael Schmidt, assistant superintendent for operations and recreation, said the Park Board already is $500,000 over budget on diseased-tree removal. "The Board hasn't told me to stop," he said.
In order to replant boulevard trees, the Park Board has to grind 7,000 elm stumps (including 3,000 left over from 2003), a Park Board report said. The stump grinding alone will cost an estimated $525,000.
In 1977, the city lost 31,000 elms on public and private property, the peak loss year, Sievert said. In 1978, the city lost 20,000 elms, the second-worst year.
Between 1992 and 2001, the city lost fewer than 3,100 elms a year. This year, the city has lost 9,873 elms, more than triple the 1990s baseline.
The diseased elms are split roughly 50-50 on public and private land, meaning the city is losing approximately 4,900 public trees, Sievert said. For comparison, the Park Board typically plants 3,000 trees a year.
(With the help of Mayor R.T. Rybak's tree initiative, the Park Board was going to plant 5,000 trees this year. That appears out of the question, since forestry crews will be cutting, not planting.)
The elm loss has hit a nerve with city residents, such as Joe Shierl of Kenwood. "These [diseased trees] are not being removed in a timely manner," he wrote in an e-mail to the Southwest Journal. "I am very concerned that the longer these diseased trees remain standing, the faster the remaining elm trees will be lost."
Sievert said one day this summer, Park Board staff received 100 Dutch elm calls by 10 a.m. "We get a range, from 'You marked the tree and why isn't it down?' to 'You've marked the tree, and I am not sure you know what you are doing. Does it really have Dutch elm disease?'" he said.
Jim Hermann, Park Board forestry program manager, said he is gearing up for a similar number of diseased trees next year.
The city had its first reported cases of Dutch elm disease in 1963. It lost four elms out of nearly 130,000 on public property alone, mostly boulevards and parkland, according to Park Board data. By the end of 2003, the city was down to 41,000 public elms.
Many factors have contributed to the spread of Dutch elm disease, including the weather, stressed trees, delays in removing diseased trees, public complacency and budget cuts, experts say.
Here are 10 possible reasons for the Dutch elm disease boom, in no particular order, according to interviews.
1. Weather has helped the beetles: Beetles spread the Dutch elm fungus, so the more beetles, the bigger the problem. A warm fall could add an extra beetle hatch, Sievert said. A mild winter means more beetles survive until spring.
2. Weather has stressed the trees: Warm, dry summers stress the elms, weakening their ability to fight Dutch elm infection, said Park Board Commissioner John Erwin, an associate professor in horticulture at the University of Minnesota. "When a [stressed] tree gets infected, it comes down with the disease more quickly."
3. Small boulevards stress trees: Don Willeke, a citizen activist who championed the fast-response to Dutch elm disease when it first hit Minneapolis, said the trees saved in the 1970s have gotten bigger.
"But they are in narrow, small locations," he said, which again adds stress and reduces disease resistance. "They get so big, they don't have any more soil to grow in."
4. Complacency: Willeke said the city does not have the energy and focus to fight Dutch elm disease as it did in the 1970s.
"When was the last time some group did an elm watch inspection of people's back yards and woodpiles? That was very commonplace," he said. "When was the last time you saw a sign on a diseased tree: 'Do not keep elm wood around. Elm wood is the source of Dutch elm disease,'" he asked. "They did years ago. They haven't in recent years."
5. Deferred maintenance: Willeke said the Park Board cut back the tree-trimming cycle to save money, allowing dead elm wood to build up -- creating more beetle-breeding spots.
Gary Johnson, a professor and extension educator in forestry at the University of Minnesota, said tree budgets around the state are seeing the same pressures as every other public service. "There is so much obsession with paring back city budgets and services," he said. "Delayed maintenance of trees is no different than delayed maintenance of buildings and roads. It doesn't work."
Sievert said longer trimming cycles could contribute to the Dutch elm disease problem, but it is not his major worry. The Park Board trims trees on a seven-year cycle and has since the late 1980s, he said. Before that, it trimmed on a four-year cycle.
6. Delays in removing diseased trees from public land:
Years ago, the state of Minnesota gave cities matching money to respond to the Dutch elm crisis, said Geir Friisoe, manager of the plant protection program for the State Department of Agriculture. The state program required tree removal within 20 days.
The state funding disappeared years ago.
Optimally, the Park Board would remove a diseased boulevard tree within four to six weeks of marking it, Sievert said. That isn't happening in every case.
The longer a diseased tree stands, the longer beetles breed in it and the more beetles move the disease to other trees, he said.
How big is the problem created by tree removal delays? "You don't know exactly," Sievert said.
Forestry staff was short-handed last year due to budget fixes, but Sievert said his department has filled vacant positions.
Willeke said the Park Board needed to add more forestry workers, given the three-fold increase in diseased trees. Sievert said he would try to handle the increased tree removal by changing priorities, including less tree trimming.
Erwin said he hoped to increase forestry's 2005 budget.
7. Border beetles: Johnson said some suburbs do not support Dutch elm disease programs as strongly as they once did, in part because elms' share of the urban forest has dropped from 90 percent to below 15 percent.
"A political border doesn't stop a fungus and a beetle," he said. "It is very easy for these diseases to get into trees in Minneapolis."
Schmidt put it in stronger terms: "There are municipalities around us that are doing nothing in terms of elm tree removal," he said.
Edina City Forester Tom Horwath said the number of diseased trees has doubled for the past three years. He said he has been vigilant but acknowledged that wilder areas in the larger parks might get less attention than in the 1970s and 1980s when programs had more money.
"I wouldn't blow it out of proportion," he said.
He said the problem is worse outside the urban core. "You don't have to go far and you see a ton of elms diseased and gone out in the countryside where there is no enforcement anymore," he said.
Paul Buck, city forester for Plymouth, said his city used to have two or three tree inspectors. It got to a point where they only marked 200 to 300 trees a year, an inefficient use of their time. One position got phased out, he said.
This year, the city had more thatn 1,600 diseased trees, Buck said. "We probably should have had at least two inspectors."
Willeke downplayed the beetle migration problem. He said Evanston, Ill., had successfully fought Dutch elm disease, despite the disease's spread in neighboring Chicago.
"The bugs don't go that far. They never did," he said. "If the disease knows no political borders, Minneapolis wouldn't be able to do what it did over the years."
8. Private property problems: The Park Board only removes diseased trees from public land -- boulevards and parks. Schmidt and Sievert said private property owners have to hire their own contractors and are experiencing delays.
"The biggest problem we are having right now is not with the public trees -- it is with the trees on private property," Schmidt said. "There are not enough licensed contractors doing the work."
Further, private trees take longer to remove because of complications working near houses, he said. A park forestry crew could remove 15 boulevard trees on a good day, compared to two or three per day for a private company.
The Park Board estimated that, at the end of 2003, 40 percent of the city's 68,710 elms were on private property.
Reed Bales of Aspen Tree Service said he has seen a three- to four-fold increase in Dutch elm disease calls. "We do a lot of work in Crystal and Edina and Plymouth and Minnetonka. They are all having a boom," he said.
He is backed up three to four weeks, and Dutch elm disease has contributed to the backlog, he said.
9. Wild elms have spread: Some trees appear to exist in something of a nether-land. Johnson said American elms create a large number of seeds that sprout everywhere -- alleys, fence lines, roads and ditches. "No one takes care of them. No one knows who owns them. They get the disease, and it builds up," he said.
10. Small increases lead to big increases: Johnson said the number of infected trees in the area didn't jump all of a sudden but has built for the last three to four years.
He compared it to catching a cold. Someone in a room with one infected person sneezing probably won't get sick. Someone in a room with a number of people sneezing probably will, he said.
While the city lost fewer than 3,000 public and private elms a year for most of the 1990s, the last two years have seen an increase: 4,198 in 2002 and 3,628 in 2003, according to Park Board data.
The big jump came this year.
Said Willeke: "Duh. Anyone could have predicted this."