D.C. Agencies Spar Over Elm Trees : Washington: Park Service and Smithsonian at odds over steps needed to save 550 trees and limits on activities on ‘nation’s front yard.’

In this city, where debate is a way of life, not even trees are beyond the reach of politics.

These particular trees line the Mall--that grassy, museum-lined park that stretches about a mile between the Capitol and the Washington Monument. Sometimes called the nation’s front yard, it’s the city’s most popular tourist attraction and an irresistible backdrop for political demonstrations and cultural events.

But the U.S. Park Service says such activity is slowly killing the 550 American elm trees that provide shade and beauty along the edges of the Mall.

The constant stress of about 23 million visitors a year has compressed the soil around the trees’ roots to an almost brick-like consistency, say Park Service soil scientists.

The Park Service would like to restrict activities on the Mall, particularly the annual Folklife Festival sponsored by the Smithsonian Institution.

“If we can eliminate large-scale activities from the panels and let people casually picnic, that would go a long way toward the revival of the elm trees,” said Arnold Goldstein, the Park Service’s superintendent for the parks and monuments in the downtown area.

But the Smithsonian, whose museums line the Mall, has resisted limitations on where it can locate the summertime festival, which each year focuses on different cultures and their foods, crafts, homes and hobbies. This year, there was even a Mexican rodeo ring.

Both sides have bolstered their point of view with scientific studies that support opposite conclusions about the health of the elm trees.

In 1989, the Park Service commissioned a study from the State University of New York at Syracuse that concluded that compressed soil around the elms’ roots is weakening the trees.

“There is certainly a very high increase in the mortality of those trees,” said Phillip J. Craul the SUNY soil scientist who wrote the study. “Because there are so many events, it’s almost to the point where it’s out of hand.”

Craul says that while the Folklife Festival is just one of many activities each year, it’s also one of the most harmful.

The event requires heavy equipment to set up temporary buildings, public address systems and stages. Trenches are dug for pipes and electrical lines that cut the trees’ roots. When the festival is up and running, it draws 100,000 to 120,000 people a day for about 10 days.

The Smithsonian study, conducted last year by the U.S. Department of Agriculture’s National Soil Dynamics Laboratory at the University of Auburn, concluded that the festival was not seriously hurting the trees.

“That the Mall is having a problem with its trees seems to fly in the face of the scientific evidence, so a total solution for the Mall seems unrealistic and unfounded,” said Richard Kurin, director of the Smithsonian Center for Folklife Programs and Cultural Studies.

Craul said: “It’s a paradox. We want people to know it’s a symbol of our national heritage, but then the public feels that that’s the best place to demonstrate, and it’s the demonstrations that lead to the trouble.”

“The Mall is for the American public,” Goldstein said. “It has a purpose, and we’re just trying to keep that purpose alive and keep those trees alive.”