Hours after a congressional budget stalemate shut down all but essential federal operations Saturday, a work crew pulled up along Pennsylvania Avenue and cut down 45 shade trees in the heart of the Federal Triangle.

The work order originated with the Pennsylvania Avenue Development Corp., the federal agency created to guide the renewal of the Pennsylvania Avenue corridor between the Capitol and the White House. Agency officials said removing the linden trees in front of the FBI building was needed as part of the beautification project.

But weekend passersby and many government workers were angry.

"It is pretty outrageous," said Paul Wolfteich, 28, a Justice Department employee from Alexandria who was showing tourists around downtown and noticed the workers cutting down the linden trees. "It is really striking that the environment president would allow that many trees to be cut down" on the very street where he lives.

Agency officials said the trees were chopped down to prepare for a planned sidewalk regrading and construction project and because the nearly 20-year-old lindens did not match the willow oak trees newly planted along the rest of the refurbished corridor.

"You'll have heavy construction equipment going in there to change the grade of the sidewalk," said Ann Hartzell, a spokeswoman for the agency. "You probably would do some damage to the roots."

Aside from replacing the trees at a cost of $60,000, the agency plans to repave the sidewalk area with thicker tile, replace the lighting and metal grates around the trees and eliminate the steps that had been set up for parade viewing, according to the contractor.

"If you go from Capitol Hill {almost} to the White House, both sides are identical," said Steve Salehi, of Fort Myer Construction Corp. "This was the last part."

The Pennsylvania Avenue Development Corp. has been planting willow oaks along the street since 1978, when the first ones were put in along the East Wing of the National Gallery of Art.

The lindens in front of the FBI building, however, were planted in the early 1970s in neat rows along the red-tile sidewalk and stood about 15 feet high. Wooden benches had been placed beneath the trees with their heart-shaped leaves, creating a shady oasis for federal office workers and tourists along "America's Main Street."

Passersby Tuesday complained it would be years before new trees would grow tall enough to provide shade like the old ones. "Look at how big they were," said Jackie Boehme, a former Washington area resident who now lives in rural upstate New York.

"It's crazy," said flower vendor Ahmed Alaoui. "You could leave the tree and they could {still} change everything on the floor."

Agency officials, who said they had received a number of calls from people concerned about the fate of the trees, offered an optimistic outlook. Afterall, Hartzell said, "They will eventually grow to that height."

But Phillip Rodbell, an urban forester with the American Forestry Association, said it will take at least 10 to 15 years for new trees to create the same benefit for the downtown area.

"To totally remove healthy trees . . . seems absurd to me," he said.