Dozens of trees are falling on downtown streets to improve sight lines for spectators at the Baltimore Grand Prix, but event planners intend to replace them after the race — half of them in large pots so that they can be moved, not destroyed, in future years.

Workers on Monday took saws to a few trees that lined a section of West Pratt Street in front of the Baltimore Convention Center to make room for a prime grandstand viewing area. More trees, in five other downtown areas, are being removed to accommodate the thousands of spectators who are expected to watch the races Labor Day weekend.

In total, 136 trees will be removed before the race and 139 planted after it, said Lonnie Fisher, assistant general manager of the Grand Prix.

Fisher said Baltimore Racing Development, the company running the three-day event, worked out a plan with the city's Office of Sustainability, the Downtown Partnership and the Waterfront Partnership that includes removing and replacing trees on along West Pratt Street, at the Inner Harbor and near Camden Yards.

BRD hired Mahan Rykiel Associates, the Baltimore-based landscape architectural firm, to produce a plan for six sites where existing trees had to be removed for grandstands. About 40 percent of the trees, Fisher said, have been in decline, were species inappropriate for their location or were planted in small tree pits that limited their growth.

When they are replaced, about half of the trees will be planted in large pots that can be moved when the Grand Prix returns to Baltimore each of the next four years, Fisher says.

In addition to removing and replacing trees along Pratt Street, and at the Inner Harbor between the visitor center and the Maryland Science Center, workers will take out a grove of trees along Russell Street near Camden Yards. The area will be replanted with crepe myrtles.

As part of its agreement with the city, Fisher said, BRD will also plant trees in sidewalk pits in areas of downtown away from the harbor.