The 46,500 trees growing on public land in Salt Lake City now fall under the protection of an urban forestry ordinance recently passed by the City Council that sets up guidelines to control tree planting and trimming.

"The City Council and the mayor of Salt Lake City recognize the importance of the urban forest to the quality of life in Salt Lake City," the ordinance said.The ordinance establishes a permit process to control the way city residents and utilities plant, trim and prune trees that grow in city parks, on boulevards and on other public lands.

The permits will ensure that trees are trimmed properly, instead of people "just hacking away at them," said Karen Salisbury, project manager for the city's Parks and Recreation Department.

Utah Power & Light Co., which trims 100,000 trees a year to keep branches free of high-tension wires, said the law is burdensome.

"We'll do our best to comply with the ordinance. It poses some additional administrative duties. But we think that we have always been sensitive to the efforts of trimming trees," said UP&L spokesman Dave Mead.

"We have always tried in the past to keep the aesthetics of trees in mind," he said.

Under the ordinance, topping - or cutting the top off a tree - is illegal except in emergency situations created by, for example, wind storms. Trees under utility wires where standard trimming is impossible are also exempt.

Damaging, transplanting or mutilating trees on public property is prohibited by the ordinance. In addition, trees on public property must be protected from nearby construction activity.

Commercial companies and public utilities must pay a $15-per-job or $75-per-year fee to get a permit to trim trees, under the ordinance.

Trees play an important role in promoting quality of life and economic vitality in a city, Salisbury said.

"They add to the streetscape, they add to property value and there's the value of them cleaning the air for us so that it cuts down on air pollution," she said.

Well-maintained trees also serve as noise and visual barriers to unsightly construction projects or freeways and ensure privacy for home-owners, she said.