The city's been cutting back on sprucing up street trees, and City Comptroller Scott Stringer said it's been costing taxpayers millions from various lawsuits.

A audit by Stringer released Sunday of the parks department's forestry service, which oversees tree maintenance, said that the agency has been mismanaging its pruning program that's responsible for 650,000 trees in the city.

The parks department failed to provide accurate lists from its contractors on work done on street trees in Manhattan and Staten Island and failed to prevent payments on work done on trees that didn't pruning. Stringer said the report is troubling because those overgrown branches have hurt pedestrians in the past and led to multimillion dollar lawsuits against the city.

"This audit gives the parks department a road map for better record keeping," the comptroller said during a news conference in Chelsea.

Stringer's analysis, which examined records between July 2012 and November 2013, found that contractors in all of the boroughs, except for Queens, kept poor records and in many cases failed to prune trees that were dangerous. One Manhattan contractor, which performed 2,363 prunings, had 99 trees that were too small to be serviced, according to the audit.

The comptroller said the City Council has been cutting back on funding for tree pruning since 2011 but the amount of money doled out in tree related suits against city has risen. In 2011, the city paid out $300,000 in those settlements, but in 2013, they handed out $14 million, including one settlement that was $11 million for a 2009 incident in Central Park.Sasha Blair-Goldensohn fractured his skull when a 100-pound branch struck him. The audit only examined street prunings.

"You can see that correlation between the funding and the claims easily," Stringer said.

The parks department said it has already pruned 57,000 trees throughout the city this fiscal year through May, 10,000 more than the previous year, and it added a million dollars to its tree-trimming budget.

"This high number of prunings has made a positive impact on neighborhoods throughout the city, and has minimized the risk of injures to people and damage to property from fallen limbs," the park department said in a statement.

Stringer recommended the agency to make a better list of its contracts, perform post-pruning inspections and investigate any report of a contractor falsifying invoices.

"The lesson here is we can distinguish the people doing their jobs and the ones that aren't" he said.