This morning, U.S. Forest Service Chief Tom Tidwell traveled to Philadelphia -- city of many street trees -- to unveil a new version of the service's i-Tree software.

Not quite an ap -- but the same idea -- it helps both planners and regular citizens assess the monetary value of the street trees plus quantify the environmental services the trees provide.

It factors how the trees help with temperature control, with water quality by filtering out contaminants, with air quality by filtering out pollutants, and with climate change by sequestering carbon.  

Tidwell, who planned to debut the new i-Tree at an event at the Fairmount Horticultural Center, calls urban trees "the hardest working trees in America. Urban trees’ roots are paved over, and they are assaulted by pollution and exhaust, but they keep working for us.”

According to the Forest Service, one recent i-Tree study found that street trees in Minneapolis provided $25 million in benefits ranging from energy savings to increased property values. Urban planners in Chattanooga, Tenn., were able to show that for every dollar invested in their urban forests, the city received $12.18 in benefits. New York City used i-Tree to justify $220 million for planting trees during the next decade.

“Forest Service research and models on the benefits of urban trees are now in the hands of people who can make a difference in our communities,” said Paul Ries, director of Cooperative Forestry for the Forest Service, ion a press release. “The work of Forest Service researchers, the best in the world, is not just sitting on a shelf, but is now being widely applied in communities of all sizes, around the world, to help people understand and leverage the benefits of trees in their communities.”

In particular, i-Tree Design is designed to be easily used by homeowners, garden centers, and in school classrooms, the service says. "People can use i-Tree Design and its link to Google maps to see the impact of the trees in their yard, neighborhood and classrooms, and what benefits they can see by adding new trees. i-Tree Canopy and VUE with their links to Google maps now also make it much easier and less expensive for communities and managers to analyze the extent and values of their tree canopy, analyses that up to this point have been prohibitively expensive for many communities."

i-Tree also has a "Hydro" application that looks at stormwater and water quality.

You can delve into it here, at www.itreetools.org