Crews planted trees last week in St. Paul’s Payne-Phalen neighborhood using a new science-based mapping tool that specifies which areas would most benefit from more greenery.

“We’ve brought together data to inform where we should plant,” said Marya McIntosh, conservation specialist with the Nature Conservancy, which developed the tool.

“There are huge discrepancies where there are trees and where there are not. We are planting in areas where the benefits of trees are most needed.”

The mapping tool will be made available to local governments and organizations to identify sites in the metro area most in need of tree planting.

The tool looks at factors such as existing tree canopy, air quality and tree loss from pestilence and disease, such as an emerald ash borer infestation. It also looks at neighborhoods with historically disadvantaged communities and urban heat islands — areas significantly warmer than surrounding areas because of buildings, pavement and human activity.

The hope is that the newly planted trees will flourish, clean and cool the air, and improve the health of neighborhoods most in need.

Last week, 82 trees were planted on bare stretches of Johnson Parkway and around the sun-drenched playgrounds and ball fields at Duluth and Case Recreation Center in Payne-Phalen, on St. Paul’s East Side. “Trees are really connected to our health in an intimate way,” McIntosh said. “We know that trees combat all these issues, give us shade and improve communities.”

Research has shown that the presence — or absence — of trees in America’s neighborhoods and the ensuing health benefits often correspond with socioeconomic and racial lines.

A 2017 analysis in the Journal of Environmental Management found “evidence of significant race-based inequity in urban forest cover,” and encouraged forestry professionals to consider the equity consequences of urban forestry projects.

“There is a desire for everyone to be very intentional where we plant trees,” said Karen Zumach, director of community forestry at the nonprofit Tree Trust, which is working on the East Side planting with the Nature Conservancy and St. Paul’s forestry unit.

Last week, Tree Trust crews planted 19 tree species including swamp white oak, prairiefire crabapple, ivory silk lilac and Kentucky coffee trees. The trees replaced a multitude of ash trees cut down in recent years in response to the emerald ash borer.

Tree Trust will water and care for the young trees for the next two years.

“By increasing the diversity of species, it’s going to help build resiliency in the urban forest in the face of climate change,” McIntosh said.

Tree Trust arborist Daniel Schmitter planted a lilac next to the Duluth and Case Recreation Center playground, stirring the soil with water as he positioned the tree.

Schmitter, who is also part of a state arbor apprentice program, said the overarching goal is improvement of the community and the health of those who live there for generations to come.