An aerial map of tree canopy in any large U.S. city will give you a relatively accurate picture of income and racial demographics: with few exceptions, the more tree cover a neighborhood has, the more likely it is to be wealthy and predominantly white. Tree Equity Score, a new tool by American Forests, helps quantify this disparity. Ian Leahy, VP of Urban Forestry at American Forests, walks us through the process of developing Tree Equity Score, and how it can be used to promote healthier, greener, more equitable cities.
Despite three centuries of intermittent deforestation, Pennsylvania is still one of the woodsiest states in the country, with trees covering more than 58% of its land. Throughout our history, trees have been been a vital resource and a source of economic prosperity for Pennsylvania. They’re also critical to urban ecosystems: trees keep neighborhoods cool, mitigate air pollution, support biodiversity, and manage erosion and stormwater runoff. Abundant tree cover also correlates to lower crime rates, greater social cohesion, and better quality of life for residents.
But those benefits are not evenly distributed across the Commonwealth. New research from the group American Forests shows there are almost always fewer trees in low-income neighborhoods and communities of color than in wealthier, whiter neighborhoods, even if the neighborhoods are within a few blocks of one another.
“You can fly over almost any city in the country and you can tell where the wealthy areas are, versus where the low-income areas are, based on where tree canopy is,” said Ian Leahy, VP of Urban Forestry at American Forests.
Disparities in tree canopy are linked with higher temperatures, lower air quality, and associated health impacts which, in turn, correspond to a range of negative social outcomes. Historically, all of these effects are related to the discriminatory lending practice known as redlining, which effectively barred Black families from buying homes in desirable areas throughout much of the 20th century.
American Forests’ Tree Equity Score initiative aims to visualize and quantify the disparity, in order to help planners more effectively and equitably allocate limited funding for urban tree-planting projects.
“It’s more than just a number; it’s a tool, designed to really help identify at any given time where the biggest bang for your buck is,” said Leahy. “It’s a way to say where the most impact for that dollar is going to be in terms of saving lives, in terms of reducing respiratory illnesses, creating jobs, that sort of thing.”
“You can fly over almost any city in the country and you can tell where the wealthy areas are, versus where the low-income areas, are based on where tree canopy is.”
Philadelphia presents a good case study for differences in tree canopy. Chestnut Hill, which has an average annual income around $130,000, has 60% tree canopy, while Nicetown-Tioga has an average annual income of around $37,000 and about 6% tree canopy. These neighborhoods are only about five miles apart.
“Generally speaking, Philadelphia doesn’t have a low overall score… It has a score of about 83 out of 100. But when you really dig into the communities of color and communities with high poverty, you see just a direct line straight down from the wealthier areas to the lower income areas. Communities of color have almost 5% less tree canopy cover, communities in poverty have about 7% less,” said Leahy.
Scranton is an even more extreme example. Communities of color have 16% less tree canopy cover, and high-poverty neighborhoods have nearly 20% less tree canopy than the wealthiest neighborhoods. Meanwhile, Pittsburgh has a smaller disparity because the steep hillsides are difficult to develop, preserving tree cover throughout the city. However, the same inequities still exist despite this geographic advantage, according to Leahy.