Citylab April 9, 2015
A new study finds a strong correlation between income level and canopy cover. But the solution involves more than just planting additional trees.
By now, researchers have well established the benefits of trees in urban neighborhoods. Trees are correlated with better health outcomes. They mitigate the urban heat-island effect and lower energy bills. They raise overall property values.
But how trees and their benefits are distributed across neighborhoods is a complicated picture. A new study published in PLOS ONE offers a provocative look across several U.S. cities at what neighborhoods are most likely to have urban tree canopy (UTC) cover. Money may not grow on trees, the authors write, but in a way, trees grow on money.
Led by Kirsten Schwarz, assistant professor of biology at Northern Kentucky University, the researchers used high-res land-cover data and census information to study the distribution of trees in relationship to race and income in Baltimore, Los Angeles, New York, Philadelphia, Raleigh, Sacramento, and Washington, D.C.
Schwarz’s research is among the first to calculate, in a comparative way, what is most strongly correlated with tree density and distribution across multiple cities. Previous studies that examine tree cover and socioeconomic variableshave mostly focused on single cities. There’s also been research to show that African Americans, Hispanics, and Latinos are more likely than whites to live in neighborhoods highly vulnerable to the urban heat-island effect—which is related to UTC cover, since shady trees can mitigate it.