THURSDAY, Jan. 2, 2025 (HealthDay News) -- Tree-lined streets and lush public parks appear to provide city schoolkids a brain boost.

Chicago students’ test scores suffered when an invasive insect wiped out half the city’s ash trees, researchers reported in the journal Global Environmental Change.

“We found that test scores in areas with ash borer infestations were reduced after the onset of those infestations, relative to unaffected areas that were similar,” lead researcher Alberto Garcia, an economics professor with the University of Utah, said in a news release from the college.

Prior studies have found that students in neighborhoods with greater tree cover have better test scores, researchers said in background notes.

The emerald ash borer provided a chance to gather more evidence, unfortunately.

The ash borer has killed millions of ash trees along the streets and yards of Midwestern cities, researchers said.

The invasive pest killed off half of Chicago’s ash trees between 2010 and 2020, leaving the remaining half dying or in decline, researchers said. Ash trees account for 18% of Chicago’s street trees.

For this study, researchers tracked students’ standardized test scores from grades 3 through 8, between 2003 and 2012, to see whether the loss of the trees might affect their academic performance.

“We got kind of lucky that the state of Illinois was administering this standardized test in that same window when the ash borer first arrived in the area,” Garcia said. “Every school in Illinois was taking the same test, so we had consistent data across schools and through time.”

Results show that 1.2% fewer students met or exceeded standardized testing benchmarks in areas hit by the ash borer -- a seemingly modest drop that carries significant implications considering that there are more than 320,000 Chicago schoolkids.

“We found that schools with more low-income students were less likely to experience infestations because these neighborhoods have less tree cover,” Garcia said. “But the low-income students at wealthier schools, where infestations were more common, seemed to bear the brunt of the impacts.”

The loss of tree cover could affect student performance by increasing heat on city streets, contributing to air pollution, and robbing kids of the psychological benefits of greenery, researchers speculated.

“Some possible explanations are just that those students don't have the same resources to go home and recover from, for example, extreme temperatures or pollution-induced headaches the same way that higher-income students at the same schools might have,” Garcia said.

Efforts to maintain and restore urban tree cover could play a vital role in boosting kids’ education, particularly in poorer neighborhoods, Garcia concluded.

“It’s not just about access to environmental amenities,” Garcia said. “It’s about understanding how their absence can create inequities that ripple through critical aspects of life, like education.”

More information

Harvard Medical School has more on the health benefits of trees and green spaces.

SOURCE: University of Utah, news release, Dec. 17, 2024