It’s widely recognized that trees in urban areas offer various environmental and mental health advantages to residents. Recent research from social scientists at the University of Utah suggests that urban trees can enhance educational outcomes, and their removal may have a more severe impact on students from low-income backgrounds.
Economics professor Alberto Garcia examined the effects on school attendance and standardized test scores in the Chicago metropolitan area over ten years following the introduction of the emerald ash borer, a non-native beetle. This infestation resulted in the death of millions of ash trees in the region. The findings reveal a concerning and intricate relationship between environmental harm and social inequalities.
Connecting tree loss to educational performance
The research investigates how the decline of tree cover affected educational outcomes in Chicago, which experienced significant loss due to the beetle infestation. Ash trees were the most prevalent non-invasive species in the area, comprising 18% of the street trees, or approximately 85,000 trees. Between 2010 and 2020, Chicago lost half of its remaining ash trees, with the other half either dead or in poor health, according to the Morton Arboretum.
The study focused on changes in student performance on statewide standardized tests for 3rd- to 8th-graders in Illinois, covering the years from 2003 to 2012.
“We observed a decline in test scores in areas affected by the ash borer compared to similar areas that were not impacted,” said Garcia.
“We also analyzed income distribution and found that schools with higher proportions of low-income students were less likely to experience infestations. These neighborhoods typically have less tree cover, reducing the chances of the ash borer establishing itself,” he added. “While it appears that low-income students in unaffected neighborhoods are not impacted, those in schools that were affected seem to be more adversely affected than their wealthier peers in the same schools.”
This research was published this month in the journal Global Environmental Change, co-authored by ecologist Michelle Lee, who recently joined Utah’s College of Social & Behavioral Science after a postdoctoral stint at Penn State.
Previous studies indicate that students in neighborhoods with more trees tend to achieve higher test scores. For instance, a recent study by sociologists and geographers at U showed that low-income neighborhoods in Utah contain less tree cover near schools. In contrast, schools with more trees had fewer students performing below the proficiency level in year-end math and language arts tests.
Garcia mentioned that better educational outcomes might simply correlate with the higher incomes found in leafy neighborhoods.
“Our research aims to establish a more direct causal connection,” he explained. “We utilized the natural experiment created by the arrival of the emerald ash borer, which spread in various neighborhoods throughout the Chicago area.”
Garcia and Lee developed a unique dataset by combining satellite imagery with standardized testing data from Illinois and survey data about the emerald ash borer.
“We were fortunate that the state of Illinois was administering standardized tests during the same period the ash borer arrived,” Garcia said. “Every school in Illinois was taking the same test, providing us with consistent data across schools over time.”
Unequal effects on students
Rather than simply confirming the correlation between tree cover and test scores, Garcia and Lee tracked changes in school attendance and test scores as the beetle infestation devastated Chicago’s ash trees over a decade.
The study revealed a 1.22% decrease in the percentage of students meeting or surpassing Illinois’ standardized testing benchmarks in areas affected by the ash borer. While this drop might seem negligible, it carries significant implications when considered across the entire student population.
“We found that schools with a higher number of low-income students were less likely to face infestations because these neighborhoods generally have fewer trees,” said Garcia. “However, low-income students at wealthier schools, where infestations were more widespread, appeared to suffer the most from these impacts.”
Reflecting on the reasons for these results, Garcia noted that the loss of tree cover might worsen urban heat effects, increase air pollution, and reduce the psychological and health benefits associated with greenery.
“Some potential reasons could be that these students lack the resources to recover from extreme temperatures or pollution-related headaches like their wealthier classmates might,” Garcia suggested.
Low-income students may also spend more time outdoors near their schools, resulting in increased exposure to poor environmental conditions, while wealthier students often commute longer distances or enjoy climate-controlled environments that can shield them from these effects.
Environmental justice considerations
The findings emphasize how environmental changes disproportionately impact vulnerable groups. While low-income neighborhoods were less likely to lose trees, low-income students—especially those in more affluent schools—faced setbacks during infestations.
“It’s not only about having access to environmental resources,” Garcia stated. “It’s also crucial to understand how the absence of these resources can create disparities in vital life areas like education.”
The study highlights the need for urban forestry initiatives and effective management of invasive species. Efforts aimed at maintaining and restoring tree cover could be essential in reducing environmental and social inequalities. Garcia’s research also sets the stage for more investigations into how changes in ecosystems affect human outcomes, particularly in urban contexts where environmental disparities are pronounced.
