Beyond the school grounds: Links between density of tree cover in school surroundings and high school academic performance

Low academic performance in high school and increasing drop-out rates are major issues in the United States. While curricula and instruction clearly impact academic performance, less is known about how the outdoor environment surrounding the school impacts performance. In this study, we examined the association between tree cover density in school surroundings and school-level academic performance of public high schools in Illinois, US (N = 624). Performance data, extracted from the Illinois Report Card provided by the Illinois State Board of Education, included ACT scores, four-year graduation rates, college readiness and freshman-on-track. The tree cover density in school surroundings was derived from the 2011 National Land Cover Database canopy product. The appropriate ordinary least squares (OLS) or simultaneous autoregressive (SAR) models were fitted to test the associations between canopy cover and the students' performance. We found that tree cover density within a 1-mile radius of high schools was positively associated with ACT scores, college readiness, and nearly significantly associated with freshman-on-track, even after controlling for factors known to influence academic performance. However, tree cover density was not significantly correlated with four-year graduation rates. Testing the effects of different buffer distances, tree cover density at 0.5-mile and 1-mile buffer distances showed a stronger association with ACT scores and college readiness. Freshman on track was correlated with tree cover density at all distances, except the 2-mile buffer distance. Our findings contribute to an emerging body of evidence showing that tree cover density is positively associated with adolescents' academic performance, suggesting the importance of forestry management in school surroundings in support of learning.