School greenspace is associated with enhanced benefits of academic interventions on annual reading improvement for children of color in California

The restorative benefits of nature on children's cognition suggest the potential for nature exposure to further enhance the impacts of instruction on academic achievement. However, prior research has focused primarily on examining main effects of greenspace on academic performance, and have seldom examined interactions (i.e., moderation) between greenspace and other school variables on academic performance. We examined the statistical interaction of school greenspace (based on 1 m by 1 m land-use classification) and a standard literacy enrichment program on reading improvement over a one-year period for a large sample of ethnic minority (95%) elementary school children (n = 6080, k-6th grade, estimated mean age = 7.9 years) attending predominantly low-income schools (n = 85) throughout the state of California. Our analyses employed multi-level modeling to account for random effects associated with school and neighborhood environments, and incorporated extensive individual, school, and community level covariates. Results from the hypothesized interaction effects demonstrate school greenspace to accentuate the positive association between literacy interventions and improved test scores. Moreover, specific components of greenspace, namely herbaceous and tree cover each enhanced the effect of academic instruction on annual reading improvement. However, no direct association between greenspace cover and academic improvement was found. In addition to several methodological strengths, this study is one of the first to show the interaction between nature and school instruction affecting academic learning.