Tree cover and species composition effects on academic performance of primary school students

Sivarajah, S., Smith, S.M., & Thomas, S.C. (2018). Tree cover and species composition effects on academic performance of primary school students. PLOS ONE, 13(2). http://dx.doi.org/10.1371/journal.pone.0193254

Tree cover and species composition have a positive effect on children’s academic performance, especially for children in socio-economically challenged schoolsPrevious research on the impact of vegetation on school grounds suggests that green space creates a supportive environment for children and may enhance academic performance. Previous research, however, does not distinguish potential effects of tree cover from other green spaces. The term “tree cover” refers to the layer of leaves, branches, and stems of trees that cover the ground when viewed from above. This study adds to previous research by examining the potential effects of tree cover, diversity, and species composition on academic performance.

Researchers collected academic performance and socio-economic data of students from 387 schools across the Toronto District School Board in Canada. Academic data consisted of the collective student performance for each school based on the percentage of students at or above the provincial standard in Grade 3 and Grade 6 for reading, writing, and mathematics between the years of 2006 to 2010. School-related data also included information about socioeconomic limitations to academic performance as measured by a Learning Opportunity Index (LOI). The LOI is a regional composite index of external challenges to learning, such as low-income, parents with low education, and single-parent families. Researchers used the LOI scores to separate schools into “highly challenged” and “less challenged” categories. ArcGIS -- an online mapping tool -- was used to obtain information about each school’s total land area, total soft surface available for vegetation, tree canopy cover, and the ratio of tree canopy cover area to ground area available for vegetation. Additional data about the number of tree species, conifers, and hardwood trees for each school was based on an inventory conducted in collaboration with the Faculty of Forestry, University of Toronto.

While LOI had the greatest influence on academic performance, the proportion of tree cover (as distinct from other types of “green space”) was a significant predictor of student performance. Tree cover had a positive effect on children’s academic performance, with the greatest impact in schools with the highest level of external challenges. Species composition also made a difference on math – but not reading – test results.

These findings support previous research demonstrating a positive association between academic performance and “green space.” The present study adds to that research by highlighting tree cover as a more pronounced predictor of children’s academic performance than other vegetation types. These results support an increased expenditure on greening schoolyards and highlight the importance of increasing tree cover and planting a diverse array of trees on grounds of schools facing external challenges to learning.

The Bottom Line

Tree cover and species composition have a positive effect on children’s academic performance, especially for children in socio-economically challenged schools