Trees are nature’s air purifiers—they provide us with oxygen and absorb CO2, which makes them a key component of the global fight against climate change. However, they also have an influence over our individual health, both mentally and physically.

A new study published in Nature Sustainability reports that children between the ages of nine and 15 who spend a lot of time around trees experience several cognitive benefits.

3,568 students in London were included in the study, which tracked the participants’ cognitive performance and mental health over their early adolescent years. They found that children who spent time in woodland areas demonstrated improved cognitive performance and better mental health than those who didn’t visit the woods as frequently. Surprisingly, time spent in grassy areas or around lakes didn’t have the same benefits as time spent in woodlands, suggesting that trees specifically may be a protective factor for children as they mature.

We have written in the past how green spaces are beneficial to both children and adults, but the study’s emphasis on trees as an important factor contributing to these health benefits creates new and exciting avenues of research. It’s still unclear why nature seems to boost cognition. Some believe that it may increase gray matter in our brains or elicit changes in the amygdala which helps us regulate our emotions, or even just calm our minds with the pleasing patterns of their branches.

The study also highlights the importance of equitable urban planning when it comes to green spaces. They are beneficial to all and should be accessible to everyone, no matter their socioeconomic status or zip code.