Marselle and colleagues link more street trees closer to homes to a decreased likelihood that residents will be depressed. The investigators report that they “analysed the association of street tree density and species richness with antidepressant prescribing for 9751 inhabitants of Leipzig, Germany. We examined spatial scale effects of street trees at different distances around participant’s homes, using . . . buffers of 100, 300, 500, and 1000 m. . . . we found a lower rate of antidepressant prescriptions for people living within 100 m of higher density of street trees. . . .
Research confirms that trees do indeed add value to our lives. Kuo, Klein, Browning, and Zaplatosch collected data for 450 schools and 50,000 students in communities ranging from rural to urban in Washington State and report that “‘Hundreds of studies show a positive link between contact with nature and learning outcomes. . . . We wanted to make sure the same pattern was true in this vulnerable and overlooked population,’ says Ming Kuo. . .
Jiang, He, Chen, Larsen, and Wang evaluated how driving on a freeway through various sorts of urban environments influences driver experience. They found via 90-minute simulations of environments through which study participants “drove” at the legal speed limit (70–120 km/hour) that: “The summarized mental status measure is the average value of the seven measures of negative mental status (boredom, anger, frustration, tension, anxiety, avoidance, mental fatigue). . . . the tree-regularcondition evoked significantly lower levels of negative mental status than all other conditions.
Kondo and colleagues studied links between tree cover and human longevity.
Tallis and teammates looked into relationships between the number of trees near schools and the academic test scores of elementary school students.
Greenery at universities, indoors and out, has positive implications.
Zolch and colleagues studied how the presence of plants influences comfort in public squares, and their findings are applicable in many outdoor spaces.
Trees in schoolyards have again been linked to improved academic performance.
The right answer depends on location
Dadvand and his large team have gathered additional evidence indicating how important it is that people have ready access to green spaces.