Land Sparing Protects Urban Ecosystems Better Than Land Sharing

Rio de Janeiro is a tightly-packed city with large tracts of natural land surrounding it. Portland, Oregon intersperses many small parks throughout a sprawling urban landscape. A new study by a team of biology researchers finds that the Rio model sustains better natural services, including cleaning water and air, reducing noise, pest control, agriculture, carbon storage, and pollination. Denser cities with large adjoining parks also do a better job of mitigating the "heat island effect," a local temperature increase caused by the concentration of heat-absorbing metal and concrete.

The study finds, however, that less-dense cities with many small parks offer residents a better sense of well-being. As previously reported, there is evidence that walking in a natural setting is more beneficial to mental health than walking in an urban setting. Thus, "policymakers can improve dense cities' healthfulness, the researchers write, by adding some greenery in the form of sidewalk trees, green walls, and green roofs," Francie Diep writes.

Furthermore, Diep reports, "Moderate levels of development, like that of the suburbs, made natural lands lose their services at a disproportionately fast rate, compared to intense development."