A suite of papers illustrate that streetscapes serve as habitats for
plants and animals. However, the extent to which distinct species,
communities, or ecosystems function as ES providing units
(Kremen, 2005) is an open yet important question because specific
answers would help link approaches toward human wellbeing
with biodiversity conservation. Biodiversity in streetscapes might
yield psychological benefits, but such effects still need testing
(Keniger et al., 2013).