Cities tend to have a warmer microclimate than their surroundings—the so-called “urban heat island” effect. The elevated temperature, along with other aspects of the urban environment, can have a marked influence on the organisms that live in cities. Duffy and Chown find that plants with C4 photosynthetic metabolism, a trait that is favored in warmer herbaceous communities, are more common in European cities than in adjacent nonurban habitats. They predict that under further climatic warming, C4 species may become generally more widespread in temperate habitats, compared with C3 species that are adapted to cooler conditions.
Higher temperatures in cities select for C4 plants.
PHOTO: MATTHIAS SCHOLZ/ALAMY STOCK PHOTO
J. Ecol. 104, 1618 (2016).
