Desiging cities to maximise biodiversity (#journal)

Sharing or sparing? How should we grow the world's cities?

There has long been a debate about how agricultural land use should be distributed spatially. Advocates of land sparing argue that high-intensity food production on small units of land will conserve more natural habitat, but others argue that less intensive production over a greater area of land will reduce the overall load of human stressors upon ecosystems. This article applies some of this thinking to urbanization, reviewing the similarities and differences between the two systems and setting out a research agenda.

Intensification of urban systems to increase housing density leads to buildings being interspersed with small tracts of natural or semi-natural habitat patches (e.g. forest patches, parks). Urban extensification, on the other hand, is characterized by sprawling suburbanization with less concentrated, more distributed green space, predominantly in the form of backyard or streetscape vegetation. Regional scale analyses are urgently needed to determine which of these patterns of urban growth has a lower overall impact on biodiversity and to explore the most ecologically appropriate city layout.