Ecosystems as infrastructure

Infrastructure is usually defined as all elements of interrelated systems that provide goods and services essential to enabling, sustaining or enhancing societal living conditions. Although traditionally, infrastructure included only all human-made assets, since the 1980s, both scientists and conservationists have suggested that ecosystems should be also considered as a type of infrastructure. Here we review the evolution of the concepts of 'ecological', 'green', 'natural' and 'blue' infrastructures and evaluate how these concepts have been used in the scientific literature. We found that although the term 'ecological infrastructure' was the most used until 2004, 'green infrastructure' became the dominant one after then. All terms have been applied mostly to urban settings, terrestrial ecosystems and emphasised supporting and regulating ecosystem services, with a strong emphasis on the mediation of water flows in urban centres and the maintenance of species lifecycles, habitat and gene pool protection. We suggest that green infrastructure should be the term adopted to facilitate communication between scientists, conservationists and decision-makers. We also suggest a general concept for green infrastructure aligned with the major global conventions alongside a set of design principles.