Ecologically intensifying the green infrastructure strategy for urban sustainability: The BiodiverCITY initiative as a catalyst
The extent of urban land use and the proportion of the human population living in urban contexts across the globe continue to increase annually. Many cities are turning to widespread implementation of ‘green infrastructure’ as a redevelopment strategy that promises improved ecological services of existing and new development; however, this approach appears primarily based in urban planning, engineering, and landscape architecture; is variably defined, implemented, and often under evaluated; and rarely involves ecologists or current ecological knowledge.
This study involved three approaches to evaluate the role of ecology in green infrastructure as a strategy for urban sustainability and resilience. We conducted a systematic review and critical analysis of how green infrastructure is defined, implemented, and evaluated in multiple urban contexts and scales (site, city, national) across the globe. We then evaluated how these approaches are supportive of or in opposition to the state of ecological knowledge with a focus on multifunctional landscapes, connectivity, and urban ecology. Case studies for green infrastructure implementation were analyzed for their ecological integrity. Lastly, using Pittsburgh, PA as an in-depth case study, we evaluated and made recommendations for the city’s approach to ‘green infrastructure’ in the context of the global spectrum of approaches and ecological basis.
From broad and more ecologically-based to narrow and stormwater-centric, the results illustrate the variability in how green infrastructure is defined, moved to action, and evaluated in urban settings around the globe. Green infrastructure in the United States is largely limited to reducing urban stormwater quantity. Evaluation of the green infrastructure case studies also highlights the difference between more ecologically-based and stormwater-centric projects, but some provide examples for multifunctional landscape approaches to green infrastructure. Lastly, Pittsburgh’s strategy toward ‘green infrastructure’ is primarily focused on reducing stormwater quantity, but other initiatives around the city, lacking the green infrastructure label, are more ecologically-based and expand the restoration of ecological services underway in the city. Overall, Pittsburgh’s redevelopment initiatives have yet to incorporate the role of ecologists and ecological knowledge. To overcome this, we systematically conclude with suggestions and recommendations that connect ecological research scientists, communities, development organizations, informal learning institutions, local governments, landscape architects, and engineers. Finally, the BiodiverCITY initiative and its pilot projects (urban biodiversity assessments, art-science exhibits and programming, and community-based course projects) are described as a potential catalyst for increasing the role of ecological science in urban landscape redesign.