Naturing the City: First Glance
As climate change increasingly permeates urban planning discourse, the image of the “sustainable city” has evolved as planners, policymakers, and citizens grapple with what a term like “sustainability” actually implies. In some ways, the growing discourse around sustainability planning is outpacing knowledge about how to implement meaningful change. Some of that delay is a consequence of the different rates at which elements of a city change. Brenda Scheer elaborates this idea in her 2001 paper “The Anatomy of Sprawl,” in which she identifies the ways in which slower-changing elements of a city’s layout, such as the property lines of surrounding farmland, directly inform spatial patterns of later development, such as suburban sprawl (Scheer 1). Scheer uses an urban morphology technique, which she defines as the “study of the city as physical form” (Scheer 1). This approach echoes one proposed by Emilio Jose Garcia and Brenda Vale in their 2017 book Unraveling Sustainability and Resilience in the Built Environment. Garcia and Vale describe the idea of “morphogenesis,” defining it as an analysis of how a given environment has changed (Garcia and Vale 2017, p. 167).
Garcia and Vale suggest morphogenesis as a partial solution to the problem of measuring urban ecosystems, which they present as a significant challenge in better understanding ideas of resilience and sustainability in the urban context. Ecologists, according to these authors, have well-established methods of measuring natural ecosystems, but the rates of change are so different between these systems and urban ecosystems that it is impossible to directly translate these strategies into a planning framework. Instead, planners must “analyse cities as urban landscapes that depend on ecosystem services, which have their own scales and dynamics of change” (Garcia and Vale 2017, p. 206). By using a morphogenesis framework, planners can measure different rates of change in the city and thus pursue what the authors refer to as a Panarchy, which emphasizes the importance of implementing resilience strategies at multiple scales (i.e. street, block, city, region) (Garcia and Vale 2017, p. 40).
The subject of nature has taken its place the broader discussion of how to design more resilient cities, reflecting an increased understanding of the value of ecosystem services in improving environmental quality as well as a city’s capacity to recover from environmental stress. For instance, SWA’s 2015 plan for Buffalo Bayou Park connected and repurposed 2.3 miles of green space, designing the expansive park to double as flood infrastructure. This park, along with similar projects around the world, is an example of what planners refer to as Urban Green Infrastructure (UGI). A number of recent renaturing efforts focus on introducing or improving UGI in a city. Other instances of renaturing are more focused on encouraging biodiversity, which has its own positive impacts on a city’s resilience. As Garcia and Vale discuss, a more complex system is a more resilient one, thus a city may benefit from investing in higher biodiversity of flora as well as fauna (Garcia and Vale 2017, p. 36).
|Houston’s Buffalo Bayou Park, designed by SWA in 2015, is an example of urban green infrastructure (UGI). Image from SWA.|
Rumble et al discuss two cases of renaturing in their chapter “Understanding and Applying Ecological Principles in Cities,” which appears in the 2019 book Planning Cities with Nature: Theory, Strategies, and Methods. The first of the two cases the authors discuss that of Rondonópolis, Brazil, where the Urban Macaws of Rondonópolis project aims to conserve declining populations of blue-and-yellow and red-and-green macaws in the city. As Brazil’s rapid rate of urbanization threatens its wealth of biodiversity, the aim of this project was to study the habitats and behaviors of the macaws in order to shape the city around their needs. For instance, researchers found that macaws used deadwood from a particular species of palm, which happened to be a non-native species, to nest as well as to feed (Rumble et al 2019, p. 226). Using this data, the city could adapt their deadwood clearance practices in order to meet the macaw’s needs and thus support a higher urban population of the birds.
|Blue and yellow macaws in Rondonópolis. Image source.|
The second case the authors describe is similarly focused on habit conservation and urban biodiversity, however, it takes place in a very different context. Unlike Brazil, the United Kingdom has experienced stable urbanization over a long period of time, and thus is facing different issues when it comes to nature in the city. For London, the authors point out, the issue is less about conserving existing species and more geared towards encouraging the return of species to the city (Rumble et al 2019, p. 217). The case the authors present centers around brownfield development along the Thames. Commonly thought of as “unproductive” space, brownfield sites in this study are shown to be valuable habitats for a wide range of species, especially invertebrates, who are increasingly displaced from natural ecosystems (Rumble et al 2019, p. 227). The authors describe a brownfield development known as Barking Riverside, which was designed to accommodate such biodiversity, taking special care to provide habitat niches for the various species living on the site. This project used green roofs, which, like Houston’s Buffalo Bayou Park, acted as a form of UGI to serve the city as well as promote biodiversity through thoughtful, contextualized design (Rumble et al 2019, p. 228).
|Green roofs at the Barking Riverside development in London. Image source.|
As many benefits that nature does offer a city, both strategically and socially, its status as an amenity requires a critical discussion of access and inclusion. Improved green space can have a direct effect on property values, which threatens residents with displacement and prevents equitable access to the benefits that green space provides. This is especially important in reference to nature’s ability to mitigate the consequences of climate change, among which are poor air quality, flooding, and urban heat island effect. In pursuing renatured, resilient, and sustainable design, it is essential that planners not simply reproduce the environmental inequities that already exist but actively work to reduce them through design, policy, and advocacy.
This post is the first in a 7-part series focused on resilience, renaturing, and the city.
Garcia and Vale, Unraveling Sustainability and Resilience in the Built Environment (2017). Routledge, London.
Rumble et al, “Understanding and Applying Ecological Principles in Cities,” Planning Cities with Nature: Theories, Strategies, and Methods (2019). Ed. de Olivera, Fabiano and Mell, Ian. Springer, Cham.
Scheer, Brenda. (2001). The Anatomy of Sprawl. Places: A Forum of Environmental Design. 14.