Nature working for the city: Perspectives on ecological urbanism

Landscape architecture as an occupation, and later as a profession, has only 300 years of history; as a particular human activity, though, it essentially dates back to the emergence of humanity itself.  This activity of human beings – to change their environment for their own survival, prosperity and enjoyment – definitely predates the construction of buildings and contains within itself the intellectual exercise of self-definition.  The modification of the environment by humans, today as 25,000 years ago, always involves some definition or concept of nature in relation to humans.  That is why landscape architecture, and “landscape” itself, is always and primarily a cultural expression.  And nowhere can we see this expression more clearly than through the history of nature in the city.

If we take the book of Genesis as an allegory or interpretation of prehistory, Adam and Eve’s exit out of the Garden of Eden comes to represent the first definition of nature as “other” in the Western tradition.  And, perhaps, the Tower of Babel is the symbol of the “abandonment of nature” by humanity.  However, reconciliation already appears in the form of the “garden-mediator” in the first successful cities that emerged in the Valley of the Tigris and Euphrates.  This “garden-mediator” represents the longing to reengage a domesticated nature and may in many ways have performed the interlocutory role in this new, urban relationship between humans and the rest of nature.

Later, in the Roman city, urban nature takes the form of the civic garden, a space that allows its citizens to conduct the affairs of the polis in a relaxed and familiar context.  And in the medieval town nature is now found in an even more intimate form, enclosed in the walls of the hortus conclusus – a private and safe space for contemplation.

The great cultural changes of the Renaissance and the Enlightenment also transformed the human relationship with the rest of nature in the city.  The great voyages of “discovery” caused a revolution in the understanding of nature and the new trade flows created an urban bourgeois class that delighted in the parks of the mercantile city.  These new large parks in Europe represent not just the material but also the intellectual affluence of bourgeois society and a new theatrical form to display the “dominion” of humans over nature on all corners of the Earth.

Subsequently, the industrial city appeals to nature as savior of the mental and physical health of its citizens.  In this great hygienic enterprise to improve and humanize the industrial city, landscape architecture is born as a profession, championing a reinterpretation of nature as a source of health and wellness, not as a savage that needs enculturation.  This is the time of the Garden City movement and projects such as Central Park (NYC) and the Emerald Necklace (Boston), designed by Frederick Law Olmsted.  By the time the great wars are over the modern city is born and, dazzled by technology as panacea, the city relegates nature (again) to a mere theatrical background and assigns it the role of the hortus ludi – the garden of play and pleasure.

In the late 20th century, in the aftermath of the rejection of modernism in architecture in the 1950s and of the rise of the environmental movement in the 1960s, landscape architects and urban designers pondered a new way to see nature in the city.  What if, instead of being merely a “decoration” or the “stage” for relaxation, urban nature actually plays an important role in the city?  What if humans and wildlife could actually coexist in the city for their mutual benefit?

In parallel to these cultural movements, ecology also begins to see in the city the same natural systems that it studied in remote ecosystems.  Visionaries appear, such as Ian McHarg, who wrote the famous book Design with Nature (1969), and even new scientific disciples emerge, such as landscape ecology and urban ecology.

All this evolution of thought and cultural attitudes brings us to the contemporary vision of the ecological city – the city that is planned, designed, built, and operated as what it actually is – an ecosystem.  Nature in the eco-city does not exist merely for the pleasure of the human eye or as theatrical scenery or as decoration for buildings – it exists to perform a job, multiple jobs, actually.  In the ecological city, landscape is the urbanizing medium, the synthesizer and generator of new city fabric (whether it is an addition to or a restructuring of old city fabric).  And “landscape” is understood as the particular and identifiable socio-eco-cultural context where human life occurs; it is not merely vegetation – it is the set of social, natural, and cultural (built) systems that serve as the human environment (and as environment for wildlife or the non-human life of the city).  In the ecological city, landscape is undistinguishable from the city and the natural and cultural (built) exist as a cyborg (living being which is half human and half robot).  In this hybrid condition of the ecological city even buildings and structures are also wildlife habitat.

Fig 1

The eco-city is part of its landscape context and landscape is its urbanizing medium.  Landscape is the synthesizer and generator of new eco-city.


This concept of the ecological city, as a cyborg or hybrid between the wild and the constructed, is part of a new eco-functionalist view of the city and a post-conservationist view of nature.  The “natural” elements of the city (or the “wildlife” in it), either on purpose (by design) or not, perform multiple functions that benefit human life.  The organisms that inhabit even the channeled and piped urban river known as the Río Piedras, in San Juan, Puerto Rico, help to oxygenate its water, reduce excess nitrates and phosphates, and reduce water temperature, among the many other services they perform.  These many wild organisms in the Río Piedras not only improve the environmental conditions for humans swimming in the San Juan Bay Estuary but also allow other wildlife to colonize the river and enable them to persist in the city as well, increasing overall biodiversity and improving the overall ecological functioning of the city.

The post-conservationist view of nature holds that, while “nature reserves” are always needed, it is important to recognize that urban and peri-urban nature performs important ecological functions that in many cases are equivalent or superior to those carried out by nature in “reserves.”  In Puerto Rico, we have researchers, like Dr. Ariel Lugo, that have recently focused on the ecological value of urban and peri-urban nature and have shown that the ecological functions it provides are often equivalent to comparable “pristine” ecosystems.  Therefore, it is not enough to preserve wildlife in “reservations,” but urban and peri-urban wildlife also needs to be conserved for a better human environment and to increase the overall biodiversity of our islands.

The ecological functions provided by urban nature are very many and they make life, human and nonhuman, possible in the city (1).  We generally focus on vegetation, but the richness of microbial life in an urban soil, for example, is essential for it to be productive and effective in reducing the levels of pollution that we often see in the city.  The possibility of stormwater infiltrating urban soils and flowing through them, instead of being intercepted and taken quickly to the sea, increases their fertility and enhances their functioning.  In fact, the enhancement of the city’s hydrological cycle supports all of the vital functions of urban nature and increases the overall resiliency of the city.

The ecological city requires for its operation that urban nature is well “tuned” to the social and built (cultural) systems of the city.  The cyborg condition of urban nature – both dependent upon but also contributing to the functioning of built systems – requires a “fine-tuning” that only good design can provide.  Green infrastructure, for example, is just that – a combination of live and constructed elements that together provide greater social benefit and allow greater biodiversity in the city (that a greater number of species are able to coexist).  Put in another way, green infrastructure is “nature designed” doing work in the city.


Fig 2

The hybrid or cyborg nature of urban natural systems in the eco-city requires the careful calibration between living and constructed elements through good design.


Green infrastructure – whose function is not merely to manage stormwater runoff, but is in fact much more than that – has become the preferred instrument for achieving the objectives of the ecological city or ecological urban design.  For green infrastructure it is meant any system that performs an urban function (transportation, waste removal, temperature control, removal of air pollutants, power generation, stormwater management, etc.) in which active biological organisms participate, and that generates multiple benefits.  In contrast, ordinary infrastructure (or gray infrastructure) always performs a single function.  The well-known and extremely popular High Line in New York City is a great example of green infrastructure not related to stormwater management.  The High Line is not just a transportation corridor but a whole park in the air that inserts nature into the city through a raised platform (former elevated train).

Green infrastructure reaches its full potential in the ecological city when it performs multiple functions simultaneously (2).  Green infrastructure should not simply provide a service, like any other element of infrastructure, but must also create better urban spaces and allow human contact with nature.  In this sense, green infrastructure represents the ideal of the ecological city in enabling urban functions in a friendly way towards wild urban nature and providing a vehicle to restore ecological functions long lost through traditional urban development.

Fig 3

In the green infrastructure plan prepared for La Parguera (see Note 2), the analysis of existing conditions was very important to achieve a balanced design between natural and built systems.


At the end of the day, the vision of the ecological city is about creating the right conditions for the coexistence of humans with the rest of nature, in a classical mutualistic relationship.  The hybrid condition of the ecological city also makes it more resilient – better able to flourish under changing conditions (3).  And these changing conditions have already arrived (or have been accelerated) by global climate change.  If our cities do not move to the eco-city model, with modest but steady green infrastructure interventions, it will be very difficult to face the future that our own human activity will bring on the planet.



  1. See: Forman, Richard T.T.  2014.  Urban Ecology: Science of Cities. New York: Cambridge University Press.
  2. See: Terrasa-Soler, J.J., M. Bingen, and L. Lugo-Caro.  2015.  The Caribbean Landscape Cyborg: Designing Green Infrastructure for La Parguera, Puerto Rico.  Chapter 20 In:  Czechowski, D., T. Hauck, and G. Hausladen, eds.  Revising Green Infrastructure: Concepts between Nature and Design.  London: CRC Press / Taylor & Francis.  488 p.
  3. See:  Topos The International Review of Landscape Architecture and Urban Design, Issue number 90 (2015), Resilient Cities and Landscapes.


Originally published in Spanish (on 29 June 2015) at:



About José Juan Terrasa-Soler

JJ is a registered landscape architect, ecologist, and university professor living in San Juan, Puerto Rico. He is a practicing Buddhist and enjoys hiking, nature exploration, amateur astronomy, and fountain pens.
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