With conviction that the values of inhabitants of cities shape environmental futures, I will flip the question posed by the Senior Scholars and ask: How is an urban ethic critical to 21st century nature? This provocation frames an approach to design inquiry in higher education that challenges a future generation of architects to work toward creating urban environments that contribute to broader ecological function and the imaginaries of those who dwell there.
The following points and principles guide our investigations.
Intensified Urban Place Making
Assuming human-dominated landscapes cannot accommodate native species, and accounting for species/area curves (more space = more species), urban growth, and climate change, we are running out of land. Publicly managed natural areas harboring “inherited diversity” will become so isolated that we may, according to population biologist Michael Rosenzweig, lose up to 95% of the world’s species in the next century (others predict less dramatic declines in biodiversity, with extinction rates varying between 20 and 50%).
By retrofitting urban environments to better support nonhuman populations, the situation is less dire. Given many cities were settled in areas of high biological productivity, for example along riparian corridors, the possibility exists to couple restoration and redevelopment and to improve biodiversity levels dramatically. Particularly promising are sites where the grid confronts marked topographical change or otherwise “unruly” physical circumstance (creeks and outcrops and the like). Having often been given over to low-value human uses such as storage facilities, landfills, and junkyards, these marginalized lands can become centers of experimentation, learning, and biological regeneration.
Landscape architectural educator Bart Johnson believes we are now equipped to harness hard urban systems as a locus for perpetuating the softly biological. Cities exhibit structural uniformity: raised vertical masses (blocky buildings) akin to rock outcrops sitting atop impervious planes. These conditions attract shelf-nesting birds and species with like spatial requirements, yet are suited poorly to the needs of others. An aggressive urban ecological design requires construction of heterogeneous mosaics of built/urban systems to meet needs of a greater number of species. This patterning has potential to enliven the city and elevate phenomenal experience, awareness, and delight.
Futures of Differential Possibility
Collapsing and combining of biological, economic, and social functions must occur at all scales: public transit corridors can double as wildlife corridors; urban alleys can convey storm water, district-scale electricity, social ferment, invertebrates and amphibians; buildings can furnish niches and other habitat structures for a variety of species. We have to embrace an ethos where we reimagine and redesign primary forms of constraint as dramatically improving system-wide access for a diversity of beings.
Enlisting built infrastructures to support the needs of species is hardly returning to a “state of nature.”Landscapes throughout North America have been managed actively for millennia, and for the majority of urban spaces human activity will continue to dominate. This endeavor speaks to how deeper awareness of past processes of species dispersal and habitat formation and other attributes of complex ecosystems can inspire an urban design as material and energy redistribution in support of diverse need. Gap formation in a forest ecosystem, the fall of a tree and the sudden availability of nutrients, inspires strategic acts of removal of urban tarmac to reconnect sky and ground.
Aqueous Architectures in the Dynamic City
Healthy wild salmon populations in the Pacific Northwest provide evidence of regional watershed and riparian habitat quality and the state of forest ecologies. Studies on toxic effects of non-point source pollutants on coho salmon moving upstream through urban waterways reinforce the importance of integrated storm water practices, essentially the elaboration of the journey of rainwater from clouds to buildings to streets to waterways to support and activate processes of cleansing. The hope is that greater numbers of salmon will avoid the elixir of toxins, make their way to upper reaches of rivers, and spawn.
A design ethos of an urban nature seeks expressive inspiration in these challenging circumstances. Poised amidst bodies of water in the city, works of architecture can do more than shed and become activators of watersheds. The forested landscape furnishes a model for envisioning undulating built forests. Prattling drops collect on foliage and stream along fissures of trunks. Decaying organic matter on the forest floor absorbs this surcharge, sponge-like. A proliferation of designed surfaces and elements could emulate this performance at a range of scales: furrows in the outer layers of building façades could be designed to descend to filtering terraces that channel rainfall to civic cleansing fountains at neighborhood centers.
A work of architecture as an aqueous mat could collect and decelerate water during peak rain events and deliver it to urban streams and wetlands at a cadence that helps keep channelized bodies from overflowing. A project could function as an oxygenating rift, where water flows, acting as dramatic tissue linking heretofore isolated bodies and planes of activity. Architecture could be thought of as strategic placement of stone-like masses that form stepped pools staging filtration processes—with overflow from one basin to the next providing indication of the severity of a rain event, and dynamic processes becoming part of the tissue of the city. Building elements could frame bodies that mirror the starry firmament while recharging the ground.
Biological cues in the urban landscape trigger a work of architecture to act with others in providing timely, beneficial responses. In this illustration, buildings collect storm water, cleanse it, and deliver it to urban waterways during times of critical importance in the life cycle histories of aquatic species. (Source: author)
Performance of an Urban Nature
The ecologically minded designer is charged with contriving a cubist plurality of space: overlaps, folds, and fractures that enable simultaneous occupation of the social and ecological. The goal is not simply better functioning, more habitat-friendly urban environments. It is also a matter of revealing the human hand in affecting ecological processes and choreographing the wonder of encounter. There is theatrical potential to urban ecological design, a scripting of events and celebration of a multitude of lifestyles and life histories that become part of the everyday. Given the expanding territory of the city, minimization of environmental impact no longer obtains; a responsive design ethic is a transformed notion of cosmopolitanism that is a performance of an urban nature.
Photo: © Jeremy Atherton, 2006
