The importance of visibility
Many designers and planners have become concerned in recent years with "revealing" (i.e., making visually apparent) ecological processes in their designs so that the users of the environment may experience, learn about, and appreciate those processes. In practice, "revelation" of ecological process has meant everything from capturing stormwater on the surface of the land before it drains away to the storm sewers (and creates flooding problems) to planting a row of trees in a plaza where a creek once ran (and may still, but in a concrete culvert underneath the ground). In addition, the ecological processes that are revealed may themselves be truly "natural," in the sense that they could continue to exist without the management of humans, or they may be highly artificial, engineered systems that need constant supervision if they are to persist in an urbanized context.
The range of design possibilities lumped together under the banner of "eco-revelatory design," therefore, is very broad indeed. Some such designs make tangible improvements in local ecological health--by treating wastewater, for example--while others are merely symbolic gestures that at best remind users of the pre-development site conditions. Curiously, almost all designs within this large spectrum are casually assumed to yield the same outcome in terms of the ecological education of the user. This is one indication of how undefined the presumption of a significant psychological and educational impact from design often is. In other words, the visibility of ecological process in design is often assumed to be adequate for people to develop ecological perspectives, without considering in detail how such a thing might occur.
The Arcata Marsh and Wildlife Sanctuary, a real-world example of eco-revelatory design, highlights some of the positive potential of using visibility as a design strategy. Since 1986, this constructed wetland on the shores of Humboldt Bay has performed secondary treatment on the city of Arcata's sewage water before it is discharged into the larger environment. This type of treatment, required by law, ordinarily is performed by massive indoor treatment plants, such as the Southeast Water Pollution Control Facility in San Francisco. By creating a wetland to do the same thing, the city is not only able to provide this critical infrastructural service, but also to design a recreational and cultural amenity for the community. The residents of Arcata who stroll by the wetland can, for instance, see that wastewater treatment wetlands can be important habitat for fish and birds, as well as an energy-efficient, biologically based method of controlling water pollution. The experience of the Arcata wetland shows that ecological processes, even if designed and controlled by engineers, can be brought into a constructive partnership with human settlements. For the residents of Arcata, it is not just "human society" or "wastewater" in the abstract that is creating the wetland; it is their wastewater. What goes into that wastewater therefore becomes an issue of more visible, more immediate, and more local consequence than it had been before.
How, then, can we ensure that lessons about not only ecological processes themselves, but also the relationship between ecological processes and urban life, are available to the users of the urban environment? One way to approach this problem is to consider what environmental psychologists and architectural researchers have said about how people derive meaning from the built environment. A major theory in this field--called the theory of non-verbal communication--holds that people receive non-verbal "messages" from the built environment in much the same way as we do when interacting with other people. In the latter case, we gather much more information from another person than simply what their words communicate; their facial expressions, gestures, clothing, personal appearance, and other nonverbal aspects of their behavior also send us powerful signals. And as most of us can attest from experience, these "signals" to a large extent only have meaning within a given cultural context. When we travel abroad or interact with another culture, many of these subtleties are lost to us, and communication suffers as a result.
The architectural scholar Amos Rapoport has argued that the built environment is itself a powerful form of non-verbal communication. Our everyday environment contains large numbers of non-verbal "cues" which communicate messages about cultural expectations for behavior in a given context. As with inter-personal communications, the meaning of these cues is highly context-dependent (and culture-bound) and must be interpreted holistically in concert with other cues in a given environment. The list of potential cues in the built environment is very long; in some sense almost any design feature can be used to communicate cultural meanings and behavioral expectations if the user of the environment is able to interpret the "messages" properly. Among the most common environmental cues in cultures throughout the world are the use of height, size, color, details and decorations in buildings, and horizontal scale, plantings, and materials in landscapes. A moment's reflection upon famous cathedrals, imperial palaces, and corporate headquarters around the world unsurprisingly tends to confirm the simple idea that these and other design elements are used to communicate meanings about power, cultural importance, and sacredness.
If we propose to use ecological design of urban places to promote cultural change in the human relationship to the environment, then, we should be thinking about how to create physical settings with cues for sustainable behavior. How can stormwater swales, solar-oriented structures, sewage treatment wetlands, and energy-efficient building clustering patterns--in short, the elements of an ecologically designed urban landscape--become part of settings that, when viewed and experienced holistically, communicate cultural expectations for sustainability?
Characteristics of settings
According to Rapoport, for a setting to communicate meanings and cultural behavior expectations effectively the cues must be characterized by three things: clarity; strong, noticeable differences, and redundancy. These characteristics reflect the fact that nonverbal communications are often quite subtle, and need to be reinforced through a variety of channels simultaneously if they are to be understood.
At first glance, this appears to return us to the issue of visibility discussed earlier. But it also points up the fact that not all kinds of visibility are made equal. Some eco-revelatory designs, for example, have sought to bring ecological processes (such as water flows) into the open, but then blend them in with the surrounding landscape as much as possible. Many proposals to capture rainfall in grassy areas and infiltrate it into the soil before it runs off into the storm sewers would use either parks or front lawns for this purpose. Although this strategy reveals an ecological process occurring during and just after a rainfall, the rest of the time these spaces would simply look like what they have always looked like--large grassy expanses--and would forfeit an opportunity to communicate a clear, consistent, and meaningful landscape message.
By contrast, a real-world project that created "stormwater gardens" in a working-class neighborhood in Minnesota achieved the same ecological purpose--infiltration of rainwater--but marked the places in the landscape where infiltration occurred with plantings of native vegetation. Thus, the plants could make the infiltration spots clear and noticeable even when no rain was falling, and, at the same time, achieve beneficial redundancy by incorporating more than one ecological good (native plant restoration and stormwater infiltration) into the same design.
In an intensely urban setting, there are valuable opportunities to achieve this clarity and redundancy with the interplay of buildings and landscapes. There are important ecological implications to the built form of cities, and sound planning and design decisions that minimize negative impacts should be understandable to the public. The siting and design of a building, for example, has a tremendous influence on the overall energy consumption of that building over its lifetime. But the major decisions about siting and design are made early in a development process, and few members of the public will ever know whether they were made correctly from an energy point of view. How, then, would such buildings ever be able to communicate cultural meanings to their users unless there were other elements in the environment that were helping to reinforce these ideas? The creation of clearer and more noticeable small-scale energy-efficient design features both within the building (operable windows, perhaps) and in the landscape around it (trees or vine trellises to shade windows on the south side, for example) are then crucial to creating a cultural setting for sustainability.
Partnership with ecological education
The foregoing examples also require that the cues in the designed environment be interpretable by the user. At some level, no amount of eco-revelatory design will help people to think and act more sustainably if they have no understanding of simple ecological relationships. A design difference between the south and north sides of a building will have very little significance for the building's users if they do not know that far more sunlight strikes a south-facing surface than a north-facing one (at least in the northern hemisphere).
Any transformation of the physical environment intended to support sustainability must therefore be carried out in concert with efforts to increase and improve ecological education. Basic knowledge of ecological processes will be a necessary complement to the implementation of ecologically designed urban landscapes. Though much of this education undoubtedly would occur through schools, books, and other traditional means, it should be noted that the landscape itself could play a major role. The philosopher Marcia Mulder Eaton, for example, has noted that the aesthetics of landscapes may be crucial to the process of learning about ecological processes. She argues that "[a]esthetically relevant information helps to enable sustained attention; indeed it not only sustains but 'regenerates' it. When one learns something that directs perception to or stimulates reflection on an aesthetic property of an object or an event, one is drawn back to the object or event-- and, in turn, the rich experience that results may lead one to seek for more information about the object."
The experimental results of the environmental psychologists Rachel and Stephen Kaplan about Americans' landscape preferences support this conclusion. Their research shows that these preferences are strongly shaped by whether the spatial organization of the elements in the space (or scene) suggests opportunities for two key things: understanding and exploration. This finding lends credence to the notion that aesthetics and education share a symbiotic relationship in the landscape, and that landscapes themselves can therefore be crucial educational tools. This is especially true if local, site-specific ecological processes are not obscured, as they often are in traditional park designs.
Ecological landscapes and local place values
A third major design implication for ecological urban landscapes follows from this emphasis on using local ecological processes as an educational tool. Because ecological design is inherently site-specific, the cultural formations that are encouraged by it will tend to be local as well. While the overall imperatives of sustainability may be somewhat generalizable across the world's cities--the need for compact, transit-oriented urban form, for example--the techniques for actually building sustainable human settlements in specific places will differ importantly based on local ecological characteristics.
As ecological urban landscapes would differ among cities, so too would the cues, settings, and environmental meanings that influence sustainable behavior. In California, for example, the great majority of the annual rainfall occurs in the winter, meaning that stormwater swales and infiltration basins will be dry much of the year, yielding a very different landscape appearance than the same system would possess in a place where precipitation is more uniform. The same thing is true of passively heated and cooled buildings, which take very different forms in various climates. These diverse forms would in turn create very different physical settings on the ground.
Far from being a handicap for the formation of cultures of sustainability, this sort of local distinctiveness is usually thought to be crucial to the development of local place values (i.e., the sense of affection for and loyalty to a specific place). As the landscape architect Randolph Hester discovered in community design exercises in Manteo, North Carolina, a small town grappling with major development proposals, place values are often formed through the day-to-day interaction of people in familiar local settings. In Manteo, in fact, the places that the community most valued were so humble and outwardly unremarkable that they were not even consciously identified by the community until they were threatened with irreversible change. They were meaningful as cultural settings only to the relatively small group of local people that lived close enough to use them, and interact with other community members in them, on a consistent basis.
This is a significant finding for the implementation of ecologically educational and culturally meaningful urban landscapes. As ecological processes are made visible through design--whether they be water flows, energy flows, or some other process--designers should think about how the unique building and landscape forms that arise from each local ecological context can form the basis for place values to flourish. As these values emerge, people will develop more intimate cultural associations with the features of the landscape that make their place special--in other words, the same features that manifest and make meaningful their particular tangible relationship to the larger natural world.
Here again, there are important distinctions among various methods of making ecological process visible. While stormwater swales and constructed wetlands are important ecological design techniques, they tend to look much the same everywhere they are employed. Energy-efficient building forms, by contrast, look dramatically different across the world, from the tightly clustered, white-washed structures of Middle Eastern towns to the individual earth-covered house of the American Great Plains. The building forms of traditional and indigenous cultures were often exquisitely well suited to local climatic conditions and strikingly varied in their aesthetics. Even in relatively homogenous modern cities, the clear and noticeable physical differences between different places are one of the first and most significant devices that we use to distinguish "our" place from somewhere else (think of how unmistakable San Francisco's waterfront is). Ecological design has tremendous potential to amplify these locally unique features in the landscape and thereby foster ecologically informed local place values.
Conclusion
Overall, ecological design will be a crucial component of the sustainable city, not only because of its potential to reduce the ecological impacts of urban life, but also because of its potential to communicate new cultural conceptions of the human relationship to nature. If designed to embody clarity, noticeable differences, and adequate redundancy, if implemented in partnership with ecological education efforts (of which landscapes form a crucial part), and if created to be meaningful and interpretable to local communities, ecologically designed urban landscapes can create a fertile piece of cultural and educational ground in which sustainability can take root and spread to neighboring communities and to generations beyond.