Designed experiments: new approaches to studying urban ecosystems

CONCEPTS AND QUESTIONS Designed experiments: new approaches to studying urban ecosystems Alexander J Felson1 and Steward TA Pickett2 Although ecologists want to conduct research in urban systems, cultural constraints, spatial complexity, and institutional agendas limit the establishment of ecological experiments. Recent approaches using household landscaping have begun to tackle these obstacles; others, including adaptive management, restoration, reclamation, and wetland construction, reveal overlaps between ecological experiments and urban design. “Designed experiments” propose going beyond current strategies to partner with urban designers, landscape architects, and architects to insert architecturally designed experiments into the urban mosaic. The interdisciplinary approach of designed experiments exploits the aesthetics and functions of urban design, balancing ecological goals with important design factors such as context, public amenities, and safety. Designed experiments represent a novel way for ecologists to help improve urban environments by providing a means with which to work with urban designers in creating attractive, practical, and replicated experimental designs that generate quality ecological data from metropolitan sites. Front Ecol Environ 2005; 3(10): 549–556 C ities are inhospitable to the scientific method of experimentation for several reasons. First, there is the variety of human activities throughout metropolitan areas. Most ecological research in cities has avoided translating human actions into ecological terms, focusing instead on familiar ecological factors such as plants, animals, water, and nutrient flows (Sukopp et al. 1987; Gilbert 1989). Second, there is the need to take into account the complexity of the urban spatial mosaic, comprising infrastructure, buildings, roadways, and green spaces. Finally, there is the problem of intricate patterns of ownership and occupancy. Establishing controlled studies and replicate sites within this complex environment is difficult. Although social interventions in cities may resemble ecological experiments, they often have a much lower In a nutshell: • Urban ecological experiments must accommodate the physical, cultural, economic, political, and ecological complexities of urban systems • Designed experiments result from a partnership between ecologists and urban designers to develop ecological experiments as socially and politically desirable projects • Integrating rigorous ecological experiments with the design of urban spaces creates research opportunities throughout the urban environment • This approach allows ecologists to work towards sustainable urban systems by incorporating ecological function in cities 1 Rutgers University, Ecology and Evolution Department, 14 College Farm Road, New Brunswick, NJ 08901 and EDAW INC, 104 West 27th Street 4th Floor, New York, NY 10001 (afelson@post. harvard.edu); 2Institute of Ecosystem Studies, Box AB, Millbrook, NY 12545 © The Ecological Society of America level of experimental control (Whyte 1980; Alberti 2003). The city therefore requires new types of experiments that address the highly modified and culturally rich urban space (Table 1). “Designed experiments” take advantage of an area of overlap between ecologists and urban designers. Cook et al. (2004), treating urban landscaping as an experimental substrate, tested the ecological effects of different landscaping strategies using “adaptive experimentation”, while accounting for social and household differentiation. Similarly, Palmer et al. (2004) have called for ecologists to shift ecological management towards designed solutions and “designer ecosystems”. Here, we advocate a much stronger partnership between ecologists and designers, by proposing the use of urban design projects as ecological experiments in metropolitan systems. By embracing urban design, ecologists can become integral to the improvement and development of cities. Assimilating ecological research within urban design projects also creates research opportunities for ecologists throughout the urban environment.
Urban experimentation: opportunities and obstacles Experimentation provides an opportunity to link urban design and ecology. Both disciplines use experimentation, although in complementary ways. While ecologists develop experiments as a means to an end – to obtain quantitative data through simple and efficient manipulations (Hairston 1990) – designers use experimentation primarily as a creative and exploratory tool (Banham 1960; Halprin 1969; Johnson and Hill 2001). Ecologists use statistics, mathematics, and logic to establish experimental layouts for testing hypotheses. Designers tinker www.frontiersinecology.org 549 Designed experiments in urban ecosystems 550 AJ Felson and STA Pickett high priority (Berkowitz et al. 2003). The current tendency Approach Advantages Disadvantages Example to spend most of a project Urban–rural Non-manipulative Correlative McDonnell and budget on design and construcgradients Pickett 1993 tion, leaving little for mainteSocial interventions Unpredictable Poor control Pickett et al. 2004 nance and repair, may limit Fine-scale Rigorous; inconspicuous Address only finePickett et al. 2001 opportunities to generate and experiments scale processes monitor experiments. FurtherTemporal analysis Non-manipulative Correlative Grove and Burch 1997 more, clients and agencies tend Designed Rigorous; replicated; Partnerships required; This paper to believe that anything “experiexperiments educational value funding requirements mental” is risky. Developing new strategies for funding experiwith layout, details, materials, and form, while also tak- ments and for long-term monitoring is therefore essential. ing into account ergonomics, safety, and construction. Perhaps most importantly, ecologists make design deci-
Urban design as a way forward sions during the development of experiments. This activity, known as “experimental design”, involves formulat- Taking an active approach to research in urban environing research questions, choosing sites, configuring ments, rather than relying only on existing conditions of treatments, and planning measurements and statistical the city would permit ecologists to generate new kinds of tests (Kohler 2002). Moreover, the scale and spatial lay- experiments in various urban locations. Working with out of ecological experiments often match the scale of urban designers, architects, and landscape architects, ecolodesign projects. Thus, through experimentation, the two gists could exploit sites to which they usually would not disciplines overlap and provide opportunities for collabo- have access. Rather than focusing on green spaces or underration (Dickinson 1999; Cook 2004). utilized parcels in cities, ecologists could work within the In spite of the potential for experiments to link ecology built and developing areas of the metropolis as well. This and urban design, there are challenges to overcome. involvement with a wider variety of urban sites could Enhanced communication between designers and ecolo- enhance the educational and social meaning of their gists is a crucial step in integrating experiments into urban research (Cook et al. 2004; Pickett et al. 2004). Through space (Thompson and Steiner 1997; Pickett et al. 2004). the use of biologically monitored urban designs, urbanism Initially, the fields may appear incompatible: ecologists and research could overlap. value the scientific rigor of experimental practices while Cities are designed and managed ecosystems and are thus designers emphasize aesthetics and functionality. The key arenas in which to exercise a vision of ecological design of ecological experiments is currently a low-cost, engagement, such as pursuing designer ecosystems recomefficient, and results-oriented pursuit, but this will require mended by Palmer et al. (2004). Multiple influences, modifications in urban ecosystems, to incorporate aes- including human occupation and resource consumption, thetics, urban function, political processes, and human nascent and evolving biological processes, and highly modneeds while maintaining scientific rigor. ified abiotic conditions, affect cities (Jacobs 1961; McHarg A second obstacle is lack of control over experimental 1969; Clay 1973; Spirn 1996). Cities are dynamic and installations. In non-urban systems, ecologists often have highly managed environments, with accretion of waste, complete freedom in the design and installation of experi- renovation of buildings and infrastructure, and destruction ments. Typically, they use randomization and clear con- all contributing to urban growth and decay (Giedion trols in experiments (Underwood 1997). Using these sta- 1963). Many biological properties have already been highly tistical practices while engaging with the diverse political, modified (eg hydrology, nutrient cycles, species composisocial, and economic components of the city presents a tion, and vegetation fragmentation). Nevertheless, innovachallenge. Unlike less human-dominated environments, tion and human requirements contribute significantly to cities are an outcome of many human processes, including evolving urban conditions and provide a unique opportuingenuity, choice, familial ties, mistakes, and self-interest – nity for researchers to participate in defining a new direcall permeated with cultural meaning and intention. In tion for these highly altered environments (Cronon 1991; addition, land ownership and land regulations, as well as Goudie 1994; Forman 1995). politics, thwart any idealized approach to urban experiments. The questions asked, methods used, analyses and
Creative design process display of results may all require adjustments for research Designers use the creative design process as a fundamenin the metropolis. Finding support for ecological experiments in cities is tal tool for synthesizing complex factors into cohesive an additional challenge. Convincing governments, real designs (Lynch 1984; Calthorpe 1995; Corner 1999). estate developers, and funding agencies of the value of This method allows designers to develop aesthetic and linking ecological research with urban design projects is a functional physical forms for neighborhoods, buildings, Table 1. Approaches to urban ecological research www.frontiersinecology.org © The Ecological Society of America AJ Felson and STA Pickett and landscapes that address issues such as site conditions, client requests, regulations, building limitations, and material costs. Ecologists could utilize this same creative process to integrate experiments into the urban fabric and to make ecological research more public and visible as well as inventive and aesthetically pleasing. Such a creative response to human needs, taking into account managerial concerns, political pressures, and budgetary constraints, would improve the chances of projects being built and help to reconcile the complex and often contrasting conditions of urban space. But it will take some effort to bridge ecology and urban design. Designed experiments suggest an active role for ecologists in constructing experimental sites. While ecologists on occasion manipulate sites to understand existing or hypothesized conditions, more often they simply study existing conditions.
Urban regeneration and community development Linking designed experiments to communities and educating people about the role of experimentation in the urban landscape is a key strategy for encouraging community support. Ecologists are looking for research opportunities in cities and ways of interfacing with communities, culture, economics, and other social factors (Grimm et al. 2000; Pickett et al. 2001). Also, many communities are seeking ways of improving their environments (Grove and Burch 1997). Designed experiments provide an opportunity to connect the experimental function of research to community or neighborhood development and urban regeneration. Similar to the role of parks, which originally developed to counter the ill effects of industrialization and provide recreational space for less privileged urban dwellers, designed experiments can respond to societal needs to enhance city environments (Spirn 1996; Meyer 2000). Through a creative blend of traditional research, urban design, and community involvement, practitioners could generate reproducible ecological units that combine ecological experiments with public space and urban function. Encouraging community involvement and linking experiments to urban design should benefit the management and maintenance of urban landscapes. Everything in cities requires some form of maintenance. For urban experiments, like other green spaces, upkeep and repair are required. Linking research to design can create a cultural identity for experiments, and thus encourage maintenance. Over time, experiments could receive similar treatment as other designed spaces, such as memorials or parks. Linking experiments with social activism provides a set of social pressures that blends science with community development (Grove and Burch 1997), thus adding to the cultural relevance of experiments.
What, then, are designed experiments? Designed experiments, achieved through the collaboration of ecologists and urban designers, are a novel strategy © The Ecological Society of America Designed experiments in urban ecosystems for turning city spaces towards research and other social goals. They rely on design to synthesize complex factors and manipulate the urban environment. They are multifunctional, combining ecological research sites with designed urban strategies, and balancing scientific rigor with creative design. While the urban design component and aesthetic value are integral elements of designed experiments, for ecological purposes the quality of the data remains paramount. In order to produce quality data, designed experiments should strive for statistical clarity, reduction in variables, and replicability, and should be structured to create quantifiable conditions that enable researchers to make comparisons. “Piggybacking” is an important feature of designed experiments. Ecologists, working with designers, can harness the existing creative energy and established political channels for designing, planning, and constructing cities. Engagement with designers should enable ecologists to capitalize on the designers’ knowledge of cities and their ability to create new urban forms. The ability to merge experiments with urban design, and to incorporate human activity as a component of research, will require considerable ingenuity.
Precursors and early examples of designed experiments To demonstrate the variety of scales and configurations designed experiments may take, a sample of existing and proposed design projects that embody experimentation or strategies that could promote designed experiments are presented in the following sections. Jordan Cove urban watershed The Jordan Cove project in Waterford, CT, is an example of a clearly interpretable experimental treatment and control in the design of an American suburb (Figure 1). It also illustrates the integration of experiments into a common social framework and suburban footprint. The 7.3 ha residential subdivision was divided into two watersheds. One of these was developed as a traditional or control subdivision, with 17 lots (each 0.2 ha) covering 4.2 ha total. The control design includes curbs, catch basins, storm sewers, and 24 ft wide impervious streets. The second experimental watershed uses best management practices, and includes 12 clustered lots on 2.8 ha, with nontraditional zoning setbacks, grass drainage swales, rainand bioretention gardens, 20 ft wide pervious streets, and mowing and non-mowing strategies to create conservation zones. Construction for the sites began in 1997 and 2000 respectively. The stormwater from each treatment watershed is being monitored for 6–10 years to assess the effectiveness of environmental technologies for treating non-point source pollution. Technical modifications were made to regulations by Waterford’s town government, and included waivers, special design or operation www.frontiersinecology.org 551 Designed experiments in urban ecosystems 552 (a) AJ Felson and STA Pickett and the developer (Connecticut Department of Environmental Protection 2002). (b) Low mow conservation zone No mow area Bio retentiongardens Landschaftpark This project illustrates how experiments can fit into a design aesthetic. It also shows how experiments might contribute to urban regeneration and take advantage of post-industrial land or 20 ft wide brownfields, which otherwise pose conpervious streets straints to redevelopment. The exodus Landscaped of industry from urban areas in many cul-de-sac countries has resulted in the possibility Drainage of opening up brownfield sites. Their swales prime urban location provides visibility and high potential real estate value. Best management practices Traditional approach This, coupled with high remediation costs and the difficulty of mitigation, Figure 1. Jordan Cove’s comparable housing developments include (a) best encourages governments and landownmanagement practices and (b) traditional. As part of the EPA’s National Monitoring ers to seek innovative solutions. One Program, experiments on the 7.2 ha site were calibrated in 1996 and initiated in 1998. such solution is for scientists and Plans adapted from the University of Connecticut’s program“Nonpoint Education for designers to experiment with techMunicipal Officials”. niques, such as phytoremediation, phytoextraction, and rhizofiltration, which controls, mitigation, and discretionary actions. The pro- might otherwise seem too costly in the long term, as well ject is a joint public–private effort funded partly through as wasteful of valuable land (Bradshaw et al. 1980). the US EPA National Monitoring Program and includes There are a variety of precedents that incorporate 40% matching funds through other project participants urban design, aesthetics, and experimentation (Kirkwood 2001). The company of Latz + Partner transformed Duisburg-Nord (Germany) from a former industrial site into a park, comprising industrial remnants, vegetative remediation, public space, and recreation (Figure 2). Latz explored the science of cleaning contaminated soils and converting post-industrial sites into parkland. Remediation gardens on contaminated land are off-limits to pedestrians, but are viewable from an elevated walkway. Courtesy of C Panick Revival Field Figure 2. A field of birch trees remediate the soil on the site of the former blast furnaces of Duisburg-Nord Park, Germany. (Latz + Partner; built 1993–2001.) www.frontiersinecology.org Public art can also serve as a venue for experimental installations. One example of collaboration between artist and scientist is Mel Chin’s Revival Field, an 18.2 x 18.2 m remediation project built on a landfill in St Paul, MN (Figure 3). Revival Field was the first replicated field test conducted as an art installation in the US. Working with Rufus Cheney, now a USDA chemist, Chin selected plants thought to remove toxins from degraded land and arranged them into a bulls-eye shape, surrounded by industrial fencing. At the time, little was known about the effectiveness of phytoremediation, and both research efforts and money were scarce. The project helped to confirm the effectiveness of the technique. Chin received funding from the National Endowment for the Arts and the Walker Art Center (Beardsley 1984; © The Ecological Society of America AJ Felson and STA Pickett Designed experiments in urban ecosystems Matilsky 1992). Thus, in addition to showing the role art can play in generating research with cultural meaning, his efforts also represent an alternative route to funding urban ecological experiments. 553 The marsh planter project illustrates how experiments can combine education and aesthetics while acting as a functioning research tool. In addition, it shows that installing experiments in active urban zones creates opportunities for connecting the public with ecological research. The proposed project consists of a small-scale, experimental saltwater marsh planter to be constructed on Manhattan’s East River (Figure 4). The design, conceived by the firm Ken Smith Landscape Architect, is Figure 3. Mel Chin’s Revival Field exemplifies an interdisciplinary approach to intended to bring together aesthetics and urban research. Built between 1990 and 1993, it is located on Pig’s Eye Landfill in function (Amidon 2005). With the East St Paul, Minnesota. River banks converted to vertical walls and ocean-going boats creating severe wakes, the riparian ings and infrastructure provide potential locations for edge is no longer hospitable to plant growth. Therefore, designed experiments. Alterations in biodiversity, heavy eight wooden planter boxes are to be placed on a pier, metal pollution, microclimate, and a host of other factors above mean high water, to avoid detrimental river condi- can be measured, along with the master variables of water tions; saltwater grasses planted in the boxes will be grown flow and quality, as greening in different sub-catchments in a sand and organic compost mix, with a bottom layer of proceeds. Through a partnership between ecologists and water-retaining polymers that substitute for the mud layer. designers at Columbia University’s Graduate School of The irrigation system will be flexible, including both Architecture, Planning and Preservation, students are freshwater sprinklers and an exposed saltwater system that exploring experimental approaches for neighborhoods pumps water from the river into the planters. Flooding within the watershed (McGrath et al. in press). with the brackish East River water introduces nutrients, Partnerships between the city managers, not-for-profit larvae, and minerals into the constructed wetland. organizations, and community groups are also proving to Scientists can develop small-scale controlled experiments be important for the planning and maintenance of ecologto study salinity gradients or to test restoration techniques ical experiments. and observe the creation of a mineral and nutrient plume below the planter, which will attract small bait fish and, in turn, lure larger predatory fish. Watershed 263 Long-term, large-scale, and planned mitigations provide an opportunity to build and test multiple experiments within a watershed. Civic community engagement also has a role to play in facilitating urban experiments. The “greening” of a 367-ha storm drain watershed in Baltimore City, MD, is intended to reduce stormwater flow and improve its quality (Figure 5). Plans involve increasing canopy cover and reducing the impervious cover on Figure 4. The saltwater marsh planter by Ken Smith Landscape Architect, public lands. Numerous vacant lots, miles scheduled for construction in 2007, is an aesthetic research tool adjacent to the 34th of piped streams, and under-used build- Street Ferry Terminal on the East River in Manhattan. Drawing by author. © The Ecological Society of America www.frontiersinecology.org Courtesy of M Chin East River marsh planter Designed experiments in urban ecosystems (Figure 6). The reliance on the city’s large capital budget instead of the NYCP’s limited annual expenses, and the permission granted to Green Streets to contract out for each project, allows the program to mobilize quickly in an otherwise slow-moving bureaucracy. To date, over 2000 sites have been converted to planters. While the program currently has loosely environmental aims, partnerships between ecologists and urban designers could transform Green Streets into multiple small-scale ecological experiments (B Gunther pers comm). The projects discussed above demonstrate a variety of ways in which ecological data collection can be planned, installed, funded, and supported by communities and governFigure 5. This diagram, developed in BP McGrath's urban design studio at Columbia ment agencies. While only a few are University, explores the design opportunities within Watershed 263 in Baltimore, actually producing ecological data, Maryland. together they illustrate ways of integrating experiments into development Green Streets or revitalization projects that governments, developers, New York City Parks Department’s (NYCP) Green Streets and communities will value and support. Program acquires remnant land in dense urban areas for urban greening. This project represents a modular, replica-
Anticipated outcomes ble, and adaptable approach to urban design installations, and also involves the application of temporary urban What will designed experiments contribute to cities? We installations. Green Streets, which capitalizes on remnant envision five possible outcomes. spaces including medians, triangles, and unused sidewalks, is the result of an agreement between the NYCP and New Meld analysis and aesthetics York City Department of Transportation (NYCDOT) to install Parks planters on NYCDOT property, with the The blending of quantitative analysis with aesthetics and understanding that plants can be removed for roadwork function will generate opportunities for research while North Bronx Manhattan Queens Legend Figure 6. New York City Parks Department’s Green Streets Program, initiated in 1986 and reintroduced in 1996, has installed over 2000 planters throughout the five New York boroughs. www.frontiersinecology.org Staten Island Brooklyn Greenstreet Open space Park 1 0 1 Miles © The Ecological Society of America Courtesy of D Arroyo Courtesy of J Tran and M Brossa 554 AJ Felson and STA Pickett AJ Felson and STA Pickett creating aesthetically pleasing amenities and enhancing urban space. For designers, the approach could provide a new design paradigm that builds on past movements, including modernism or the picturesque. Infusing educational and aesthetic qualities into urban experimentation will raise its public value and help bring identity to otherwise often inconspicuous research sites. Play a useful role in the city Such experiments would create design solutions that adapt to site context and constraints, and address the multifaceted conditions of cities. They would function as part of the city fabric, for example by improving safety, facilitating circulation, and creating park spaces. In this way they would play a social or functional role, thus becoming a conspicuous and lasting part of the city. Allow research in multiple locations Channeling experiments through urban design projects will help spread research sites throughout the city. Exploiting the range of conditions available in the metropolis is already one of the goals that ecologists recognize through such approaches as urban–rural gradients (McDonnell and Pickett 1993; Table 1). Designed experiments take this further by making all designed buildings, infrastructure and landscapes accessible as potential sites for experimentation. Provide a public identity for urban ecology Inserting simple experimental units into multiple research sites would help produce a set of common experimental designs that become recognizable figures in everyday landscapes. These informational, functional, and aesthetic additions to the city should foster public appreciation and understanding. This, in turn, could help to reduce vandalism, encourage public participation in sustaining and maintaining the experiments, and increase demand for similar experiments elsewhere. Public involvement may also be essential for tackling obstacles such as highly fragmented private land ownership or regulatory controls. Reintegrate ecological processes into cities Designed experiments could reintroduce biological activity, such as enhanced vegetative structure, increased soil microbial activity, or improved riparian function, to urban areas. This infusion of ecological functions into urban design practices, could ultimately result in a “retrofitting” of urban environments to include more biologically diverse systems and to better accommodate ecological functions.
Conclusions Designed experiments are a potential means for ecologists to investigate urban ecology collaboratively with archi© The Ecological Society of America Designed experiments in urban ecosystems tects, landscape architects, and urban designers. This interdisciplinary effort raises the potential for ecologists to become involved in the actual design process of urban areas. This allows the infusion of experimental goals and monitoring approaches into the projects. Such experiments would take advantage of designed urban components, including buildings, streetscapes, parks, and infrastructure, to establish further research sites. Functioning both for research and urban design, experiments will blend quantitative analysis with aesthetics and function, providing a cultural identity for experimental research, creating usable spaces for people, and contributing to urban evolution. Through the effort of creating and then studying these spaces, ecologists will accumulate quantitative data, which can then be fed back into new experimental design proposals. Over time, designed experiments have the potential to deepen our understanding of human impacts on biological processes and to improve the ecological function of human-dominated landscapes. Designed experiments expand traditional ecological goals to include the new role of urban place-making. Merging ecology with design will help engage ecologists in attempts to structure and maintain urban environments. Focusing on the creation of urban ecological forms that integrate traditional research with the functional and aesthetic design of urban space, ecologists will contribute to urban processes and growth. As in adaptive management used in forests and fisheries (Likens et al. 1995; Holling et al. 1996), urban ecologists could use designed experiments as a management tool to predict, monitor, and regulate urban ecological patterns and processes. Through a crossdisciplinary exchange, these experimental strategies would help place research within cultural, aesthetic, informational, and functional urban networks.
Acknowledgements This paper is a contribution to the Baltimore Ecosystem Study, LTER (NSF DEB 9714835), and to the program of the Institute of Ecosystem Studies, with partial support from the Mary Flagler Cary Charitable Trust.
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