Introduction
Landscape urbanism, an emerging concept, is a theory of urban planning and design based on ideals found in disciplines such as ecology, landscape architecture, engineering, and systems theory. It is generally defined as the theory and practice of using landscape—as opposed to architecture—as the medium for structuring the built environment. Further, it seeks to explore the use of landscape systems as infrastructure in urban environments. But why is landscape urbanism considered by some to be a unique discipline and/or theoretical framework? How is it (or is it) different from other closely related disciplines, primarily landscape architecture?
This paper explores how the postmodern ideals of landscape urbanism are—or are not—similar to the over-arching principles of landscape architecture. To do this, I use literature review and case study examples to demonstrate how landscape architecture has evolved alongside changing theories and attitudes towards urban planning and design and how that evolution has culminated with the term ‘landscape urbanism’ today. The past century-and-a-half is examined in four time periods: 19th Century Romanticism, Modernism, the Environmental Movement of the mid-20th Century, and the recent, postmodern Landscape Urbanist movement.
The Context of Terminology and the Birth of a Profession
The term ‘landscape’ was first used in the 16th Century by Italian art connoisseurs in reference to a specific type of painting, and it was in north-east Italy and southern Germany where landscape painting—alongside map making and printing—became popular (Cosgrove, 2006). Thus a scenic dimension was connected to the word ‘landscape’ and very much still is today.
The term ‘landscape architecture’ was coined as early as 1828, again in reference to painting in a book by Gilbert L. Meason titled On the Landscape Architecture of the Great Painters of Italy, in which he describes the connection between architecture and land as a picturesque affair where building and ground are united to blend into the surrounding scenery (Pregill and Volkman, 1993). Many attribute the beginning of the profession of landscape architecture with Frederick Law Olmsted, Sr., who adopted the title professionally in 1863. Horace Cleveland, a professional landscape architect and a long-time acquaintance and collaborator with Olmsted (Nadenicek, 1993), begins his own book, Landscape Architecture as Applied to the Wants of the West, by declaring “the term ‘Landscape Architecture’ is objectionable” and that he only uses it for lack of a better description (1965:Preface [1873]). Still, he makes one of the first attempts at a definition (1965:5 [1873]):
Landscape Gardening, or more properly Landscape Architecture, is the art of arranging land so as to adapt it most conveniently, economically and gracefully, to any of the varied wants of civilization.
Further, Cleveland outlines a sample of questions that ought to be on the mind of a landscape architect upon visiting a new project site, such as land use considerations, site specifics (i.e. taking advantage of “opportunities offered by nature” to save costs of cut and fill and facilitate positive street drainage), and taking notice of local scenic qualities in nature so they may be used to enhance the development aesthetically (1965:17 [1873]).
The 19th Century: From Romancing the Park to City Planning
Cleveland’s notions echo Olmsted and his English architect partner Calvert Vaux in their seminal project of Central Park in New York City. In 1858, Olmsted (then the current superintendent of the park site) and Vaux proposed a park plan specific to the site’s terrain as well as to the culture of the city. The park was to be “a model of pastoral freedom,” a place where individuals could rest their minds and take in a visually pleasing experience, and a place where “inhabitants of New York would look closely on each other with sympathy and understanding” in a part of the city “that encouraged them to do so” (Menard, 2010:518). With Central Park, we see the ideas behind park planning and design that would continue to shape the profession of landscape architecture and the concepts of interconnected elements—aesthetics, functionality, and society—within urban settings. Olmsted thought of parks as places where nature and the built environment met harmoniously, where society of all classes could interact, and where infrastructure services (drainage, water filtration, flood control) could occur naturally (Daniels, 2009; cf Girardet, 2004 and Schuyer, 1986).
The idea of multiple uses and functions in park design are further developed in Boston’s park system in what would come to be called the “Emerald Necklace” (Figure 1). Originally conceived by Olmsted in 1880 and later carried out by his apprentice, Charles Eliot, the concept called for an interconnected trail system, which in itself was quite unique in its time. The plan also sought to remedy the increasingly problematic drainage issues in the city (Pregill and Volkman, 1993). One portion of the park system, a 115-acre wetland called the Back Bay Fens area, was re-graded to facilitate the retention of seasonal floodwaters. The ground from Commonwealth Avenue to the Back Bay area was all fill, a process begun as early as 1804, from cut taken from nearby hills (Bunting, 1954). The most naturalistic parts of the park connection, the Riverway and the Muddy River areas, were revitalized from their brackish condition by channelling spring water, thus creating a naturalized reclamation of the river as well as a recreational addition of paths, seating areas, and vegetation (Pregill and Volkman, 1993).
Equally important to Olmsted’s work were health and sanitary concerns (Peterson, 1979). “Air is disinfected by sunlight and foliage” Olmsted wrote, in his book Public Parks and the Enlargement of Towns (1970:15 [1870]). Providing fresh air and wide-open park space would allow citizens to escape from the crowded confines of their day-to-day occupations.
Another dimension to the Emerald Necklace plan is found in the design as applied to social considerations. Olmsted observed that within the diverse and distinct communities that made up Boston, there was a tendency for each community to focus more inwardly and independently to the point they exhibited jealously and competition with one another (Menard, 2010). A careful consideration on Olmsted’s part was to provide “a proposal that would honour the singularity of each locality while linking them together in a synergistic sequence of contrasts” (Menard, 2010:520). Olmsted advised that the Boston Parks Commission should develop qualities along the park network that would give each location a distinct character (Menard, 2010).
Figure 1: Historic (top) and modern map (middle), and photo (bottom) looking north over the Back Bay Fens of the Emerald Necklace park system in Boston, MA. (Sources: Emerald Necklace Conservancy, www.emeraldnecklace.org and the Cultural Landscape Foundation, www.tclf.org)Landscape architecture’s influence on the planning and design of urban environments had become pervasive in North America by the end of the 19th Century. These outlooks on park planning and design, based on aesthetics and functionality, as well as health and social reform, would come to shape the future of the city planning ideology in North America (Pregill and Volkman, 1993; Peterson, 2009). However, despite the undercurrent of Olmsted’s attention to social matters with his park designs, the next major period of city planning—the City Beautiful movement (late 19th and early 20th Centuries)—focused on the aesthetic aspects of the city but largely failed to address more pressing social concerns resulting from the increase of urban populations (Pregill and Volkman, 1993).
Frederick Law Olmsted, Jr., would carry on his father’s legacy in professional practice as well as go on to form the first curriculum of landscape architecture in 1900 at Harvard. During the Progressive Era reforms[1] of the early 20th Century, F.L. Olmsted, Jr., as well as landscape architect John Nolen, a student of Olmsted, Jr., were setting a pace toward new planning methods. Olmsted, Jr., would come to be “viewed as the father of organized city planning in the United States” (Peterson, 2009:129). Additionally, many of Nolen’s concepts would later influence late 20th Century New Urbanism (Stephenson, 2002).
Modernism: The Rise of Rationality
The distinguishing feature of landscape perception and planning in the 20th Century was objectivity: Advances in science throughout the 19th Century eventually swept away romantic notions of the physical world by the beginning of the 20th Century (Pregill and Volkman, 1993). Perhaps no other phrase appropriately describes the rational architectural aesthetic of the Modernist Period[2] than “form follows function,” a concept originally put forth by American architect Louis Sullivan as ‘form ever follows function’ (1896:4). In Sullivan’s view, the tall office building was a new typology; it therefore required a new form, just as Greek temples and medieval fortresses had in centuries past (Sullivan, 1896). Sullivan saw this new form as liberation from the ‘asylum’ of traditional schools, and a form of architecture that would become an art of, for, and by the people.
Le Corbusier took the concepts of freedom and the modern ethic even further by applying them to town planning. In La Ville Radieuse (The Radiant City), Le Corbusier envisions a society whose thought is technological, whose goal is production, whose highest value is organization, all with architecture “in the service of collective pleasure” (Fishman, 2003:57 [1977]). His utopian city was a “rationally controlled ensemble, where all parts are smoothly co-ordinated beforehand” (Besteliu and Doevendans, 2002:237). However, the form of his plans would come under criticism as “the great surgical amputation of the building from the land” (Bacon, 1967:217). This ‘amputation’ (Figure 2) demonstrates how the ‘man-nature’ relationship of the modern era was typified by the perspective that nature was a resource to be used for society’s needs (Harvey, 2009 [1973]). Regarding the Radiant City’s function, Jane Jacobs writes that “as to how the city works, it tells… nothing but lies” (2003:73 [1961]). Nevertheless, modernist ideals persisted, and many plans of the early to mid-20th Century were based wholly or in part on Le Corbusier’s Radiant City concept. Planning remained deterministic in its outlook of controlling city development by means of scientific operations and processes for decades to come (Besteliu and Doevendans, 2002).
Figure 2: Le Corbusier sketch, 1922, from Edmund Bacon, and what he referred to as the amputation of building from land (1967:217)The Environmental Movement
The Environmental Movement One important contributor to these ‘modern’ operations and processes was Patrick Geddes. A Scottish biologist also considered a pioneer in the field of regional planning, Geddes is noted for his observations on the correlation of environment, society, and land use (Mehmood, 2010). Geddes, and his contemporary Lewis Mumford, sought to coherently link natural and social knowledge as a regional approach to social development (Carter and Charles, 2010; cf Jamison, 2001 and Studholme, 2007). In spite of this, the idea of a separation between nature and society—both physically and philosophically—would continue through most of the 20th Century. However, social movements of the mid-20th Century, such as feminism and environmentalism, challenged these dualist notions and the scientific community’s exploitative attitude toward nature (Carter and Charles, 2010; cf Jamison, 2001).
Ian McHarg, a Scottish landscape architect and student of planning, likewise rejected exploitative attitudes toward nature. He admired the work of Patrick Geddes and Lewis Mumford, as well as the naturalist and environmentalist writers Aldo Leopold and Rachel Carson. He lamented that nature had been reduced to a backdrop for Corbusian modernism and how environmental science was rarely considered as a part of the planning process (McHarg, 1996). In his work throughout the 1960s-1980s, McHarg would strive to rectify the seemingly continuous battle of ‘nature vs. culture.’ The growing concern over environmental issues in the 1960s and 1970s helped strengthen the credibility of his environmental method of planning which has been referred to as “ecological regionalism” (Ndubisi, 2008) or even “restriction planning” (Andersson, 2010). The Woodlands project (Figure 3), set within 200,000 acres of forested land outside Houston, Texas, would be a project McHarg felt was one the best examples of his ideas and of ecological town planning in the 1970s (Forsyth, 2003, 2002). The project demonstrates the success of McHarg’s ‘layer cake’ (Figure 4) method of analysis (based on methods pioneered by landscape architects Charles Eliot and Warren Manning half a century prior {Daniels, 2008; Steiner, 2000; Thompson, 1991}) in determining appropriate placement of new development as well as defining areas of environmental preservation. McHarg’s firm, Wallace, McHarg, Roberts and Todd (WMRT), developed a plan that would not increase runoff, not lower the water table, and minimize clearing of existing woodlands throughout. Essentially, the firm determined development densities and land use, primarily residential and open space, with some commercial uses, based on environmental analysis (McHarg, 1996).
Figure 3 (top) and Figure 4 (bottom) – Layers of functionality and conceptual site planning strategies for the Woodlands, Texas, demonstrating the clear distinction between ‘nature and culture’ (Wallace, McHarg, Roberts and Todd, 1973) and the “layer cake” concept
To achieve this, several ecological elements were analyzed, and the plan responded to many objectives, including:
Preservation of a woodland environment; a natural drainage system which would utilize existing floodplains, drainage channels, ponds, and recharge soils; preservation of certain areas of vegetation noted for species diversity, high quality, stability, and uniqueness; provision for wildlife habitats and movement, so that wildlife now living on the site may remain. (Wallace, McHarg, Roberts and Todd, 1973, Woodlands: Guidelines for Site Planning).
It is reminiscent of one dimension in Leopold’s ‘land ethic,’ which would enlarge the boundaries of community to “include soils, waters, plants, and animals, or collectively: the land” (1966:239 [1949]).
In retrospect, the project still holds up as a model of good environmental town planning (McHarg, 1996; Forsyth, 2003) in spite of its relative lack of regional transit connections and prevalence of detached, single family housing. However, Harvey cautions that the rise of modern natural science should not be viewed as a change in thought which had no connection to the economy (2009 [1973]). The Woodlands was an economic success in that no storm drainage system had to be built, meaning a cost savings of $14 million in the first phase compared to traditional building practices of the time (McHarg, 1996; Forsyth, 2003). As McHarg would write, the project demonstrated “it is not only possible, but profitable, to design with nature” (1996).
Towards Landscape Urbanism
Landscape urbanism, a term first coined by Charles Waldheim in 1997, endeavors to place landscape as the organizing process for urban environments (Corner, 2006), just as architect and historian Kenneth Frampton had proclaimed—almost prophetically—a few years prior (Pollack, 2006; Weller, 2008). There are several definitions of landscape urbanism, the most widely accepted being that landscape, not architecture, is the medium more appropriate for guiding the planning and design of urban areas. It allows for a view of the urban landscape as a living mat, a patchwork of layered systems, with no one authority or control over its arrangement or evolution (Corner, 2003). Corner states that landscape urbanism is “an ethos, an attitude, a way of thinking and acting” (2003:58) and that it is utopian, providing “a hopeful and optimistic framework for new forms of experimentation, research and practice” (2010:27).
Landscape urbanists also recognize the early 20th Century transition from romanticism to scientific rationality within urban planning as a turning point in landscape architecture where practitioners splintered into two distinct categories: landscape as a decorative art form, and landscape as a scientific planning methodology (Reed, 2006). In light of this, landscape urbanism seeks to bring together and overlap many professional and theoretical disciplines and to bridge the perceived gap between landscape planning and design (Corner, 2003, 2010; Reed, 2006; Weller, 2006; Shane, 2003); a gap that was perhaps created at Harvard when city planning and landscape architecture went separate ways academically (Seddon, 1986).
Landscape urbanism is also partly a reaction against modernism and New Urbanism (Corner, 2003; Waldheim, 2006; Andersson, 2010). Corner hopes to move from those neo-traditional models to more open-ended, strategic ones that are less dependent on formal, stylistic precedents alone (Shane, 2003). A clear difference between landscape urbanist thought and modernist/new urbanist thought is found in how landscape urbanism seeks to embrace the indeterminate and ever-changing nature of cities and culture. It seeks to dissolve the dualist ‘nature and culture’ debate and takes apart classical notions of city building (Corner, 2003). Heavily contrasted against landscape urbanism, New Urbanism is a movement that would not leave anything to chance (Weller, 2008).
Taking his cue from geographer David Harvey, Corner points out that the search for new city structure should derive from “a Utopia of process rather than a Utopia of form” (Corner, 2003:61). Today, design is being utilized more often to drive land use planning conceptualization and sustainable design approaches (Godschalk, 2004), but the designer’s role shifts in landscape urbanist practice to a focus on process and not simply on what things look like (Corner, 2003).
Corner’s firm, Field Operations, has begun to accumulate a prolific and high-profile portfolio of planning and design projects over the past decade. In 2001, they began planning the ‘fresh kills’ park site in Stanton Island, NY, on 2,200 acres of former landfill area. The first phase, a $150 million implementation, began in 2007[3]. In the Fresh Kills project (Figure 5), Corner stresses process over time more so than design aesthetics. “Parks all look the same… and that sameness is either the pastoral model or the modernist formal model… we try not to have style” (Sullivan, 2008; cf Corner, 2008). As both an environmental reclamation as well as a recreational objective, the plan begins with creating green mounds which settle over time. Next, more strategic native and ornamental plantings are added and then are combined with a gradual increase in passive and active uses. Finally, the introduction of park amenities creates the last phase of development. Like a forest succession over time, this all creates Corner’s idea of the ‘Lifescape’ (Sullivan, 2008).
In the Knowledge Corridor project (Figure 6), Field Operations was hired by Puerto Rico develop the area adjacent to the University of Puerto Rico in San Juan. Corner’s firm sought to bring together three elements, or layers, in synthesis: transportation, development, and environment. According to Corner, indeterminacy and uncertainty are figured into the equation by means of influencing and guiding—as opposed to prescribing—what the precise build-out will be (Corner, 2010). In the Corridor project, “nature, ecology, reclamation, lifestyle, and urban culture could merge with education, research and experimentation” suggesting that the development itself is like knowledge, which is not only “dispensed and acquired, but also something made, evolved and invented” (Corner, 2010:28).
Figure 5: The Fresh Kills process over time and the ‘Lifescape’ (Source: www.fieldoperations.net, and www.metropolismag.com/story/20081119/the-long-view)
Figure 6: the landscape of postmodern urbanism? The Knowledge Corridor, San Juan, a mixed-use urban core with housing, retail, school, hotel, and public space integrated with research laboratories (Source: Topos v71, 2010, and www.fieldoperations.net)
The concept of city, society, and nature as all one contiguous, complex, layered entity is a main theory behind the landscape urbanist movement. Corner, a student and fellow faculty member when McHarg taught at Univesity of Pennsylvania, rejects the notion of nature and culture as separate entities in the urban setting (Waldheim, 2006). But the cultural context was different in McHarg’s era. The environmental movement undermined scientific knowledge and created a crisis-mode relationship between nature and society (Carter and Charles, 2010). McHarg realized that where there were conflicts between land preservation and exploitation, exploitation would win (Andersson, 2010); thus, preservation was the prime alternative, and his ‘layer cake’ planning method provided this. Today, planning ideology is based in globally competitive market logics combined with “utopian transcendent ideals of sustainability, progress, and betterment” (Gunder, 2010:308).
Conclusion
This paper has shown how landscape urbanism, slated as an emerging trend in urban planning and design, traces its origins back through the history of landscape architectural theory and practice. Landscape architecture, traditionally both a planning and design discipline, became splintered throughout the 20th Century into variations of land planning and landscape design and now attempts to re-emerge in the 21st Century as a new, ideologically distinct discipline. However, the rationale for a new ‘landscape urbanist’ ideology remains uncertain in light of its similarities—which appear to outweigh the differences—to its Olmstedian and McHargian lineage. The landscape urbanism ‘lens,’ through which the urban landscape appears complex, layered, multidisciplinary, and indeterminate, may offer a way to ‘choreograph[4]’ the postmodern urban themes as described by the geographers Dear and Flusty (“globalization, polarization, fragmentation and cultural hybrids, and cybercities” {1998:67}). However, it is plausible that landscape urbanists, as designers of urban green spaces produced for human enjoyment and as ecological infrastructure, are replicating what modernists did years ago by “crystallising a conception of social and environmental progress into tangible landscape form” (Hebbert, 2008:54).
Looking back in time, F.L. Olmsted and H.W.S. Cleveland were both keenly aware of the rise in urbanisation and a need for the betterment of society, and endeavoured to do so with their plans and designs. They continually advocated the importance of city planning based on a natural aesthetic. They understood the importance of considering natural site features, socio-political factors, and market forces in their work. So too did Ian McHarg’s ‘ecological regionalism’ which additionally offered a barrier between nature and the culture of technology which threatened to destroy it.
Today, Waldheim and Corner’s ‘landscape urbanism’ offers an optimistic urban synergy between natural and cultural existence and a framework for postmodern urbanism. But are these ideals really so different from those of Olmsted’s pastoral park aesthetic, Leopold’s eloquent ‘land ethic,’ or even McHarg’s design with nature? Are not landscape architects supposed to juggle the complex co-existence of nature and culture, for the betterment of both? Corner’s theories no doubt stem from the lineage of landscape architects. Yet, he poetically adapts these notions to the seemingly different urbanism of today, writing that landscape urbanists should not overlook the dualism of “the lyrical play between nectar and NutraSweet, between birdsong and Beastie Boys…” (2006:33).
Perhaps Olmsted’s landscape architecture was for the survival of culture, and McHarg’s was for the survival of nature (Andersson, 2010). So far, Corner’s greatest contribution to landscape architecture is perhaps the promise of a harmonious embrace of both, in a complex postmodern urbanism.
Based on a paper originally written December, 2010. All content (c) Noah S. unless otherwise noted/cited.
Footnotes:
[1] The Progressive Era is characterized by Peterson (2009) as a shift from private-charitable endeavor toward social work, a greater use of government authority, and the utilization of political activism.
[2] For the purpose of this paper, the Modernist Period is defined relative to the modern architecture movement of the 20th Century, which coincides with Le Corbusier’s ideas of the Radiant City, and exists primarily between the 1920s-1970s.
[3] See also www.fieldoperations.net.
[4] From Corner, 2010, where “landscape urbanism elevates the role of the landscape architect to that of the master choreographer, the great generalist who is able to see and shape enormously complex phenomena into new organizations” p. 26.
Bibliography
Andersson, T. (2010) “Landscape urbanism versus landscape design.” Topos: the international review of landscape architecture and urban design. 71: 80-83.
Besteliu, I. and K. Doevendans. (2002) “Planning, design and the post-modernity of cities.” Design Studies. 23: 233-244.
Carter, B. and N. Charles (2010) “Society, nature and sociology.” The Sociological Review. 57(2): 1-20.
Cleveland, H.W.S. (1873 [1965]) Landscape Architecture as Applied to the Wants of the West. Pittsburgh, PA: University of Pittsburgh Press.
Corner, J. (2010) “Landscape Urbanism in the Field: the Knowledge Corridor, San Juan, Puerto Rico.” Topos: the international review of landscape architecture and urban design. 71: 25-29.
Corner, J. (2006) “Terra Fluxus.” The Landscape Urbanism Reader. C. Waldheim, ed. New York, NY: Princeton Architectural Press; 21-34.
Corner, J. (2003) “Landscape Urbanism.” Landscape Urbanism. Mostafavi, M. and C. Najle eds. London, UK: Architectural Assocation; 58-62.
Cosgrove, D. (2006) “Modernity, Community, and the Landscape Idea.” Journal of Material Culture. 11(1/2): 49-66.
Daniels, T.L. (2009) “A Trail Across Time: American Environmental Planning from City Beautiful to Sustainability.” Journal of the American Planning Association. 75(2): 178-192.
Dear, M. and Flusty, S. (1998) “Postmodern Urbanism.” Annals of the Association of American Geographers, 88(1): 50-72.
Fishman, R. (2003 [1977]) “Urban Utopias: Ebenezer Howard and Le Corbusier”, in S. Campbell and S. Fainstein, eds. Readings in Planning Theory (2nd edition). Cambridge, MA: Blackwell, pp. 21-60.
Forsyth, A. (2002) “Planning Lessons from Three U.S. New Towns of the 1960s and 1970s: Irvine, Columbia, and The Woodlands.” Journal of the American Planning Association. 68(4): 387-415.
Godschalk, D.R. (2004) “Land Use Planning Challenges: Coping with Conflicts in Visions of Sustainable Development and Livable Communities.” Journal of the American Planning Association. 70(1): 5-13.
Harvey, D. (2009) Social Justice and the City. Athens, GA: University of Georgia Press.
McHarg, I.L. (1996) A Quest for Life. New York, NY: John Wiley & Sons.
Mehmood, A. (2010) “On the History and Potentials of Evolutionary Metaphors in Urban Planning.” Planning Theory. 9(1): 63-87.
Menard, A. (2010) “The Enlarged Freedom of Frederick Law Olmsted.” The New England Quarterly. 83(3): 508-538.
Nadenicek, D.J. (1993) “Nature in the city: Horace Cleveland’s aesthetic.” Landscape and Urban Planning. 26: 5-15.
Ndubisi, F. (2008) “Sustainable Regionalism: Evolutionary Framework and Prospects for Managing Metropolitan Landscapes.” Landscape Journal. 27(1): 51-68.
Olmsted, F.L. (1970 [1870]) Public Parks and the Enlargement of Towns. New York, NY: Arno Press.
Peterson, J.A. (2009) “The Birth of Organized City Planning in the United States, 1909-1910.” Journal of the American Planning Association. 75(2): 123-133.
Pregill, P. and N. Volkman (1993) Landscapes in History. New York, NY: Van Nostrand Reinhold.
Pollack, L. (2006) “Constructed Ground: Questions of Scale.” The Landscape Urbanism Reader. C. Waldheim, ed. New York, NY: Princeton Architectural Press; 125-140.
Reed, C. (2006) “Public Works Practice.” The Landscape Urbanism Reader. C. Waldheim, ed. New York, NY: Princeton Architectural Press; 267-287.
Seddon, G. (1986) “Landscape Planning: A Conceptual Perspective.” Landscape and Urban Planning. 13: 335-347.
Shane, G. (2003) “The Emergence of ‘Landscape Urbanism’: Reflections on Stalking Detroit.” Harvard Design Magazine. 19: 1-8.
Steiner, Frederick R. (2000), The Living Landscape: an ecological approach to landscape planning, 2nd addition. New York, NY: McGraw Hill.
Sullivan, L.H. (1896) “The tall office building artistically considered.” Lippincott’s Magazine. March. Retrieved from http://www.personalweb.unito.it/andrea.carosso/nyc/texts/Louis%20Sullivan%20-%20The%20Tall%20Office%20building.pdf on December 6, 2010.
Sullivan, R (2008) “Wall-E Park.” New York Magazine, Dec 2008. Retrieved from http://nymag.com/news/features/52452/ on December 6, 2010.
Thompson, W. (1991) “A Natural Legacy: Ian McHarg and His Followers.” Planning. 57(11): 14-19.
Tishler, W.H. and W.S. Luckhardt (1985) “H.W.S. Cleveland: Pioneer Landscape Architect to the Upper Midwest.” Minnesota History. Fall: 281-291.
Waldheim, C. (2006) “Landscape as Urbanism.” The Landscape Urbanism Reader. C. Waldheim, ed. New York, NY: Princeton Architectural Press; 35-54.
Weller, R. (2008) “Landscape (Sub)Urbanism in Theory and Practice.” Landscape Journal. 27(2): 247-267.
Weller, R. (2006) “An Art of Instrumentality: Thinking Through Landscape Urbanism.” The Landscape Urbanism Reader. C. Waldheim, ed. New York, NY: Princeton Architectural Press; 69-86.