The Importance of Being with Nature
The estimated exponential rise in urban population densities raises obvious sustainability concerns. Given the dramatic increase in city inhabitation it is increasingly important that people feel ownership and responsibility for shared public spaces. The emotional, cultural and social well-being of urban communities is dependent on numerous considerations and factors. The establishment of a sense of place and the role of ecology in achieving this is fundamental to the long term health or urban environments.
The conceptions of urban settlements as vehicles for green corridors, ecological-networks, green wedges and greenways (to borrow from fashionable terminology on the subject) have begun to take traction in urban landscape planning. On the face of it there are some stakeholder professionals willing to embrace green technological solutions to issues such as carbon emissions, waste management and water resource management. However, the rise in urban growth and higher density living present challenging conceptual predicaments for planners and architects wishing to apply bio-diverse and ecologically functioning green spaces.
The restorative qualities created by designed green spaces are all important to the ultimate objective of sustainable urbanity. As population thresholds increase, how the emotional health of urban dwellers is assisted through the deployment of imaginatively designed green spaces, becomes a marker for livability. Increasing nature within the city connects humanity with nature establishing regional identities and a sense of place. Furthermore, green spaces are a formative element in supporting energy conservation, economic benefits and reduction of the urban heat island effect as they mitigate the effect of higher urban temperatures. As new developments are constructed, carpeting urban areas with more impervious surfaces and reducing water infiltration, offsetting this effect is significantly assisted by urban green spaces. For example, in forests 95% of rainfall is absorbed whereas only about 25% is absorbed in cities. This has obvious implications for flooding, but also for the retention of heat, contributing to the urban heat island effect. If water is not retained as a result of run off from impervious surfaces, the quantity of water available for evaporation is reduced.
The application of diverse ecologies within cities is for most part viewed as a valuable addition to energy conservation and also a fundamental element in establishing unique regional identities.
Increasing the scale and scope of green spaces is a major challenge for architects, designers and planners. The process of marrying environmental principles with well-designed and aesthetically engaging green spaces is a fundamental issue. As such, green roofs are increasingly being viewed as a cost effective way of introducing environmentally dependable features within new and existing structures. London has installed 230,000 square metres in the last decade, and Chicago now has approximately 278,700 square meters of green roof space. They are also described as eco-roofs, living roofs and brown roofs, but essentially provide an option for the adoption of a holistic, multi-disciplinary move towards the notion of living architecture.
The constituent elements of green roofs can vary depending on the needs of the client and location of the building. Generally, they are comprised of a substrate material usually composed of local non-organic materials that primarily act as a drainage medium. This underpins a vegetation support course of predominantly organic material, acting as the growing medium. The plant materials can vary depending on climatic and design requirements, but are typically sedum mixtures, herbaceous materials and grasses.
Living walls are a vertical correlation of green roof processes. Living walls can improve indoor air quality by removing toxic chemicals and carbon dioxide and can insulate against summer heat and winter cold. They are a visible reference to living architecture and also connect urban dwellers with nature. Although construction materials and installation techniques are similar regardless of location, different climates and economies can determine local substrate materials and plant materials. The use of local materials and ecologies affords the architect and designer the opportunity to create corresponding regionally distinct living architecture. The living wall’s principle benefit when compared with green roofs is its visibility. If people are to engage and feel ownership of a more nature inspired urban landscape they need to feel part of it, visually attached to the ecology of place.
The notion that ‘placeness’ can be realised through utilising the fortuitous landscape of forgotten places has been a source of theoretical deliberation for designers, planners and academics. This rationale contends that the creation of place is dependent on its regional identity. Connected to local ecological values and principles, the natural urban plants of forgotten places within the city, such as cracks in the pavement, walls, rooftops, or wherever a foothold can be gained. This natural process driven ecological approach to landscaping urbanity runs counter to well-established pedigreed landscapes of mown turf and formal planting. The theories expounded by some academics and designers offer an alternative model to fixed conventions. Nevertheless, in practice for most part urban landscaping follows the traditional modernist method of applying vegetation and ecology. The conspicuous absence of less traditional approaches to designed urban ecology is mainly due to the negative perception of aesthetic accessibility. This is combined with a culture of the play it safe approach within civic authorities and built environment professions. For all of that, there are imaginative projects and developments that point to a more progressive move towards a more sustainable, culturally welcoming spatial landscape form. One of the more celebrated examples of an alternative vision of urban green spaces is the NYC High Line. Originally an iron clad raised freight train track built 30 ft. above the street in the 1930’s until its disuse in 1980, the “High Line” has been transformed into a public park. The rail runs north to south from the terminus on 30th Street to the meatpacking district and is a visually distinct reference to post-industrial age resilience. Rail tracks and planted sections harmoniously co-exist with engineered sections and designed paving systems. The plantings are inspired by the fortuitous self-seeded landscape that grew in the track’s period of dereliction. Grasses trees and shrubs were chosen for their colour, texture and sustainability, with the focus being on local species. Perhaps surprisingly, the radical complexion of the development was embraced by the city, and the risk appears to have paid off. Crickets can now be heard in lower Manhattan and the public has responded positively to this connection to nature. The “High Line” provides a potential benchmark for the future development of post industrial or brown field sites. It demonstrates a more nature driven approach to urban landscape design and establishes the function of the vernacular landscape in establishing a regional identity. As such it provides a radical alternative to the corporate modernist designs that are such a familiar feature of the contemporary multi-use urban developments. The “High Line” is the inspiration for other green developments within similar settings of urban deterioration. La Petite Ceinture in Paris for example is an abandoned section of rail track running between the Porte d’Auteuil and the Gare de Passy-la-Muette. The first section open to walkers was opened in 2008 and is promoted as a haven of a rare bio-diversity of flora and fauna. Though the track does not ‘benefit’ from developers and designer input as yet, the track is becoming increasingly popular with tourists and further sections of track are to be made available to the public in the near future.
Dubbed Mexico’s High Line, the Chapultepec Project invokes obvious visual comparisons with the High Line – an elevated garden walkway running through a densely populated and developed urban environment. The fundamental difference between the two is that the Chapultepec Project will be built from scratch. The ‘bridge’ will link a metro station to the Chapultepec forest also known as the lungs of the city. The walkway is viewed as an arm of the forest, designed to be family friendly and is routed to dip under existing roadway intersections.
The High Line is indicative of both a willingness of civic authorities and designers to take calculated risks and the inclination of local communities to embrace an aesthetic previously associated with inaccessibility. In common with many successful projects the High Line has prompted what have been pejoratively termed ‘copy cat’ developments such as in Mexico City and Rotterdam. However, the underlying message should be viewed as positive additions to a more bio-diverse urban environment.
The integration of ecology and design holds great promise for a more nature inspired urbanity. The marriage of logical and intuitive thinking and science, designed landscape pattern and ecology, provide a basis for the planning and design of sustainable environments. In reality, for most part the spatial and formal characteristics of cities continue to be determined by modernist and postmodernist design sensibilities. Attempting to define both narratives is a complex piece of business, though it is necessary to endeavor to represent their philosophical influence on everyday existence.