Urban Regeneration: Foresting Vacancy In Philadelphia

Project: Urban Regeneration: Foresting Vacancy In Philadelphia
Location: Philadelphia, PA
Designer: Chieh Huang
Year: 2013
Program: University of Pennsylvania School of Design
Faculty Advisor: Christopher Marcinkoski

Project Description: Instead of trying to fill up the “black hole” of vacancy, Urban Regeneration: Foresting Vacancy in Philadelphia envisions a different future for the city of Philadelphia — one that not only embraces, but expands vacancy. With the assistance of a proposed Philadelphia Land Bank, the system accumulates and transforms vacant property as well as under-used infrastructure into an adaptive and productive urban forest, not only increasing the biodiversity of the urban environment, but in the long run, also lowering maintenance costs and balancing the real estate market for the city.

Contemporary American cities such as Detroit, Cleveland, and Philadelphia have been struggling with population decline and consequently with the problem of vacancy. Property values in the vacant areas of these cities continue to plunge, while crime rates sky-rocket. Tax delinquent properties turn into city’s burdens instead of revenue sources, and infrastructures become inefficient and redundant. Altogether these issues start snowballing into an irreversible vicious cycle.

Upon acknowledging that there is “more vacant property than can be filled,” the question is no longer “how to fill up the void?” but rather “how to utilize the void?” Under the complex settings, this project proposes a landscape planning and land management strategy that adapts both spatially and economically to a shrinking population.

The project is inspired by the remnants of post-industrial train tracks that formerly stretched into the urban grid. By thickening the Northeast Corridor with robust forests, wetland and habitat patches, a river-to-river connection is established. The urban fabric is also diversified with successional forests, while stormwater is managed locally in acupunctural wetlands, reducing CSO overflows into the Schuylkill River and Delaware River. The system then expands, with spurs growing out from the thickened spine into the city. Along these former under-used streets, active programs like community farms, rain gardens, and linear parks will become the new urban edge that redefines its adjacent neighborhoods. Superimposed on top of these, a bike trail network interconnects the city with its two river fronts.

In addition to the spatial intervention, a new land bank system is proposed as a tool of land management for the project. Unlike a conventional land bank, the Philadelphia Land Bank is set up not only to acquire and manage vacant property but to take them permanently off the market for urban forestry, allowing the population to concentrate in livable areas. By cutting down the housing supply to match the low demand in the area, a balance in the real estate market will be achieved. Once the physical conditions of the areas have been improved and the market structure been restored, the remaining lands in North Philadelphia can begin to recover in market value. Unlike the over-sized Fairmount Park with its large portions of green space hidden deep inside the park, the systematic, growing network of linear urban forests creates a maximum number of green interfaces directly to the urban fabric, stretching nature into the heart of the city. Along these interfaces, new urban lifestyles will emerge: kids biking through the green linear parks to get to school; the community gathering in the urban farm to grow their own fresh produce; couples taking a romantic stroll in the woods after dinner; recycled materials from abandoned factories and rail constructions being used to build low-budget scaffolding bridges, providing easy and scenic access across the railway and the forests.

By strategically accumulating and turning vacancy into an urban forest, the project reorganizes the spatial disruption of the existing fabric. By reshaping the city and its neighborhoods into an economically efficient and manageable size, and reducing service costs by replacing under-used infrastructure with a sustainable landscape, this project aims to redefine the meaning and function of vacancy in the city.


Featured in Scenario 4: Building the Urban Forest 


Invasive Species

Project: Invasive Species
Location: Cape Town, South Africa
Artist: Dillon Marsh
Year: 2014
Artist website: http://dillonmarsh.com

Project Description: I
n 1996 a palm tree appeared almost overnight in a suburb of Cape Town, South Africa. This was supposedly one of the world’s first disguised cell phone tower. Since then these trees have spread across the city, the country and the rest of the world. Invasive Species explores the relationship between the environment and the disguised towers of Cape Town and its surrounds.


Featured in Scenario 4: Building the Urban Forest 

Big Old Tree, New Big Easy

Project: Big Old Tree, New Big Easy
Location: New Orleans, LA
Designer: Karen Lutsky
Year: 2010
Program: University of Pennsylvania School of Design
Faculty Advisor: David Governeur, Nicholas Pevzner

Project Description: ‘Big Old Tree, New Big Easy’ is an adaptable design proposal built upon the inherent qualities and capabilities of New Orleans’ native tree species. The project explores the potential of a simple urban afforestation strategy to engage the past, respond to critical current social and infrastructural issues, and support a ‘sustainable’ future. 

The strategy begins and ends with the trees. The plan uses well-known attributes of three native tree species (the high-ground live oak, the mid-ground pecan, and the water-loving cypress) to maximize the capacity of the resulting urban canopy to manage water through evapotranspiration, to stabilize the currently sinking ground with extensive root systems, to connect neighborhoods and promote recreation with new shade and structure, to produce valued goods such as nuts and wood, and to harbor and nurture the growth of a strong community.

Maintenance-heavy areas such as orchards and community gardens are located adjacent to schools and community centers. The labor of planting and pruning trees, and harvesting fruit and wood is work that is easily managed, quickly taught, and carried out with accessible training. This allows it to be managed by a volunteer-based, multi-generational workforce without much risk, and lends itself well to larger group participation, promoting communal interaction and engagement. Utilizing the availability of the city’s post-Katrina ‘volun-tourism’ work-force provides an initial source of individuals and communities that value and have experience in collective organization.

As they grow, the trees also begin to engage the community in new ways. Early phasing of tightly planted groves in the project require that trees be thinned out over time. This management practice not only supports the healthy maturation of old-growth trees in the corridor, but also provides a ‘nursery’ source for native trees that may be transplanted into rest of the community, allowing the maintenance of the corridor to continually populate the greater neighborhood with these trees.

The key armature of the proposal is a clear, striated planting plan, in which trees are planted linearly across the site with variation in spacing and species in response to varying ground conditions. This formation creates a planting plan that provides consistency across the landscape, structurally unifying and visually connecting the entirety of the corridor. The responsive planting strategy places water-loving trees on wetter ground, pecan or harvestable trees near schools and local community organizations, and live oaks on high ground and along the main path.

The simplicity of the planting plan also allows the project to continue to function under reduced maintenance. Even if nothing is provided beyond initial planting of the trees and sufficient care to assure their establishment, the trees will still provide the much needed functions of mitigating water, creating habitat, cooling urban climate, increasing the quality of our air, and ensuring another crop of ‘big, old trees’ for the next generation. 


Additional Project Information:

2011 National ASLA Honor Award in Analysis and Planning


This project was featured in Scenario 4: Building the Urban Forest 


50,000 Trees

Project: 50,000 Trees
Location: San Francisco, CA
Designer: Sarah Moos
Year: 2013
Program: University of California, Berkeley
Faculty Advisor: Judith Stilgenbauer

Project Description: Freeways and highway overpasses are often seen as the epitome of environmental destruction in the urban landscape. Yet the complex spaces below and around urban freeways may be productively re-imagined as beneficial working landscapes, deploying trees en masse to buffer the harmful effects of these traffic conduits. This project explores how freeway urban forests could strategically offset a significant part of the city’s carbon emissions at the source.

In this project, a 30-acre site of underutilized space beneath a multi-level interchange in San Francisco, CA is envisioned as a productive urban forest. The design for the site has three primary goals.  First, it seeks to plant a robust forest of enough trees to offset a portion of the annual CO2 emissions from the adjacent freeway. Second, it devises an irrigation system that builds upon existing infrastructure to irrigate the forest and to reduce persistent stormwater flooding on this former marshland. Third, it establishes pedestrian pathways and provides amenities throughout the forest to create a memorable and interactive landscape. The forest is a new urban landscape that emerges over time, transforming the driving experience at the freeway level and establishing places for pedestrian interaction at street level. If the freeway is rendered obsolete in the future, the interchange will transition from a mono-functional freeway into a multi-use interchange for pedestrians, public transportation, flora, and fauna amid a dense urban forest.

The project’s design also takes advantage of innovative forest sequestration techniques, resulting in a cycling strategy that alternates phases of growth, partial removal, afforestation, and diversification. This compact planting and maintenance strategy allows for the sequestration CO2 and other emitted compounds within a significantly reduced footprint.

The estimated $1.7 million of annual urban ecosystem services generated at the interchange – including the value of trees, soil, captured water, wind energy, and jobs – can then be used over time to expand the afforestation effort to at least 90 other underutilized freeway right-of-ways throughout the entire San Francisco Bay Area. Taken together, the resulting urban forest would become a “new and powerful” sequestration infrastructure functioning at the metropolitan scale.


Additional Information:

The City of San Francisco has utilized the research, analysis, and design of this strategy to inform aspects of the 2014 Urban Forest Master Plan — a component of the One Bay Area Plan that is aimed at offsetting emissions through innovative solutions.

This project received the 2013 National ASLA Honor Award in General Design.


Featured in Scenario 4: Building the Urban Forest 

Roundabout Vancouver

Project: Roundabout Vancouver
Location: Vancouver, British Columbia, Canada
Firm: Goodweather Collective
Year: 2011
Website: http://www.goodweather.ca/

Project Description: What would a metropolis in the Pacific Northwest look like if urban planners at the turn of the twentieth century had recognized and exploited the spatial potential of old-growth trees rather than their resource potential? Employing techniques of photomontage and urban mapping, we have proposed an anachronistic detour that decouples empirical fact from historical memory.

While in the present city of Vancouver, the center space of traffic roundabouts is given over to various sanctioned treatments—community gardens, a monumental rock, and so on—in this “retroprojective” proposal an alternative vision of the not-so-distant past is offered, one in which forward-thinking city planners leave an old-growth tree in the middle of each future roundabout.

With this simple gesture, we can envisage an entirely different city, one in which massive trees are no longer a rarity but instead fundamentally define and shape our movement through the urban fabric of Vancouver. While the singular presence of each tree is in itself remarkable, their collective existence is a legacy comparable in size and density to that of Stanley Park, Vancouver’s beloved urban green space. With this action on the civic imagination, the city becomes a forest, and the forest a city.

This project was featured in Scenario 4: Building the Urban Forest 


Landscaping Schiphol Airport

Project: Landscaping Schiphol Airport
Location: Schiphol, Amsterdam, The Netherlands
Firm: West 8
Year: 1992
Firm website: www.west8.nl

Project Description: When West 8 was asked to take on this project in the late 80s, the question emerged of whether it was actually possible to ‘landscape’ an airport. In an environment that is so dynamic, there seemed to be nothing to design; no durable plan drawing to be delivered. There were no precedents or examples; it had not been done before. This forced the team to start thinking in terms of a ‘menu’ rather than about a final design. West 8 pitched to Schiphol management, that they should get rid of all the patches of dirt, all the unnecessary tarmac, all the vacant gravel lots, the unused sidewalks, the maintenance-intensive garden beds and half-empty storage compounds. Everything was to be taken away and all those vacant bits of land should be planted with trees. Young small trees, planted in masses, which were cheap, would be spread across the airport area like a veil.

Rather than starting with an image, West 8 began by reconsidering the process by in which an airport landscape is designed and built. West 8 abandoned the notion that that there should be a project landscape architect which attends weekly meetings. Instead the approach was that as soon as a site was cleaned up, became vacant, or was left abandoned, a bombardment of trees took place, which required very little maintenance.

The airport strategy had four simple layers:

  • Runway verges: For those arriving at Schiphol, Holland’s green and tidy image needs to be confirmed. The green grassed verges are well maintained at all times.
  • Green route: Various airport services, facilities and centers, are positioned along a loop road. A uniform landscape treatment links and characterizes these auxiliary areas.
  • Infill planting: In amongst the airport buildings, facilities and services are many areas of open space and vacant land. All those areas, without an identifiable purpose, are planted with trees.
  • Visual access: The most impressive visual quality of an airport is the landing and take-off of planes. Coinciding with air-safety, visual corridors are kept open for people to enjoy.

The Right Tree: Special attention had to be paid to the selection of the tree species for the project. Schiphol Airport as a territory has a wide range of urban soil conditions. The airport is also situated in a polder, which is up to five meters below sea level. The water tables vary significantly across the site and vegetation is often subjected to high wind conditions. Finally, it is not acceptable that any vegetation attract or support bird populations.

After considerable investigation, it turned out that Betula pubescens, was the tree that ticked all the boxes. We proceeded to plant hundreds of thousands of these trees across the airport. As a natural pioneer species the birches were hardy and adaptable to the numerous growing conditions that occur at Schiphol. As unlikely as it may sound there are no birds perching in these trees, ever. In the past twenty years there has been only a single pair of European magpies who, in 2006/07 had a nest two years running, but they have since moved on.

So the diligent planting of trees and treating every spare, unused bit of airport surface with grass is now a 20 years strategy. West 8 is still commissioned on an ongoing basis to advise on landscape matters but essentially the project and the ever-changing landscape look after themselves.


Featured in Scenario 4: Building the Urban Forest