Triangle Park Urban Forest by Stoss Lanscape Urbanism
Massachusetts / USA / Built in 2024 /
stoss.net
Triangle Park reshapes an empty traffic island into an urban forest demonstration project—a first of its kind—bringing needed shade, biodiversity, and open space to an underserved area of East Cambridge. Guided by the city’s Urban Forest Master Plan, this 1-acre site hosts 400 new trees across a rolling landscape, offering a pocket of relief amidst an increasingly warming climate. The park is composed of 3 distinct habitat types which act in tandem to buffer traffic, capture stormwater, and allow for social gathering. The project implements intensive bare root plantings and innovative maintenance routines to foster natural competition, ensure ecological health, and support plant adaptation, thus acting as a model for urban forests of the future.
A small and contaminated traffic island is an unlikely place for a thriving ecosystem. In the southeast corner of Cambridge, Massachusetts, Triangle Park hosts a model urban forest, a system of shaded groves and lush berms that provides one of few natural respites amidst a rapidly developing city—and amidst an increasingly warming climate. This one-acre site, surrounded on three sides by traffic, has been, at various times in its history, a tidal mudflat, a fuelling station, a parking lot, and a dumping ground; such fraught history has left the site limited in its potential use, its soil having been contaminated and its extents being collared by traffic. For this reason, the site has been called a “leftover” space by the City of Cambridge—one of several intended to be redesigned and brought into the urban fabric as more active landscapes.
Guiding the design is the City’s Urban Forestry Plan, which aims to expand tree coverage throughout Cambridge. Under these guidelines, the site’s transformation would focus on providing shade, recreational space, and biodiversity — particularly in an area that borders a rapidly developing commercial district while also being adjacent to a lower income, racially and ethnically diverse residential community with limited access to open space. but how can a compact, contaminated site sustain a forest, especially one with ecological diversity?
The design approach involves a system of three habitats, each distinct in species and function. The “upland forest” features dense bare root saplings planted atop grassy berms that act as a buffer zone from the busy street; these berms are supported by custom, undulating seat walls, creating a stepped landscape and central gathering space. The “midland forest,” or urban grove, is inscribed of the upland forest and offers seating and shade from small, flowering trees—the park’s social nucleus. The “lowland forest” exists at the tail of the site—the triangle’s point—and captures surface run-off to an extensive and lushly planted infiltration grove.
Across these three habitat types, the site’s canopy coverage has increased by four hundred percent, with 12 existing trees being retained and 400 new ones being planted in clean soil. The park’s tree palette now includes fifteen new species, all urban tolerant, and a variety of intensive bare root plantings. The latter are intended to encourage natural competition among species, allowing individual trees to outcompete one another as some become more adapted to their urban context, increasing temperatures, and intensifying storms. This requires a partnership with the City, who is devoting additional long-term monitoring and care: they will cull out less successful trees over time, allowing for a healthy and well-adapted mature forest to emerge. This experimental technique is more akin to ecological processes in a forest, less so in city parks.
Importantly, the park is also designed for people, offering various clearings intended for quiet gathering, relaxation and informal play. The park allows people the health and benefits of exposure to verdant greenery without being too removed from its urban context—a wooded oasis amidst a tangle of traffic and commercial development. Triangle Park now serves as a model for the City’s Urban Forestry Plan, repurposing a “leftover” space to one of social and environmental significance.
• All landscape architecture offices involved in the design of landscape:
Chris Reed
Joonyon Kim
Albert Chen
Sookyung Shin
Han Yu
Hongfei Li
Shirley Yang
• All architecture offices involved in the design:
Nitsch Engineering (Civil Engineering)
Simpson Gumpertz & Heger (Structural Engineering)
Thompson Engineering Company Inc (Electrical Engineering)
Irrigation Consulting Inc. (Irrigation)
Pine + Swallow Environmental (Soil Consulting)
Fennessy Consulting (Cost Estimator)
Kleinfelder (Environmental Consultant)
Horton Lees Brogdon Lighting Design (Lighting)
