Vacant or abandoned land

"The Neighborhood, Environment & Water Research Collaborations for Green Infrastructure (NEW-GI)" project in Warrendale, Detroit, aims to advance green stormwater infrastructure (GSI) knowledge and practice in legacy cities by integrating research on water quality, community well-being, governance, and ecological design. This collaborative effort, involving community members, government entities, and academic researchers, seeks to develop evidence-based strategies for sustainable stormwater management while enhancing urban landscapes and improving residents' quality of life.
In its first phase (2014-2015), the project created bioretention four bioretention gardens, each on two vacant residential properties in the Warrendale neighborhood. in Detroit's Warrendale neighborhood. These sites, constructed by the Detroit Water and Sewerage Department (DWSD) on vacant lots owned by the Detroit Land Bank Authority (DLBA), were monitored for water quality, and resident surveys were conducted to gauge the gardens' impact on neighborhood satisfaction and stormwater management.
The second phase (2016-2019) expanded the scope to refine GSI designs to reduce maintenance needs and further assess their effects on water management and community well-being. It also explored governance structures that impact GSI success, both in Detroit and other legacy cities, contributing to the development of guidance documents for GSI planning and decision-making.
Funded by the Fred A. and Barbara M. Erb Family Foundation, the NEW-GI project represents a transdisciplinary approach to urban ecological challenges, offering valuable insights into how GSI can deliver both environmental and social benefits in cities like Detroit.
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Due to rapid urbanization and development, cities in China, including Kunming, face challenges in managing neglected urban spaces, particularly vacated demolition sites and leftover land (Ref 1, 2, 3). To address this issue and enhance residents' well-being, Kunming has created 400 pocket parks since 2022, transforming forgotten corners into vibrant green spaces (Ref 4, 5).
One of these parks, Wenxing Pocket Park in Xishan District, was built in 2023 on 2.3 hectares of land (Ref 6). Located next to a secondary school and two protected historical relics, the park not only preserves historical heritage but also reflects cultural value (Ref 6, 7). In addition to increasing urban green spaces, the park provides recreational and physical facilities for residents, children, and students (Ref 6). Its design is inspired by traditional architectural styles and incorporates wood craftsmanship, as well as ecological sponge facilities (Ref 6, 7).
The park also features science gardens, promoting awareness and knowledge of herbs and sustainability (Ref 6). The project employs methods such as infiltration, stagnation, storage, purification, and drainage to manage rainwater effectively. By utilizing the natural terrain, it creates ecological dry streams and sunken gardens that absorb and store rainwater, helping to control runoff. This approach aligns with the "sponge city" concept, promoting natural water accumulation, infiltration, and purification.
Additionally, the integration of various plants enhances the microclimate, supporting local wildlife and creating a healthy, vibrant public space. The Wenxing Pocket Park has been implemented by the Municipality of Xishan. (Ref.6,7)

The Urban Forestry Plan for Cartagena, led by EPA Cartagena, outlines a comprehensive strategy for enhancing the city's green infrastructure. The plan focuses on selecting suitable tree species, planting, and management to achieve several goals: reducing heat through shade, creating microclimates, protecting against climatic events such as coastal erosion and windstorms, enhancing food security, and enhancing the landscape's beauty. Over 10 years, the plan aims to establish at least 100,000 additional trees, increase overall tree cover, enhance accessibility to green spaces, and build a main ecological structure based on natural resources and biodiversity. It also emphasises the importance of local knowledge and resources (ref 1).
Formulated with community input, the plan commenced in 2013 and involved a detailed assessment of existing urban vegetation and climate conditions, utilising tools such as iTree. The development included international conferences and expert consultations to ensure a robust and informed approach (ref 1).

Historically, the area of San Paolo in Cagliari has suffered from environmental degradation and illegal dumping, making it an unsightly entrance to the city. In 2022, the Città Metropolitana di Cagliari, initiated a project to transform this degraded area into a urban park featuring 7,000 new plants, including olive trees, junipers, lentisks, myrtle, rosemary, tamarisks, and Aleppo pines. Managed by the municiplaity of Cagliari, and funded by a €500,000 grant from the Ministry of Ecological Transition, this initiative will cover 4.7 hectares between Via San Paolo and the Santa Gilla Lagoon, creating a natural corridor connecting the city to the lagoon. The project aims not only to restore the land but also to enhance both metropolitan and municipal environmental requalification plans.
A multidisciplinary team, including a forestry technician, agronomist, and biologist, developed the project to ensure it is environmentally sustainable and suited to the local ecosystem.
The work on the project began in June of 2022 with land preparation, removal of invasive species, and waste collection, resulting in the clearing of over 5 tons of rubbish. By December, around 3,000 plants had already been planted, with the remaining work, including the installation of an irrigation system, scheduled for completion by January 2023. The selected plant species are fast-growing, and within two years, the shrubs are expected to reach a height of about two meters. The park is planned to open to the public in 2024, providing a new green space for walking and outdoor activities.
The San Paolo urban park project has encountered obstacles, mainly due to the expropriation of buildings, leading to legal disputes, permit delays, and a temporary halt caused by a tender-related issue. The site is currently overgrown and unused, showing clear signs of neglect. (Refs. 1, 2, 3, 4 & 5).

The Chaowan Nursery Garden Base Project (潮玩苗圃基地), located along the Dianchi Greenway in Kunming, was established by the Kunming Gardens Virescence Bureau (昆明市园林绿化局) in 2022 as part of the city's efforts to transform into a "city of parks" (Ref 2, 3). Covering 639 mu (42.6 hectares), the Chaowan Nursery Garden has introduced over 1.4 million plants, including trees, flowers, and grasses, greatly expanding the city's green spaces (Ref 3). It serves as a key resource for the Kunming Greening Service Center (昆明市绿化服务中心), providing seedlings for major greening projects along roads like Guangfu Road, Airport Road, Beijing Road, and the Second Ring Elevated Road (Ref 4).
Innovatively designed, the nursery also functions as a park, offering an "immersive" experience with various themed areas such as rainwater gardens, rural gardens, Chinese gardens, and scenic balconies. These spaces allow visitors to stroll through and enjoy the beauty of various flowers and natural surroundings (Ref 4). The project also collaborates with local universities on seedling research, capacity building, and resource sharing, further enhancing its multifaceted role (Ref 3).
Since opening to the public in 2023, the Chaowan Nursery Garden has become a popular destination for families, young people, and children, offering both recreational and educational experiences (Ref 5, 6, 7, 8).

The PARK(ing) project, completed in April 2022, is an urban private intervention in Core City neighborhood in Detroit, that re-imagines a vacant 24,000-square-foot lot into a dual-purpose public park and a 28-car parking lot. Designed by Julie Bargmann of D.I.R.T. Studio, in collaboration with Prince Concepts and in-house landscape designer Andrew Schwartz, this innovative green space harmonizes urban infrastructure with natural elements. The site is punctuated with 78 newly planted trees, including sumac, maple, and evergreen species, creating an environment rich in vegetation that seamlessly integrates with its urban surroundings.
The design incorporates permeable pavers and sloped berms, which effectively manage storm-water by absorbing and channeling rainwater, mitigating the risk of flooding—an often-overlooked challenge in traditional parking lots. This approach reflects sensitivity to the local environment and a commitment to sustainable urban design.
By day, the park discreetly functions as a parking facility, with cars nestled among dense greenery, while by evening, it transforms into a public garden, extending the communal space of Core City Park. This dual functionality addresses the needs of a car-dependent community while promoting walkability and enhancing the neighborhood's ecological footprint.
PARK(ing) exemplifies a shift in Detroit's urban planning, moving away from the car-centric developments of the past toward a more balanced relationship between people, nature, and infrastructure. The project stands as a testament to the evolving identity of American cities, particularly those like Detroit, historically shaped by the automobile. It offers a vision of urban spaces that prioritize community well-being and environmental stewardship while acknowledging the realities of modern urban life. (Ref. 1, 2)

The Joe Louis Greenway is a 27.5-mile recreational pathway designed to create safe, connected, and equitable spaces throughout Detroit. It will link 23 neighborhoods across Detroit, Hamtramck, Highland Park, and Dearborn, connecting them to each other and to the Detroit riverfront. The greenway will transform a blighted, abandoned rail corridor into a park that runs through the heart of Detroit's communities. (Ref. 2, 3)
This project is guided by a Framework Plan funded by the Ralph C. Wilson, Jr. Foundation and shaped by extensive community input. Residents voiced a strong desire for the greenway to provide off-street recreation and increased access to green spaces across Detroit. Additionally, they advocated for the restoration and remediation of former industrial sites, which the Conrail section of the greenway will address. (Ref. 4) The design incorporates stormwater management to mitigate flooding, native meadow plantings to support bird habitats, and tree-lined paths for shade and improved air quality. The Framework Plan ensures the Joe Louis Greenway will transform infrastructure that once divided neighborhoods into one that unites them, reconnects natural systems, drives economic redevelopment, and fosters a resilient social network. (Ref. 13)
The concept originated in 2007 with the Friends of the Inner Circle Greenway local NGO and became part of the Detroit Greenways Coalition Network Vision in 2009. The Detroit Greenways Coalition Network Vision is a comprehensive plan developed by the Detroit Greenways Coalition (NGO), an organization dedicated to promoting non-motorized transportation and green infrastructure throughout the city. After years of advocacy and collaboration with the city of Detroit, the project’s route was finalized. In 2017, Mayor Mike Duggan announced the greenway would be renamed in honor of Joe Louis, the legendary boxer and Detroit native who championed African Americans' rights and symbolized social justice. (Ref. 1, 2,)

The Floating University was initiated in 2018 at the rainwater retention basin of the former Tempelhof airport in Berlin. Though not an official university, it serves as a space for transdisciplinary, communal learning, transforming an abandoned urban site into a vibrant community resource. The project reclaims the basin, hosting workshops and events that range from ecological lectures to cultural and art programs, fostering collaboration between diverse disciplines and communities.
The architecture collective raumlaborberlin originally envisioned the project as a six-month initiative. Artists, universities, and seminar groups contributed to designing the space and organizing workshops. However, due to its success, an NGO, Floating e.V., was established to sustain the project. Today, the NGO manages the site and continues its mission of engaging communities with urban and ecological themes.
After Tempelhof airport closed in 2008, the basin was infrequently cleaned, leading to contamination and sediment accumulation. Over time, a wetland ecosystem emerged, attracting plants, insects, birds, mammals, and amphibians. This natural development complements the Floating University’s infrastructure, which consists of open timber structures like a kitchen, art installations, communal spaces, vertical gardens, gardening beds, and an auditorium. These structures integrate seamlessly with the basin’s existing technical framework and wetland environment.
Floating e.V. aims to make the basin accessible to Berlin’s urban population while sparking discussions about urban climate, resource management, and water cycles through diverse and artistic programs. Smaller initiatives focus on specific ecological themes, such as plant diversity and soil health, through projects like a seed archive and soil lab.
The Floating University exemplifies how abandoned urban spaces can be revitalized into hubs for learning, creativity, and ecological awareness. (1-3, 8, 9)

A community garden opened in 2023 on the Technological University (TU) Dublin Blanchardstown campus. This environmental education and social inclusion project is a collaborative effort involving Fingal County Council, Global Action Plan Ireland, TU Dublin, and the local community. It provides a space for local groups and schools to grow fresh produce, reconnect with nature, and foster a stronger sense of community.
Rooted in a successful template developed by Global Action Plan in Ballymun, this initiative promotes social and cultural inclusion alongside environmental education. The Green Living & Sustainability Community Garden (GLAS) aims to create an inclusive environment that welcomes individuals of all ages, abilities, and backgrounds. More than a site for cultivating plants, flowers, and vegetables, the garden serves as a hub for fostering social connections, enhancing well-being, and offering valuable educational opportunities.
The garden provides individuals with the chance to engage in social horticulture, exploring the connections between food, health, biodiversity, and global issues such as climate change. It operates on organic and regenerative principles, with all tasks and harvests shared by volunteers. Additionally, the garden will support youth gardening projects and public workshops on topics such as growing food, composting, water harvesting, and waste management. Beyond its environmental benefits, the garden helps people connect with one another, positively impacting social, physical, and mental well-being.

The city-wide project Urban Trees for Berlin was launched in 2012 with an ambitious goal: to plant 10,000 roadside trees within five years. This campaign, a key part of the Berlin Senate's Urban Green Space Strategy, is a collaboration between the Senate Department responsible for the environment and Berlin’s district authorities. Initially set to end in 2017, the campaign was extended through 2026.
The project was created to address the loss of numerous roadside trees that were removed due to age, pests, climate stress, and other factors. Limited funds had been available to replace these trees, resulting in negative impacts on Berlin's urban climate, including higher temperatures and worsened air quality, which affect both residents and visitors. The campaign aims to reverse these impacts by securing funding for new trees, restoring greenery to the city streets, and promoting a lasting positive image of Berlin’s urban trees.
The campaign operates on a co-funding model, where individuals, organizations, and companies donate €500 per tree (individually or collectively), with the Senate covering the remaining costs from the state budget (approximately €2,000 per tree). The planting schedule and locations are organized twice annually, with information shared online to keep the public informed.
In 2022, a new assessment of the project’s progress was conducted, commissioned by the Senate to the Arbo-tec office. Around 1,000 of the 3,500 trees planted as part of the campaign by autumn 2022 were evaluated. The selected locations included plantings from all previous construction phases, spanning 12 Berlin districts, with each district having 80 trees assessed from various phases and construction lots. This comprehensive evaluation is intended to ensure the long-term success and sustainability of the Urban Trees for Berlin initiative. (3, 4)