Tempelhofer Field
Tempelhofer Feld stands as an innovative green solution in the heart of Berlin, addressing several issues of environmental justice, biodiversity, and urban resilience. Within the S-Bahn ring, only one in 20 residents lives in areas well-served by green spaces, and districts like Neukölln, Kreuzberg, and Tempelhof would face even greater scarcity without this vast expanse. Many residents in these neighborhoods lack access to private green spaces such as gardens or balconies. Without nearby parks, people are compelled to travel to other districts, exacerbating the congestion of green spaces and increasing local traffic.
Since its opening in 2010, Tempelhofer Feld has provided Berlin with over 300 hectares of open, green, leisure, and recreational space, making it one of the largest urban open spaces globally. Once the site of bustling air traffic, it is now a sanctuary for activities such as skating, strolling, gardening, picnicking, birdwatching, kiteboarding, and more. These wide-ranging uses showcase its transformation into an accessible, multifunctional green space that serves as a social equalizer, particularly for disadvantaged neighborhoods, a significance amplified during the Covid-19 pandemic.
The field is not just a recreational haven but also a vital ecological refuge. With over two-thirds of its area designated as green space, it hosts diverse ecosystems, including extensive natural meadows, lawns, and protected habitats for birds and other species. Certain areas are closed to the public to preserve these sensitive environments, emphasizing the balance between human activity and ecological conservation. Since 2019, animal landscape keepers, including around 100 resident sheep, have contributed to sustainable land management practices, promoting biodiversity and ecological health (Ref. 2).
Managed collaboratively by political, administrative, and societal actors, the site exemplifies integrated citizen participation in urban planning. (Ref. 3)
Since its opening in 2010, Tempelhofer Feld has provided Berlin with over 300 hectares of open, green, leisure, and recreational space, making it one of the largest urban open spaces globally. Once the site of bustling air traffic, it is now a sanctuary for activities such as skating, strolling, gardening, picnicking, birdwatching, kiteboarding, and more. These wide-ranging uses showcase its transformation into an accessible, multifunctional green space that serves as a social equalizer, particularly for disadvantaged neighborhoods, a significance amplified during the Covid-19 pandemic.
The field is not just a recreational haven but also a vital ecological refuge. With over two-thirds of its area designated as green space, it hosts diverse ecosystems, including extensive natural meadows, lawns, and protected habitats for birds and other species. Certain areas are closed to the public to preserve these sensitive environments, emphasizing the balance between human activity and ecological conservation. Since 2019, animal landscape keepers, including around 100 resident sheep, have contributed to sustainable land management practices, promoting biodiversity and ecological health (Ref. 2).
Managed collaboratively by political, administrative, and societal actors, the site exemplifies integrated citizen participation in urban planning. (Ref. 3)
City of Gothenburg Tree Policy
The City of Gothenburg's policy for park and street trees was updated in 2016 and has the overarching aim to maintain and develop the ecological, historical, social and economic values of the city's trees and tree environments. Trees are described as having ecological, historical, cultural and economic values. They can provide ecosystem services such as habitat and biodiversity, air quality improvement, flood prevention, heat mitigation, recreation and aesthetic values [Ref. 1].
The policy applies to all trees in the streets, squares, and parks within the municipality but not to natural environments such as forests at the city's edge. Further, the policy is mostly relevant for municipality employees whenever they make decisions that will affect trees or tree-covered areas, such as zoning/planning and construction projects. Other actors in the city, such as private real estate or construction companies, are not required to follow the policy but are encouraged to consider it. The policy formulates sub-goals and guidances regarding the preservation of existing trees (prioritising large and old ones), the planting of new trees, the maintenance of trees, protection during construction work and finally, the taking down of trees, including compensation measures. The policy's direct effects is an expected improved management of trees within the municipal organisation. This may have further indirect benefits in the form of increased ecosystem service provision when the policy affects other projects [Ref. 1, 2].
The policy applies to all trees in the streets, squares, and parks within the municipality but not to natural environments such as forests at the city's edge. Further, the policy is mostly relevant for municipality employees whenever they make decisions that will affect trees or tree-covered areas, such as zoning/planning and construction projects. Other actors in the city, such as private real estate or construction companies, are not required to follow the policy but are encouraged to consider it. The policy formulates sub-goals and guidances regarding the preservation of existing trees (prioritising large and old ones), the planting of new trees, the maintenance of trees, protection during construction work and finally, the taking down of trees, including compensation measures. The policy's direct effects is an expected improved management of trees within the municipal organisation. This may have further indirect benefits in the form of increased ecosystem service provision when the policy affects other projects [Ref. 1, 2].
The Lower Salt River Restoration Project
The Lower Salt River Restoration Project (LSRRP) is a riparian restoration initiative located along the Lower Salt River within the Mesa Ranger District of the Tonto National Forest. This collaborative project seeks to restore a section of the Lower Salt River Recreation Area that was severely impacted by the 2017 Cactus Fire. The Cactus Fire was a significant wildfire that caused extensive damage to vegetation and habitat in the area, highlighting the need for targeted restoration efforts to rebuild the ecosystem and mitigate future fire risks.
The LSRRP’s primary activities focus on removing invasive tamarisk trees, which are highly flammable and contribute to the intensity of wildfires, and planting native seedlings to reestablish local flora. By removing tamarisk trees, the project aims to create a landscape that is more resistant to fire, reducing the wildfire risk for the region. Additionally, the project supports the abundance and diversity of native plant species by removing invasive plants and planting thousands of native riparian tree species.
The restoration efforts also aim to enhance the riparian habitat by expanding two critical vegetation communities—the mesquite bosque and the cottonwood-willow gallery forest. These communities support rich biodiversity and offer essential habitats for local wildlife.
Beyond ecological restoration, the project emphasizes community involvement and awareness. It provides opportunities for the local community to participate in the project through environmental education events for K-12 students and ongoing volunteer involvement in monitoring and maintaining restored areas.
Overall, the Lower Salt River Restoration Project is a proactive effort to protect and revitalize the Lower Salt River Recreation Area, enhancing its ecological resilience and engaging the community in long-term conservation. (2-4, 6, 8, 11)
The LSRRP’s primary activities focus on removing invasive tamarisk trees, which are highly flammable and contribute to the intensity of wildfires, and planting native seedlings to reestablish local flora. By removing tamarisk trees, the project aims to create a landscape that is more resistant to fire, reducing the wildfire risk for the region. Additionally, the project supports the abundance and diversity of native plant species by removing invasive plants and planting thousands of native riparian tree species.
The restoration efforts also aim to enhance the riparian habitat by expanding two critical vegetation communities—the mesquite bosque and the cottonwood-willow gallery forest. These communities support rich biodiversity and offer essential habitats for local wildlife.
Beyond ecological restoration, the project emphasizes community involvement and awareness. It provides opportunities for the local community to participate in the project through environmental education events for K-12 students and ongoing volunteer involvement in monitoring and maintaining restored areas.
Overall, the Lower Salt River Restoration Project is a proactive effort to protect and revitalize the Lower Salt River Recreation Area, enhancing its ecological resilience and engaging the community in long-term conservation. (2-4, 6, 8, 11)
Green Corridor Südpanke
The Green Corridor Südpanke is a transformative restoration project that unveiled 700 meters of the river Südpanke, connecting Invalidenpark and Südpankepark in the heart of Berlin. This initiative, part of Berlin's broader mission to restore the Panke River, was spearheaded by the state of Berlin with a focus on ecological restoration, biodiversity enhancement, microclimate cooling, and creating recreational spaces to improve the quality of life for residents (Ref. 2; Ref. 3).
Historically, the river in this area was channeled underground. The project brought the Südpanke back to the surface, integrating ecological principles and landscape planning into the design. The restored section of the river now flows openly in a natural watercourse bed, making it accessible to the public (Ref. 5). The restoration was completed in 2021, transforming the area with features such as playgrounds, lawns, benches, and a continuous biking and walking path that weaves through the green spaces.
Work on the project began in 2010 but was interrupted by the construction of the neighboring headquarters of the Federal Intelligence Service. As a result, parts of the green corridor were opened to the public in 2012, with the full restoration completed nearly a decade later, in 2021 (Ref. 3; Ref. 6).
The project established a seamless connection for cyclists and pedestrians from Invalidenpark in the south to Südpankepark in the north. The new open water section cools the microclimate in Berlin's densely built-up center while providing a critical habitat for plants and animals. Embankments and meadows near the Federal Intelligence Service's property support wild bees and other pollinators, fostering biodiversity. The Green Corridor Südpanke is a vibrant example of how urban ecological restoration can contribute to sustainability, quality of life, and resilience in a growing city. (Ref. 2)
Historically, the river in this area was channeled underground. The project brought the Südpanke back to the surface, integrating ecological principles and landscape planning into the design. The restored section of the river now flows openly in a natural watercourse bed, making it accessible to the public (Ref. 5). The restoration was completed in 2021, transforming the area with features such as playgrounds, lawns, benches, and a continuous biking and walking path that weaves through the green spaces.
Work on the project began in 2010 but was interrupted by the construction of the neighboring headquarters of the Federal Intelligence Service. As a result, parts of the green corridor were opened to the public in 2012, with the full restoration completed nearly a decade later, in 2021 (Ref. 3; Ref. 6).
The project established a seamless connection for cyclists and pedestrians from Invalidenpark in the south to Südpankepark in the north. The new open water section cools the microclimate in Berlin's densely built-up center while providing a critical habitat for plants and animals. Embankments and meadows near the Federal Intelligence Service's property support wild bees and other pollinators, fostering biodiversity. The Green Corridor Südpanke is a vibrant example of how urban ecological restoration can contribute to sustainability, quality of life, and resilience in a growing city. (Ref. 2)
Brookley by the Bay
Brookley by the Bay is a 98-acre new waterfront park project along Mobile Bay's western shore (Ref 1). The park aims to reconnect people with the Mobile waterfront and coastal ecosystem (Ref 2). The area, once an abundant mosaic of tidal marshes, forested wetlands, and shallow lagoons, became a port, leading residents to lose contact with the natural landscape (Ref 2).
The park serves both recreational and environmental purposes, aiming to create and restore areas that enhance habitat resilience and allow coastal ecosystems to thrive (Ref 1). It features sports facilities, including kayaking, volleyball, golf, and biking, along with social gathering and educational spaces such as an amphitheatre lawn, a performance pavilion, and picnic tables (Ref 3, Images 1-3). The park provides safe and equitable access for all Mobile residents to nature, beaches, tree canopies, open fields, and varied shorelines, all connected by pedestrian and bike lanes (Ref 2). The project also focuses on habitat enhancement and restoration for biodiversity (Ref 3, Images 1 & 4), as well as flood protection through shoreline get-downs, vegetated edges (Image 4), and undulating berms and swales that serve as a layered protection system against stormwater and coastal flooding (Ref 2).
The development of Brookley by the Bay was guided by input from over 300 community members (Ref 1), local stakeholder organizations, and project partners, with the goal of establishing a more resilient, accessible, and enduring space for generations to come (Ref 2).
The park serves both recreational and environmental purposes, aiming to create and restore areas that enhance habitat resilience and allow coastal ecosystems to thrive (Ref 1). It features sports facilities, including kayaking, volleyball, golf, and biking, along with social gathering and educational spaces such as an amphitheatre lawn, a performance pavilion, and picnic tables (Ref 3, Images 1-3). The park provides safe and equitable access for all Mobile residents to nature, beaches, tree canopies, open fields, and varied shorelines, all connected by pedestrian and bike lanes (Ref 2). The project also focuses on habitat enhancement and restoration for biodiversity (Ref 3, Images 1 & 4), as well as flood protection through shoreline get-downs, vegetated edges (Image 4), and undulating berms and swales that serve as a layered protection system against stormwater and coastal flooding (Ref 2).
The development of Brookley by the Bay was guided by input from over 300 community members (Ref 1), local stakeholder organizations, and project partners, with the goal of establishing a more resilient, accessible, and enduring space for generations to come (Ref 2).
Core City Park(ing)
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 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)
Rain Garden 2.0
The Rain Garden 2.0 project at Gdańsk University of Technology is an innovative green infrastructure initiative that manages and purifies rainwater while enhancing biodiversity. Part of the international NICE (Nature-based solutions for urban climate adaptation) initiative, this project serves as a living hub for testing solutions to address urban climate challenges. Opened in July 2023, the rain garden exemplifies a multifunctional approach to water retention, pollutant filtration, and urban biodiversity support. It is located behind the Faculty of Chemistry's Building C and has a capacity exceeding 11 cubic meters. (Ref. 1; Ref. 6)
The garden, designed by researchers from the Faculty of Civil and Environmental Engineering under the leadership of Prof. Magdalena Gajewska, captures rainwater runoff to prevent urban flooding and mitigate the strain on storm sewer systems. It absorbs pollutants, improves water quality, and supports over 1,100 hydrophyte plants, creating a natural solution for heavy rainfall events.
Beyond water management, the garden contributes significantly to urban biodiversity. Its moist soil and diverse plant species—designed to thrive in a range of conditions—help create habitats for insects and other small wildlife, boosting ecological resilience. (Ref. 1)
The rain garden’s innovative design consists of several key components. The first stage channels rainwater into reservoirs, reducing the energy of inflowing water. Subsequent parts purify the water through sedimentation processes, effectively filtering out pollutants such as those from streets and roads. Early research shows that these purification methods work exceptionally well, retaining a broad spectrum of pollutants before the water reaches the garden’s main basin. The project also benefits from cutting-edge laboratory equipment, allowing for detailed monitoring and analysis of water quality. (Ref. 1)
The garden, designed by researchers from the Faculty of Civil and Environmental Engineering under the leadership of Prof. Magdalena Gajewska, captures rainwater runoff to prevent urban flooding and mitigate the strain on storm sewer systems. It absorbs pollutants, improves water quality, and supports over 1,100 hydrophyte plants, creating a natural solution for heavy rainfall events.
Beyond water management, the garden contributes significantly to urban biodiversity. Its moist soil and diverse plant species—designed to thrive in a range of conditions—help create habitats for insects and other small wildlife, boosting ecological resilience. (Ref. 1)
The rain garden’s innovative design consists of several key components. The first stage channels rainwater into reservoirs, reducing the energy of inflowing water. Subsequent parts purify the water through sedimentation processes, effectively filtering out pollutants such as those from streets and roads. Early research shows that these purification methods work exceptionally well, retaining a broad spectrum of pollutants before the water reaches the garden’s main basin. The project also benefits from cutting-edge laboratory equipment, allowing for detailed monitoring and analysis of water quality. (Ref. 1)
Roof Water Farm
The ROOF WATER-FARM is an innovative demonstration site located in the heart of Berlin, near Potsdamer Platz, showcasing sustainable urban infrastructure that integrates wastewater treatment and food production. Situated in the "Block 6" quarter of the 1987 International Building Exhibition in Berlin-Kreuzberg, the site transforms wastewater and rainwater collected from nearby buildings into usable resources for farming and fertilizer production (Ref. 1). This project provides a real-world example of how sustainable systems can be incorporated into everyday urban design to enhance resilience and functionality.
At the ROOF WATER-FARM, water from rooftops and surrounding households is channeled into a treatment plant, where it is analyzed for micropollutants and purified. The treated water is then used for both fish farming in aquaponics systems and plant irrigation in hydroponic farming. The nutrient-rich water from the fish tanks nourishes plants, while also contributing to the production of food. This integrated approach actively supports climate protection by managing rainwater runoff and using plants for CO2 storage, helping to mitigate the urban heat island effect (Ref. 4).
This demonstration site embodies how cities can move toward a circular economy, where wastewater is reused for both farming and water management. The project also serves as a hub for learning and experimentation in sustainable urban design, with the greenhouse acting as a space for collaboration and innovation in infrastructure development (Ref. 2; Ref. 5). By incorporating these technologies into urban environments, the ROOF WATER-FARM demonstrates a future where buildings and neighborhoods efficiently recycle water, produce food, and reduce environmental impact.
At the ROOF WATER-FARM, water from rooftops and surrounding households is channeled into a treatment plant, where it is analyzed for micropollutants and purified. The treated water is then used for both fish farming in aquaponics systems and plant irrigation in hydroponic farming. The nutrient-rich water from the fish tanks nourishes plants, while also contributing to the production of food. This integrated approach actively supports climate protection by managing rainwater runoff and using plants for CO2 storage, helping to mitigate the urban heat island effect (Ref. 4).
This demonstration site embodies how cities can move toward a circular economy, where wastewater is reused for both farming and water management. The project also serves as a hub for learning and experimentation in sustainable urban design, with the greenhouse acting as a space for collaboration and innovation in infrastructure development (Ref. 2; Ref. 5). By incorporating these technologies into urban environments, the ROOF WATER-FARM demonstrates a future where buildings and neighborhoods efficiently recycle water, produce food, and reduce environmental impact.
The Line Park: Redeveloping old Railway Tracks
The "Line Park" project in Belgrade aims to create a continuous green belt spanning 4.6 kilometres and covering over 48 hectares. As such, the project will revitalize the former railway corridor from "Beton Hala", just below the Belgrade Fortress, to the Pancevac Bridge. Inspired by notable urban parks like New York's "High Line", Moscow's "Zagrađe," and Toronto's "Rail Corridor," it will become a major recreational destination and also help to alleviate the pressures from the city's heavy air pollution and summer heat (Ref. 5, 6).
The park will be divided into ten thematic sections dedicated to aromatic plant and flower gardens, urban gardening and beekeeping, sports facilities, a newly built university campus and more. Additionally, there will be an amphitheatre and facilities for outdoor education. To further integrate green infrastructure, new buildings will have green roofs and walls (Ref. 2,5). Ultimately, the park integrates a number of amenities into the entire city.
The development of the park also introduced innovative co-creation mechanisms in terms of governance and planning. Since Belgrade is part of the multinational CLEVER Cities Initiative, the city's Secretariat for Environmental Protection suggested the use of the site as a pilot test for introducing nature-based solutions in urban planning and with diverse stakeholders' input. Several workshops, focus groups, and consultations took place between 2019 and 2021, which facilitated the diversity of ideas that have been adopted into the official construction plan (Ref. 1, 2). Despite these successes, civil society groups raise concerns over the extraordinary cost of 70 million euros, displacement of Roma communities and the interest of real estate developers that may undermine the project's original cause (Ref. 3, 8).
The park will be divided into ten thematic sections dedicated to aromatic plant and flower gardens, urban gardening and beekeeping, sports facilities, a newly built university campus and more. Additionally, there will be an amphitheatre and facilities for outdoor education. To further integrate green infrastructure, new buildings will have green roofs and walls (Ref. 2,5). Ultimately, the park integrates a number of amenities into the entire city.
The development of the park also introduced innovative co-creation mechanisms in terms of governance and planning. Since Belgrade is part of the multinational CLEVER Cities Initiative, the city's Secretariat for Environmental Protection suggested the use of the site as a pilot test for introducing nature-based solutions in urban planning and with diverse stakeholders' input. Several workshops, focus groups, and consultations took place between 2019 and 2021, which facilitated the diversity of ideas that have been adopted into the official construction plan (Ref. 1, 2). Despite these successes, civil society groups raise concerns over the extraordinary cost of 70 million euros, displacement of Roma communities and the interest of real estate developers that may undermine the project's original cause (Ref. 3, 8).
Green Spaces at Palas Campus
The Palas Campus project is a real estate investment by the private company IULIUS, involving the construction of a mixed-use development with integrated green elements, including a green terrace (1–3, 5). The project spans approximately 86,000 sq.m., of which 4,500 sq.m. are dedicated to green spaces (1–3, 5). In these green spaces, 200 trees and 7,000 bushes of various species were planted (1, 2). The landscape design was created by a team of international experts, with some plant species imported from Italy (1, 5). The primary goal of the project is urban regeneration in a specific district of the city, building on similar projects previously implemented by IULIUS (1, 2, 5). The Palas Campus landscape includes relaxation spaces and pedestrian walkways (1).
The buildings were designed to meet the standards for two green certifications: EDGE and LEED, both of which were awarded in 2024 (4, 6–10). The EDGE certification signifies a 20–40% reduction in energy and water use compared to standard buildings (4, 8). The LEED certification, awarded based on various sustainability criteria, saw Palas Campus achieve one of the highest scores (4, 9, 10). One key aspect of the certification was the reduction of the "heat island" effect (10).
The total cost of the project reached 120 million euros, with 3.8 million euros allocated to the green spaces (1, 2, 5). The project was partially financed by a 72 million euro "green" loan from the IFC, a member of the World Bank Group, which also provided expertise to help secure the EDGE certification (6–8). The LEED certification was obtained with the support of the consulting firm BuildGreen (11).
The buildings were designed to meet the standards for two green certifications: EDGE and LEED, both of which were awarded in 2024 (4, 6–10). The EDGE certification signifies a 20–40% reduction in energy and water use compared to standard buildings (4, 8). The LEED certification, awarded based on various sustainability criteria, saw Palas Campus achieve one of the highest scores (4, 9, 10). One key aspect of the certification was the reduction of the "heat island" effect (10).
The total cost of the project reached 120 million euros, with 3.8 million euros allocated to the green spaces (1, 2, 5). The project was partially financed by a 72 million euro "green" loan from the IFC, a member of the World Bank Group, which also provided expertise to help secure the EDGE certification (6–8). The LEED certification was obtained with the support of the consulting firm BuildGreen (11).
