Land use and Socio-economic change

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 Africatown Connections Blueway project aims to create a recreational water trail by linking 14 culturally and historically significant points along a 10-mile route (Ref 1). Central to this initiative is the preservation of Africatown's rich heritage and natural resources. The project seeks to reconnect residents of Africatown, descendants of the original founders of this self-governing community, which maintained a strong sense of African cultural heritage, to waterways that were historically vital for food, transport, and spiritual practices (Ref 1). By restoring access to these waters, the community can address both environmental and social issues, promoting eco-tourism and business growth while safeguarding cultural heritage (Ref 2). Local leaders emphasize the environment’s role in healing the community and preserving history, highlighting how this initiative can provide economic opportunities and improve quality of life (Ref 2). The project seeks to address the environmental injustices that Africatown communities have endured for decades. The area surrounding Africatown has long been dominated by harmful industries, including aluminium plants and paper mills, which have heavily polluted the water and restricted residents' access to it (Ref 1). With support from the National Park Service and contributions from Mississippi State University, the Blueway transforms neglected river access points into recreational areas, promoting environmental stewardship and cultural awareness (Ref 2).

In 2017, many public parks in Iași were in poor condition, suffering from neglect and inadequate maintenance. Parks like Barboi were left unmanaged, with deteriorating infrastructure and overgrown vegetation. In response, the municipality of Iași initiated efforts to revitalize these green spaces.
The Barboi Park revitalization focused on rehabilitating 8,200 sqm of a degraded area (1 & 6, p. 106). Accessible pathways were repaired, and benches were installed to create a relaxing environment (1 & 4). Existing trees and vegetation were pruned, new trees and ornamental plants were introduced, and the soil was enhanced with more fertile layers to correct uneven levels (1 & 4). The primary aim of the new vegetation was to improve the park’s aesthetic appeal and boost biodiversity (1).
The project was led by the Municipality of Iași through its Public Services Department (Servicii Publice Iași), which oversaw the improvements (1 & 6, p. 106). It was part of a larger urban plan to expand and enhance the city’s green spaces (6, p. 106 & 7, p. 336). This plan aimed to improve the city’s visual appeal and increase livability for residents (6, p. 106). The project’s total cost was approximately €260,450.45 (6, p. 107). Later that year, the park was renamed "Woodrow Wilson" to commemorate the 100th anniversary of the U.S. mission to Iași during WWI, with a small monument erected to mark the occasion (5). The initiative also aligned with national guidelines on green space regeneration, per capita green space, and accessibility (7 & 9).

A new addition has enriched Gdańsk's green spaces: the park at Szubieniczna Mountain near the Gdańsk University of Technology. This area, located behind the cutting-edge STOS building housing the "Kraken" supercomputer, has been transformed into a vibrant urban oasis. Covering approximately 7,500 square meters and costing 3.5 million zlotys, the park introduces a sustainable and welcoming environment for students, residents, and visitors alike.
The park aligns with the university's PG Climate Plan, a strategic initiative promoting environmental sustainability through research, education, and green infrastructure. Historically a neglected area with overgrown trees and bushes, it has now been revitalized to create a functional and aesthetic space that merges ecological values with public utility.
Key features of the park include over 1,500 new plantings—trees, shrubs, and flowers—that enhance biodiversity and create a visually appealing landscape. Ecological innovations such as a rain garden and energy-efficient lighting reflect the park's commitment to sustainability. Recreational and educational facilities include a mini amphitheater, an outdoor gym, and walking paths interspersed with gravel squares surrounded by flower meadows.
A new pathway connects the campus to Szubieniczna Hill, granting access to Gdańsk's largest water reservoir and offering stunning panoramic views. This transformation underscores how urban green spaces can address climate challenges while improving quality of life for the community. The Szubieniczna Mountain Park is not just a park—it’s a symbol of progress toward a greener future for Gdańsk. (1-2)

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)

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).

In Lisbon's Areeiro district, Urbem, a non-profit organization, is leading the creation of a 2500m2 Miyawaki mini-forest in Casal Vistoso Urban Park. This initiative involves densely planting native species to rapidly establish a diverse, self-sustaining forest ecosystem. Supported by the Lisbon City Council, the project aims to enhance urban biodiversity, improve air quality, and contribute to climate resilience. Volunteers from the local community play a crucial role in every stage, from preparing the land to planting and maintaining the forest. Despite initial challenges, such as a 40-50% plant survival rate, the forest is expected to become self-sustaining within three years. The project focuses on environmental restoration and seeks to engage and educate the community, fostering a sense of ownership and connection to these new green spaces (Ref 1; Ref 2; Ref 3; Ref 4).

FoodLink, a network for food transition in the Lisbon Metropolitan Area (LMA), aims to create sustainable, competitive, and resilient agri-food systems closely integrated with regional and local spatial planning. The network's goals are to promote food security, economic and energy efficiency, environmental sustainability, and socio-territorial cohesion by 2030. The network seeks to ensure that by 2030, 15% of the metropolitan area's food supply is secured locally through sustainable production methods, innovative solutions in water management, soil conservation, climate adaptation, and low-carbon distribution networks involving community gardens, urban allotments, and agricultural spaces within the Lisbon Metropolitan Area. (Ref 2)

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 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.