Social justice and conflicts

The Mediterranean climate in Lisbon, already characterised by low precipitation, has been further exacerbated by climate change. The city faces challenges related to biodiversity loss, urban loneliness, and climate anxiety (1). To address these issues, Lisbon's urban development plans have prioritised the re-naturalisation of urban spaces and the integration of ecological networks. Urban nature is now a central component of the city's Master Plan (2012) and other strategic agendas (1).
It is being developed by the LISGREEN project, which aims to enhance ecological connectivity and mitigate the effects of urban heat islands in Lisbon. By establishing nature-based solutions, it aims to restore forests within the city (1, 2, 3). This project encompasses different strategies, such as the RENATURA pilot project. It is a collaboration with the NGO URBEM and involves active public participation in tree planting and forest maintenance. This initiative aims to educate the community about nature, promote well-being, and mitigate extreme climate events (1), through the creation of urban forests.
The main strategy is to create fast forests using the Miyawaki method, which involves dense planting of native trees, removal of invasive plants, and intensive initial care. This approach accelerates the growth of natural forests within a short period, using native species and reducing the need for watering (1)
The first fast forest was developed in Parque Casal Vistoso within Bela Vista Park, within the Eastern Green Corridor of Lisbon. The park is being underutilised because of the lack of shade (1). Thus, this initiative encouraged volunteers to participate in tree planting and forest maintenance activities (3). The NbS intervention began with a 300m² experimental plot near the Vale da Montanha pedestrian bridge and has since expanded to a new 1,500m² plot on the opposite side of the bridge (2). Over 500 volunteers joined the effort, planting more than 3,800 trees (1)

Sri Lanka, particularly its low-lying coastal areas, faces recurring flooding challenges exacerbated by climate change, coastal erosion, and urbanization (1). Wetlands have emerged as crucial ecosystems in mitigating these risks, acting as natural sponges during heavy rainfall and releasing water gradually as flood levels subside (1). Beyond flood control, wetlands play a vital role in environmental quality. Their biodiversity helps filter pollutants and chemicals from the air and water, creating a healthier environment for both humans and wildlife (1). In 2018, Colombo was designated as a Global Wetland City under the Ramsar Convention, becoming the first and only capital city to receive this recognition (1). Recognizing the significance of wetlands as nature-based solutions, international institutions have prioritized their conservation through financing programs (1), and the city has developed projects to raise awareness and involve its citizens in their protection (1). These efforts have resulted in the creation of four wetland parks in the city, that comparing to a wetland, the wetland parks have more human intervention. Thus, they are focused on different topics and activities (2): Diyasaru Park, Beddagana Wetland Park (managed by the Urban Development Authority), Kotte Rampart Wetland Park (managed by the Urban Development Authority), and the Gothatuwa Wetland Park (managed by the Sri Lanka Land Development Corporation) (2). Gothatuwa Park is the newest wetland park and it is located in the flood-prone Gothatuwa neighbourhood (1). Inaugurated in 2024, It has a recreational focus, with trails for cyclists and hikers, and together with the other wetland complex, this park is designed to make the wetlands a cornerstone of local people's lives (1). Currently, environmental education activities are carried out in the park, focusing on managing aquatic invasive plants, tree planting and solid waste collection (3).

The Thalangama wetlands are part of a network of wetland ecosystems around Colombo city that spread over 20 km2 and provide critical life support to the city. These ecosystems keep people safe from floods, cool the air, filter polluted water, provide food and medicines, and fight climate change (10). These wetlands have become an environmental protection area and a biodiversity hotspot in a rapidly urbanising environment, as they host an array of plants and animals, including the endangered fishing cat and otter (5, 10). In 2007, Thalangama Lake and its surroundings were declared an Environmental Protection Area (EPA) under the National Environmental Act (4, 5). This protected area covers approximately 118 hectares (4) and includes two man-made reservoirs: Thalangama Tank (11 ha) and Averihena Tank (3.2 ha), located just 300 meters apart (5). The area hosts floating and rooted plants, scrublands, and trees that provide habitat to up to 100 species of migratory, resident, and endemic birds throughout the year. In addition, the area supports 30 species of dragonflies, 12 species of reptiles, 10 species of mammals, and 15 species of freshwater fish (1, 4). Since the lakes and their surroundings were declared an EPA, only limited uses are permitted, such as traditional fishing and rice cultivation (4, 5). The lakes are also important for floodwater retention and have high scenic and aesthetic value, attracting many visitors, and scientific and educational activities (5, 13).
However, due to the area's rapid urbanisation, land values have increased significantly, leading to excessive landfilling and the reclamation of paddy lands for housing. This is compounded by the indiscriminate disposal of garbage and construction waste and the spread of invasive species (5). These challenges have also led to the engagement of surrounding communities in managing and maintaining it (11).

The Prinzessinnengarten Kollektiv Berlin is a community garden in the New St Jacobi Cemetery in Berlin-Neukölln that invites people to join in gardening and experience nature. As part of open gardening days, people can participate in the design of the garden areas and gain experience in the local, ecological cultivation of useful plants. The main aim of their work is to provide opportunities for education and participation. Activities are open to everyone and range from sowing, planting and harvesting to seed production, processing and preserving vegetables, keeping bees to questions of community-based urban habitat design.The community also has its own farm shop where seeds, food and processed products are sold. (Ref. 1; Ref. 4) Numerous projects for recycling and upcycling, innovative cultivation methods, organic beekeeping, composting methods and post-fossil mobility use the Prinzessinnengarten as a platform for sustainable urban living. Artists also work in the garden with participatory methods on the question of how cities and their coexistence can be designed in a sustainable and resource-saving way. Outside the Prinzessinnengarten, offshoot gardens are set up and collaborations are developed to build nationwide and European networks. Through lectures, workshops, study visits and participatory research in the garden, we endeavour to include and further develop the topics associated with the Prinzessinnengarten in discussions and education. (Ref. 7)

The project is located on a cemetery, which has been partially closed since 2016. This means that burials are no longer carried out on the site and the existing rights of use of the 500 or so remaining graves will no longer be extended after expiry. The church association lends the land to the project in exchange for maintenance work on the surrounding grounds. (Ref. 6)

Ballymun is a suburban area on the north side of Dublin, Ireland. Originally developed in the 1960s, Ballymun was built to address Dublin’s post-war housing shortages, with iconic high-rise towers and flat complexes. However, over the years, the area faced social and economic challenges, leading to a reputation for issues such as poverty, unemployment, and lack of services.
In response, the Irish government launched the Ballymun Regeneration Project in the late 1990s. As part of the Ballymun Regeneration, Poppintree Park has been transformed into a 45-acre public space at the heart of Ireland’s celebrated urban renewal project in Ballymun Town Centre. This redevelopment followed an extensive public consultation process, incorporating input from local residents, sports clubs, community groups, and youth organizations.
Poppintree Park now offers a range of upgraded amenities, including a Tree Trail featuring 15 native tree species, enhanced biodiversity, extensive wetlands, sustainable drainage systems, and spaces for passive and active recreation. The park also features a 1.25-acre playground for children aged 0-12, an amphitheater with a permanent pond, and a fully accessible pathway network with abundant seating and viewing areas. Over 50,000 plants have been added to enhance the park’s natural beauty.
The park’s transformation, led by Ballymun Regeneration Ltd., involved significant engineering and landscaping efforts. Mitchell + Associates provided the detailed landscape design, construction drawings, and supervised the landscape works.
Completed in 2010, Phase 1 of Poppintree Park’s redevelopment represents an investment exceeding €6 million. The project includes substantial earthworks, drainage systems, gabion walls, three limestone-paved entrance plazas, structural retaining walls, a cantilevered pond walkway, diverse path surfaces, and high-quality playground construction. (1-7, 10)

The Loma del Marión recovery project in Cartagena, Colombia, is a community-driven initiative supported by EPA Cartagena that focuses on restoring and conserving the remaining 1.2 hectares of tropical dry forest. Initially covering 33 hectares, the area has suffered degradation due to illegal encroachments, deforestation, and waste burning. The project has included planting over 3,000 plants and fostering community involvement in environmental conservation (ref 1). The main goals are to restore the ecosystem by reforesting native species, preventing landslide risks, and developing an ecopark that will serve as an educational and recreational space. Planned facilities include a library for learning about local flora and fauna, hiking trails, and a community garden to enhance local food security (ref 1,4). A notable educational initiative in the project is the formation of "Vigías del Ambiente" (Environmental Watchers), a group of 40 youths from the Red Nacional Jóvenes de Ambiente, supported by EPA Cartagena and CDKN. This initiative educates young people on climate change, conservation, and waste management through workshops and activities (ref 2, 3). In addition, the EPA is leading detailed studies of the tropical dry forest to identify and protect endemic species (ref 5). The project has resulted in significant environmental and social benefits, such as planting thousands of trees, boosting community engagement in conservation, and establishing youth groups dedicated to sustainable development and climate action (ref 3, 5).

The Stora Amundö and Billdal archipelago nature reserve is in the southernmost part of the City of Gothenburg. The proximity to the city makes it a popular recreational destination, with about 73000 visitors each year. In 2018, the area was protected as a nature reserve to preserve its recreational, natural and historical values. The status as a nature reserve prohibits any exploitation and other harmful activities in the area. The area of the reserve is 1103 ha, of which 259 ha is land area and the rest is water [Ref. 1-3]. The management of the reserve includes promoting recreational and educational activities by creating new entrances, paths and signs, as well as holding guided tours. The management also includes restoring and improving terrestrial ecosystems such as grasslands through mowing and grazing and deciduous forests through selective clearing. A wetland has been restored to promote biodiversity further [Ref. 2, 4]. The reserve was created and is managed by the City of Gothenburg, the process of creating it involved consultation of stakeholders such as land owners, government agencies and NGO's [Ref. 1]. Some local landowners disagreed with the borders of the nature reserve having an impact on their land, leading to an appeal that was ultimately denied [Ref. 5, 6]

Thessaloniki, Greece's second-largest urban center, is a key hub for economic growth and outward trade in the Balkans. The city hosts the country’s second-largest export port, which plays a crucial role in connecting European trade routes with Asia and China. However, until 2014, Thessaloniki's waterfront was poorly maintained, largely inaccessible, and unattractive. Moreover, major flooding events, connected to extreme weather events, exposed significant deficiencies in the city's flood mitigation infrastructure, leading to damage to housing and critical services. (5, 10, 11)
To address these issues, the Municipality of Thessaloniki launched an International Architectural Competition for the redevelopment of the New Waterfront. From 2006 to 2014, Thessaloniki's waterfront underwent a significant regeneration aimed at benefiting the city's population of 1.1 million and stimulating the local economy. The revitalized waterfront now stretches 3 kilometers between land and sea, featuring 58,000 acres of green space an playgrounds.. In total, 2,353 new trees and 118,432 plants were added across an area of 238,800 m² (Refs 1, 3, 4).
The project also introduced walking routes, sports and recreational facilities, seating areas, and scenic viewing points. The waterfront now has a bicycle path along the entire walkway, and an arbour of 660 umbrella pine trees, serving as shade from the midday sun. Completed in 2014, the New Waterfront has already become a vibrant urban green space, enjoyed by both Thessaloniki's citizens and visitors alike (Ref 4).

Masthuggsparken is a planned park in the Masthuggskajen district, which is undergoing development and construction. The park will measure about 2000 m2, and serve as a green oasis and meeting place for locals. It will have ameneties such as benches and areas for play, and a noise barrier against a large nearby road. The park will connect to the adjacent square and street, making it accessible to visit. The street will be renovated to have more trees and plants, increasing green connectivity in the district. The park will be surrounded by trees and other plants, which are planted to promote biodiversity and be adapted to a changing climate [Ref. 1-5, 7]. The park is at a low point, where up to 800 m3 of stormwater will flow during heavy rainfall, reducing flood risk in the surroundings [Ref. 1, 2, 6]. The Masthuggskajen district has a sustainability program, establishing goals for green environments which the park will contribute to. Green areas should be accessible to the entire district and provide ecosystem services such as rainwater management, climate adaptation, biodiversity and recreation. The program was created by the City of Gothenburg in collaboration with construction companies active in the area and was supported by Citylab Action, a national competence program in sustainable urban development [Ref. 7]. The City of Gothenburg is the primary responsible for the park, which will be constructed between 2025 and 2026 [Ref. 1, 2, 4].

The Tirana Vertical Forest is part of the city's 2030 Master Plan and aims to enhance urban biodiversity and create green spaces through innovative urban design (Ref. 1,2). The project was developed by Stefano Boeri Architetti, the same studio that has designed similar, well-known structures in cities like Milan, Utrecht and Nanjing (Ref. 6). The completion of the 21-floor building is expected in late 2024 and will feature 105 apartments and a commercial ground floor as well as 145 trees and over 3,200 shrubs and bushes which are integrated into the balconies and façade of the project (Ref. 1,2,3). Various Mediterranean plants have been incorporated, including colourful, scented and aromatic types, which harmonize with the local ecosystem. To maximise the space available for green features, a dynamic structure with alternating balconies and full-height windows has been built (Ref. 1,2). Ultimately, the project anticipates improving air quality, reducing noise, and providing insulation. The greenery is expected to capture fine particulate matter and up to 8 tones of Co2 per year while also creating a healthier microclimate for those inside the building (Ref. 1,6).