Green space and habitat

Barranco, the smallest district of Metropolitan Lima, is suffering from serious environmental problems that are affecting its inhabitants. Environmental degradation is a consequence of the increase in large buildings (real estate boom), which reduces green space areas and causes a deficit of vegetation in the district. Additionally, there are high levels of air pollution due to car traffic, which has been accentuated by the lack of green areas in the area, which affects the environmental quality and the population's quality of life (1).
Additionally, the district doesn't have more free public areas where new green areas can be created. Due to these combined pressures, the local government has looked for alternatives, considering private areas, which have a high potential to implement green roofs and vertical gardens, which can contribute to face Climate Change as a mitigation strategy and improve the quality of life (1). The Green Roofs and Green Walls strategy is proposed to build citizen culture, nature appreciation, landscape, and ecosystems (2, 3). The aim is, therefore, to encourage the inhabitants of the district to progressively install green roofs and walls, employing an economic incentive in the taxes paid to maintain public green areas (4).
The programme is oriented to generate environmental benefits such as the reduction of air pollution, acoustic insulation, thermal comfort, and increase of green areas (m2) per inhabitant, and social benefits such as the improvement of the living conditions and health of the inhabitants of the district (1, 3), the promotion of social relations (1), the aesthetic improvement of the city, and the possibility of producing food for self-consumption, as there is support in the implementation of hydroponic systems in the green walls and roofs (1, 3). Its implementation focuses on new, under construction or existing residential, commercial, office or lodging buildings (3).

The Martinican Marine Natural Park (MMNP) was established in 2018 to protect key marine habitats, including coral reefs, mangroves, seagrass beds, and open waters. These areas are home to important species like sea turtles, dolphins, and tropical fish. The park’s conservation efforts focus on addressing threats from human activities such as pollution and overfishing. It also collaborates with ocean-related industries, such as tourism and fishing, by recommending, funding, or conducting research aimed at promoting more sustainable practices within the MMNP.

To support its work, the park operates a growing fleet of boats that raise public awareness, resolve conflicts, and enforce the protection of designated areas. The MMNP spans an area of 47,340 km², extending from Martinique's coast to the boundary of the French Exclusive Economic Zone. The park's management board, which includes diverse stakeholders, must be consulted for advice on development activities that impact the marine environment. Their goal is to balance competing interests within the region.

The park receives funding from the French Office for Biodiversity (OBF) to carry out initiatives that protect the marine environment, promote sustainability, and raise public awareness. Notable efforts include creating or restoring habitats for species such as sea turtles and sea urchins, managing invasive species like sargassum algae, restoring coral reefs, and training resource users such as whale-watching companies and diving clubs. Other initiatives include reducing plastic pollution through clean-ups, supporting sustainable fishing practices (e.g., artisanal coastal fishing), installing eco-friendly moorings, funding Marine Educational Areas (MEAs), and sponsoring cultural events that promote marine conservation (Ref 1; 2; 3).

The municipal real estate company Higab partnered with The Foodprint Lab Architects, an architecture firm specialising in food system design, in a three-year pilot project to create urban farms in three of their properties in Gothenburg. The Foodprint Lab designed the urban farms based on the conditions of each property and connected Higab with potential farmers. The urban farms are located at Slakthuset (an old industrial area), Kviberg (by an empty building undergoing renovation) and Musikens hus (an old building used for music events and a restaurant). The farms are established in unused, mostly grey areas such as parking lots. In all sites, the farming is run by local farming associations; some sell vegetables on site and in Kviberg, there has also been a commercial production of vegetables. Sustainable food production, entrepreneurship opportunities, a nicer and safer environment, and the promotion of biodiversity are highlighted as benefits of the project. In total, about 50 different plant species are found across the locations. The establishment of the urban farms was part of the Grow Gothenburg project within the Sharing Cities Sweden program, which provided some of the funding [Ref. 1-5, 7].

Dudley, a historic market town in England and part of Birmingham's metro area, is reported to have some of the lowest rates of public access to nature in the country, ranking in the bottom 10% of governmental statistics for available greenspace relative to population density (Ref 1). To address this issue, the Dudley's Path to Nature Recovery project was launched in 2024 by the Birmingham and Black Country Wildlife Trust (BBCWT). The initiative aims to reduce inequalities in access to nature and create a greener future for local residents (ibid.).
Funded by the West Midlands Combined Authority, the project seeks to reconnect local communities with nature through five key activities: conservation work, community engagement, citizen science, partnership development, and the creation of new walking routes (Ref 1, 2, 3).
Among the project's activities, conservation efforts will include community engagement and focus on woodland improvement, heathland creation, and more. Additionally, the project will bring together key partners and community groups to explore collaboration models and identify potential sites for joint projects. Lastly, new walking routes will be created across the project’s landscape (Ref 1).

The pilot project in Bairro Padre Cruz, Carnide, Lisbon, is a groundbreaking initiative aimed at enhancing women's safety in public spaces and improving access to public transport. Launched in June 2024, this project stems from extensive consultations with local women to address their specific security concerns (Ref1). It involves strategic interventions like better lighting and the relocation of bus stops to safer areas, ensuring a more secure environment for women (Ref4). A key element of the project is the greening of the area through tree planting and the creation of more harmonised public spaces, contributing to a more pleasant and welcoming neighbourhood (Ref2). Funded by the Recovery and Resilience Plan (RRP), this initiative aims to foster greater inclusivity and safety in urban design, with completion expected by 2025 (Ref4).

Civic Space Park, located in the heart of Phoenix, Arizona, is a notable example of urban design aimed at addressing the region’s increasing urban heat. In Phoenix, rising temperatures affect health, safety, comfort, and economic growth, and this impact is expected to worsen over time. In response, the park was developed to transform an underused site into a vibrant public space that prioritizes community engagement, sustainability, and urban revitalization.
The project was realized through a public-private partnership between the City of Phoenix and Arizona State University, with strong community involvement shaping its development. This collaboration led to the “Urban Weave” concept, a design that embodies the identity and values of the local community.
Civic Space Park was designed with several goals in mind. Increasing the tree canopy was essential to help reduce the urban heat island effect and improve air quality. Creating a welcoming area for social interaction, recreation, and relaxation was equally important to enhance community well-being. Water conservation was also prioritized, achieved through innovative stormwater management techniques such as permeable paving and underground infiltration. The park incorporates renewable energy generation as well, with on-site solar power helping to reduce energy consumption.
One of the park’s unique features is its extensive use of pervious concrete paving, designed to allow stormwater to permeate directly into the subsurface. However, during installation, it became clear that placing the material over highly compacted soil limited water infiltration. To improve its effectiveness, future designs could include a plastic vapor barrier beneath the permeable paving to capture water and direct it to planting beds. This adjustment would enable the paving to act as a collection and storage system, gradually releasing water into the surrounding vegetation.
(1-6)

The "Jubilee Park" (Jubileumsparken) is a city park in the developing area of Frihamnen in central Gothenburg. The first part of the park finished construction in 2024, but the aim is that the park will continue to grow and develop until the year 2035 [Ref. 1-2, 5]. The park is said to be the result of the wishes of the people of Gothenburg to have better access to green areas and water before the city's 400-year jubilee in 2023 [Ref. 2]. To achieve this, the park has been constructed gradually in cooperation with residents, using a method called placemaking, where activities and amenities are tested in place to get feedback from residents before being made permanent [Ref. 2, 4]. Additionally, activities in the park are being run by a youth organisations, which also offers summer jobs to young people from across the city and aims to engage marginalised groups [Ref. 1, 6]. The park provides amenities a sculpture-based playground, an outdoor classroom, places to sit and a harbour bath at the edge of the park, with outdoor pools and a sauna. The park contains elements for biodiversity such as trees, meadows and an area for urban farming, increasing biodiversity and connectivity compared to the previous land use as a harbour [Ref. 1, 2, 9].

The Juan Angola River is an urban channel included in the system of rivers and channels of Cartagena, and it connects the Ciénaga de la Virgen wetland and the Bay of Cartagena, facing similar issues as the Cienaga de la Virgen such as illegal occupation of its shores, illegal waste dumping, deforestation of mangroves, and pollution. The recovery plan for the Juan Angola River is led by the EPA Cartagena (Environmental Protection Agency), with the support of other institutions, aiming to restore the Juan Angola’s ecosystem. This includes targeting the mangrove forest, dredging the natural channel, and delineating buffer zones with urban infrastructure to create public recreational spaces. The activities involve relocating people illegalling cupping informal settlements from the river shore, moving an existing bridge (the Benjamín Herrera bridge) which obstructs the current, recovering the low tide and riverbed areas, building pedestrian paths, clean the riverbank, recover mangrove areas and establish programs of education and environmental awareness (ref 1 and 2).

The Tres Rios Ecosystem Restoration Project is an ambitious initiative aimed at revitalizing a seven-mile stretch of the Salt and Gila Rivers in Phoenix, Arizona. The Tres Rios Environmental Restoration project involves the rehabilitation of nearly 700 acres in and around the Salt River, restoring a vital wetland and riparian habitat. Initially conceived in 1993 to tackle water quality issues and improve flood control, the project gained significant traction in the 2000s through a partnership between the City of Phoenix and the U.S. Army Corps of Engineers (USACE). Funding was structured with 65 percent from the USACE and 35 percent from the City of Phoenix and the Sub-Regional Operating Group Members, including Scottsdale, Tempe, Glendale, and Mesa.
The Tres Rios project encompasses habitat restoration, flood control, and recreational development, with the primary objectives being to restore a degraded ecosystem, enhance water quality, and provide new recreational spaces. Construction involved relocating 1.6 million cubic yards of earth to shape three large wetland zones and two deep-water retention basins. Additionally, 18,000 feet of underground water lines and 600 feet of 84-inch fiberglass effluent pipelines were installed. To establish a thriving wetland habitat, the project coordinated the planting of over 300,000 aquatic and terrestrial plants.
Habitat restoration efforts re-establish native vegetation and create wetland areas that support local biodiversity. The lush and scenic Tres Rios is now home to more than 150 different species of birds and animals like muskrats, raccoons, skunks, coyotes, bobcats, and beavers. By using treated wastewater to sustain the ecosystem, the project reduces dependency on natural water sources, thereby helping to mitigate water scarcity. The Tres Rios Ecosystem Restoration Project serves as a model for sustainable urban ecological initiatives, combining environmental health with community benefits. (1-8, 10-13)

As an industrial city under climate change, Birmingham has been confronted with multiple environmental risks such as air pollution, fluctuating precipitation and flooding (Ref 3). The Big City Plan is a 20-year city center regeneration plan to support Birmingham’s sustainable transformation, where the delivery of the Eastside City Park was prioritized (Ref 1, 2). Completed and opened to public in 2013, this first new park in Birmingham for 130 years is a linear site which connects the city center along the frontage of Millennium Point eastwards towards the Digbeth canal. (Ref 1, 4, 5). Providing 2.73 ha of urban green spaces, the multi-award winning development features more than 300 trees, a 110 meter canal water feature and a public square with 21 jet fountains, and offers “a moment of green in a journey through the city” (Ref 1, 6).