Local government/municipality

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)

The project aims to modernize Ciurchi Park, also known as "Tătărași Park," due to the degraded state of its current infrastructure (1 - 8). Initiated by the Municipality of Iași, the initiative seeks furthermore to increase the amount of green space per inhabitant in the city and reduce overcrowding in other parks, thereby diversifying options for citizens (1 - 9). Planning for the project began in 2022, and the bidding process for its execution was released in April 2024, which is still awaiting a decision (1, 2. 7).
The implementation is expected to involve interventions in existing green spaces, including the planting of 120 trees, 1,000 bushes, and approximately 2,000 species of flowers and ornamental plants. The project will also feature a monitoring program for tree species, management of existing vegetation to protect healthy trees, and removal of invasive or degraded plants (1, 2, 4, 8). Additionally, it will include benches, facilities for physical exercise, an underground waste collector, and a rainwater drainage system, among other infrastructure improvements (1 to 8).
The project is expected to be financed by the local budget and EU funds, with a total estimated cost exceeding 5,000,000 euros, including taxes (2, 4). It is included in the Integrated Urban Development Strategy 2015-2030 for the city (8, p. 12).
The goals of the project are to modernize the park, improve accessibility for citizens in the surrounding area, minimize management costs for the municipality, ensure a sustainable habitat for flora and fauna with minimal invasive interventions, and harmonize architectural proposals with the landscape (6, 8, p. 32). Other objectives include protecting biodiversity, enhancing the park’s aesthetics and the overall city environment, and reducing CO2 emissions, which will ultimately improve the quality of life for surrounding residents (8, p. 141).

The renovation of the "Marechal Humberto Delgado" Square focused on transforming the area into a more pedestrian-friendly and sustainable urban space. The project included reorganising the traffic system, creating a new urban green square, requalifying the bus terminal, enhancing the integration of different transport modes and improving pedestrian access (Ref 1). Key features of the intervention were the introduction of cycle paths, wider sidewalks, green spaces with 200 new trees, and recreational facilities such as a children's playground and water features (Ref 2). The project also addressed critical infrastructural needs, including constructing a rainwater collector as part of Lisbon's General Drainage Plan to mitigate the city's frequent flooding issues (Ref 3). The renovation, completed in 2024, was part of the 'A Square in Every Neighborhood' program, emphasizing community involvement and sustainable urban development (Ref 3).

Bound by miles of steel, concrete, or brick walls, Berlin’s rivers and artificial canals often look alike. Plastic bottles, along with ducks, swans, and perhaps the occasional coot seeking scraps from humans, are some of the few visible signs of life. Underwater, the scene is similarly sparse and monotonous, with only a handful of resilient species able to endure the harsh conditions.
In response to this lack of biodiversity, researchers from the Leibniz Institute for Freshwater Ecology and Inland Fisheries in Berlin collaborated with the engineering firm Wite to create the Vertical Wetland project. This initiative introduced plant boxes that attach to sheet piling along canal walls, extending into the water to form miniature habitats. These boxes serve as refuges for insects, birds, fish, and other small animals, offering hiding spots and sheltered spaces for egg-laying among the roots and boxes protruding into the water. Known as "ecological stepping stones," vertical wetlands enable animals to rest and safely traverse urban waterways, fostering biodiversity along urban riverbanks.
Vertical wetlands present a quick and cost-effective way to ecologically upgrade sections of urban waterways. Although they can’t fully replace natural riverside habitats, these mini-habitats offer substantial ecological benefits. Native river floodplain plants, including willows, reeds, rushes, and shallow-water species like irises and marsh marigolds, provide the foundation of these structures. All materials used are environmentally friendly and biodegradable.
By covering the grey, industrial surfaces of riversides, the vegetation cools the local environment, both on land and in the water, and helps improve water quality. Plant shading cools water, reducing eutrophication risks and creating a healthier habitat for aquatic life.
The Vertical Wetland project’s pilot installation was successfully implemented and tested in 2023 in the Berlin-Spandau Ship Canal. (1, 3, 6)

The Detroit RiverWalk is an urban development project along the Detroit River, designed to reconnect residents with their waterfront and revitalize a historically industrial area. Once characterized by abandoned buildings and industrial debris, the riverfront between the MacArthur and Ambassador Bridges had long been inaccessible to the public. To address this, the Detroit Riverfront Conservancy was established in 2003 to lead the redevelopment of this space.
The RiverWalk currently stretches along a 3.5-mile section, with plans to expand to 5.5 miles, integrating ecological restoration, public access, and recreational opportunities. The esplanade features native landscaping, artistic elements, and amenities, including four pavilions, a custom carousel, and areas for fishing, walking, biking, and inline skating.
Environmental remediation has been a crucial part of the project. In collaboration with the U.S. Environmental Protection Agency’s Great Lakes National Program Office, the Detroit Riverfront Conservancy successfully cleaned up 13,000 cubic yards of contaminated sediment, significantly reducing pollution and contributing to the removal of the Detroit River from the list of the most polluted sites in the Great Lakes. Furthermore, the project also includes greenways, park creation and revitalization.
The RiverWalk is not just a public space; it symbolizes Detroit’s transformation from a Rust Belt city to a sustainable urban environment. It exemplifies the power of public-private partnerships in revitalizing urban areas. The RiverWalk continues to expand, with plans to connect various parks and extend to the Ambassador Bridge, further enhancing the city’s waterfront. Its success was recognized in 2021 when it was named the Best Riverwalk in America by USA Today, cementing its status as a model for urban renewal and community engagement. (Ref. 1, 2, 3, 4)

Salines Beach, a popular destination for over a million visitors annually (Ref 9), is facing severe erosion due to rising sea levels and poor coastal management. Since 1995, the beach has lost more than 20 meters in width. This loss has been worsened by vehicle traffic and the introduction of coconut trees in the 1950s, which reduced the native root systems that once helped to stabilize the coast (Ref 5). Now, the encroaching sea threatens to swallow the road that runs along the beach.
In response, the Salines Conservation Committee—comprised of concerned community members and environmental groups—has been advocating for urgent action to halt the erosion. They have called for a renaturalization of the area through the replanting of endemic species and restrictions on car traffic, both aimed at restoring the beach’s natural resilience.
When part of the road collapsed in July 2022, the committee took immediate action, organizing community-based interventions. These efforts included blocking traffic, raising public awareness, and planting over 60 endemic plants in the damaged area. The aim was to reestablish a root network capable of anchoring the coastline and capturing shifting sands (Ref 1; 2). The intervention was described as "a response to the urgent need to rebuild the root network, an ecological engineering solution recognized as the most effective method for retaining beach sand and slowing coastal erosion" (Ref 2; 1). The intervention on this section of the coast was first completed, then discarded by the municipality of Sainte-Anne (Ref 2). Regional and National agencies are currently undertaking the restoration works but it is unclear the stage of completion (See Ref 3).

In 2021, the real estate company Inamstro, in collaboration with the Municipality of Iași, the civil organization "Glasul Vieții" (Voice of Life), and local citizens, initiated a tree-planting initiative that involved planting 250 trees near a residential area and a parking lot in the Frumoasa neighborhood of Iași. This neighborhood is smaller compared to other areas of the city and was developed during the communist systematization of the 1970s and 1980s. It consists of groups of four-story blocks arranged around common spaces, situated near the Frumoasa Monastery complex.
The main goals of the 2021 planting action were to enhance green space, lower air temperatures, reduce urban air pollutants—such as fine particulate matter—absorb CO2, and improve overall health and quality of life (1–5). Additionally, the implementing company concluded that the trees planted near residential areas can significantly reduce energy needs for air conditioning and heating, leading to an average cost decrease of 30% during summer and winter (1, 2).
Volunteers participating in the project received a "tree certificate," signifying their commitment to planting and adopting a tree (7). In this initiative, volunteers were also tasked with monitoring the growth of their adopted trees to ensure their health (1–6).

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].