Unknown

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)

The Acropora Project is a coral restoration initiative launched in 2015 by the Martinican Regional Directorate of Environment, Planning, and Housing, primarily implemented by the nonprofit organization Assomer. It focuses on two critically endangered Caribbean coral species: Acropora cervicornis and Acropora palmata, as classified by the International Union for Conservation of Nature. While Acropora palmata thrives on the Atlantic seabed of Martinique, Acropora cervicornis had seemingly vanished from local waters by 2007, despite previously providing crucial habitats for marine life. However, this species was rediscovered in 2013 at Loup Caravelle on the Atlantic side of Martinique.
The initiative began by extracting cuttings from both species at Loup Caravelle and nurturing them at a separate site in Le Diamant. In 2019, these corals were transplanted to three locations on the seabed of Sainte-Luce, demonstrating surprising growth patterns despite the site's low to medium environmental quality.
The project's primary aim was to prevent the permanent disappearance of both coral species through spatial replication techniques, including cutting and transplantation. Particular attention was given to enhancing the genetic variability and range of Acropora cervicornis. The initiative also aimed to raise awareness about current coral conservation challenges.
Additionally, the project included a research component that contributed to a better understanding of environmental conservation and the restoration of Acropora cervicornis populations. Unfortunately, a temperature increase at the end of 2023 resulted in the decimation of all corals at the transplant sites. (Ref. 1 -5)

The Fairy Garden, also known as the WOW Recreational Park, is a distinctive green space located near Diósgyőr Castle in Miskolc, Hungary. Since its opening in April 2020, the park has quickly gained popularity, earning third place in the 2020 Tourism Attraction of the Year award in the professional category. Once a neglected and polluted site with historical significance, the area was transformed by a local entrepreneur. After removing over sixty containers of waste, including hazardous materials, a park was created that harmonizes with the natural environment, preserving existing willow trees and integrating water features fed by local streams. When creating the park, the creators respected the plants of the area to the maximum, not a single tree was cut down, and the fruit trees were also kept.
The park boasts various decorative elements, including a carousel, a garden cinema, and other amenities. However, in September 2021, it was closed indefinitely for renovations. Gábor Vaszil, the lessee who had rented the land from the Miskolc municipality, intended to purchase the property for further development. Despite initial support from the local government, the transaction was halted due to concerns raised by the regional Water Management and Protection Authority regarding the protection of Miskolc's drinking water resources. Their ongoing investigation has delayed any further decisions about the sale or the future of the park. In the meantime, the garden remains open to the public for leisurely walks, similar to other municipal parks in Miskolc.
(Ref.1-4)

In the bay of Fort-de-France, mangroves cover nearly 1,300 hectares, representing about 70% of the total mangrove area in Martinique. This plant formation, characteristic of tropical marine environments, is essential for the ecological balance of the bay. Mangroves act as filters, purifying marine and river waters, protecting the coastline against erosion, and providing habitat for various marine flora and fauna.
However, this fragile ecosystem is threatened by wave-induced erosion, urbanization, the spread of invasive species, and pollution. In response to these challenges, the French Coastal Protection Agency (Conservatoire de l'espace littoral et des rivages lacustres, CELRL) and its partners have launched an initiative to restore several mangrove areas as part of the “Contrat de la Grande Baie de Martinique" which is a collaborative initiative aimed at the sustainable management and restoration of the coastal and marine environment of the Greater Bay of Martinique. This contract typically involves partnerships between various stakeholders, including government agencies, local municipalities, environmental organizations, and community groups. The project identified several sites totaling 3.81 hectares in the Greater Bay area that require reclamation.
The project aims to restore mangrove populations by creating favorable conditions through actions such as clearing invasive species and trash, followed by replanting with white, black, or red mangrove seedlings, depending on the environmental characteristics of each site. Additionally, the initiative seeks to engage the public and youth through volunteering days and awareness campaigns (Refs 1-9).

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.

Mehr Bienen für Berln - Berlin blüht auf is a project that aims to provide an example of how public green spaces can be upgraded to be pollinator-friendly, thus creating urban habitats for wild bees and other insect species (Ref. 4). The project was implemented by the German Wildlife Foundation in cooperation with the Berlin Senate Department for Mobility, Transport, Climate Protection and Environment and other stakeholders, in all 12 Berlin districts, whereby the districts support the allocation of the exact location for the NBS (Ref. 3; Ref. 4). Measures for each location are compiled based on the specific surroundings, use and existing vegetation with a low mowing frequency in all areas (Ref. 2; Ref. 4). Most of the areas are road median strips, roundabouts, designated areas in parks or residual commercial areas (Ref. 4). After the first phase (2018-2022), the project has now entered its second phase (2023-2025) and was renamed to “Mehr Bienen in Berlin - Aus Grün wird Bunt” (engl.: More bees in Berlin - from green to colourful) (Ref. 3). The main goals are to reach a minimum of 100 flowering areas in 2025, to halt the sharp decline in bees and other insects, and to inspire citizens to protect wild bees (Ref. 1,2, 3). The project has so far limited acceptance among the population, as the areas are regarded as unkempt due to the low mowing frequency. Public relations work, like the installation of information signs next to the areas, is intended to increase understanding among the public (Ref. 4).