Biodiversity loss

Kungsgärdet Byaodling is an urban farm set up by local farming association Kungsbacka Tillsammansodling, in Kungsbacka south of Gothenburg. Since 2023, the project has been funded by a 78 000 EUR grant via the non-profit organisation Lokalt ledd utveckling Halland (locally led development) using funds from the EU and the Swedish Board of Agriculture (Jordbruksverket) [Ref. 1, 2, 4]. The goal is to grow food in a sustainable and circular way, building soil health and promoting biodiversity. Using a total area of 4500 m2 on former unused grassland, the urban farm includes: 1100 m2 of effective growing area, 1000 m2 of flowering meadows, fruit and berry trees and bushes, and functional and social areas. The meadows and trees are intended to contribute to biodiversity, while social areas are meant to create a sense of community and benefit the well-being of the people active at the farm [Ref. 1, 3]. The farming association has been around for a few years, but the project funds will allow them to expand and develop the farm over three years, invest in new equipment and arrange free lectures for the public about sustainable farming practices [Ref. 1, 4]. The grant will also allow them to take in more members without anyone having to pay anything, promoting social inclusion.

In an architecturally important area of Berlin, situated between the Landwehr Canal, the Kulturforum (the Berliner Philharmonie and the Berlin State Library) and the new construction on Potsdamer Platz, a combination of green and grey infrastructure has been realised to minimise the burden on Berlin’s existing water infrastructure.
Green and non-green roofs harvest annual rain, which flows through the site’s buildings and is used for toilet flushing, irrigation, and fire systems. The roofs retain and then release water to the large on-site buffer pond, which has five underground storage tanks. Next to the roofs, a series of urban ponds and connecting canals have been implemented, with a combined area of approximately 1.2 hectares. They are filled with rainwater, creating an oasis for urban life. Vegetated biotopes are integrated into the overland landscape and serve to filter and circulate the water that runs along streets and walkways. The lake’s water quality is excellent, forming a natural habitat for animals and cooling the surroundings, while fresh water usage in the buildings has been reduced. (Ref. 1; Ref. 2; Ref. 3; Ref. 6)
The project was implemented in the 1990s as part of the development of Potsdamer Platz in the wake of the reunification of Germany. Several architects collaborated on the implementation that was completely privately funded. Beyond its ecological and technical features, the site is a blue natural site in the heavily built city centre of Berlin and allows people to linger and enjoy natural features. The drainage system won several sustainability prices and is considered a successful integration of nature and technology-based mechanisms to foster climate change adaptation. As the rainwater system stores rainwater in underground tanks and ponds, the urban sewage system is relieved during heavy rain, and water can evaporate. Therefore, the small water circle is closed, and the microclimate is cooled. (Ref. 2; Ref. 6)

The Metropolitan Linear Park is a project initiated by the national government of Bolivia, funded by the Inter-American Development Bank (IDB) (1-8). The proposed park will be located along a disused railway corridor between the cities of La Paz and El Alto, spanning 18.2 km (8, p. 8). The project involves the construction of a linear park, divided into five sections, each with distinct objectives, uses, and designs (8, p. 9). This large-scale initiative aims to improve access to public spaces in La Paz and El Alto, enhance connectivity between the two cities, protect surrounding biodiversity and natural spaces, and strengthen resilience to and mitigate the effects of climate change (3 & 8, pp. 11-12).
To achieve these goals, the project design includes outdoor sports and recreational facilities, pedestrian and cycling circuits, as well as the restoration of parks, squares, and public spaces adjacent to the park corridor (8, p. 9). Some features include balcony corridors, flower and food-producing urban gardens, and viewpoints (5). The project also plans for the re-vegetation of the area with native species and aims to stop the environmental degradation of surrounding natural environments, such as the Pura Pura forest, which has been suffering from ongoing deforestation and waste dumping (8, p. 9). These efforts are expected to increase and support biodiversity in the area (7 & 8, p. 12).
Additionally, the project emphasizes social inclusion, with policies designed to incorporate women, indigenous populations, and persons with disabilities (8, pp. 7-8). The park is intended to raise awareness about climate change and biodiversity, ultimately improving the quality of life and health of nearby residents and the citizens of La Paz and El Alto (8, p. 13).

The Recovery of Cienaga Juan Polo project is primarily aimed at reopening the natural mouth of the Manzanillos to restore water flow between the sea and the Juan Polo coastal wetland, which has been affected by human activities leading to high salinity and water stagnation issues (ref 2). The project is led by Fundacion Serena del Mar. Environmental and social sustainability are core components of the project design, which has included extensive community consultations since 2013. These consultations have resulted in agreements covering employment opportunities, education, and infrastructure development (ref 2). Key implementation activities include the reforestation of mangroves and targeted interventions to address ecological degradation, such as increased salinity, water stagnation, and biodiversity loss (ref 2). The project also seeks to enhance the quality of life for surrounding communities by restoring traditional economic activities, particularly fishing, and integrating sustainable urban planning elements such as canals, sluices, and navigable waterways. These features are designed to support the development of a "blue corridor" for aquatic mobility within Serena del Mar (ref 2, 3). In addition, it also contributes to local capacity building through environmental education programs that engage community members, researchers, and NGOs in biodiversity monitoring and sustainable practices​ (ref 1).

Seaweeds are of immense value to marine ecosystems, and Kelp, the largest of them all, forms spectacular underwater forests that provide habitat for fish, clean the water, and sequester carbon. Unfortunately, large swathes of these subaquatic forests have disappeared from the coasts of many European countries, including Portugal (Ref. 2).
The "Sea Forester" project in Cascais aims to restore local kelp forests, which are essential for marine biodiversity and carbon sequestration. In collaboration with the Câmara Municipal de Cascais and Mossy Earth (social enterprise), the project assesses the historical and current state of seaweed populations and identifies environmental stressors. It employs innovative techniques like the "green gravel" method to restore kelp ecosystems. This project supports the region’s blue economy and resilience to climate change through carbon offsetting and enhanced ecosystem services (Ref 1; 6; 7). Supported by the EEA Innovation Grant, it combines scientific research and community engagement, positioning Cascais as a leader in marine conservation efforts (Ref 6).

The Pantanos de Villa Wildlife Refuge is a natural oasis in the heart of Lima. It is considered a marsh of international Ramsar importance, as it is home to a large number of species of flora and fauna. It includes 5 bodies of water with about 210 species of birds, 13 species of fish, and 5 species of amphibians and reptiles, among others (1). It was created in 2006, by Supreme Decree N°055-2006-AG, which established the definitive category for the Pantanos de Villa, under the name of The Pantanos de Villa Wildlife Refuge (2). This protected area was established over an area of 263.27 ha, and its main goal is to conserve a representative sample of the Marshes of the Subtropical Pacific Desert, including important plant communities, as well as migratory and resident avifauna, focusing mainly on species with some degree of threat (1, 2, 6).
In 2016, a Master Plan was approved aimed at strengthening the conservation of the biological diversity of this coastal marsh and ensuring conditions to promote inter-institutional cooperation and participatory management, including neighbours, authorities, municipalities and interested institutions (2).
This Master Plan establishes environmental, economic and cultural indicators defined to be met over 5 years. These are focused on protecting water resources, conserving migratory and resident bird species, ensuring the conservation of the cattail, promoting tourism and recreational activities, fostering environmental awareness activities and engaging citizens in the management of the Refuge (2)
This plan seeks to confront a series of threats that endanger the conservation of this ecosystem. Among the main problems are the illegal extraction of natural resources, such as cattail; the improper use of the space for activities such as bonfires, consumption of illicit substances and pet walks; the change in land use due to urban expansion; pollution from effluent discharges and solid waste disposal; and illegal fishing (2)

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]

Biotope City Wienerberg is located in the southern part of Vienna on a 5.4-hectare site that once housed a Coca-Cola factory. It lies at the edge of the Wienerberg recreational area, surrounded by business parks and tower blocks to the west and predominantly detached houses to the east (Ref. 1).
The project embodies the concept of an "urban biotope" (Ref. 2), grounded in the principle that nature's mechanisms of self-regeneration are essential for mitigating the challenges of urban living and climate change. By integrating urban and natural spaces, Biotope City fosters both human-nature connections and social interactions through activities like community gardening. The project’s centerpiece is its extensive green infrastructure, including trees and green roofs, which serve to cool the microclimate, purify the air, enhance water retention, and create carbon sinks while providing habitats for local wildlife. These green spaces aim to improve physical health through cooling effects on hot days and support mental well-being with their calming influence (Ref. 1; Ref. 2).
Biotope City encompasses:
Around 980 flats, including 400 subsidized flats and 200 SMART flats
A school, a kindergarten, and 2,000 square meters of children's and youth playgrounds
600 square meters of community gardens and 3,850 square meters of ground-floor gardens
250 trees, 8,900 square meters of meadows, and 13,600 square meters of green roofs
2,200 square meters of façade greening
The inner courtyards and roof areas are designed for gardening, while façades are greened, and balconies are equipped with integrated plant troughs. Even the spaces between buildings are climate-effective, featuring unsealed catchment and seepage areas to manage water sustainably (Ref. 1).
The project’s implementation took 18 years and involved collaboration among various stakeholders. The concept was initiated by the Biotope City Foundation and funded by eight different investors (Ref. 2).

The project La Ruée Verte aims to create a green corridor connecting two emblematic locations for social and environmental justice: La Base Marseille and L’Après M. The route spans over 7 km and passes through La Friche de La Belle de Mai and aims to bring more nature into the city on a larger scale in a fair and equitable way (Ref 2).
Given the challenges of climate change—rising temperatures, urban heat islands, fewer trees in Marseille, and increasing urbanization—the green corridor will offer a solution to combat the suffocating effects of the city’s concrete sprawl (Ref 2). Additionally, it aims to reduce pollution peaks and improve air quality (Ref 2), increase biodiversity (Ref 2), and provide access to green spaces and places for social interaction (Ref 2).
The project also addresses the broader social crisis, with rising costs of food, housing, and transportation (Ref 2). Local solidarity is key, ensuring that all green initiatives foster community interaction and consider the urgent needs of residents, such as precarious living conditions and isolation (Ref 2). Collective participation is central to the project, ensuring that it is designed by and for residents of different neighborhoods, reflecting their realities. The project, called “La Ruée Verte,” aims to unite various citizen groups, social centers, and associations to amplify their voices (Ref 2).
The project's first phase, “La Petite Ruée,” will launch in October 2024, following a year of preparation. It will start with neighbourhood micro-projects and shared advocacy, including events and gatherings (Ref 2). The goal is to collectively think about social and climate justice and begin taking concrete actions towards popular ecology in each neighbourhood (Ref 2).

The Leopold-Rister park, named after a former district officer, is located in the Margareten district in Vienna and was renovated in 2023 based on the community's wishes for recreational opportunities. The park is surrounded by residential buildings and featured a playground for children, some greens and a football pitch. (Ref. 1) On the initiative of the city government, local residents and people using the park were surveyed on their preferences and needs for a potential redesign of the park. (Ref. 8) Within a year, the park was remodelled, featuring the wished for elements by locals, and was opened in 2024.
Spaces for recreation like playgrounds, benches, and gaming tables were increased or installed. To reduce the heat stress of the urban environment, trees were planted that provide shadow and water play for children to cool down were implemented. Already existing lawns and greens were restored, and new shrubs were added to provide habitats for different local insect and bird species. (Ref. 1; Ref. 6)
The project was initiated and financed by the City of Vienna and presents one of many greening activities that the city pursues to adapt to climate change. (Ref. 1; Ref. 2)