Soil quality improvement

The intervention is a project of historic memory, it seeks to pay tribute to those individuals who were taken and assassinated as part of the resistance movement during the Civil War and the Franco dictatorship by planting a forest with Mediterranean species. In the forest, each tree represents one of these persons, thus combining aspects of recent history with the natural environment. (ref 1) Each tree represents real people, as the project collaborated with the families of the victims (Ref 1), to create a space of conscience about what happened in the Franco's period, as well as a memorial for them.

Sofia is Europe's most polluted capital and the World Health Organization alarmed that Bulgaria ranks second in the world in terms of deaths due to air pollution per capita. In response to that, the coalition Sofia - Green Capital planned to buy neglected urban land and plant an Urban Forest in order to restore the green passes that lead the fresh air from the mountain to the city. The Urban Forest is expected to improve the air quality, sequestrate carbon emissions, and also provide a place for walks and play. (Ref. 1; Ref. 2). The planting process started in 2018 and around nearly 60,000 saplings were planted over 225 acres by over 6,500 volunteers and over 50 companies joined in. (Ref 7, 8)

"Formerly a 10 hectare market gardening site, the Repainville area is rich in environmental potential: ponds, streams, springs ... the aquatic environment is present everywhere. There is a great variety of fauna and flora. As an ecosystem that is particularly rare in urban areas, protection and recovery measures are being undertaken" (Ref. 1). The restoration of the wetland of Repainville is part of a flagship project of the municipality in terms of safeguarding biodiversity in urban areas. With arrangements allowing the public to walk there without harming the biological and natural diversity of the place, the site has an educational dimension in order in particular to make young audiences aware of the preservation of the ecosystem (Ref. 7).

The Tree Master Plan of Barcelona is a long-term (20-year) plan, running from 2017 to 2037. The ultimate goal of the Tree Master Plan is to ensure the presence of dynamic, healthy and diverse urban trees in Barcelona. According to the Plan, urban trees are essential for green infrastructure and for creating quality public space in the city. An innovative feature of this intervention is the use of biological approaches to the tree maintenance (no pesticides or chemicals) (Ref 1, 2 and 3).

The Barcelona Green Infrastructure and Biodiversity Plan 2020 includes the development of several urban green corridors to increase ecological and social connectivity within the city. The green corridor of Passeig de Sant Joan is one of the first of these corridors implemented. The project consisted of the renovation of the promenade through tree and shrub planting and permeable green pavement installation, creating a green boulevard that benefits pedestrians and extend the urban green spaces, which gave new life to the neighborhood and allowed the expansion of small businesses and tourism (Ref 1).

The Urban Park of Pasteleira is a public park located in the parish of Lordelo do Ouro, in the city of Porto. The park extends over an extensive area (7 hectares) of forest, divided into two plots by the street of Afonso de Paiva. The forest, an example that remains of the natural vegetation of the Porto area, consists essentially of wild pines and cork oaks, and enrichment of vegetation by the planting of trees and shrubs of Portuguese flora and exotic species. It was designed in 2004 and completed in 2009 (1).

Situated next to Bebington railway station, the site is of biological importance within Wirral. This urban nature reserve was developed on a former railway sidings and is now an oasis of green tranquility in densely populated urban area; its industrial past has been put to good use as a home for wildlife (e.g. on the thin, nutrient there are now carpets of wild flowers, including wild carrot & occasional bee orchids). Up to 26 species of butterfly have been recorded here, with 18 species breeding on site - giving the park its rather apt name. (Ref. 1, 2)

New Ferry Butterfly Park has been awarded a Green Flag for the seventh year, which signifies that the space boasts the "highest possible environmental standards, is beautifully maintained and has excellent visitor facilities". (Ref. 12)

The Haumanngarten is a community garden in Essen founded by the Transition Town movement (Ref. 1). Since May 2015 a mixed group have been growing vegetables, herbs, flowers and berries on a former playground. Fellow gardeners with and without knowledge of gardening participate in the garden (Ref. 2).

This NBS is a part of the "Horta à Porta" (allotments at the door) programme which enhances the economic, environmental and social dynamics of the Porto region through the creation of community organic gardens and the promotion of active involvement which empowers local people and institutions. The program is led by the Greater Porto Metropolitan Waste Management Service, LIPOR. Implementation of vegetable gardens began in 2003. In the Metropolitan Region of Porto, there are 23 of these community gardens totalling four hectares, and the forecast is for a large-scale increase in the near future(1)

The Pré Muché garden is part of the AJONC, Amis des Jardins Ouverts et néanmoins clôturés. This is the community garden of the St-Maurice Pellevoisin neighbourhood. Located behind the church of St-Maurice des Champs and the new Maison de quartier, Pré Muché has been in existence since 2007 on the initiative of the inhabitants. The garden is arranged according to the principles of the natural garden, a space that combines a place of life, cultivated plots and more wild areas. Its maintenance is ecological. It is a living garden where the pond meets the flowered meadow and the regional shrubs (Ref 2).