Increase or improve urban vegetation cover to help reduce outdoor temperature

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 Senate of Hamburg commissioned IBA Hamburg GmbH with the development of the project which aims at realizing two new, family friendly residential districts in Neugraben-Fischbek, the Fischbecker Heidbrook and Fischbeker Reethen, which will offer 3000 residential units in total. (Reference 10) Out of the two districts, Fischbeker Reethen is planned to be the "Garden City of the 21st century", which is why this NBS case focuses on that project. The Fischbeker Reethen project pays attention to sustainability, having a blue-green infrastructure (large green surfaces, waterways and a lake that serves as a basis for the rainwater management of the area). A further aim of the project is to create a new district for the growing city, that with its good infrastructure, public transport connection and educational offers will help the integration of refugees into German society. (Reference 12) The construction of the buildings followed by the green and recreational elements is will start in the second half of 2020, and the handover is planned for 2022 the earliest. (Reference 7)

The FUTURE - a project of 100,000 trees in the Porto Metropolitan Area - is a planned and coordinated effort of various organizations and citizens to create and maintain native urban forests in this region, which needs to enrich its biodiversity, sequester carbon, improve quality of air, protect their soil and contribute to a better quality of life for regional people. The 100,000 Trees Project for the Porto Metropolitan Area” intends to restore 100 hectares of urban forest with native trees. (1, 2)

In 2014, local residents of the St. Pauli neighbourhood of Hamburg supported by architects decided to reshape the Hilldegarden bunker built during WW II. They managed to convince the owner of the bunker, who currently leases the rooms of the bunker to a nightclub, a music school, an instrument store and a photography studio, to re-create the bunker in a way that pays special attention to ecological and social aspects. (Reference 1-3). ”The new project would see the space continue its mixed-use atmosphere, but topped with a massive public rooftop garden with walking trails.” The 800 sqm garden will use sustainable techniques for its operation, including renewable energies and greywater collection for irrigation and will offer a public garden where residents can engage in urban food production. (Reference 2) In September 2020, the reconstruction of the bunker is still in its early phases. (Ref. 8)

The Oriental Park of the City of Porto is an urban natural park designed by the landscape architect Sidónio Pardal. It will be one of the largest urban parks in the country and the second-largest in the city of Porto. This NBS focused on the transformation of a derelict, depressed urban area into a green space. The first part of the park was inaugurated in July 2010 and the municipality has plans to build it through several phases over the next decade until it reaches its project area. (1)

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).

A tree planting programme (part of existing community greening initiative in the Mersey Forest) that is helping to transform Wirral into a thriving economic hub (trees planted on streets including Price Street, Cleveland Street, Argyle Street, and Hamilton Street, which are key transport routes around the Wirral Waters investment area). Trees will also be planted at Wirral Met College, as well as in social housing landscapes and gardens. (Ref. 1, 2). The project was completed in 2015 but similar initiatives have been taking place in Wirral since. There is no apparent connection between these projects and the 2012-15 project. (Ref. 7, 8)

This NBS is Porto’s largest green roof, sometimes referred as the "Fifth Façade Urban Rooftop Garden", the "Olive Trees Garden" is an oasis of 50 olive trees and lush grass on top of a semi-open gallery of shops, restaurants, and cafés with an underground parking garage.
It’s an urban park escape for city workers, tourists, and university students. Located on top of "Praça de Lisboa" (Lisbon square), this is a fantastic concept of urban planning done right: green space co-existing with commerce and vehicles below street level. This project was completed in 2013 as an effort to improve an area in decline in the middle of the cultural centre of Porto by creating a green space for the community (Ref. 1, 2).

Hamburg decided to increase the number of trees in the city, however, the budget was not enough to completely fulfil this goal. Therefore, the city not only tripled the municipal budget dedicated to tree planting and but began encouraging the citizens to contribute to greening the city through the donation campaign "My tree - My city”. The project was launched in 2011 as part of the European Green Capital programme of Hamburg. Citizens can donate and by using an interactive map, can choose a site and a tree species to be planted, and follow-up the implementation of their tree. (Reference 1, 3) The City of Hamburg gave for each tree that reached donations of 500 Euro the same amount on top to cover the average costs of 1.000 Euro per tree, which includes the preparation of the planting pit, the planting itself and maintenance. (Reference 4) The campaign was so successful that it continued even after Hamburg’s year as the European Green Capital and is still going on in 2020. (Reference 2, 7)

While Hamburg has already had an impressive green infrastructure, it is now (since 2013) implementing an interconnected green network that will cover the 40 % of its area and support commuting by bicycle, recreation and climate change resilience. The project is planned to be completed by 2034. (Reference 9) The project aims to connect the two green belts, parks, recreational areas, cemeteries and animal habitats to each other with green paths and with the already existing “green axes” leading from the agglomeration to the urban core. The green network could not only absorb more CO2 but also prevent flooding by soaking up an increased amount of rain- and seawater caused by storms. (Reference 1, 2). An extensive network of cycle paths is also being built as part of the project. (Reference 2)