Participating Cities

The city of Linz is located in the center of Upper-Austria and accounts for about 200,000 inhabitants. This city is facing multiple climate-related challenges including the urban heat island effect. In 2019, Linz adopted its first ”Climate Strategy“ covering six thematic areas including organization, research and information, urban design, building and green space, energy, nature and food, mobility and traffic. One of the most important actions the city follows to reduce the urban heat island effect is called the "tree planting offensive". This offensive includes planting 1,000 large-crowned trees on eleven streets. To reduce heat stress for citizens and optimize the urban ventilation, another 30 trees have been planted at Linzer main square. By planting trees, the city seeks to enhance the natural environment and air quality, improve its resilience to climate change impacts and contribute to a healthier, more livable urban environment. 

With 309,721 inhabitants, Mannheim is the second largest city in the Baden-Württemberg region of Germany. Over 1,800 hectares of forest surround the city and with the mission statement "Mannheim 2030", the city is implementing the 17 SDGs of the United Nations at the local level. In particular, the city is focusing on SDG 15, "Manage forests sustainably" and "Halt biodiversity loss". As a Local Green Deal pilot city, Mannheim also supports the EU-Green Deal field of action, "Preserving ecosystems and biodiversity" with concrete agreements. The city's vision for their forest is to develop a healthy, ecologically valuable and climate-stable mixed forest. Mannheim's forest invites recreation, provides habitat for species and contributes to the city's CO2 neutrality through sustainable wood use. Pine forests in Mannheim, that are not adapted to the climate, are being converted into near-natural, multi-level mixed deciduous forests. The focus of all forestry activities is the long-term and permanent preservation of the recreational forest, taking into account the protection of species. Areas are planted where pines are dying and where there are not enough climate-stable tree species to expect natural regeneration of suitable tree species.

With a population of 350,000 people, Aarhus is the second-largest city in Denmark. The city dates back to the late 8th century and has been growing rapidly for the past 20 years. Believing that city development and a green transition can go hand in hand, Aarhus has goals to reach net zero emissions by 2030. Afforestation and planting trees in urban areas is a part of the plan to reach that goal. By participating in the “Trees in Cities Challenge” Aarhus aims to increase the number of trees in the city to unlock all the benefits that trees and forests in urban environments provide. Therefor Aarhus pledges to plant 77.800 trees by the end of 2022.

In 2017, the Municipality of Lincoln created a plant nursery to produce plants and trees, supplementing the acquisition of more mature trees. This supports tree planting and afforestation in city squares, parks and public spaces in the city, including deliberate efforts to diversify the tree species in the city. 

Many of the trees that are renewed in the city are native species from the region, as part of an intentional effort to strengthen the local ecosystem as a home to Argentinian flora and fauna.

In 2020, the Tel Aviv-Yafo Municipality launched its Climate Adaptation Action Plan. One of the flagship programs developed within this framework is the "Urban Forest Plan" addressing issues of protection, scaling up, and management of the trees across the city.

The "Urban Forest Plan" aims to promote a green and solid urban framework, based on high-quality trees that provide shade, in areas across the city, benefitting the city's residents, visitors and the overall ecosystem. The plan addresses different aspects related to trees in the city: construction plans, mapping and maintenance, planting new trees, and community participation. This can strengthen planning mechanisms and expand the scope of participation to additional audiences, both internal and external. The plan was launched with, among other things, a quantitative target of adding 100,000 trees by 2030.

With a population of over 1.6 million, Barcelona is the second-largest city in Spain and is located on the Mediterranean coast. The local authorities understand the planting of trees to be a simple but powerful way to create more sustainable and resilient cities. This is reflected in the “Nature Plan 2020-2030”, aimed at increasing the city’s canopy cover by 100 hectares and the “Master Plan for Barcelona’s Trees 2017-2030”. The city wants to be even greener and thus introduced a 10-year plan – the superblock model “Superilla Barcelona” – that will turn 1-in-3 streets in the commercial and residential area into green zones. The city’s recent participation in the “Trees in Cities Challenge” aligns well with such existing efforts. Barcelona pledged to plant almost 8,000 new trees throughout 2021 and 2022. The city aims to maximize the benefits of urban trees and forests, integrate the new trees in the urban environment as well as use a diverse species selection adapted to the changing climate. At the core of the tree planting activities is the sustainable management of urban and peri-urban trees and forests as well as the coexistence between citizens and nature to create a long-lasting impact.