Small green spaces can play a bigger role in climate adaptation than their size might suggest.
In Vienna, the city is planting "Wiener Wäldchen", small urban forests made up of densely planted native trees and shrubs. The approach turns residual green spaces, parks and public open areas into compact biodiversity islands that can grow into wilder, more resilient pockets of urban nature.
A new USE case study looks at how the project works in practice, from site selection and planting to maintenance, school participation and coordination between municipal departments.
The forests are designed to strengthen biodiversity, improve soil functions, support rainwater retention and contribute to local cooling through shade and evaporation as they mature. They also help bring children and young people closer to nature, with schoolchildren often taking part in the planting process alongside municipal staff and local representatives.
The City of Vienna presents the measure as one part of a broader adaptation strategy, not as a single solution to urban heat. Its value lies in the combination of climate adaptation, biodiversity, education and the careful use of small spaces that might otherwise remain underused.
For other cities, the case study offers practical lessons on how to identify suitable sites, coordinate across departments, manage early maintenance and build public acceptance for wilder forms of urban green.