GrüneLünge 1.0

Inter- and transdisciplinary approaches to develop strategies for increasing the resilience of trees in growing cities and urban regions

Trees characterize the cityscape: view from Vierordtbad in the direction of the castle.  ©Stephan Gehrlein,
Trees characterize the cityscape: view from Vierordtbad in the direction of the castle. ©Stephan Gehrlein

Urban trees and forests shape the cityscape and increase the quality of life for residents. Increasing the appreciation of trees and their benefits for humans and animals was just as much a part of the goals of the GrüneLunge 1.0 project as educating people about what trees can offer in urban areas (ecosystem services). They provide shade in summer and provide an additional cooling effect by evaporating water through their leaves (transpiration), thus mitigating heat stress in cities. They filter and bind air pollutants, produce oxygen and thus improve air quality. In the process, they sequester carbon, storing it for the long term and thus counteracting climate change (climate mitigation). They regulate the water balance and improve the water quality of percolating rainwater, which is often the basis for drinking water production. They provide a habitat for a variety of life forms and accordingly promote biodiversity (species diversity). They improve the appearance of cities through their colorfulness, and provide variety and space for recreation. But these diverse benefits in cities are under threat.


Ongoing climate change and urbanization (urbanization, redensification), as well as new pests and diseases of trees, are threatening inner-city and peri-urban tree populations. The combination of the various stressors (negative influencing factors) leads to trees first becoming weakened, then more susceptible, and in some cases even dying completely; and this affects not only individual trees but entire tree species and stands. This also threatens a loss of the services and benefits that urban trees and forests provide. One of the goals of the GrüneLunge 1.0 project was to start research in order to develop solutions for counteracting these threats to trees in urban areas and to preserve the diverse ecosystem services.


In addition, transdisciplinary methods were applied in the KIT real laboratory "Quartier Zukunft - Labor Stadt": In a technical dialogue, the research results of all subprojects of GrüneLunge were discussed with the participating offices, institutions, and technical representatives of Karlsruhe and Rheinstetten in order to create an optimized tree management system with a focus on climate adaptation. The social dialogue focused on how to make society aware of the importance of a green city with a healthy plant population. With the campaign "Naturnah Gärtnern - Für Mensch, Tier & Klima" (Gardening close to nature - for people, animals and the climate), the city of Rheinstetten tried out how each and every individual can contribute to climate protection and biodiversity.


On the following pages you will find more information about the results of the project GrüneLunge 1.0, especially regarding urban forests' ecosystem services, dendrochronology of urban trees, the subprojects GrüneLunge in the flow and GrüneLunge in dialogue as well as the application and implementation of the project results by the city of Karlsruhe.

© Photo: Stephan Gehrlein