Hamburg’s Strategy for Tree Preservation – An Integrated Approach to Managing Tree Diseases 

To effectively combat tree diseases, a long-term strategy is required. In Hamburg, efforts have been underway for more than two decades to better understand tree diseases through monitoring programs, aiming to preserve trees as long as possible and provide a sustainable future for the respective tree species. This article presents the epidemiological strategy using three tree diseases as examples. In addition to an overview of the elm monitoring program, which has been in place for over 20 years, recent results from the horse chestnut monitoring are also presented. Furthermore, the procedure in the event of the emergence of a new tree disease is explained. In September 2024, two pathogens involved in Acute Oak Decline (AOD) were detected in Hamburg. The risk potential for the city of Hamburg is assessed as high by the State Ministry, as the genus Quercus is already represented as the main tree species in the street area with a population of 50,000 specimens.