With Sanasilva and the Long-term Forest Ecosystem Research (LWF), Switzerland has been participating in one of the longest and most comprehensive cooperation programs for forest condition surveys and forest ecosystem research in Europe for 40 years. A workshop organized by the SwissForestLab on this anniversary offers the opportunity to get to know the measurement methods in detail during a tour of our research facilities in the morning. In the afternoon, the most important results will be presented and the knowledge gained about the processes in our forests will be presented and discussed. Participants are also invited to present their findings in the form of posters. In addition, we invite participants to take part in a preliminary survey and a final plenary discussion on the requirements and needs of a future LWF. All interested parties are cordially invited to develop the LWF further together in order to meet the demands and challenges of our forests of tomorrow.