Presenter Inge Diepman talks to Jan Jaap de Graeff (Rli), Bart Kruijt (WUR) and Joost Buntsma (STOWA) about the relationship between measuring and monitoring, and the importance of monitoring for the long term. At what levels are measurements made, and why is it important to measure and monitor on a long-term basis? In the field reports, researcher Ronald Hutjes (WUR) reports from the air on monitoring and at the Zegveld measurement site he explains the eddy covariance mast used to measure greenhouse gas fluxes.