The study of the ‘green wave’ and their temporal changes require the linkage of phenological surface events to satellite images. Although some methods already exist, the problem of relating satellite observations as species-averaged information over large and diverse spatial areas to traditional species-level phenological events is not well understood yet. In POSITIVE (Phenological Observations and Satellite data (NDVI): Trends in the Vegetation Cycle in Europe, project funded by the 5th Framework Programme of the European Union), different NDVI products from the NOAA AVHRR and SPOT4 Vegetation instruments have been used to study the green vegetation dynamics in Europe from 1982-2001. These data sets were linked to the European phenological data base of POSITIVE to identify key species for the seasonal cycle. The correlation between satellite images and ‘ground truth’ was analysed for the onset and the end of the growing season. Ancillary information, such as CO2 fluxes and GPP, at single EUROFLUX sites allowed deeper interpretation of the results.