Résumé
Pollen stratigraphies are the most spatially extensive data available for the reconstruction of past land-cover change. Detailed knowledge of past land-cover is becoming increasingly important to evaluate the present trends in, and drivers of, vegetation composition. The European Pollen Database (EPD) was established in the late 1980s and developed in the early 1990s to provide a structure for archiving, exchanging, and analysing Quaternary pollen data from Europe. It provides a forum for scientists to meet and engage in collaborative investigations or data analysis. In May 2007 several EPD support groups were developed to assist in the task of maintaining and updating the database. The mapping and data accuracy work group (MADCAP) aims to produce an atlas of past plant distributions as detected by pollen analyses in Europe, in order to meet the growing need for this data from palaeoecologists and the wider scientific community. Due to data handling problems in the past, a significant number of EPD datasets have errors. The initial task of the work group, therefore, was a systematic review of pollen sequences, in order to identify and correct errors. The EPD currently (January 2009) archives 1,032 pollen sequences, of which 668 have age-depth models that allow chronological comparison. Many errors have been identified and corrected, or flagged for users, most notably errors in the pollen count data. The application of spatial analyses to pollen data is related to the number of data points that are available for analysis. We therefore take this opportunity to encourage the submission of pollen analytical results to the EPD or other relevant pollen databases. Only in this way will the scientific community be able to gain a better understanding of past vegetation dynamics.