The International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM)

The International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM) presents a comprehensive long-term dataset of ongoing integrated ecosystem monitoring from European forested catchments. The dataset encompasses measurements from monitoring stations across 14 European countries, with temporal coverage extending for most sites from the 1990s to 2020. The dataset will be updated with new data once per year. The integrated monitoring approach applies over multiple monitoring subprogrammes to simultaneously measure physical, chemical, and biological properties across ecosystem compartments including atmosphere, precipitation, throughfall, soil, soil water, groundwater, runoff water, vegetation, and biota. All measurements follow standardised protocols detailed in the ICP IM Manual, ensuring data quality and comparability across sites and time periods. The dataset supports research on ecosystem responses to air pollution, climate change impacts, and biogeochemical cycling. Data is provided by sub-programme (all sites and all years with data in one file), geographic co-ordinates for sites are available in a separate file. Historical data from inactive sites in Belarus, Denmark, Iceland and the United Kingdom are currently available by request, as is data from Finland in sub-programmes TF,SF,SC,SW,FC,LF,FD,VG,EP and BV, and data from Poland. The monitoring is done under the framework of the UN Convention on Long-Range Transboundary Air Pollution (CLRTAP) and also has an important role in reporting under the EU national emissions ceiling directive (NECD). Users are strongly encouraged to refer to the ICP IM Monitoring Manual which describes in detail the methods used to make measurements in the field and the laboratory, the data formats used, explanations of column headers and flags used in all subprogrammes and example files. This is provided alongside the data.