Basic dendrometric data were gathered for 260,000 national forest inventory plot locations from 17 countries to compile these maps. Forest plot data collected in a European-wide network (ICP Level I) have been used to extend the available data for the remaining European countries. Furthermore, forest inventory statistics have been applied. These statistics are based on forest plot data that are aggregated over regions in the Nomenclature of Territorial Units for Statistics (NUTS). 

In areas with available national forest inventory data, area proportions covered by the 20 species were obtained by compositional kriging (based on the assumption that the parameter being interpolated can be treated as a regionalised variable.)

For the rest of Europe a multinomial logistic regression model was fitted to ICP-level-I plots using various abiotic factors as predictors (soil, biogeographical zones, and bio indicators derived from temperature and precipitation data).

The regression results were iteratively scaled to fit NUTS-II forest inventory statistics and the European Forest Map. The predictions for the twenty tree species were validated using 230 plot data separated from the calibration.

EFI offers a disclaimer that users should realise that for some countries, at the national level, moreaccurate maps are available from the national forest inventories (NFI).

The current map's advantage lies in its European scale synchronisation and is greatly indebted to the Forest Focus programme and the national forest inventory institute’s correspondents.

The work was carried out by EFI and Alterra. NFI plot data were received from: Flanders and Walloon region of Belgium, Croatia, Estonia, Finland, France, Germany, five regional inventories of Italy, Lithuania, Netherlands, Norway, Portugal, Romania, Slovak Republic, Slovenia, Spain, Sweden, and the United Kingdom.

To view the Forestry Commission National Forest Inventory - Scotland