European Forest Institute (EFI) in cooperation with Alterra / Wageningen University and Research Centre has released a set of 1x1 km tree species maps showing the distribution of 20 tree species over Europe. 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. 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 bioindicators 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.
1. D. J. Brus, G. M. Hengeveld, D. J. J. Walvoort, P. W. Goedhart, A. H. Heidema, G. J. Nabuurs, K. Gunia. Statistical mapping of tree species over Europe. European Journal of Forest Research, 2011; 131 (1): 145 DOI: 10.1007/s10342-011-0513-5