The file was produced using the command 'save()' from the R software. This resulted in the file “introgression.RData”, which includes two dataframes: (1) intro.rates.paper and (2) tree.data. The first dataframe comprises the empirical introgression rates recorded by Bialozyt et al. (2012). The columns are the individual tree number followed by the percentage of introgression for year 2006 and 2007 respectively. The second dataframe (tree.data) comprises the name, coordinates, sex and taxa of all trees used in the simulation. In the column 'SEX' females are coded '0' and males are coded '1'. In the column 'SPECIES' Populus nigra are coded '0' and the hybrids (Populus × canadenis) are coded '1'
