Each EU member state shall draw up a national list of the basic material of various species approved in its territory.
Format of national list (Commission regulation No 1597/2002) (pdf)
The area information in the 'source identified' category of the national list is calculated by tree species and is based on the ninth inventory of state forests, except for the area of the Forestry Centre of Lapland, for which the material is VMI8. As concerns broad-leaved trees, area information is based on inventory data by the Finnish Environment Institute (SYKE).
Calculations are performed for forest land and land on which forest management is performed. Protected forests are excluded from this calculation, as are expanses for which no tree species could be determined.
Forests that naturally originate from seeds or are regenerated vegetatively (root suggers, sprout, etc.) are counted as indigenous. Alongside shelterwoods and stands of seed-trees, forest that have reached regeneration maturity are treated as indigenous. If no information on another origin is available, indigenous forest stands are considered autochthonous while cultivated stands are viewed as being of unknown origin.
More about elsewhere on the web
European Commission> Health and Food Safety> Forest Reproductive Material>FRM-List