Syntaxonomy of Norwegian forest vegetation 1993
The number of geographical vicariant forest associations described and recognized in Norway is 5 in the class Alnetea glutinosae, 13 in the Vaccinio-Piceetea and 12 in Querco-Fagetea. There are also 2 associations of forest-bog communities of the Oxycocco-Sphagnetea. Only one of these 32 associations (Alno-Prunetum) occurs throughout the country, one is of north-easterly distribution, 5 are montane, 7 are eastern, 5 are south-eastern, 5 are southern and no less than 12 are western. Further studies are needed in the upper-boreal (subalpine) zone and the Lapland area.