Forest structure classes in central Finnish Lapland

Abstract

Structure classes and changes in the vegetation attributable to the altitude of the terrain were studied in the Hammastunturi virgin coniferous forest area. The area is located in Finnish Lapland, approximately 250–350 km to the north of the Arctic Circle (68°15'N; 68°45'N). The following forest classes were formed on the basis of the ground vegetation and stand coverage: (1) Pine stands, with birch admixture (n=14), (2) Vaccinium‐vitis‐idaea‐type pine stands (n = 24), (3) Vaccinium myrtillus‐type pine stands (n = 17), (4) mixed stands, dominated by pine (n = 8), (5) mixed stands, dominated by spruce (n=18), (6) paludified spruce stands (n = 3) and (7) vigorously growing spruce stands (n = 6). The forest structure classes were depicted using DCA ordinates. The differences were more distinct than those between the normal forest type classifications of the same sample plots. The basal area and volume of pine decreased with increasing altitude, while the proportion of spruce on those sample plots where it was present increased. Birch was present at an equal frequency at all altitudes. The floral composition and between‐species abundance changed along with increasing altitude. The change in floral frequencies could not be designated to a specific altitude zone.