fulltext - DiVA

The mountain regions of Lappland 69Fig. 3. One of the northernmostelm occurrences in Sweden, Ulmusglabra ssp. montana growing on asouth-facing scree slope at Bangnas,Vilhelmina, Asele Lappmark,with Aconitum septent1·ionale, Chamctenerionangustifolium, Filipendulaulmaria and ferns. Aug. 1948.Photo 0. Rune.to KIHLMAN (1890), due to extermination throughforest fires, according to TH. C. E. FRIES (1913),due to a slow immigration and, according to KuJALA(1929), due to lack of sufficiently fertile soilswhich are necessary to the spruce.The eastern border of the mountain area appearsas an important floristic boundary. Some plants ofa north-eastern type of distribution occur abun-. dantly in the infra-montane forest region of NorthSweden but do not ascend into the mountain area,viz. Ledum palustre, Carex globularis and Betulaverrucosa var. lapponica. Although far less commonthe following plants have a similar distribution:Carex tenella, C. tenuiflora, C. laxa (except for outposts),C. heleonastes, Ranunculus lapponicus,Calypso bulbosa. A number of common water andmire plants with a wide distribution in Swedencease abruptly in front of the mountain area or inthe lower parts of its valleys, viz. Phragmitescommunis, Scirpus lacustris, Eleocharis palustris,Juncus stygius, Potamogeton natans, Nymphaea candida,Alisma plantago-aquatica, V accinium oxycoccus,Carex diandra, Lysimachia thyrsiflora, Scutellariagalericulata.The upper limit of the continuous conifer beltcorresponds to the upper limit of natural reproductionby seeds of the coniferous trees. Singlesmall trees may occur above this level although .unable to reproduce themselves by seeds. In theeastern parts of northernmost Lappland (N. TorneLappmark) this limit lies at about 500 m. In centralLappland (S. Lule Lappmark) the correspondingaltitude is at 650-675 m, in southern Lappland atabout 700 m, in Jamtland at 750 and in northernDalarna at about 800-900 m. These figures arevalid for the eastern fringe of the Scandes.The limit falls considerably towards the west.In the district of Tarna (S. Lappland, Lat. N 66°)the spruce limit on Mt. Ryfjallet is at 700 m, nearTarnaby (20 km due west) at 600 m, and 20 kmfarther west or north-west, at Joestrom andHemavan, the limit is at about 500 m. Similarvalues were obtained by HEINTZE (1913) in AseleLappmark, about 70 km farther south. However,the upper limit of the conifer forest is difficult toestablish. It depends on edaphic conditions and maydiffer from one hillside to another.This limit coincides with the upper limits ofseveral plants. The companion species of the coniferforest give additional importance to the upper limitof the conifer belt. The following species, mostlycommon below the mountain area, reach the vicinityof the upper limit of conifer forest, viz. Scheuchzeriapalustris, N uphar pumilum, M oneses uniflora, Erio-Acta Phytogeogr. Suec. 50