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Mountain mires 251Fig. I. Part of a subalpine, markedlysloping fen dominatedmainly by Trichophorum caespitosum.Extremely rich fen vegetationwith, e.g., Oarex capitata,0. capillaris, Eriophorum latifoliumand Juncus arcticus. TorneLappmark, Mt. Snoritjakko. 1950.Photo A. Persson.edly different containing important elements thatdo not even reach the subalpine areas.In somewhat drier localities in the alpine as wellas in the subalpine region Tomentypnum nitens andSphagnum warnstorfianum are the most prominentbottom layer species often together with Paludellasquarrosa, Aulacomnium palustre, Mnium rugicum,M. pseudopunctatum and Campylium stellatum. Inthe alpine region this vegetation is closely relatedto the Carex atrofusca and 0. saxatilis communitiesmentioned above, and in the subalpine region tocorresponding subalpine communities. DAHL (1956)distinguishes such vegetation as a separate alliance,the Sphagneto-Tomentypnion. The bottom layeris sharply different, but at least in rich types,there are no obvious differences regarding the fieldlayer when compared with the above-mentionedvegetation with Drepanocladus revolvens var. intermediusand Oampylium stellatum (cf. KALEL.A 1939,pp. 405-406, A. PERSSON 1961, pp. 62 and 129)".Therefore it seems better to include this vegetationin the Caricion atrofuscae- saxatilis.From the northern side of Tornetrask a Filipendula-Mniumassociation was described (A. PERS­SON op. c., p. 62). It is not included in, but closelyrelated to the preceding alliance, and has a treeor tall shrub layer of Betula pubescens, Salix myrsinifoliassp. borealis, Alnus incana and Salix17 - 652 151 APhS 50glauca. It is a typical mire margin community,and plants shared with the meadow-birchwoodsare especially prominent.The bulk of the communities described abovebelong to the extremely rich fen vegetation (Euscorpidion,Du RrETZ 1949 a, 1954 b). EspeciallyCaricion atrofuscae-saxatilis contains a large numberof differential species of extremely rich fenabsent from moderately (or transitional) rich fenvegetation (Warnstorfio-Scorpidion). Such specieshave been listed by A. PERSSON (1961, p. 110).To Warnstorfio-Scorpidion belong certain communitiesin which Drepanocladus exannulatus, D.procerus, D. tundrae, D. revolvens s. str. andOalliergon sarmentosum are prominent, besidesDrepanocladus revolvens var. intermedius, Oampyliumstellatum and Scorpidium scorpioides. In themoderately rich fen vegetation could also be includedthe communities treated below as a separategroup, intermediate between the moderately richfen vegetation and the poor fen vegetation.Intermediate fen vegetationIn non-calcareous areas in the northern coniferousforest region and in the mountains, there occurs avegetation characterized by Calliergon sarmentosum,C. stramineum, Drepanocladus exannulatus, D.badius, Paludella squarrosa and Sphagnum teres. AllActa Phytogeogr. Suec. 50