fulltext - DiVA

Subalpine tall herb vegetation, site and standing crop243Fig. 2. Lactuca alpina - Athyriumjilix-jemina sociation on a fairlywet site. Other important speciesare Aconitum septentrionale, Filipendulaulmaria, Orepis paludosa,Geranium silvaticum. Frostviken,Jamtland, altitude 620 m. Aug. 6,1956. Photo H. Holmen.%Geranium silvaticum 90 OhamaenerionLactuca alpina 90 angusti foliumAconitumOrepis paludosaseptentrionale 83 Milium effusumAnemone nemorosa 81 Trientalis europaeaRumex acetosa 81 Equisetum pratense%6866666661Filipendula ulmaria 78 Valeriana sambucifolia 61Paris quadrifolia 76 Equisetum silvaticumStellaria nemorum 76 Rubus saxatilis 56Viola biflora 76 OalamagrostisAthyrium filix-femina 71 purpurea 51Lastrea dryopteris 71 Polygonatumverticillatum 51As an example the species composition, frequency% and degree of cover (exponent) will be given fora typical sample plot analysed by ten one sq. mquadrats.Aconitum Filipendula ulmaria 701septentrionale 1003 Geranium silvaticum 901Lactuca alpina 1005 Lastrea dryopteris 501Athyrium filix- L. phegopteris 1002femina 902 Milium effusum 1001Anemone nemorosa 1003 Myosotis silvatica 201Ohamaenerion Oxalis acetosella 701angusti folium 101 Paris quadrifolia 801Orepis paludosa 901 Poa nemoralis 101EquisetumPolygonatumsilvaticum 701 verticillatum 100159Py1·ola minor 101 Solidago virgaurea 801Ranunculus Stellaria nemorum 1001platani folius 201 Trientalis europaea 201Rubus idaeus 101 ValerianaR. saxatilis 601 sambucifolia 101Rumex acetosa 701 Viola biflora 701The figures for average cover were calculated accordingto SJORS (1954, p. 35) . and given in the 5-graded scale according to Du RIETZ (1921 b, p. 223).The bottom layer is weakly developed and containsonly four species (Brachythecium reflexum, B. salebrosumand two M nium species).There ar:e many communities of a lower rankwithin the Aconitum-Lactuca association, includingthose that contain a great number of tall ferns(Athyrium filix-femina, Dryopteris dilatata, D. filixmas,Matteuccia struthiopteris).The Matteuccia community is peculiar. Here thefern frouds grow so densely that there is very littleplace for other species. An extreme example (southof the area) was analyzed by ten sample quadrats(1 sq. m) in which only twelve species of vascularplants were recorded.AconitumseptentrionaleDryopteris dilatataMatteuccia702 struthiopteris 1005601 Anemone nemorosa 101Acta Phytogeogr. Suec. 50