Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 119

are much more numerous in Equisetum mires which have not been
used as meadows as is indicated hy the analyses, but though Ch
hecomes fairly frequent, the scrub-plants are always inconspicuous
in physiognomy and covering in this association. The Equisetum
mire seems to be a fairly stable vegetation form. If it dries up it is
soon transformed into grassland without the total disappearance of
Equisetum as may often be seen where it has been poorly drained.
As far as can be determined from the most common species of the
Equisetum mire it appears to be eutrophic, but the following species
are most common:
Equisetum palustre: eutroph-mesotrophic
Agrostis tenuis: indifferent
Carex nigra: eutroph-mesotrophic
Agrostis canina: eutroph-mesotrophic
Anthoxanthum odoratum: eutroph-mesotrophic
Festuca ruhra: eutrophic
Polygonum viviparum: indifferent
Luzula multiflora: indifferent
Cardamine pratensis: eutroph-mesotrophic
Festuca vivipara: eutrophic
Pinguicula vulgaris: eutroph-mesotrophic
Thalictrum alpinum: eutrophic
Thus, out of 12 species 3 are eutrophic, 6 are eutroph-mesotrophic
and three appear to be indifferent with respect to acidity. As re-
ferred to earlier in connection with the C. nigra —- E. palustre
sociation 46 I believe that this formation does not occur in Scandi-
navia or in the British Isles. Apparently the combination Equi-
setum palustre — Carex nigra is a unique characteristic of the
Icelandic mires. It may be said, however, that an Equisetum Anth-
oxantum rich mire approximates an Equisetum Wiese which Kalela
describes in his observations from Fischerhalbinsel (Kalela 1939
p. 483).
I have included 6 sociations in this association; they are all re-
lated, however, and it is hard to distinguish between them. Possibly
some of them are only variants occurring in particular localities.
Sociation 68 has only been studied in an area which has long been
utilized for haymaking and grazing, but the others are not from
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