Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 75

C. Bigelowii: indifferent
Vaccinium uliginosum: subcalciphobous
Menyanthes trifoliata: indifferent
Calamagrostis neglecta: eutroph-mesotrophic
Equisetum palustre: eutroph-mesotrophic
Salix glauca: eutroph-mesotrophic
Agrostis tenuis: indifferent
Half the species appear to be eutroph-mesotrophic, but only one,
i.e. Vaccinium uliginosum, seems to be predisposed to acidity,
whereas the others are more or less indifferent.
Some eutrophic species are fairly common in C. nigra mýri such
as Thalictrum alpinum, Tofieldia pusilla, Carex dioica, but no oligo-
trophic or mesooligotrophic species unless Vaccinium uliginosum
is included. This would indicate that the C. nigra mýri is closest
to being eutroph-mesotrophic, since it has already been mentioned
that the Icelandic mires generally belong to such mýri sociations.
36. Carex nigra sociation
(Tab. IX A-B 10-14 and 17)
Observations of this sociation emanate from Vestfirðir and one
location in Borgarfjörður, and finally from two places in Land-
rnannaafréttur, Laugar and Hattver, at both of which sites geo-
thermal heat is present, so that all vegetation has a lowland appear-
ance, since this is altogether a lowland sociation.
I was in doubt as to what name I should give to this sociation,
°r if perhaps it should be regarded as consisting of two sociations,
I*e. a) C. nigra ■—■ Cardamine pratensis sociation 10-11 and b) C.
nigra — Epilobium palustre sociation. Common constant species
other than C. nigra are only Calamagrostis neglecta and Carda-
niine pratensis. On the other hand there is considerable harmony
xn the biological spectrmn, which indicates high percentage of E
and H. But I consider it proper, however, to describe this sociation
m two separate parts.
As earlier stated specimen a emanates from Vestfirðir. This so-
ciation is common throughout the country, at least near the sea.
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