Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 112

in Vestfirðir where this is its most common sociation. Notihing can
be stated, however, as to the general distribution of individual so-
ciations, beyond what has been said with regard to the association
as a whole. The character species are Scirpus cæspitosus and Eri-
ophorum angustifolium which relate the sociation to Eriophorum
flói, but generally only few flói species proper occur here. Cala-
magrostis neglecta, however, occurs sporadically. The most com-
mon accompanying species are Vaccinium uliginosmn and Polygo-
num viviparum. Vaccinium, however, is usually so prostrate as
to be physiognomically insignificant. Other fairly frequent species
are: Carex Bigelowii, C. capillaris, Pinguicula culgaris, Tofieldia
pusilla and Thalictrum alpinum. All those species indicate that
this is a rather eutrophic sociation. The biological spectrmn shows
an average of species and a fairly high E percentage, but there
are generally some fluctuations in the percentages of lifeforms.
The Ch percentage is, however, most commonly low, except in I
where there is an exceptionally large number of scrub plants.
Otherwise the Ch percentage does not differ much from the C.
nigra — E. angustifolium mire. The G percentage is generally
somewhat higher than the EI percentage, but the difference is in-
significant, and sometimes the percentages of these two lifeforms
are reversed.
Although E. angustifolium is a character species here, the socia-
tion invariably occurs in relatively dry tracts, the surface is mostly
flat, or characterised by small mounds, generally sloping, but the
slope is often very gentle. In most places there are indications of
a prolonged snow cover in winter, at least the snow seems to last
longer than in neighbouring sociations. At Isafjarðardjúp Carex
saxatilis often occurs in this sociation although it is absent from
the analyses.
Analysis 1 is from Brjánslækur where the mýri is particularly
mound-patterned, with Ch growing on the mounds. A little Sphag-
num occurs there. Analysis 2 is from Máberg in Rauðisandur
where S. cæspitosus is dominant to such an extent that it covers
75% of the surface. In this area, the eastern part of Rauðisandur,
this sociation is very prominent in distribution. At Melanes I have
noted the following, apart from the character species: C. nigra,
C. dioica, C. capillaris, C. microglochin, C. panicea, C. rariflora,
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