Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 117

be concluded that the sociation occurs in many places in the west?
but it does not cover large continuous tracts.
66. S. cæspitosus — C. Bigelowii — Carex echinata sociation
(Tab. XIVx A-B 12)
Only one observation exists which was made in Grundarfjörður
at an altitude of approximately 150 m above sea level. The ground
is somewhat sloping, moderately moist, with a flat surface. Sphag-
num is so abundant here that it covers up to 30% of the surface.
Nothing further is to be stated about this sociation as most of the
comments that apply here have already been made elsewhere. The
sociation can hardly be expected to occur widely since C. echinata
is a rather uncommon species.
67. Scirpus pauciflorus — Equisetum palustre — Festuca
vivipara sociation (Tab. XIV A-B 16)
I have included this sociation in Scirpétum cæspitosi on the basis
of the only observation available, although S cæspitosmn hardly
ever occurs there. The sociation is unique and sparsely distributed
in this country. Nowhere else have I encountered S. pauciflorus
as a dominant species, both in frequency and covering, except in
such small patches that they hardly deserved to be referred to as
a sociation. Apart from that, some species occur there which are
niost notable in Scirpetum cæspitosi. Apart from the character spe-
cies the following are conspicuous: E. angustifolium, Agrostis tenuis,
Carex panicea and C. capillaris. In addition, Betula nana occurs,
but this species has generally been absent from the Scirpus mire.
The biological spectrum does not indicate any significant depar-
ture from the other analyses of the Scirpus mire. Analysis 1 is
made near Strandhöfn in Vopnafjörður, close to a seaside gravel
bank on relatively dry, almost level ground with low, flat mounds.
The conditions there were in most respects similar to those which
apply to the Scirpus mire. There was no species dominant in
physiognomy; S. pauciflorus and Festuca vivipara were dominant
117