Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 129

Judging from statements about the Scandinavian rismyr one
nright expect the shrub-mire to be rather acidiphilous, since Sphag-
num often occurs in it. If we look at the most common species of
the shrub-mire it becomes apparent that its three character species:
V. uliginosum, Empetrum hermafroditum and B. nana are all con-
sidered mesotroph-oligotrophic and that E. angustifolium is one of
those which thrive almost anywhere in varying degrees of acidity.
Of conrse many of the eutroph-mesotrophic mire species are com-
mon there as well, such as Carex rariflora, and eutrophic species
like Festuca also occur. But despite that I believe this to be the most
acidiphilous division of Icelandic mires.
75. Yaeeinium iiliginosum — Betula nana — Empetrum
— Eriophorum angustifolium sociation (Tab. XVI A-B 1-5)
The observations here are from Melrakkaslétta, Fljótsdalshérað
and Borgarfjörður, and the sociation may be said to be widely dis-
tributed all over the country and in many places it is among the
most extensive mire sociations, e.g. in Fljótsdalshérað where it is
one of the most common mire-sociations in many localities, parti-
cularly on mountain slopes. This is especially true of the north-
eastem areas of Fljótsdalshérað which are closest to the sea. Among
the character species Betula nana is the most unstable in quantity;
it usually comes behind V. uliginosum, but Empetrum is surpassed
by both of these. I am here referring to Empetrum sensu latu,
because it is generally hard to detect the difference between E.
hermafroditum and E. nigrum, but both of those species occm in
lowland areas, in spite of statement to the contrary. The biological
spectrum shows a high A percentage, which is somewhat variable,
however. Ch is very high as is to be expected and the G percen-
tage is similar whereas the H percentage is markedly lower. There
is considerable moss. There is some vegetation difference between
mounds and hollows which is manifested by the fact that the shrubs
mostly occur on the mounds, but the Cyperéas are found in the
hollows, with the exception of Carex Bigelowii which tends to
occur on the mounds. There are no particular statements to be
made with regard to individual analyses.
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