Rit (Vísindafélag Íslendinga) - 01.06.1975, Qupperneq 76

Those species which are most noticeable apart from C. nigra, al-
though none of them is prevalent in physiognomy are: Calamag-
rostis neglecta, Comarum palustre, Cardamine pratensis, Polygo-
num viviparum and Thalictrum alpimnn. These are seconded by
Anthoxanthum odoratum and Carex Lyngbyei.
Where this sociation grows the terrain is relatively dry, sloping
and evenly pattemed by mounds. In both places at Tindar and
at Máberg the areas in question were quite extensive. At Laugar-
holt in Borgarfjörður, analysis 17, the sociation grew in a mýri
with average moisture content, where a reservoir had been formed
by damming. Previously this was the site of an Eriophorum flói,
but the terrain was drained at the time of the dam construction.
A similar change and vegetation occurs in all places under these
circumstanses. This sociation is in most respects related to C. nigra
—■ Equisetum palustre sociation no. 46, both of which grow in
similar topography.
As has been stated before b) comes from geothermal areas in
the highland where it constitutes a unique sociation. Of particular
interest is the high percentage of E, wherein the influence of the
geothermal heat is evident. Among individual, noteworthy spe-
cies the following may be mentioned: Epilobimn palustre, Viola
palustris, Agrostis colonifera, Sagina procumbens and Montia lam-
prosperma, but E. palustris, Viola and Montia are all considered
eutrophic and Sagina oligotropic, but here they grow together in
wonderful harmony. Otherwise I do not recall seeing S. procum-
bens in mire tracts outside geothermal areas. These mýri tracts
are level and quite wet.
37. C. nigra — Eriopliornm angustifolium sociation
(Tab. VII A-B 1-9)
The observations available here are from 3 parts of the country,
three from Flói, two from Vestfirðir and one from each of the fol-
lowing places: Bárðdælaafréttur, Kaldidalur, Snæfellsnes and from
Vatnsskarð in Skagafjörður. This indicates that the sociation is
widely distributed throughout the lowland and occurs as such in
many of the lowest parts of the highland.
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