Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 103

observation was made the moisture content of the soil is average,
the ground is drier than in 55, the surface is finely patterned and
sloping. In some respects the conditions resembles the C. nigra-
E. palustre mýri and this is probably a transitional phase between
the associations, that is, C. nigra is disappearing due to the eleva-
tion and is being replaced by C. Bigelowii and Chamaphytes.
57. C. Bigehnvii — Salix herbacea sociation
(Tab. Xn A-B 10-19 and Tab. XIHx A-B 5)
Here the observations originate in the Yestfirðir (west fiords),
the central highland and one at Húsafell in Rorgarfjörður. This
sociation and the next two to be described are the most common
sociations of the C. Bigelowii mýri throughout the country, both
in the border areas between highland and lowland and also in
the highland proper. They may be regarded as constituting the
typical C. Bigelowii mýri. A related sociation or a variant of this
one occurs in places in the West fiords at an altitude of 150-200 m
above sea level. In the dampest areas Eriophorum angustifolium is
noticeable in many places, but Rhacomitrium becomes conspicuous
in the drier parts and where mounds are most abundant. Apart
from the character species, the following are most important:
Polygonum viviparum, Equisetum arvense, E. variegatum, Eriop-
horum angustifohum, Salix glauca, Thalictrum alpinmn, and Cala-
magrostis neglecta. In some parts Deschampsia alpina is fairly
noticeable. Here the main distinguishing characteristic from socia-
tion 55 is the absence of C. rariflora and it may be separated from
56 by the fact that E. palustre does not occur. Furthermore, it can
be distinguished from both these sociations by the absence of Vac-
cinium uliginosum. I observed the sociation at Gróustaðir in Geira-
dalur without taking an analysis. There the following character
species occurred: Festuca rubra, subdominant; Alchemilla minor,
A. alpina, Empetrum hermafroditmn, Equisetum arvense, E. vari-
egatum, Luzula spicata, Poa alpina, Pjcrola minor, Polygonum
viviparum, Rumex acetosa, Salix glauca, Silene acaulis, Taraxa-
cum sp. Thalictrum alpinum and Veronica alpina. Typical snow-
patch species which occur there indicate a fairly heavy snow
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